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M27500 Shielded Wire For Strobe

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billhuntersemail(at)gmail
Guest

Posted: Fri Mar 03, 2017 6:00 am Post subject: M27500 Shielded Wire For Strobe

Greetings,Â 



I am wiring a Velocity composite aircraft.Â 

For my Whelen HDACF strobe light circuit I was planning on using the gold colored copper strand lamp cord from Home Depot... just kidding... I am actually planning on using Tefzel M22759/16 wire 18 guage from the CB to the overhead switch and then from the switch way back to the strobe unit mounted on the firewall (pusher airplane).Â 

Then... I read "somewhere" that the M27500 Shielded wire is recommended for this application so as to suppress the noise.Â 

Is this really necessary?Â 

THANKS!!!Â 



Bill Hunter

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nuckolls.bob(at)aeroelect
Guest

Posted: Fri Mar 03, 2017 6:48 am Post subject: M27500 Shielded Wire For Strobe

At 07:58 AM 3/3/2017, you wrote:

  	  Quote: 	
		  Greetings,Â 



 I am wiring a Velocity composite aircraft.Â 



 For my Whelen HDACF strobe light circuit I was planning on using the gold colored copper strand lamp cord from Home Depot... just kidding... I am actually planning on using Tefzel M22759/16 wire 18 guage from the CB to the overhead switch and then from the switch way back to the strobe unit mounted on the firewall (pusher airplane).Â 



 Then... I read "somewhere" that the M27500 Shielded wire is recommended for this application so as to suppress the noise.Â 



 Is this really necessary?Â 	


   Shielding of wires breaks only ONE kind

   of noise propagation mode. This mode is very weak

   and then only applies to certain kinds of

   fast rising antagonists. No such antagonists exist

   on the DC power line to any modern piece of

   electronics . . . if it DOES demonstrate such

   antagonists, then those will be CONDUCTED into

   the rest of the system whether the wire is shielded

   or not . . . short answer:



   No

   



 

   Bob . . .

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billhuntersemail(at)gmail
Guest

Posted: Fri Mar 03, 2017 11:16 am Post subject: M27500 Shielded Wire For Strobe

Wow... Bob and Simon I am very grateful for your time. I cannot contribute much back to this forum however on other forums where I have some tid bits of ignorance to expound upon I try to help where I can so as to "cyber pay it forward".Â 



Yes it seemed odd to me to have to shield a DC supply wire to the power inputs of a DC unit. Output wires from the strobe box to the strobe lights on the wings could have a argument.Â 

I will certainly twist the power feed wire pairs as suggested for this box.Â 

I also have two Light Speed Plasma III ignition units and two aircraft batteries. Since Klaus recommends running the POS and NEG wires directly from the battery terminals (through a reset able CB) to the units I will also twist those pairs.Â 

My power feeds from the associated CB to the radios is a very small run and there is no negative wire nearby to twist so I guess that is a wash.Â 

I do have some other wires from DC CBs to switches and then to appliances such as landing /taxi/beacon /voltage regulators and some of those wires runs will be bundled next to the XPNDR /ADS-B /NAV/COM coaxial cables (using the coaxial cable Bob recommended). I suppose the shield on the coax will do the trick.Â 



Bill Hunter 



On Mar 3, 2017 09:56, "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote: 	  Quote: 	
		    At 07:58 AM 3/3/2017, you wrote:

  	  Quote: 	
		  Greetings,Ã‚ 



 I am wiring a Velocity composite aircraft.Ã‚ 



 For my Whelen HDACF strobe light circuit I was planning on using the gold colored copper strand lamp cord from Home Depot... just kidding... I am actually planning on using Tefzel M22759/16 wire 18 guage from the CB to the overhead switch and then from the switch way back to the strobe unit mounted on the firewall (pusher airplane).Ã‚ 



 Then... I read "somewhere" that the M27500 Shielded wire is recommended for this application so as to suppress the noise.Ã‚ 



 Is this really necessary?Ã‚ 	


 Â  Shielding of wires breaks only ONE kind

 Â  of noise propagation mode. This mode is very weak

 Â  and then only applies to certain kinds of

 Â  fast rising antagonists. No such antagonists exist

 Â  on the DC power line to any modern piece of

 Â  electronics . . . if it DOES demonstrate such

 Â  antagonists, then those will be CONDUCTED into

 Â  the rest of the system whether the wire is shielded

 Â  or not . . . short answer:



 Â  No

 Â  



 

 Â  Bob . . .

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Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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nuckolls.bob(at)aeroelect
Guest

Posted: Fri Mar 03, 2017 2:45 pm Post subject: M27500 Shielded Wire For Strobe

At 01:13 PM 3/3/2017, you wrote:

  	  Quote: 	
		  Wow... Bob and Simon I am very grateful for your time. I cannot contribute much back to this forum however on other forums where I have some tid bits of ignorance to expound upon I try to help where I can so as to "cyber pay it forward".Â 



 Yes it seemed odd to me to have to shield a DC supply wire to the power inputs of a DC unit. Output wires from the strobe box to the strobe lights on the wings could have a argument.Â 



 I will certainly twist the power feed wire pairs as suggested for this box.Â 



 I also have two Light Speed Plasma III ignition units and two aircraft batteries. Since Klaus recommends running the POS and NEG wires directly from the battery terminals (through a reset able CB) to the units I will also twist those pairs.Â 	


    That's a bit of OVERKILL . . . strike that . . .

    it's a LOT of overkill.  Klaus and I had

    had some discussions about it and he didn't

    disagree with me but still seems to get some kind

    of comfort/satisfaction from running wires directly

    to batteries.



    Failure mode effects analysis and simple probability

    studies demonstrate that each ignition simply needs

    its own power source with no chance of single failure

    bringing down both ignition systems. A prime example

    of yet another flavor of poor FMEA is illustrated

    here:   http://tinyurl.com/msfmldj



    If I were putting Lightspeed (or any other pair

    of engine support accessories) in a TC aircraft,

    I think my DARs would be happy with one ignition

    powered from the battery bus on its own breaker/fuse

    and powering the other from the main bus . . it

    too powered by its own protection. Ground the

    accessories locally (metal airplane) or to the

    grounding hub on the firewall (see Figure Z-15).



    Twisting the power/ground pairs is of no value

    in reduction of noise. If the accessory dumps

    and excessive level of noise back to the bus then

    shielding/twisting won't help . . . furhter, the

    product would not pass DO-160 qualification

    testing for installation on a TC aircraft.



  	  Quote: 	
		  My power feeds from the associated CB to the radios is a very small run and there is no negative wire nearby to twist so I guess that is a wash.Â 	


    Scrap the twisting thing . . .



 

  	  Quote: 	
		  I do have some other wires from DC CBs to switches and then to appliances such as landing /taxi/beacon /voltage regulators and some of those wires runs will be bundled next to the XPNDR /ADS-B /NAV/COM coaxial cables (using the coaxial cable Bob recommended). I suppose the shield on the coax will do the trick.Â 	


    Your filtering apples out of your sack of

    oranges. Shields on coaxes have a completely

    different task . . . they have nothing in 

    common with shielding as a noise abatement

    device. Coaxes bundled with virtually

    any other wires raises no concerns for

    inter-system interference.



 

   Bob . . .

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Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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billhuntersemail(at)gmail
Guest

Posted: Fri Mar 03, 2017 4:08 pm Post subject: M27500 Shielded Wire For Strobe

Thanks Bob for the valuable information!!!Â 



Bill Hunter 





On Mar 3, 2017 16:55, "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote: 	  Quote: 	
		    At 01:13 PM 3/3/2017, you wrote:

  	  Quote: 	
		  Wow... Bob and Simon I am very grateful for your time. I cannot contribute much back to this forum however on other forums where I have some tid bits of ignorance to expound upon I try to help where I can so as to "cyber pay it forward".Ã‚ 



 Yes it seemed odd to me to have to shield a DC supply wire to the power inputs of a DC unit. Output wires from the strobe box to the strobe lights on the wings could have a argument.Ã‚ 



 I will certainly twist the power feed wire pairs as suggested for this box.Ã‚ 



 I also have two Light Speed Plasma III ignition units and two aircraft batteries. Since Klaus recommends running the POS and NEG wires directly from the battery terminals (through a reset able CB) to the units I will also twist those pairs.Ã‚ 	


 Â Â  That's a bit of OVERKILL . . . strike that . . .

 Â Â  it's a LOT of overkill.Â  Klaus and I had

 Â Â  had some discussions about it and he didn't

 Â Â  disagree with me but still seems to get some kind

 Â Â  of comfort/satisfaction from running wires directly

 Â Â  to batteries.



 Â Â  Failure mode effects analysis and simple probability

 Â Â  studies demonstrate that each ignition simply needs

 Â Â  its own power source with no chance of single failure

 Â Â  bringing down both ignition systems. A prime example

 Â Â  of yet another flavor of poor FMEA is illustrated

 Â Â  here:Â   http://tinyurl.com/msfmldj



 Â Â  If I were putting Lightspeed (or any other pair

 Â Â  of engine support accessories) in a TC aircraft,

 Â Â  I think my DARs would be happy with one ignition

 Â Â  powered from the battery bus on its own breaker/fuse

 Â Â  and powering the other from the main bus . . it

 Â Â  too powered by its own protection. Ground the

 Â Â  accessories locally (metal airplane) or to the

 Â Â  grounding hub on the firewall (see Figure Z-15).



 Â Â  Twisting the power/ground pairs is of no value

 Â Â  in reduction of noise. If the accessory dumps

 Â Â  and excessive level of noise back to the bus then

 Â Â  shielding/twisting won't help . . . furhter, the

 Â Â  product would not pass DO-160 qualification

 Â Â  testing for installation on a TC aircraft.



  	  Quote: 	
		  My power feeds from the associated CB to the radios is a very small run and there is no negative wire nearby to twist so I guess that is a wash.Ã‚ 	


 Â Â  Scrap the twisting thing . . .



 

  	  Quote: 	
		  I do have some other wires from DC CBs to switches and then to appliances such as landing /taxi/beacon /voltage regulators and some of those wires runs will be bundled next to the XPNDR /ADS-B /NAV/COM coaxial cables (using the coaxial cable Bob recommended). I suppose the shield on the coax will do the trick.Ã‚ 	


 Â Â  Your filtering apples out of your sack of

 Â Â  oranges. Shields on coaxes have a completely

 Â Â  different task . . . they have nothing in 

 Â Â  common with shielding as a noise abatement

 Â Â  device. Coaxes bundled with virtually

 Â Â  any other wires raises no concerns for

 Â Â  inter-system interference.



 

 Â  Bob . . .

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

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