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mark.bitterlich(at)navy.m
Guest

Posted: Wed Feb 14, 2007 2:15 pm Post subject: White Paper on Russian Generator System

YAK-50 DC Power Generation and Troubleshooting by Mark Bitterlich N50YK



Warning:  This is a technical explanation of the power generation,

regulation, and connection to aircraft main's of the typical

Yak-50/52/55 or Sukhoi-26/29/31.  It is offered for those that have at

least a general understanding of electronics.  In all cases where

voltage from power supplies or from batteries were connected for

testing, circuit breakers were installed for safety. If anyone tries to

follow these notes and duplicate my efforts, beware... if you make

mistakes, or fail to include current limiting devices such as light

bulbs and circuit breakers/fuses, you could easily cause serious damage

to aircraft wiring.   Ok.. so I had to cover my six.  That said, let's

move on.  



I just spent the last few days learning my YAK-50's electrical power

generation system.  Thanks for all of those that sent schematics of what

you had on hand.  Every person contributed towards solving this puzzle!

THANKS TO EVERYONE!  The specifics in some regards focus on the YAK-50,

although all of the Yak's and Sukhoi's use close to the same design with

some slight wiring differences here and there.  The important thing is

that in most cases the parts are all identical.  Of course this does not

include "Westernized" designs, such as the 52W, 52TW, etc.  Most of

these have already had B&C (or other) products installed.   



Power generation starts with the generator.  This is a 3 KW monster that

is capable of 100 amps output if properly cooled. This same generator

can operate at 30 amps intermittent duty with no cooling air.  



There are 3 wires on the generator, + positive, - negative, and what the

Russians refer to as "Shunting Input".  This input is actually what

controls the generator output and is normally called "Field Excitation".

This generator has a very well designed voltage regulation system using

a carbon pile voltage regulator that controls field voltage within a +2

/ -2 volt range.  Voltage output is also stabilized with a bucking

transformer known in Russian as "The Stabilizing Transformer".  If you

want to see examples of systems like this, go back to WW-II designs and

you will see the exact same thing.  In other words, this is 60 year old

technology and you need to go back and read about some of the theory

involved, because like a bucking transformer, you rarely see these

components in today's designs, but they were very common before the

discovery of high current voltage regulation transistors. 



Basically, most of the system is self starting and self contained

regulating in a closed loop circuit.  As soon as the generator starts

spinning, it will put out voltage although at idle it will be much lower

than 28 volts and it will not be connected into the aircraft mains.  As

RPM comes up and voltage rises, it will eventually stabilize at the

rated voltage set by the carbon pile regulator.  So, if you have any

kind of problem, the first thing you will want to do is to gain access

to the main generator terminals (you have to remove a cover on the

generator) and hook a meter to the PLUS and MINUS connectors with LONG

meter leads so that you can then safely check the voltage when you start

the engine.  If your generator is putting out voltage at idle, give it a

quick boost to about 60% or so, and you should see your meter come up to

around 28 voltage (plus or minus a few tenths) and then start

regulating. By "starting to regulate", I mean that the voltage will stop

increasing as you continue to raise engine RPM  If you have NO output

voltage, shut the engine off, and then when you are eyeballing the

inside of the generator, slowly move the prop.  Does the generator spin?

If so, then that is a good thing. If NOT, then you have sheared a shaft,

replace the generator.  If it does rotate, start it back up and run a

test for Field Excitation Voltage.  If you have excitation voltage, then

again it is probably a bad generator.  If you have no excitation, there

are a few other things that could be wrong, such as the carbon pile

regulator itself, or your over voltage breaker has tripped.  



If at any time the generator puts out too much voltage, in the realm of

31.5 volts or so (+/- 0.5 volt) then a circuit breaker will pop on the

over/under voltage detection and protection unit.  This is a silver box

with two cannon plugs on it, that is in the nose inspection hole left

side top in the 50, and somewhere else in the 52.  I think it is in the

forward cockpit underneath the instrument panel on the 52 but don't

quote me.  This unit has a rubber covered breaker button that you can

reach in and reset if you have had an over-voltage condition.  It is

another thing to check anytime you have a problem, but typically an

over-voltage trip is not common.  



Moving on, the closed loop design has generator output going first to

the stabilization transformer primary winding, then through that

directly to a component called "The Combined Device" also known as the

DMR-200D.  This component (the DMR-200D) is located in the gray box

mounted on the firewall, top right side (looking forward) in the 50, and

by the Pilots right foot in the 52.  Power goes through a MAIN CONTACTOR

RELAY inside of the Combined Device ONLY IF CERTAIN CONDITIONS ARE MET.

Here is where things get tricky.  



Going back the Stabilizing Transformer for a minute, (just to complete

the mental image) main output voltage of the generator goes through the

primary winding as I already mentioned.  This is just a few turns of

wire, and offers VERY little resistance.  Part of the secondary windings

of this transformer system has outputs going to the voltage regulator

and the over voltage box.  The Voltage Regulator (official name "R-27")

has outputs that feed back to control the generator excitation field,

but it also has another output that goes over to the over voltage box.

If the voltage is normal, the over voltage box feeds this same voltage

(28 volts) back to pin B on the Combined Device.  (Note, it looks like a

"B" to me, that is the SHAPE of the marking, but it is actually the

Russian letter "V".)  This input voltage to pin B (V in Russian) turns

on internal relay TKE-210B INSIDE of the Combined Unit.  The

nomenclature of this relay means nothing since you can't see or touch it

without taking the whole thing apart.  Just realize that when you put 28

volts to the connection marked "B" and a ground on the connection marked

"-" (for minus), an internal relay will close and it will ENABLE the

rest of the Combined Device.  When this first relay closes, it then

enables yet another system inside of the Combined Device known as the

Polarization Relay.  The "PR" is a special dual winding relay that will

close only if current flows through the relay coil itself in the proper

direction.  If you try to flow current through this relay backwards, it

simply won't work, and that is by design.  It is SUPPOSED to do that.

After the Polarization Relay (or PR) is enabled, it has a circuit that

connects it to both the output main terminal and the input main

terminal. If the PR likes what it sees and closes, it then in turn

provides power for yet ANOTHER Relay Coil inside of the Combined Unit,

this one is known as the MAIN POWER CONTACTOR RELAY.  This is the big

boss relay in the whole thing, and when it closes, generator power then

comes OUT of the Combined Unit and is fed to the aircraft MAIN BUS BAR.

In other words, the MAIN POWER CONTACTOR actually connects the large

input terminal to the large output terminal on the Combined Unit.  



What is really tricky to understand about this whole design is the

Polarization Relay.  Consider this:  When you turn on the Aircraft

Master, Battery Voltage is fed to the MAIN BUS and as such it also is

fed right down to the large OUTPUT terminal of the Combined Unit.  At

this point, the OUTPUT of the Combined Unit is not connected to

ANYTHING, because the MAIN CONTACTOR RELAY is still OPEN.  Let's

consider our battery voltage to be a normal. As such, there is about 24

volts on the Combined Units OUTPUT terminal post coming from the battery

with the Aircraft Master switch turned on.   



Now let's start the engine. The generator starts to spin.  Everything

works properly and as your engine speed comes up, so does generator

voltage.  This voltage is now fed to the Combined Unit's INPUT power

terminal.  Assuming 28 volts is fed to terminal "B" ("V" in Russian)

thus ENABLING the Combined Unit, you will end up with battery voltage on

one side of the Polarization Relay Coil and Generator Voltage on the

OTHER side of the Polarization Relay Coil.  Once there is a difference

in voltage between battery voltage and generator voltage of about 2

volts or so, and the generator voltage is HIGHER than the battery

voltage, the Polarization Relay will CLOSE and will then in turn close

the MAIN POWER CONTACTOR.  Once the MAIN POWER CONTACTOR is closed, 28

volts will be fed out terminal "C" which will then in turn close yet

another relay (external to the Combined Device) and turn OFF the

Generator Light in the cockpit.  It also then of course is feeding

generator power directly to the aircraft main power bus.  



Not done yet!  There is yet ANOTHER relay coil in the Combined Device

that is only enabled if the main enabling relay is powered up through

terminal "B" as mentioned earlier.  If terminal B has 28 volts, then

terminal "6" becomes active (In Russian the "6" is actually the Russian

letter "B"... confused yet?  Easy to do. Just remember that as I write

this, I refer to how they look to me and how they will look to YOU!)  If

you put a GROUND on this terminal "6" it will close yet another relay

coil inside of the Combined Device and will REMOVE the generator feed

voltage from the Polarization Relay thus making it INOPERATIVE!

Remember, if you disable the PR relay, then of course you have also

disabled the MAIN CONTACTOR Relay, and thus, no voltage from the

generator will ever make it to the main aircraft bus.  The ground on

terminal "6" is usually controlled by the Generator Switch in the

cockpit.  And here is a warning... not all Russian designs work like

this.  From the Sukhoi to the Yak there are major wiring differences in

how they wire this device, but the general concepts are the same.  



Operationally testing a system like this can be difficult at best.  I

tried a method that worked for me, but is offered with a Caveat Emptor

warning... buyer beware, your mileage may vary and if you smoke you

whole aircrafts electrical system,  DO NOT blame me.  



I disconnected all three leads from the generator.  I used a small 10

watt 28 VDC light bulb connected to the field winding wire to ground.  I

took the main generator PLUS and MINUS wires off of the generator and

hooked them to a 28 volt variable DC power supply of about 20 amps

capacity.  DO NOT LEAVE ANY OF THE AIRCRAFTS WIRES CONNECTED TO THE

GENERATOR.  The Field Winding can either float or have a SMALL 28 volt

DC light bulb hooked from it to ground.  



You can now bring up voltage with the variable supply and check for

voltages at proper locations without having to run the M-14 engine

itself.  Initially set the variable supply to about 20 volts.  Look for

this 20 volts from the variable power supply at Combined Device Input

terminal.  (Right side bottom.. the BIG one).   Turn on the Aircraft

Master and look for BATTERY voltage on the OUTPUT terminal (left side

middle of the Combined Device...the OTHER big one)  Look for 20 volts on

terminal "B" and NO GROUND on terminal "6".  Increase voltage on the

variable supply to 28.0 volts even.  As you come up on the voltage, the

MAIN CONTACTOR should close with a loud WHACK.   If not, you have

problems with the Combined Device.    



Remove the Combined Device and bench check it.  Here is how you go about

doing that.   



Some of the internal relays can be checked simply by listening to them

click.  No, this does not check the relay CONTACTS themselves, but hey,

that comes later.  Using a 28 volt source, either battery or variable

supply, connect negative to the (-) terminal on the Combined Device.

Connect 28 volts to terminal B.  You should hear a relay click.

Disconnect from B.  Now connect 28 volts to terminal A..(It looks sort

of like an A anyway)  It is on the right side above the large INPUT

terminal.  You should hear a LOUD relay closing, this is the main

contactor. Remove power from "A".  Reapply power to "B"... again you

hear a relay click.  Leaving power applied to B, now hook a grounded

wire to pin 6.  This will close ANOTHER relay and you should be able to

hear it click.  You have now checked every relay coil in the Combined

Device, other than the Polarization Relay, and the internal relay

contacts themselves.  



Find a 24 volt battery, or hook two 12 volt batteries in series.   Hook

the negative lead of the battery to the negative side of your variable

power supply.  Also connect a wire from this to the MINUS (-) terminal

on the Combined Device.    So all negatives (grounds/earths) are now

common to each other.  Hook the plus lead of the battery to the OUTPUT

side of the Combined Device (Big terminal left side middle).  



Variable power supply is now OFF.  



Apply a wire from the 28 volt variable supply output (plus voltage) to

the MAIN INPUT terminal (bottom right side).  Also connect a jumper from

this terminal to terminal "B".  Put some voltmeters here and there to

monitor whatever you feel like, but most certainly variable power supply

output voltage.  Increase the variable power supply output.  When it

reaches about 2 volts or so MORE than the battery voltage, the MAIN

CONTACTOR will close, and you will now have connected your variable

power supply to your test batteries.... and remember, when you do this,

you have just created a battery charger, and the variable power supply

will now try to start charging the batteries!   If your variable power

supply is too small, as soon as it starts to try and charge the

batteries through the now closed MAIN CONTACTOR RELAY, the variable

power supply voltage will DROP.  This will trigger the Polarization

Relay to OPEN,  then causing the MAIN CONTACTOR to open as well, and

battery charging will cease... at which point the variable power supply

will jump back up in voltage, the polarization relay will close again

and the whole cycle will repeat.  This event happens very fast and will

make a lot of noise.  So... warning... use a variable power supply that

can handle more than a few amps without voltage drop for this test.  A

regulated supply that is variable as well would be ideal. 



Ok, so what if the MAIN CONTACTOR does NOT energize when you increase

the voltage?  More than likely, you have problems with the Polarization

Relay. This device seems to wear out first, and the word has it that you

can take this Combined Device apart and adjust these contacts to fix

this relay.  I have not done that yet, but am getting ready to.  



The Combined Device is a rather rare animal and sooner or later is going

to give us all a certain amount of grief.  Without a doubt, I suspect if

we continue to fly these aircraft we are going to have to get more of

these devices at a reasonable cost, or build our own, or convert the

whole aircraft power generation system over to American made.  The

latter is probably the best idea over the long run.  



So there you have it.  The methods for testing this system are my own

and not adopted from any other manual or article.  Use them at your own

risk.  Feel free to copy and distribute this article as you see fit, but

I would sincerely appreciate it if you left my name on it as the author.

Addendum: 



Every Russian aircraft owner should take a careful look at the Carbon

Pile Voltage Regulator R-27.  Vladimir Yastremski warned me about this

device, and his warning was dead on accurate.  This device is mounted on

a very very loose shock mount and rocks and rolls all over the place in

flight.  It has wires that screw onto terminals and as the thing moves,

it can cause a short circuit to certain terminals.  Sure enough, on my

YAK-50, one of the terminals was blackened by a short circuit.  As I

moved the whole thing around, I could see how it caused the short.

Second, look at all the wiring that goes anywhere near bulkheads and/or

"bulb angle".  It is common to see chaffing here, and sure enough... I

had another wire burnt almost in two by short circuits in THIS area.

So, bottom line, 50 owners... save yourself a lot of grief and get you

head up into that nose equipment compartment and inspect all wiring

CAREFULLY!!!  



Best of Luck to all who decide to fix problems with this system on their

own... it's not easy, but this article should help you get started at

least.  



Mark Bitterlich  

N50YK

talew(at)bellsouth.net
Guest

Posted: Wed Feb 14, 2007 4:38 pm Post subject: White Paper on Russian Generator System

Mark,

This is a great look at the YAK 50 Russian electrical system that would 

apply to most of the Russian electrical systems of that era.

Nice job!

This type of information will help maintain these aircraft in good working 

order.

Information that people like You and Dennis and Walt and Doug many others 

share with the group will make this a safer operation.

Thanks,

Terry Lewis

---

talew(at)bellsouth.net
Guest

Posted: Wed Feb 14, 2007 4:44 pm Post subject: White Paper on Russian Generator System

Mark,

This is a great look at the YAK 50 Russian electrical system that would

apply to most of the Russian electrical systems of that era.

Nice job!

Sharing this type of information ,with this group ,will help maintain these 

aircraft in good working order.

Information that people like You and Dennis and Walt and Doug and many 

others share makes these aircraft safer to operate and easier to maintain .

We appreciate it .

Thanks,

Terry Lewis

---

talew(at)bellsouth.net
Guest

Posted: Wed Feb 14, 2007 4:44 pm Post subject: White Paper on Russian Generator System

Mark,

This is a great look at the YAK 50 Russian electrical system that would

apply to most of the Russian electrical systems of that era.

Nice job!

Sharing this type of information ,with this group ,will help maintain these 

aircraft in good working order.

Information that people like You and Dennis and Walt and Doug and many 

others share makes these aircraft safer to operate and easier to maintain .

We appreciate it .

Thanks,

Terry Lewis

---

Rob Rowe

Joined: 10 Jan 2006
Posts: 124
Location: Berkshire, UK

Posted: Wed Feb 14, 2007 8:18 pm Post subject: Re: White Paper on Russian Generator System

Hi Mark,



Great diagnostic posting!



From the schematics ... a few points around the (western) DMD-200D "Complex Apparatus" for discussion from your description.



1 - the Polarised Relay (II) is of a differential design, comprising two windings (a) & (b) wound on the same core. 

(a) a shunt winding that is voltage (polarised) operated - used to monitor the generator voltage & close its contacts when this is 0.2-1V greater than the battery ... in turn energising the Contactor (III) that connects the generator to the power bus

(b) a series winding that is (polarised) current operated - used to monitor the current flowing in/out of the generator circuit relative to the battery ... when a reverse current of 10-25 amps flows (ie the battery is taking the load) the relay contacts open ... in turn releasing the Contactor (III) that disconnects the generator from the power bus



So essentially the generator is voltage controlled to bring it online & (negative) current controlled to take it offline ... hence the differing engine / generator speeds related to these operations ... c.38% online & c.34% offline.

 	  Quote: 	
		  If you put a GROUND on this terminal "6" it will close yet another relay 

coil inside of the Combined Device and will REMOVE the generator feed 

voltage from the Polarization Relay thus making it INOPERATIVE! 

Remember, if you disable the PR relay, then of course you have also 

disabled the MAIN CONTACTOR Relay, and thus, no voltage from the 

generator will ever make it to the main aircraft bus. The ground on 

terminal "6" is usually controlled by the Generator Switch in the 

cockpit. 	




2 - the Cyrillic "6" terminal (western "B") will release Differential Relay II(a) on the bench with a ground (reverse bias), but this input is designed in situ to monitor the battery / generator output (depending on whether the generator is offline / online).



3 - note that the Cyrillic "B" (western "V") terminal connected to the Coupling Relay (I) is fed by 28V (not ground) from a 10A protection fuse via the Over Voltage Unit / External Power Disconnect Relay contacts / Generator Switch control line. None of these external devices are connected to the Cyrillic "6" terminal. The purpose of the Coupling Relay (I) is to isolate the generator / voltage control equipment from the power bus in the event of external power connection, over voltage, negative polarity or fault conditions.

 	  Quote: 	
		  If at any time the generator puts out too much voltage, in the realm of 

31.5 volts or so (+/- 0.5 volt) then a circuit breaker will pop on the 

over/under voltage detection and protection unit 	




4 - the Over Voltage Unit (western AZP-A2) does just that ... under voltage is controlled by the DMD-200D "Complex Apparatus", with reverse polarity protection from relay IV. The AZP-A2 operates above 31-32V although it has a time delay to it that's voltage dependent to prevent short term transients tripping the device. So it can take 0.5 sec to trip up to 37V & 0.12 sec up to 60V ... note that this device has no self-test capability so we have to assume it will work when needed! Once tripped it has an external button to reset it.

Was fortunate on my -52 to have discovered (during annual checks) over the last few years both a loose carbon pile regulator and loose connections inside the DC Power relay box ... before these became a serious issue ... so certainly good advice to keep a look out for these problems.



Regarding the short circuits you found on your regulator / wiring ... could you share the info on which wires shorted (together or to earth?), as in conjunction with the schematic I sent you this might help identify which specific connected devices got zapped?



Also when you traced the voltage output from the generator were you able to see this at the DMD-200D Cyrillic "B" terminal (Coupling Relay I) control input ... as if this relay is not energised the generator will remain isolated from the power bus. Presume you found & tested the 10A protection fuse too?



Cheers, Rob R.

KingCJ6(at)aol.com
Guest

Posted: Wed Feb 14, 2007 9:27 pm Post subject: White Paper on Russian Generator System

Rob - if not previously bestowed upon you, a call sign of "Sparky" is  clearly  befitting your excellent demonstrated expertise!

  

 Dave 

  

 In a message dated 2/14/2007 8:21:15 PM Pacific Standard Time,  yak-list(at)robrowe.plus.com writes:

  	  Quote: 	
		  -->    Yak-List message posted by: "Rob Rowe"    <yak-list(at)robrowe.plus.com>



Hi Mark,



Great diagnostic    posting!



 	  Quote: 	
		  From the schematics ... a few points around the (western)    DMD-200D "Complex Apparatus" for discussion from your description.


	


1 -    the Polarised Relay (II) is of a differential design, comprising two windings    (a) & (b) wound on the same core. 

(a) a shunt winding that is voltage    (polarised) operated - used to monitor the generator voltage & close its    contacts when this is 0.2-1V greater than the battery ... in turn energising    the Contactor (III) that connects the generator to the power bus

(b) a    series winding that is (polarised) current operated - used to monitor the    current flowing in/out of the generator circuit relative to the battery ...    when a reverse current of 10-25 amps flows (ie the battery is taking the load)    the relay contacts open ... in turn releasing the Contactor (III) that    disconnects the generator from the power bus



So essentially the    generator is voltage controlled to bring it online & (negative) current    controlled to take it offline ... hence the differing engine / generator    speeds related to these operations ... c.38% online & c.34%    offline.



 	  Quote: 	
		   If you put a GROUND on this terminal "6" it will    close yet another relay 

 coil inside of the Combined Device and will    REMOVE the generator feed 

 voltage from the Polarization Relay thus    making it INOPERATIVE! 

 Remember, if you disable the PR relay, then of    course you have also 

 disabled the MAIN CONTACTOR Relay, and thus, no    voltage from the 

 generator will ever make it to the main aircraft    bus. The ground on 

 terminal "6" is usually controlled by the    Generator Switch in the 

 cockpit.


	




2 - the Cyrillic "6"    terminal (western "B") will release Differential Relay II(a) on the bench with    a ground (reverse bias), but this input is designed in situ to monitor the    battery / generator output (depending on whether the generator is offline /    online).



3 - note that the Cyrillic "B" (western "V") terminal    connected to the Coupling Relay (I) is fed by 28V (not ground) from a 10A    protection fuse via the Over Voltage Unit / External Power Disconnect Relay    contacts / Generator Switch control line. None of these external devices are    connected to the Cyrillic "6" terminal. The purpose of the Coupling Relay (I)    is to isolate the generator / voltage control equipment from the power bus in    the event of external power connection, over voltage, negative polarity or    fault conditions.



 	  Quote: 	
		   If at any time the generator puts out    too much voltage, in the realm of 

 31.5 volts or so (+/- 0.5 volt)    then a circuit breaker will pop on the 

 over/under voltage detection    and protection unit


	




4 - the Over Voltage Unit (western AZP-A2) does    just that ... under voltage is controlled by the DMD-200D "Complex Apparatus",    with reverse polarity protection from relay IV. The AZP-A2 operates above    31-32V although it has a time delay to it that's voltage dependent to prevent    short term transients tripping the device. So it can take 0.5 sec to trip up    to 37V & 0.12 sec up to 60V ... note that this device has no self-test    capability so we have to assume it will work when needed! Once tripped it has    an external button to reset it.

Was fortunate on my -52 to have    discovered (during annual checks) over the last few years both a loose carbon    pile regulator and loose connections inside the DC Power relay box ... before    these became a serious issue ... so certainly good advice to keep a look out    for these problems.



Regarding the short circuits you found on your    regulator / wiring ... could you share the info on which wires shorted    (together or to earth?), as in conjunction with the schematic I sent you this    might help identify which specific connected devices got zapped?



Also    when you traced the voltage output from the generator were you able to see    this at the DMD-200D Cyrillic "B" terminal (Coupling Relay I) control input    ... as if this relay is not energised the generator will remain isolated from    the power bus. Presume you found & tested the 10A protection fuse    too?



Cheers, Rob R.

	


 

  

  [quote][b]

jan.mevis(at)informavia.b
Guest

Posted: Wed Feb 14, 2007 10:11 pm Post subject: White Paper on Russian Generator System

What a great job, Mark, THANKS A LOT! This will help me solve the Voltage

Regulation problems in my Yak 50 !



Jan Mevis

RA2005K



--

ByronMFox(at)aol.com
Guest

Posted: Wed Feb 14, 2007 10:49 pm Post subject: White Paper on Russian Generator System

In a message dated 2/14/2007 9:29:13 PM Pacific Standard Time, KingCJ6(at)aol.com writes:

  	  Quote: 	
		   Rob - if not previously bestowed upon you, a call sign of "Sparky" is clearly  befitting your excellent demonstrated expertise!

	


 Nope,Dave. Sorry, "Sparky" already belongs to Doug Sapp's lovely daughter. I'll go for "Sparks", though. ...Blitz, Chairman

    AHSACSC

  [quote][b]

Rob Rowe

Joined: 10 Jan 2006
Posts: 124
Location: Berkshire, UK

Posted: Thu Feb 15, 2007 3:12 am Post subject: Re: White Paper on Russian Generator System

Doh! ... typo in my own post.



 	  Quote: 	
		  3 - ...... The purpose of the Coupling Relay (I) is to isolate the generator / voltage control equipment from the power bus in the event of external power connection, over voltage, negative polarity or fault conditions. 	




Strike the "negative polarity" statement from the above ... my excuse is writing posts in the early hours ... zzzzzz



Rob R

viperdoc(at)mindspring.co
Guest

Posted: Thu Feb 15, 2007 8:16 am Post subject: White Paper on Russian Generator System

Sparky should go to Mark Bitterlinch. More than one person can hold the same call sign. Just not necessarily with both being in the same squadron at the same time. Up to 3 call signs can be bestowed to a member over their career. However, after the 3 monikor has been bestowed for some usually fitting moment of buffonery that call sign becomes the members permenant identifier. 

 Doc

  

 



  

 [quote] ---

cjpilot710(at)aol.com
Guest

Posted: Thu Feb 15, 2007 8:50 am Post subject: White Paper on Russian Generator System

In a message dated 2/15/2007 11:18:35 A.M. Eastern Standard Time,  viperdoc(at)mindspring.com writes:

  

 Actually "Sparky" was given to Brain Lloyd when he shorted across his trim  cables, the terminals of a new battery he was replacing at OSH in 2001 (or  02?).   The bang and flash was VERY noticeable across the "North 40"  of the warbird area.  To say nothing of the blood curling scream from  "Pinky" aka Brain Lloyd.  Ah those were the 'good old days'.   

  

 Jim "Pappy" Goolsby

 [quote]      Sparky should go to Mark Bitterlinch. More    than one person can hold the same call sign. Just not necessarily    with both being in the same squadron at the same time. Up to 3 call signs can    be bestowed to a member over their career. However, after the 3 monikor has    been bestowed for some usually fitting moment of buffonery that call sign    becomes the members permenant identifier. 

   Doc

    

   



    

   [quote]     ---

jorgen.nielsen(at)mweb.co
Guest

Posted: Thu Feb 15, 2007 10:44 am Post subject: White Paper on Russian Generator System

How is Brian these days?  His absence on the list is noticeable.  

   

Jorgen  

         

  

From: owner-yak-list-server(at)matronics.com [mailto:owner-yak-list-server(at)matronics.com] On Behalf Of cjpilot710(at)aol.com

 Sent: 15 February 2007 06:50 PM

 To: yak-list(at)matronics.com

 Subject: Re: Re: White Paper on Russian Generator System  

  

       

In a message dated 2/15/2007 11:18:35 A.M. Eastern Standard Time, viperdoc(at)mindspring.com writes:  

    

   

    

Actually "Sparky" was given to Brain Lloyd when he shorted across his trim cables, the terminals of a new battery he was replacing at OSH in 2001 (or 02?).   The bang and flash was VERY noticeable across the "North 40" of the warbird area.  To say nothing of the blood curling scream from "Pinky" aka Brain Lloyd.  Ah those were the 'good old days'.    

    

   

    

Jim "Pappy" Goolsby  

  [quote]      

Sparky should go to Mark Bitterlinch. More than one person can hold the same call sign. Just not necessarily with both being in the same squadron at the same time. Up to 3 call signs can be bestowed to a member over their career. However, after the 3 monikor has been bestowed for some usually fitting moment of buffonery that call sign becomes the members permenant identifier.   

    

Doc  

    

   

  

    

   

  [quote]    

---

cjpilot710(at)aol.com
Guest

Posted: Thu Feb 15, 2007 11:41 am Post subject: White Paper on Russian Generator System

In a message dated 2/15/2007 1:47:01 P.M. Eastern Standard Time,  jorgen.nielsen(at)mweb.co.za writes:

  

 He's fine.  Newly married and building a new home at an airpark near  Sacramento.  He is missed.

  

  	  Quote: 	
		        

How is Brian these    days?  His absence on the list is  noticeable.   

    

Jorgen   

             

   

From:    owner-yak-list-server(at)matronics.com    [mailto:owner-yak-list-server(at)matronics.com] On Behalf Of    cjpilot710(at)aol.com

Sent: 15 February 2007 06:50    PM

To: yak-list(at)matronics.com

Subject: Re: Re: White Paper on    Russian Generator System

   

          

In a message dated    2/15/2007 11:18:35 A.M. Eastern Standard Time, viperdoc(at)mindspring.com    writes:

      

 

      

Actually "Sparky"    was given to Brain Lloyd when he shorted across his trim cables, the terminals    of a new battery he was replacing at OSH in 2001 (or 02?).   The bang    and flash was VERY noticeable across the "North 40" of the warbird area.     To say nothing of the blood curling scream from "Pinky" aka Brain Lloyd.     Ah those were the 'good old days'.   

      

 

      

Jim "Pappy"    Goolsby

    	  Quote: 	
		                 

Sparky      should go to Mark Bitterlinch.      More than one person can hold the same call sign. Just not      necessarily with both being in the same squadron at the same time. Up to 3      call signs can be bestowed to a member over their career. However, after the      3 monikor has been bestowed for some usually fitting moment of buffonery      that call sign becomes the members permenant identifier. 

          

Doc

          

 



          

 

      	  Quote: 	
		                

----- Original        Message ----- 

              

From:  (ByronMFox(at)aol.com)

              

To:        yak-list(at)matronics.com (yak-list(at)matronics.com)

              

Sent: 2/15/2007        12:55:57 AM 

              

Subject: Re: Yak-List:        Re: White Paper on Russian Generator        System

              

 

                     

In a message        dated 2/14/2007 9:29:13 PM Pacific Standard Time, KingCJ6(at)aol.com        writes:

        	  Quote: 	
		                    

Rob - if not          previously bestowed upon you, a call sign of "Sparky" is clearly           befitting your excellent demonstrated          expertise!

	


              

Nope,Dave.        Sorry, "Sparky" already belongs to Doug Sapp's lovely daughter. I'll go        for "Sparks", though. ...Blitz,        Chairman

              

          AHSACSC

 	  Quote: 	
		  <> 	
  ="http://www.matronics.com/Navigator?Yak-List">http://www.matronics.com/Navigator?Yak-List.matronics.com/">http://forums.matronics.com 	
	


      

 

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mark.bitterlich(at)navy.m
Guest

Posted: Thu Feb 15, 2007 2:06 pm Post subject: White Paper on Russian Generator System

Hi Rob, 



In the one day since I wrote that article, I have learned a lot more

than what I knew just 24 hours ago, and some of that deals with what you

have just brought up, so thank you for writing AS ALWAYS!  I am going to

change the article to correct a few mistakes, and I appreciate you

bringing any weakness to light!  I am going to address what you wrote

with my findings, but before I do, let me address the questions that you

had last... First!  



The two short circuits to ground were both intermittant.  To the best of

my knowledge, neither of them caused the problem that I now have.  Both

shorts showed black arcing, but no wires were melted.... As in no wiring

showed evidence of high current flow, instead it looked like a short

"flash" and that was it.  I did not write down the wire numbers, but on

the Voltage Regulator, it was the first terminal (the one most aft) as

you face forward in the aircraft, looking up and to the left (Yak-50).

This terminal is on the right side of the regulator mounting bracket.

It shorted to the mounting bracket mounting BOLT (right rear) as you

tilted the shock mount in that direction.  I did not even look for a

marking on the wire that shorted against the airframe, but I can later

if you like.  



Here are some comments on your "comments" per se. My findings last night

on the "polarization relay" were a big surprise.  

-------------------------

You said:

 	  Quote: 	
		  From the schematics ... a few points around the (western) DMD-200D

"Complex Apparatus" for discussion from your    description.
	




1 - the Polarised Relay (II) is of a differential design, comprising two

windings (a) & (b) wound on the same core. 

(a) a shunt winding that is voltage (polarised) operated - used to

monitor the generator voltage & close its contacts when this is 0.2-1V

greater than the battery ... in turn energising the Contactor (III) that

connects the generator to the power bus

(b) a series winding that is (polarised) current operated - used to

monitor the current flowing in/out of the generator circuit relative to

the battery ... when a reverse current of 10-25 amps flows (ie the

battery is taking the load) the relay contacts open ... in turn

releasing the Contactor (III) that disconnects the generator from the

power bus



So essentially the generator is voltage controlled to bring it online &

(negative) current controlled to take it offline ... hence the differing

engine / generator speeds related to these operations ... c.38% online &

c.34% offline.

------------------------------

My response: 



What you wrote above is exactly the same information I got from George

Coy and it also matches some information I managed to get from a Russian

manual translated to English.  I also suspect that it is 100% accurate

for SOME models of this unit.  However, as we all know, Russian parts

can sometimes have exactly the same make and part number, but what

components we find inside are NOT the same. 



I think you will find what comes next to be very interesting.  After

looking around for a new "Combined Device" and not finding any for sale

for less than $600, I decided I needed to either fix what I had, replace

the whole system, or design a replacement for the part that was bad.  I

took the whole thing apart.  What I found inside did not meet the

description that I had, or the one that you just wrote me.  What I found

was two normal 28 volt relays (one with really bad internal resistance

on the contacts, (which is the actual cause of my problem)  and the

other that was "going bad" but at least was still functional. Of note

here is that ALL relays had operating coils and made normal mechanical

sounds.  The PROBLEM was indeed high resistance on the contacts, which

my article does NOT cover, but needs to be corrected to make those

tests!  



Then we come to the "Polarized Relay".  It did NOT have two windings on

the same core.  In fact it was instead a LATCHING relay with one coil

only.  This coil and the relay are built so that if you flow current in

one direction it latches the relay in one position, and if you reverse

the polarity you simply reverse the magnetic field and latch it in the

opposite direction.  Think of the internal design to be like a See-Saw

.. I.E., a Lever Arm with a fulcrum in the middle.  The coil winding

SURROUNDS the lever arm at the fulcrum and has metal tabs to direct the

mag field to two main points.  If you energize the coil with PLUS

voltage on one side, the magnetic field will pull the lever arm down to

the left.  If you reverse the voltage polarity, then the lever arm will

pull down to the right.  Once the lever arm is in EITHER position, when

you remove voltage to it, it stays where it was last left at.  That is

what makes it a LATCHING relay.  



Even though this design is not the same as what you described (and I

read in my own material), it never-the-less does indeed FUNCTION about

the same way.  If current from the battery start flowing into the

generator, it will also flow through this coil backwards as well, and

the magnetic field will reverse, the relay will OPEN and disconnect the

main contactor just as we both described.  



Next, this coil will operate with as little as 2 volts of voltage. This

can be straight voltage with earth being 0 and input being 2 VDC, or..

It can be DIFFERENTIAL voltage.  



So, the end result here is that this relay does both jobs... Forward and

reverse current, and differential voltage.  The fact is however, that it

is a single wound coil instead of a double, and it is a latching relay

instead of non-latching type. 



Also of interest is that this relay is ADJUSTABLE.  Meaning, as it

wears, it can be RE-ADJUSTED for proper operation as long as the coil

itself is not damanged.  



You said: 

----------------------------

2 - the Cyrillic "6" terminal (western "B") will release Differential

Relay II(a) on the bench with a ground (reverse bias), but this input is

designed in situ to monitor the battery / generator output (depending on

whether the generator is offline / online).



----------------------------

My response: 

Putting a ground on this terminal (6) will cause a relay to close and

open the electrical path to the "Differential Relay".  I think we are

both saying the same thing here.  You are pointing out what it is used

for (thanks!) but I believe I was suggesting how to check to make sure

it was working (bench check).  Bottom line here is that I need to add

more to the explanation, thanks!   



You said:

----------------------------

3 - note that the Cyrillic "B" (western "V") terminal connected to the

Coupling Relay (I) is fed by 28V (not ground) from a 10A protection fuse

via the Over Voltage Unit / External Power Disconnect Relay contacts /

Generator Switch control line. None of these external devices are

connected to the Cyrillic "6" terminal. The purpose of the Coupling

Relay (I) is to isolate the generator / voltage control equipment from

the power bus in the event of external power connection, over voltage,

negative polarity or fault conditions.

-----------------------------

My Response:  

Again I believe we are saying the same thing Rob, and I did in fact

point out that there was 28 volts on V and not gound.    What I said in

my article was: (Quote)  "The Voltage Regulator (official name "R-27")

has outputs that feed back to control the generator excitation field,

but it also has another output that goes over to the over voltage box.

If the voltage is normal, the over voltage box feeds this same voltage

(28 volts) back to pin B on the Combined Device.  (Note, it looks like a

"B" to me, that is the SHAPE of the marking, but it is actually the

Russian letter "V".)"    



I believe the confusion factor here centers on what the letters actually

look like and what they actually are in Russian.  It does no good to

Americans to tell them that 28 volts goes to terminal "V" when they look

for themselves and see no letter "V" marked on the unit!  It's a problem

to write about this kind of thing to be sure.  



-------------------------------

You said: 



4 - the Over Voltage Unit (western AZP-A2) does just that ... under

voltage is controlled by the DMD-200D "Complex Apparatus", with reverse

polarity protection from relay IV. The AZP-A2 operates above 31-32V

although it has a time delay to it that's voltage dependent to prevent

short term transients tripping the device. So it can take 0.5 sec to

trip up to 37V & 0.12 sec up to 60V ... note that this device has no

self-test capability so we have to assume it will work when needed! Once

tripped it has an external button to reset it.

--------------------------------

My response: 

When I used an external variable power supply in place of the generator,

I ran it up past 30 volts to indeed check the over-voltage protection

circuit trip point.  It works.  I did not write about it simply because

I am not so sure it is a good idea to recommend to anyone else to do

that.  



I appreciate the additional info you sent me here Rob, and please keep

it coming!  



Take care, and my best, 



Mark



 



--

mark.bitterlich(at)navy.m
Guest

Posted: Thu Feb 15, 2007 2:11 pm Post subject: White Paper on Russian Generator System

Thanks Jan, 



 	  Quote: 	
		  From what I discovered last night when I took the Combined Device apart,

I need to rewrite part of that posting.  What is in the books, and what
	


is in the box, are simply not the same.  Additionally, what I found that

actually led me to be able and repair this device turned out to be bad

contacts, which is something I did NOT detail how to check in what I

wrote either.  



I'll work on it and send another one out later. 



Mark

 

--

Rob Rowe

Joined: 10 Jan 2006
Posts: 124
Location: Berkshire, UK

Posted: Fri Feb 16, 2007 8:21 pm Post subject: Re: White Paper on Russian Generator System

Hi Mark,



Thanks for all this ... a very interesting discussion ... I've added some further thoughts below.



Have also read your next edition of the white paper so will refer to some items in that too rather than creating another long message.



Btw - I'm Rob Rowe ... Rob Kent (Russian Engineering) didn't write the differential relay extract ... although he's a really helpful guy who's loaned various docs to me so I can (try to) get my head around these systems ... so thanks again Rob K from Rob R!

 	  Quote: 	
		  Hi Rob, 



In the one day since I wrote that article, I have learned a lot more 

than what I knew just 24 hours ago, and some of that deals with what you 

have just brought up, so thank you for writing AS ALWAYS! 	




Mark ... we've both learned a lot over the last few days!

 	  Quote: 	
		  The two short circuits to ground were both intermittant. To the best of 

my knowledge, neither of them caused the problem that I now have. Both 

shorts showed black arcing, but no wires were melted.... As in no wiring 

showed evidence of high current flow, instead it looked like a short 

"flash" and that was it. I did not write down the wire numbers, but on 

the Voltage Regulator, it was the first terminal (the one most aft) as 

you face forward in the aircraft, looking up and to the left (Yak-50). 

This terminal is on the right side of the regulator mounting bracket. 

It shorted to the mounting bracket mounting BOLT (right rear) as you 

tilted the shock mount in that direction. I did not even look for a 

marking on the wire that shorted against the airframe, but I can later 

if you like. 	




I posed these short circuit queries as I wasn't sure from your post whether you'd yet found a definitive cause to your problems.



Now that you have (the eroded relay contacts), & from the nature of the flash over described, there's not much to be gained from pursuing this ... but thanks for offering to try!

 	  Quote: 	
		  Here are some comments on your "comments" per se. My findings last night 

on the "polarization relay" were a big surprise. 

------------------------- 

You said: 

Quote: 

From the schematics ... a few points around the (western) DMD-200D 

"Complex Apparatus" for discussion from your description.  



...



So essentially the generator is voltage controlled to bring it online & 

(negative) current controlled to take it offline ... hence the differing 

engine / generator speeds related to these operations ... c.38% online & 

c.34% offline. 

------------------------------ 

My response: 



What you wrote above is exactly the same information I got from George 

Coy and it also matches some information I managed to get from a Russian 

manual translated to English. I also suspect that it is 100% accurate 

for SOME models of this unit. However, as we all know, Russian parts 

can sometimes have exactly the same make and part number, but what 

components we find inside are NOT the same. 

----------------------------- 	




RR Response #2:



My source comes from machine-translating extracts from my 1991 YAK-52 docs & and some schematics from a Sukhoi 29 (Jan 92) that I'd been given ... to cross-reference the discrepancies (in both!).



Btw - your Sukhoi schematic is different to mine in that its corrects a mistake on the TKE1R2D contacts (NC, not NO), labels all the connections in English (except the contactor "C" should be an English "S"), removes what appeared to be a latch on the contactor & removed a "N" & "S" (North & South?) from the polarised relay where the physically missing series coil should be ("S" on the bus side) ... more on this latter on.



 	  Quote: 	
		  

I think you will find what comes next to be very interesting. 

...



Then we come to the "Polarized Relay". It did NOT have two windings on 

the same core. In fact it was instead a LATCHING relay with one coil 

only. This coil and the relay are built so that if you flow current in 

one direction it latches the relay in one position, and if you reverse 

the polarity you simply reverse the magnetic field and latch it in the 

opposite direction. Think of the internal design to be like a See-Saw 

.. I.E., a Lever Arm with a fulcrum in the middle. The coil winding 

SURROUNDS the lever arm at the fulcrum and has metal tabs to direct the 

mag field to two main points. If you energize the coil with PLUS 

voltage on one side, the magnetic field will pull the lever arm down to 

the left. If you reverse the voltage polarity, then the lever arm will 

pull down to the right. Once the lever arm is in EITHER position, when 

you remove voltage to it, it stays where it was last left at. That is 

what makes it a LATCHING relay. 



Even though this design is not the same as what you described (and I 

read in my own material), it never-the-less does indeed FUNCTION about 

the same way. If current from the battery start flowing into the 

generator, it will also flow through this coil backwards as well, and 

the magnetic field will reverse, the relay will OPEN and disconnect the 

main contactor just as we both described. 	
 



Excellent research Mark ... well done!



With the benefit of hindsight ... in as much as I've read the next version of your YAK-50 white paper while still responding to this one ;-) ... maybe that's foresight ... whatever ... it seems there might still be some credibility to the differential relay theory.



As quoting from your next message about the polarised relay operation ... (Quote) I could find no series winding per se, which does not necessarily mean it is not there, just that I could not find it. The relay core in my unit had only two wires coming out of it. (Unquote).



This is fair of you given there's nothing obvious to suggest anything other than a single coil being present ... albeit the operation of the whole DMR-200D requires a high current detection function to be present somewhere.



So to help figure this out one way or the other perhaps you could inspect the polarised relay again (assuming you've still got it in bits ... a photograph would be useful too!) for any signs of North or South markings on the structure indicating the possibility of another polarised coil (and as hinted on my Sukhoi schematic) ... in Cyrillic this would be a "C" & "IO" respectively [or YL:"S" & YL:"Yu" ... this will make more sense when you've read the rest of this message!].



My guess is that because the series coil has to handle very high currents then this might be physically embedded in the structure of the unit with no apparent connections. So if you could check the continuity from Cyrillic "CETb" [YL: "SETs"] across the structure of the polarised relay to find out what it's connected to then this might give us some further insight ... similarly if you could trace from the Contactor output contact back to the polarised relay structure ... thanks.



Again from your next message ;-) ... I've attached a PDF image file of the DMR-200D in my 1991 YAK-52 (found a stock photo I had of the DC Power Box when the loose connection was fixed) which I've marked up with various connections & screw mounts you referenced (as best as I can make them out at the top of the image).



Could you confirm please if a/ it's the same unit as you have in your -50 & b/ whether I've got the labelling correct. I've also used the Cyrillic / Western alphabet map discussed further below ... interested in your feedback. If we could get a photograph of the polarised relay too then this could be added for future reference by anyone trying to repeat this down the line.

 	  Quote: 	
		  Next, this coil will operate with as little as 2 volts of voltage. This 

can be straight voltage with earth being 0 and input being 2 VDC, or.. 

It can be DIFFERENTIAL voltage. 	




A few questions for you Mark please ... (edited to correct relay designations after original post)

- was this polarised coil operation at 2 volts tested with the (effectively in parallel) TKE210B taken out of the circuit?

- did you have the opportunity to separately test the TKE210B operating voltage characteristics?

- can you confirm that the TKE210B connections are as per the Sukhoi schematic rather than the Yak schematics

i.e. TKE210B connection "6" goes to the DMR-200D terminal "6" (Sukhoi) & NOT to the output connection of the Contactor contacts facing the Polarised relay (Yak)



The above will help confirm the correction to the Yak schematics (50 & 52) and shed more light on the operations of both these relays, individually & collectively ... thanks. 





 	  Quote: 	
		  You said: 

---------------------------- 

2 - the Cyrillic "6" terminal (western "B") will release Differential 

Relay II(a) on the bench with a ground (reverse bias), but this input is 

designed in situ to monitor the battery / generator output (depending on 

whether the generator is offline / online). 



---------------------------- 

My response: 

Putting a ground on this terminal (6) will cause a relay to close and 

open the electrical path to the "Differential Relay". I think we are 

both saying the same thing here. You are pointing out what it is used 

for (thanks!) but I believe I was suggesting how to check to make sure 

it was working (bench check). Bottom line here is that I need to add 

more to the explanation, thanks! 

----------------------------- 	




RR Response #2:

Mark what I think we've both realised is that a narrative explanation of what a given device does in a complex system goes a long way in helping to diagnose a problem & then to create a testing regime ... these were the purpose of my comments, nothing more.



 	  Quote: 	
		  You said: 

---------------------------- 

3 - note that the Cyrillic "B" (western "V") terminal connected to the 

Coupling Relay (I) is fed by 28V (not ground) from a 10A protection fuse 

via the Over Voltage Unit / External Power Disconnect Relay contacts / 

Generator Switch control line. None of these external devices are 

connected to the Cyrillic "6" terminal. The purpose of the Coupling 

Relay (I) is to isolate the generator / voltage control equipment from 

the power bus in the event of external power connection, over voltage, 

negative polarity or fault conditions. 

----------------------------- 

My Response: 

Again I believe we are saying the same thing Rob, and I did in fact 

point out that there was 28 volts on V and not gound. What I said in 

my article was: (Quote) "The Voltage Regulator (official name "R-27") 

has outputs that feed back to control the generator excitation field, 

but it also has another output that goes over to the over voltage box. 

If the voltage is normal, the over voltage box feeds this same voltage 

(28 volts) back to pin B on the Combined Device. (Note, it looks like a 

"B" to me, that is the SHAPE of the marking, but it is actually the 

Russian letter "V".)" 



I believe the confusion factor here centers on what the letters actually 

look like and what they actually are in Russian. It does no good to 

Americans to tell them that 28 volts goes to terminal "V" when they look 

for themselves and see no letter "V" marked on the unit! It's a problem 

to write about this kind of thing to be sure.

-----------------------------  	




RR Response #2:

Guess there are two points here;



1 - while you correctly state the "how" function in the above quote Mark later on in your text this was made ambiguous by (Quote) The ground on terminal "6" is usually controlled by the Generator Switch in the cockpit.(Unquote) ... and it was this quotation that I (literally) referenced in my feedback message. Based on;

- Cyrillic "6" is not connected to the generator switch

- but Cyrillic "B" is

- neither uses a ground when operational

Again I'd added a narrative "what" explanation to help put this in context, not to challenge your original (correct) "how" statement



2 - Mark we're in need of a Yak-List nomenclature to avoid confusion between Cyrillic & Western alphabets. It's easily done in a long post and you've sometimes used one or other or both ... so I've attempted to put together a standard alphabet map between the two as per the attached PDF file. Given it's not really practical to try & describe the Cyrillic characters (the backwards E, upside down L, the one that looks like a 6 etc) nor can these characters be universally posted on the Yak-List ... fine on the web site, but plain text email trashes them. So prefixing descriptions with for example "YL: R-27" can be read from the map as "Yak-List: P-27" in Cyrillic, also useful when some of the chars look quite similar and a mug shot of the definitive version can act as a reference. If this works Ok then perhaps it could be adopted by the list for general use?



 	  Quote: 	
		  ------------------------------- 

You said: 



4 - the Over Voltage Unit (western AZP-A2) does just that ... under 

voltage is controlled by the DMD-200D "Complex Apparatus", with reverse 

polarity protection from relay IV. The AZP-A2 operates above 31-32V 

although it has a time delay to it that's voltage dependent to prevent 

short term transients tripping the device. So it can take 0.5 sec to 

trip up to 37V & 0.12 sec up to 60V ... note that this device has no 

self-test capability so we have to assume it will work when needed! Once 

tripped it has an external button to reset it. 

-------------------------------- 

My response: 

When I used an external variable power supply in place of the generator, 

I ran it up past 30 volts to indeed check the over-voltage protection 

circuit trip point. It works. I did not write about it simply because 

I am not so sure it is a good idea to recommend to anyone else to do 

that. 

----------------------------- 	




RR Response #2:

Mark my point was simply to highlight that a 10-20 year over-voltage unit with no self-test capability might not be relied upon to work when it's most needed, even if it does then the over voltage response might fry anything less than DO160 tested avionics ... bus powered portable GPS users beware!

 	  Quote: 	
		  I appreciate the additional info you sent me here Rob, and please keep 

it coming! 	




Don't worry I will ;-)



Take care & thanks for all the help,



Rob R

YAK-52 DMR-200D Connections.pdf

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YAK-LIST Alphabet Mapping.pdf

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yakplt(at)yahoo.com
Guest

Posted: Mon Feb 19, 2007 7:07 pm Post subject: White Paper on Russian Generator System

Rob,



Replying to your queries:

 	  Quote: 	
		   I posed these short circuit queries as I wasn't sure from your post

whether you'd yet found a definitive cause to your problems.
	




Understood.  The cause of my problem was resistive contacts on the relay

connected to terminal "V" which I refer to as the enabling relay.  Tapping

on this relay produced contact readings that varied from 2 to 125 ohms.



 	  Quote: 	
		   Now that you have (the eroded relay contacts), & from the nature of the

flash over described, there's not much to be gained from pursuing this ...
	


but thanks for offering to try!



No problem.



Since taking my 200D apart, I have since gotten access to a second one.

This second one had both a shunt and series wound assy on the latching

relay.  The shunt is a normal winding.  The series is a large bar

(obviously) that provides a second magnetic field for part of a lever arm

assy.  The shunt and  series windings are not on the same core.



 	  Quote: 	
		  

 >

 > I think you will find what comes next to be very interesting.

 > ...

 >

 > Then we come to the "Polarized Relay". It did NOT have two windings on

 > the same core. In fact it was instead a LATCHING relay with one coil

 > only. This coil and the relay are built so that if you flow current in

 > one direction it latches the relay in one position, and if you reverse

 > the polarity you simply reverse the magnetic field and latch it in the

 > opposite direction. Think of the internal design to be like a See-Saw

 > .. I.E., a Lever Arm with a fulcrum in the middle. The coil winding

 > SURROUNDS the lever arm at the fulcrum and has metal tabs to direct the

 > mag field to two main points. If you energize the coil with PLUS

 > voltage on one side, the magnetic field will pull the  lever arm down to

 > the left. If you reverse the voltage polarity, then the lever arm will

 > pull down to the right. Once the lever arm is in EITHER position, when

 > you remove voltage to it, it stays where it was last left at. That is

 > what makes it a LATCHING relay.

 >

 > Even though this design is not the same as what you described (and I

 > read in my own material), it never-the-less does indeed FUNCTION about

 > the same way. If current from the battery start flowing into the

 > generator, it will also flow through this coil backwards as well, and

 > the magnetic field will reverse, the relay will OPEN and disconnect the

 > main contactor just as we both described.

 Excellent research Mark ... well done!


	


Thank you.   Since then, I have seen confirmation that there are two types

of polarization relays.. if not  more... since I have taken a second 200D

apart.  The one I have in the one I am invesitagating now is almost the same

constuction, but it clearly has a large bus bar type arrangement that

surrounds the lever arm and clearly is a current operated device.  It is

possible that the first one I had, which is now back in my airplane, had

something LIKE that that might have been buried under the material that

mounted the relay.  I find it hard to believe there are two different

designs... two different relays, sure.. .but not two different designs.

Without a shadow of a doubt, this second one has a large current operated

magnetic field influencing the lever arm.



 	  Quote: 	
		   With the benefit of hindsight ... in as much as I've read the next version

of your YAK-50 white paper while still responding to this one  ... maybe
	


that's foresight ... whatever ... it seems there might still be some

credibility to the differential relay  theory.

 	  Quote: 	
		  

 As quoting from your next message about the polarised relay operation ...

(Quote) I could find no series winding per se, which does not necessarily
	


mean it is not there, just that I could not find it. The relay core in my

unit had only two wires coming out of it. (Unquote).

 	  Quote: 	
		  

 This is fair of you given there's nothing obvious to suggest anything

other than a single coil being present ... albeit the operation of the whole
	


DMR-200D requires a high current detection function to be present somewhere.



I agree with you.  It is clear that the one mis-statement is the part that

says: "Two windings on the same core".  I have a clear definition of what a

"core" is.  Others may understand that term in a different way.  What is

true regardless, is that neither the first or second polarization relay I

have examined have two systems on the same core.  BOTH have a standard coil

on core  arrangement that is normal for "typical relays".  I am assuming that

this is the shunt winding.  The series arrangment on the second example uses

bar bar material to influence the magnetic field of the first standard

winding and this I assume to be the series array.



 	  Quote: 	
		   So to help figure this out one way or the other perhaps you could inspect

the polarised relay again (assuming you've still got it in bits ... a
	


photograph would be useful too!) for any signs of North or South markings on

the structure indicating the possibility of another polarised coil (and as

hinted on my Sukhoi schematic) ... in Cyrillic this would be a "C" & "IO"

respectively [or YL:"S" & YL:"Yu" ... this will make more sense when you've

read the rest of this message!].



I understand perfectly.  Sadly, the first one that was bad has been repaired

and is back in my 50 operating perfectly.  I replaced both the TKE relays

with  American made military types with 28 VDC coils.  They were both DPST

types about 1/5th the size of what was in there to begin with.



 	  Quote: 	
		   My guess is that because the series coil has to handle very high currents

then this might be physically embedded in the structure of the unit with no
	


apparent connections.



I agree that this could very easily be the case my first example.  In the

second example, the bar surrounds the lever arm assy.



 	  Quote: 	
		  o if you could check the continuity from Cyrillic "CETb" [YL: "SETs"]

across the structure of the polarised relay to find out what it's connected
	


to then this might give us some further insight ... similarly if you could

trace from the Contactor output contact back to the polarised relay

structure ... thanks.



The bus bar arrangement described above is in series with the main current

path without question.  As to the first example, it is back in my 50 and

sadly will not  be removed again unless necessary.  Sorry.  



 	  Quote: 	
		   Again from your next message  ... I've attached a PDF image file of the

DMR-200D in my 1991 YAK-52 (found a stock photo I had of the DC Power Box
	


when the loose connection was fixed) which I've marked up with various

connections & screw mounts you referenced (as best as I can make them out at

the top of the image).



Hmm... I could not find your attachment... but I am pretty sure it is the

same device.  I looked at a 52, and it was the same part in that aircraft.

I did not open that one up though.



 	  Quote: 	
		  

 A few questions for you Mark please ...

 - was this polarised coil operation at 2 volts tested with the

(effectively in parallel) TKE1R2D taken out of the circuit?
	




Yes, the shunt coil was tested in a stand alone open circuit.



 	  Quote: 	
		   - did you have the opportunity to separately test the TKE1R2D operating

voltage  characteristics?
	




Yes, believe it or not, both TKE relays share the same housing and the same

coils.  They pull in between 5.6 and 6 volts DC (very low and yes, I was

surprised).  The current draw at 6 volts was 200 mils on the coil.  At 28

volts this went to 800 mils on the voil.



The main contactor pulled in at about 10 volts, and dropped out at around 2

volts.  Current draw at 28 volts was a healthy 3 amps.



 	  Quote: 	
		   - can you confirm that the TKE1R2D connections are as per the Sukhoi

schematic rather than the Yak schematics
	




The 200D is wired exactly as per the schematic that I included yes.  The Yak

schematics left me totally in the dark, which is why I went to the Suke

diagrams.  Although what wires are attached to the 200D differ in the Suke,

the diagram of the 200D device itself is dead on accurate.



 	  Quote: 	
		   i.e. TKE1R2D connection "6" goes to the DMR-200D terminal "6" (Sukhoi)  &

NOT to the output connection of the Contactor contacts facing the Polarised
	


relay (Yak)



I am I am not following you here.  But:



The relay in question has an A & B coil contact terminal on the 200D.  B

goes to the terminal marked negative on the 200D , and A goes to terminal V

on the 200D.  The relay contacts themselves... there are three of them..

unusual in itself.   Contact marked  number one on the relay itself feeds

two relay "arms".  These two arms are common to each other.  A wire goes

from relay terminal contact 1 and connects to the main generator input

terminal, which by the way is also connected to the "+" terminal on the 200D

with another internal connection, again as per the diagram.



On this same relay, there is a solder contact point 2 AND 3.  The diagram I

sent just shows them both marked as "3", but in reality they are marked on

the relay itself as 2  and 3.  These are both normally open contacts that

BOTH get connected to relay terminal 1 when the relay energizes.  Terminal

contact 2 goes to the Polarization relay contact terminal as shown in the

diagram.  Terminal contact 3 feeds to the normally closed contacts of relay

TKE210B as per the diagram.



 	  Quote: 	
		   The above will help confirm the correction to the Yak schematics (50 & 52)

and shed more light on the operations of both these relays, individually &
	


collectively ... thanks.

 [quote][b]

yakplt(at)yahoo.com
Guest

Posted: Mon Feb 19, 2007 7:11 pm Post subject: White Paper on Russian Generator System

Jan, while this is fresh in my mind, what kind of problems are you having with your 50?

   

  Mark

  



Jan Mevis <jan.mevis(at)informavia.be> wrote:

  [quote]--> Yak-List message posted by: "Jan Mevis" 



What a great job, Mark, THANKS A LOT! This will help me solve the Voltage

Regulation problems in my Yak 50 !



Jan Mevis

RA2005K



--

jan.mevis(at)informavia.b
Guest

Posted: Mon Feb 19, 2007 10:48 pm Post subject: White Paper on Russian Generator System

I have a lot of radio noise (rattling noise). I suspected the voltage regulation but I do have that loud noise also with the engine running and master and other switches off (the radio is connected with a separate breaker switch and fuse to the battery since the original radio switch in the front panel is faulty; when I connect the radio to this switch, the voltage over the radio drops to 3 volts).  

   

I already did Dennis’ plug conversion and I also replaced the high tension lead of the booster coil. The engine runs perfectly smooth and seems to have more power! Mag drops on 1 and on 2 at 70 % are small. So this conversion is a very good thing. I also double checked the plug wires and connexions, and strapped all the wires very securely so that they don’t move around when going negative. I also double-checked the positioning of the mag caps, and cleaned them thoroughly with alcohol. Since the engine runs so well, I hardly doubt the problem comes from the conversion. But it’s enigmatic since I had less noise with the old Russian harness.  

   

Recently I replaced my faulty ZIABRIK by a BRIZ. I tested this BRIZ on a test bench before installing. The BRIZ works good when the engine is not running. When it runs, there’s a loud and annoying noise, as if I hear the contacts of the mags. This only happens when the channel is clear. When someone sends on the frequency, reception is perfect, and when I send, they hear me 5 to 5 and in both cases I have almost no background noise at all. I ‘m going to check the cabling of the radio. Is it possible that there’s more EMI radiation of the ignition system since it works “better” than before ? Perhaps there’s a grounding problem ?  

   

Anyway, I am impressed by what you did on your plane, I don’t have the knowledge nor the experience to do these kind of checks. I am considering the B&C alternator + regulator and crowbar. Nevertheless the whole Russian system seems to be very well designed and robust. I’d like to keep the Yak 50 as original as possible, since it’s so beautiful and well designed.  

   

Best regards,  

   

Jan  

         

  

From: owner-yak-list-server(at)matronics.com [mailto:owner-yak-list-server(at)matronics.com] On Behalf Of Yak Pilot

 Sent: dinsdag 20 februari 2007 4:11

 To: yak-list(at)matronics.com

 Subject: RE: White Paper on Russian Generator System  

  

     

Jan, while this is fresh in my mind, what kind of problems are you having with your 50?  

    

   

    

Mark  

    



 

 Jan Mevis <jan.mevis(at)informavia.be> wrote:  

  [quote]  

--> Yak-List message posted by: "Jan Mevis" 

 

 What a great job, Mark, THANKS A LOT! This will help me solve the Voltage

 Regulation problems in my Yak 50 !

 

 Jan Mevis

 RA2005K

 

 --

mark.bitterlich(at)navy.m
Guest

Posted: Tue Feb 20, 2007 12:35 pm Post subject: White Paper on Russian Generator System

Jan, you are the second person I have heard from who has had radio noise

that could not be lived with after the conversion to automobile plugs,

and that fact is beginning to make me nervous about that change! As far

as your comments on the change, I have also heard that mag drops are

much less from everyone who has made the change as well.  So, there is

obviously a lot of good things going on as well!  



If you want to isolate the generator, simply remove the three wires from

the generator itself Jan.  It is pretty easy to do... You simply take a

copy off that wraps around the generator near the top.  The only warning

there is when you re-install that cover, it is easy to the threads out

of the "bar" that the screws go into.  Careful there.  Other than that,

you can simply unscrew the wires and and then start it up and listen for

your noise.  



The truth is that turning the generator OFF is supposed to kill the

excitation field and should give you the same result as removing the

wires!   However, if you want to be REALLY REALLY sure, you can remove

the wires.  In fact, an even easier way would be to simply connect a

voltmeter to the generator itself after removing the cover as described

and then with the generator switch OFF, check for voltage with the

engine running.  I never did this myself sorry to say.  But you SHOULD

get nothing coming out of the generator.  If you don't, there is no

sense in removing the wires. 



Now... That said, there IS something that will make a TON of noise into

your radio that is easily overlooked.  That is the TACH GENERATOR!

That thing is ALIVE all the time.  There is no way to switch it OFF.  It

is a 3 phase AC generator and it is absolutely ESSENTIAL that the

shielding on this wiring is perfect, and the fact is that the shielding

and other wiring at this plug routinely goes bad due to bad solder and

vibration.  You can check whether this is your noise generator very

easily by simply taking the plug OFF of the tach generator on the left

side of your engine. It's a big black thing that screws into the

accessory gear box and is slightly down and to the left of the air start

distributor. It's definitely worth looking into.  



Discussing the wires that Dennis's modification uses.  These are

actually (as I am sure you are well aware of) wires that are sold for

racing engines.  They are basically standard automobile spark plugs

wires, although a few millimeters larger and claim to have a better

conductor that standard carbon impregnated types.  The wires that came

stock with our aircraft uses solid strands of wire, and it is hard to

imagine a better conductor than those!  However, the rubber covering

these wires is inferior and breaks down and shorts out a lot.  Next,

when you run solid core wires like the Russians (and Americans as well

did on Radial Engines) did, you have little antennas hooked to a

powerful generator.  Consider that the very first radios in this world

used spark gap generators to create an RF signal and you will get the

idea here.  Since that magneto generates high voltage and sparks, there

is wide band RF noise all over the place!  To contain this, they built

the shielding and tubing system that they did, which if course was used

on EVERY radial engine out there!  



Since that period of time, spark plug wires have gotten better and types

have been built that allow them to be run out in the open and not in

shielded tubes or conduits.  This is what Dennis used.  However, there

is NO QUESTION that they are going to create more noise than the

original system did, if the original system was properly maintained.

Dennis never did any real scientific checks of what his wiring system

was going to do.  In order to check that, he would need specific test

equipment looking at the on-board radios, etc.  At the very minimum a

spectrum analyzer so as to note any changes in the RF noise floor.  He

didn't do that either.  Bottom line, there is going to be more noise

with his system... But you also gain a TERRIFIC advantage over the

original system when ever you need to do any maintenance!   



You may be able to adjust the internal setting of the radio's squelch

setting to over-come the noise problem. Some of these radios are

different from another, but I have one at home I can take pictures of

and show you how to adjust the squelch.  



As for checking your cabling... Stop right there.  



Simply do this:  Get behind your radio and disconnect the antenna.

Start the engine and see if the noise is still there.  If it IS, then

the noise is coming in via your cabling, and you very well might have

success in eliminating the noise if you use well shielded wire to

provide power from the battery to the radio as you are presently doing

since your switch failed.  Be aware that it helps to use shielded wire

for both the positive AND the negative leads of the radio directly to

the battery, but I doubt you will fix your problem by doing that.  



As I said, if the noise stays with the antenna disconnected AT THE

RADIO, then ok... But if the noise goes AWAY with the antenna

disconnected, then checking radio wiring is a waste of time.  



By the way, to carefully hear and determine the noise that you are

getting ALWAYS run your checks with the squelch switch set to OFF, so

that you can clearly hear the full extent and type of noise that you are

dealing with.



If you go with the B&C system, I would advise AGAINST their very small

PMG generator, and would instead go with their SK35 and outboard voltage

regulator.  This system comes with self-contained under/over voltage and

current protection built into the regulator.  The SK35 will give you 35

amps of output.  I think they also have a 45 or 50 amp version.  



The Russian power system is indeed robust, and can be maintained, IF you

can find the spare parts, or repair what breaks yourself.  I now have a

spare regulator, over-voltage unit, and can fix the 200D unit.  Fixing

the Russian electrical system was a real exercise for me, and working

with Avionics is what I do for a living   .  Bottom line, if you ever

have a failure, I will be glad to help talk you through fixing it. 



Mark

   

--

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