Matronics Email Lists :: View topic - BATTERY MASTER SWITCH

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

BATTERY MASTER SWITCH

Matronics Email Lists Forum Index -> AeroElectric-List

View previous topic :: View next topic

Author Message

nuckollsr(at)cox.net
Guest

Posted: Tue Aug 07, 2007 6:31 am Post subject: BATTERY MASTER SWITCH

At 10:43 AM 8/6/2007 -0400, you wrote:



 	  Quote: 	
		  



Cheers,

         I'm still searching for that elusive device - in an attempt to avoid

the cost of an ampere or two of contactor current - which will control a

primary battery source and another for secondary battery source.

         I have found several which meet one criterion or another, but not

all:

[a]     should carry as much current as a contactor for that job;

[b]     needs to be an up-down rather than rotary type switch;

[c]     should be on a remote(able) stalk so I can undo the connection to

remove the      instrument panel ;

[d]     cost less than the usual contactor - or at least be competitive.

         I have devised a system to isolate the controls from wandering

fingers so am not fussy about security. I'm not sure what a "Kill switch" is

really.

         Any help would be most appreciated.


	


   Ferg, Why not build one? You need to support two 5/16" brass

   studs on an insulating material, say 1/8" thick fiberglass/epoxy

   sheet. Taper switch ends of studs to provide a spherical tip

   with about 1/8th inch radius. Mount studs just far enough apart

   to allow connection with fat-wires . . . about 1" would probably

   do. Build box on terminal board to capture a brass "slider"

   (3/8" square stock) that is pressed against stud tips with

   spring loading from back side. You could rig a Bowden control

   cable to operate the slide (you need about 1/2 to 3/4" stroke)

   for making and breaking the switch. This seems like a project

   that could be crafted with common hand tools.  The

   end product would be on the order of 3" long, 1.5" wide and

   perhaps 2" deep. Perfect the design and we'll do an article

   on it for the website.



   Bob . . .

nuckollsr(at)cox.net
Guest

Posted: Tue Aug 07, 2007 8:09 pm Post subject: BATTERY MASTER SWITCH

At 10:43 AM 8/6/2007 -0400, you wrote:



 	  Quote: 	
		  



Cheers,

         I'm still searching for that elusive device - in an attempt to avoid

the cost of an ampere or two of contactor current - which will control a

primary battery source and another for secondary battery source.

         I have found several which meet one criterion or another, but not

all:

[a]     should carry as much current as a contactor for that job;

[b]     needs to be an up-down rather than rotary type switch;

[c]     should be on a remote(able) stalk so I can undo the connection to

remove the      instrument panel ;

[d]     cost less than the usual contactor - or at least be competitive.

         I have devised a system to isolate the controls from wandering

fingers so am not fussy about security. I'm not sure what a "Kill switch" is

really.

         Any help would be most appreciated.


	


   Ferg, Why not build one? You need to support two 5/16" brass

   studs on an insulating material, say 1/8" thick fiberglass/epoxy

   sheet. Taper switch ends of studs to provide a spherical tip

   with about 1/8th inch radius. Mount studs just far enough apart

   to allow connection with fat-wires . . . about 1" would probably

   do. Build box on terminal board to capture a brass "slider"

   (3/8" square stock) that is pressed against stud tips with

   spring loading from back side. You could rig a Bowden control

   cable to operate the slide (you need about 1/2 to 3/4" stroke)

   for making and breaking the switch. This seems like a project

   that could be crafted with common hand tools.  The

   end product would be on the order of 2.5" long, 1.2" wide and

   perhaps 2" tall overall. Perfect the design and we'll do an article

   on it for the website.



   Here's a rough layout of a possible design



http://aeroelectric.com/Catalog/AEC/9042/9042-100.pdf



   The brass stock, parts and spring-stud are McMaster catalog

   items. Side brackets can be aluminum sheet or extrusion.

   Insulating material could be Delrin or perhaps even a

   hard "machinable" wood like walnut or oak.



   Bob . . .

pwmac(at)sisna.com
Guest

Posted: Wed Aug 08, 2007 3:24 am Post subject: BATTERY MASTER SWITCH

Clever design. I guess the operating cable is non conductive, or did 

I miss something?

Paul

=======================



At 11:05 PM 8/7/2007, you wrote:

 	  Quote: 	
		  

<nuckollsr(at)cox.net>

   Ferg, Why not build one? You need to support two 5/16" brass

   studs on an insulating material, say 1/8" thick fiberglass/epoxy

   sheet. Taper switch ends of studs to provide a spherical tip

   with about 1/8th inch radius. Mount studs just far enough apart

   to allow connection with fat-wires . . . about 1" would probably

   do. Build box on terminal board to capture a brass "slider"

   (3/8" square stock) that is pressed against stud tips with

   spring loading from back side. You could rig a Bowden control

   cable to operate the slide (you need about 1/2 to 3/4" stroke)

   for making and breaking the switch. This seems like a project

   that could be crafted with common hand tools.  The

   end product would be on the order of 2.5" long, 1.2" wide and

   perhaps 2" tall overall. Perfect the design and we'll do an article

   on it for the website.



   Here's a rough layout of a possible design



http://aeroelectric.com/Catalog/AEC/9042/9042-100.pdf



   The brass stock, parts and spring-stud are McMaster catalog

   items. Side brackets can be aluminum sheet or extrusion.

   Insulating material could be Delrin or perhaps even a

   hard "machinable" wood like walnut or oak.



   Bob . . .

echristley(at)nc.rr.com
Guest

Posted: Wed Aug 08, 2007 5:24 am Post subject: BATTERY MASTER SWITCH

Robert L. Nuckolls, III wrote:

 	  Quote: 	
		  

   Here's a rough layout of a possible design



 http://aeroelectric.com/Catalog/AEC/9042/9042-100.pdf



   The brass stock, parts and spring-stud are McMaster catalog

   items. Side brackets can be aluminum sheet or extrusion.

   Insulating material could be Delrin or perhaps even a

   hard "machinable" wood like walnut or oak.



   Bob . . .



What a cool idea.  This looks like it would be a fun project, Bob.  The 
	


only thing I would change would be to make the slider a square piece and 

arrange it so that it contacts both taper switch ends at the same time.  

I know this real smart guy that taught me that contactors have multiple 

break points in order to break the arc faster.



With a couple more of those spring-studs, it should be possible to make 

the slider pop off the switch ends at a much higher rate.  Just arrange 

a few on both sides of the switch ends so that the slider is 

cantilevered away when it is slid out, but hits the springs and pushed 

against the contacts when slid in.



Dang!! I'm gonna have to make one now.  Right after I finish building 

several more earbud headsets.  I'll never get airplane finished at this 

rate (but, I will have the coolest contactor in the universe!!). 



Ernest (Is anyone else having this much fun?)

Eric M. Jones

Joined: 10 Jan 2006
Posts: 565
Location: Massachusetts

Posted: Wed Aug 08, 2007 6:02 am Post subject: Re: BATTERY MASTER SWITCH

 	  Quote: 	
		  I'm still searching for that elusive device - in an attempt to avoid 

the cost of an ampere or two of contactor current - which will control a 

primary battery source and another for secondary battery source. 

I have found several which meet one criterion or another, but not 

all: 

[a] should carry as much current as a contactor for that job; 

[b] needs to be an up-down rather than rotary type switch; 

[c] should be on a remote(able) stalk so I can undo the connection to 

remove the instrument panel ; 

[d] cost less than the usual contactor - or at least be competitive. 

I have devised a system to isolate the controls from wandering 

fingers so am not fussy about security. I'm not sure what a "Kill switch" is 

really. Any help would be most appreciated.  	




Ferg,



As Bob says you can build one; true, but I suggest Flaming River's push-pull battery switch. Not cheap but you won't have to build it.



If you want to build one, get a scrap type-70 or similar contactor, toss the coil and use the parts. You can buy high current contacts too, although you can buy silver and make contacts that will do the job for this application.



Don't neglect the patents online at USPTO. Search high current switch, etc. and see how people did it.

_________________
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net

nuckollsr(at)cox.net
Guest

Posted: Wed Aug 08, 2007 6:55 am Post subject: BATTERY MASTER SWITCH

At 04:49 AM 8/8/2007 -0600, you wrote:



 	  Quote: 	
		  



Clever design. I guess the operating cable is non conductive, or did I 

miss something?

Paul


	


   The conventional Bowden push-pull control is obviously

   metallic. I'd probably drill the slider and fit a full

   length plastic insulator tubing down the hole and craft

   insulator washers for each end that would isolate the

   wire from the slider. There's a variety of ways to

   consider for attaching the wire . . . but your

   observations concerning the need for insulation are

   correct.



   Bob . . .

Speedy11(at)aol.com
Guest

Posted: Wed Aug 08, 2007 7:26 am Post subject: BATTERY MASTER SWITCH

Eric Jones had a neat design for such a device.  Contact him at emjones(at)charter.net (emjones(at)charter.net).

 Stan Sutterfield

  	  Quote: 	
		  >Cheers,

 	  Quote: 	
		           I'm still    searching for that elusive device - in an attempt to avoid

the cost of    an ampere or two of contactor current - which will control a

primary    battery source and another for secondary battery source.

            I have found several which meet one criterion or another,    but not

all:

[a]     should carry as much current    as a contactor for that job;

[b]     needs to be an    up-down rather than rotary type switch;

[c]     should    be on a remote(able) stalk so I can undo the connection to

remove    the      instrument panel ;

[d]     cost    less than the usual contactor - or at least be competitive.

            I have devised a system to isolate the controls    from wandering

fingers so am not fussy about security. I'm not sure    what a "Kill switch" is

really.

            Any help would be most appreciated.


	


   Ferg, Why    not build one? You need to support two 5/16" brass

   studs on an    insulating material, say 1/8" thick fiberglass/epoxy

   sheet.    Taper switch ends of studs to provide a spherical tip

   with    about 1/8th inch radius. Mount studs just far enough apart

   to    allow connection with fat-wires . . . about 1" would probably

      do. Build box on terminal board to capture a brass "slider"

      (3/8" square stock) that is pressed against stud tips with

      spring loading from back side. You could rig a Bowden control

      cable to operate the slide (you need about 1/2 to 3/4" stroke)

      for making and breaking the switch. This seems like a project

      that could be crafted with common hand tools.  The

   end    product would be on the order of 3" long, 1.5" wide and

      perhaps 2" deep. Perfect the design and we'll do an article

   on    it for the website. 	


 

  



Get a sneak peek of the all-new AOL.com.

nuckollsr(at)cox.net
Guest

Posted: Wed Aug 08, 2007 1:55 pm Post subject: BATTERY MASTER SWITCH

At 09:22 AM 8/8/2007 -0400, you wrote:



 	  Quote: 	
		  

<echristley(at)nc.rr.com>



Robert L. Nuckolls, III wrote:

>

>   Here's a rough layout of a possible design

>

>http://aeroelectric.com/Catalog/AEC/9042/9042-100.pdf

>

>   The brass stock, parts and spring-stud are McMaster catalog

>   items. Side brackets can be aluminum sheet or extrusion.

>   Insulating material could be Delrin or perhaps even a

>   hard "machinable" wood like walnut or oak.

>

>   Bob . . .

What a cool idea.  This looks like it would be a fun project, Bob.  The 

only thing I would change would be to make the slider a square piece and 

arrange it so that it contacts both taper switch ends at the same time.

I know this real smart guy that taught me that contactors have multiple 

break points in order to break the arc faster.


	


    This isn't a contactor. It's a low velocity, sliding

    contact switch that depends on PRESSURE at the contact

    locations to achieve low resistance connection. This

    is a low voltage (12v) low current (10A or less) SWITCHING

    task that must handle 200+ amps only after the switch

    is static in the close position.



 	  Quote: 	
		  With a couple more of those spring-studs, it should be possible to make 

the slider pop off the switch ends at a much higher rate.  Just arrange a 

few on both sides of the switch ends so that the slider is cantilevered 

away when it is slid out, but hits the springs and pushed against the 

contacts when slid in.


	


     This borrows from some very old technology - the

     knife switch. See:



http://www.aeroelectric.com/Pictures/Switches/knife_switch_1.jpg



http://www.aeroelectric.com/Pictures/Switches/knife_switch_2.jpg



     Two pressure dependent contacts to one moving part. Operating

     velocity is not critical but good connection in the pressure

     joints is. Hence two spring-studs to maintain force against

     the slider . . . flat surface against a spherical surface.

     VERY LOW contact area, HIGH pressure.



 	  Quote: 	
		  Dang!! I'm gonna have to make one now.  Right after I finish building 

several more earbud headsets.  I'll never get airplane finished at this 

rate (but, I will have the coolest contactor in the universe!!).

Ernest (Is anyone else having this much fun?)


	


     This is properly called a SPST switch. The

    drawing is intended to be a door-opener for

    individuals who would like to expend some effort and

    acquire some real-time, hands-on experience. At the

    same time, it offers at least one compact solution

    to the remotely controlled, zero draw battery switch.



    Bob  . . .

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

        ( "Physics is like sex: sure, it may   )

        ( give some practical results, but     )

        ( that's not why we do it."            )

        (                                      )

        (                 Richard P. Feynman   )

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

nuckollsr(at)cox.net
Guest

Posted: Wed Aug 08, 2007 2:08 pm Post subject: BATTERY MASTER SWITCH

At 07:02 AM 8/8/2007 -0700, you wrote:



 	  Quote: 	
		  

 > I'm still searching for that elusive device - in an attempt to avoid

 > the cost of an ampere or two of contactor current - which will control a

 > primary battery source and another for secondary battery source.

 > I have found several which meet one criterion or another, but not

 > all:

 > [a] should carry as much current as a contactor for that job;

 > [b] needs to be an up-down rather than rotary type switch;

 > [c] should be on a remote(able) stalk so I can undo the connection to

 > remove the instrument panel ;

 > [d] cost less than the usual contactor - or at least be competitive.

 > I have devised a system to isolate the controls from wandering

 > fingers so am not fussy about security. I'm not sure what a "Kill 

 switch" is

 > really. Any help would be most appreciated.

Ferg,



As Bob says you can build one. but I suggest Flaming River's push-pull 

battery switch. Not cheap but you won't have to build it.



If you want to build one, get a scrap type-70 or similar contactor, toss 

the coil and use the parts.


	




   The type-70 is a low pressure, large area design where it's not

   clear to me how one would utilize the components . . .



http://www.aeroelectric.com/Pictures/Contactors/S701-1a.jpg

http://www.aeroelectric.com/Pictures/Contactors/S701-1b.jpg

http://www.aeroelectric.com/Pictures/Contactors/S701-1c.jpg

http://www.aeroelectric.com/Pictures/Contactors/S701-1d.jpg

http://www.aeroelectric.com/Pictures/Contactors/S701-1e.jpg

http://www.aeroelectric.com/Pictures/Contactors/S701-1f.jpg



   and craft a manually operated mechanism to achieve remote

   control.



 	  Quote: 	
		    You can buy high current contacts too, although you can buy silver and 

 make contacts that will do the job for this application.


	


   If one were seeking to craft a high cycle SWITCHING

   device, higher quality contacts would be useful as would

   some design philosophy that achieves minimum bounce on

   closure and rapid contact spreading velocity. In the

   case of a battery contactor, going beyond the requirement

   to occasionally SWITCH 10A and occasionally CARRY 200A

   in a once-per flight-cycle operation seems to have a poor

   return on infestment for the effort.

 	  Quote: 	
		  Don't neglect the patents online at USPTO. Search high current switch, 

etc. and see how people did it.


	


   Good idea . . . but keep in mind that most designs

   are at least attempting to improve on an existing design

   that exhibits less than ideal service life or performance

   as a kilo-operations switch working at or near max

   ratings. For our purposes, a wrench used to connect the

   battery terminal before flight and disconnect at the

   end of flight would have more than adequate electrical

   performance. The design goals here are to achieve convenient

   manual remote control, light weight, small size and

   use materials and techniques readily available to the

   greatest number of interested builders. I.e., the elegant

   solution.



   Bob . . .

Peter H

Joined: 20 Mar 2007
Posts: 197

Posted: Wed Aug 08, 2007 2:26 pm Post subject: BATTERY MASTER SWITCH

Bob

If you remove the circlip and fit a bolt threaded to engage at the bottom,

it could be used to pull the circular contactor down to engage with the

copper terminals. Insulate where required.

Peter 



--

nuckollsr(at)cox.net
Guest

Posted: Wed Aug 08, 2007 7:08 pm Post subject: BATTERY MASTER SWITCH

At 08:26 AM 8/9/2007 +1000, you wrote:



 	  Quote: 	
		  

<peterjfharris(at)bigpond.com>



Bob

If you remove the circlip and fit a bolt threaded to engage at the bottom,

it could be used to pull the circular contactor down to engage with the

copper terminals. Insulate where required.

Peter


	


    Not sure what you mean. The motion in

    this device is longitudinal to the "slider", I.e.,

    a Bowden wire coming in from the left would be used

    to move the slider such that it disengages from

    the left-hand stud only. The motion is not intended

    to emulated the actions of a contactor. There's

    no circlip in the assembly as illustrated. Only

    two fixed terminal studs with spherical ends

    and a brass-slide bar held against the studs

    with spring loaded balls from underneath. The

    spring-studs are threaded so that the pressure

    and spring-travel can be adjusted.



    Bob . . .

Peter H

Joined: 20 Mar 2007
Posts: 197

Posted: Wed Aug 08, 2007 10:00 pm Post subject: BATTERY MASTER SWITCH

Bob I was referring to the first of the pics you sent showing a type 70

contactor open for inspection.

It could be used by manually actuating the movement with the use of a bolt.

Peter



--

nuckollsr(at)cox.net
Guest

Posted: Thu Aug 09, 2007 6:50 am Post subject: BATTERY MASTER SWITCH

At 03:59 PM 8/9/2007 +1000, you wrote:



 	  Quote: 	
		  

<peterjfharris(at)bigpond.com>



Bob I was referring to the first of the pics you sent showing a type 70

contactor open for inspection.

It could be used by manually actuating the movement with the use of a bolt.

Peter


	


   Aha! Understand. Interestingly enough, there have been

   products offered in the distant past that allowed for

   manual operation of this style of contactor. I helped

   some folks find a suitable replacement for a contactor

   much like the Model 70 on a Lockheed Lodestar. The

   contactor they took off was much like the Model 70 except

   it had a non-metalic push-button protruding from a

   hole in the top cap that allowed one to push the

   plunger assembly down manually.



   I suppose one could use modified guts of a Model 70

   to craft a manual switch but it would not be my

   process of choice. The contactor is a large area,

   relatively low pressure connection device that would

   be more prone to failure due to contamination and/or

   corrosion. Once opened for the purpose of converting

   to manual operations, then we've exposed the innards

   to the environment which opens opportunities for

   unintended consequences for service life.



   As folks follow this thread, please keep in mind that

   in no way are we suggesting that one launch into any

   sort of modification to their stock battery contactor

   of any make. Nor are we suggesting that it's even

   desirable to replace the electro-mechanical contactor

   with a purely mechanical switch.



   This is an exercise in crafting a light, compact,

   ZERO POWER switch capable of reasonably convenient

   control by push-pull Bowden cable. It's a design study

   for specific cases (airplanes fitted with small alternators).



   We KNOW that battery contactors of any pedigree can,

   do and will fail at some point in time. In my never

   humble opinion, it's far better to craft a plan-b

   to comfortably mitigate such failures than to modify

   manufactured parts or spend a lot of $time$ crafting

   our own, one-of-a-kind, manual switch.



   Until someone has crafted what they believe is a

   part that meets the zero-power, remote-controlled

   design goal then all of the foregoing is simply an

   academic exercise to consider the options. No generalized

   recommendations to depart from what's published in the

   Z-figures or elsewhere should be inferred.



   Bob . . .

BobsV35B(at)aol.com
Guest

Posted: Thu Aug 09, 2007 7:19 am Post subject: BATTERY MASTER SWITCH

In a message dated 8/9/2007 9:53:26 A.M. Central Daylight Time,  nuckollsr(at)cox.net writes:

  	  Quote: 	
		  Aha!    Understand. Interestingly enough, there have been

   products    offered in the distant past that allowed for

   manual operation    of this style of contactor. I helped

   some folks find a    suitable replacement for a contactor

   much like the Model 70 on    a Lockheed Lodestar. The

   contactor they took off was much like    the Model 70 except

   it had a non-metalic push-button    protruding from a

   hole in the top cap that allowed one to push    the

   plunger assembly down  manually.

	


 

 For What It Is Worth, 

  

 When I was a lad, Ford automobiles had a plunger on their starter contactor  that allowed us to actuate the starter manually. There was no way to open the  contactor if it was stuck closed, but if the electrical activation option was  not operative, we could spin over the engine by pushing on the plunger.  Obviously, the battery had to be sound.

  

 Happy  Skies,



Old Bob

AKA

Bob Siegfried

Ancient Aviator

Stearman  N3977A

Brookeridge Air Park LL22

Downers Grove, IL 60516

630  985-8503



Get a sneak peek of the all-new AOL.com.

  [quote][b]

Display posts from previous:

	Matronics Email Lists Forum Index -> AeroElectric-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum