Matronics Email Lists :: View topic - push to test circuit for differing loads

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

push to test circuit for differing loads

Matronics Email Lists Forum Index -> AeroElectric-List

View previous topic :: View next topic

Author Message

pmnewlon

Joined: 20 Jan 2011
Posts: 21

Posted: Tue Jun 21, 2011 2:01 pm Post subject: push to test circuit for differing loads

I posted on VAF yesterday and got a partial answer to my question there, which caused me to have more questions so I thought I better get to the right place!



I have seven annunciator LEDs on my panel; as it turns out all but one switch the positive side of the LED but one switches the ground.  I understand how to arrange diodes in a push to test circuit if all the LEDs are switched the same way but cannot find an example of a circuit where there is a mixture of ground and positive switching with a single push to test button.  The response to my post on VAF suggested a double pole push button but I have not found a suitably small DPST (ON) device.  I'd really like to make the circuit with a small SPST (ON) pushbutton but am short on the circuit knowledge.



Does anyone have a reference diagram of such a circuit that I could 'borrow'?



Thanks!  Phil

- 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

JLuckey(at)pacbell.net
Guest

Posted: Tue Jun 21, 2011 3:06 pm Post subject: push to test circuit for differing loads

Phil,



Just off the top of my head (and without having seen a schematic of your

particular setup) I'd say that what you're asking for is not possible.  In a

single pole you could handle the ground legs of the test circuit (with

proper isolation diodes as you mentioned) or the high-side circuit, but not

both.



But I have another suggestion: You could add a small 2-pole relay to manage

the LED test circuitry and control its coil w/ your SPST pushbutton.  There

are all kinds of cheap, circuit board mountable, smaller-than-a-sugar-cube

relays that could do the job (I don't have part numbers available to me at

the moment).



--

- 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

nuckolls.bob(at)aeroelect
Guest

Posted: Tue Jun 21, 2011 6:55 pm Post subject: push to test circuit for differing loads

At 06:01 PM 6/21/2011, you wrote:

  	  Quote: 	
		  --> AeroElectric-List message posted by: "pmnewlon" <philn(at)toosan.com>



 I posted on VAF yesterday and got a partial answer to my question there, which caused me to have more questions so I thought I better get to the right place!



 I have seven annunciator LEDs on my panel; as it turns out all but one switch the positive side of the LED but one switches the ground.  I understand how to arrange diodes in a push to test circuit if all the LEDs are switched the same way but cannot find an example of a circuit where there is a mixture of ground and positive switching with a single push to test button.  The response to my post on VAF suggested a double pole push button but I have not found a suitably small DPST (ON) device.  I'd really like to make the circuit with a small SPST (ON) pushbutton but am short on the circuit knowledge.



 Does anyone have a reference diagram of such a circuit that I could 'borrow'? 	


     You betcha. Did this in some airplane wayyyyyyy back when.

     The annunciators were light bulbs instead of leds but

     the principal is the same.



     You can get the parts at Radio Shack . . .



  http://tinyurl.com/3lu334y 



     The transistors operate saturated so given

     the intermittent duty service, will not require

     heat-sinks. Wire 'em up and truck on. You could

     probably get it to work fine with physically

     smaller transistors but these TO-200 devices are

     robust and easy to mount to a piece of perf-board.



 

   Bob . . .    [quote][b]

- 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

sprocket(at)vx-aviation.c
Guest

Posted: Tue Jun 21, 2011 7:32 pm Post subject: push to test circuit for differing loads

Check out the IL-4A or IL-12A on this site:

 http://vx-aviation.com/page_2.html

  

 The datasheet has the schematic for what you want if you feel like building  your own.

  

 Thx,

 Vern Little

 Vx Aviation

    

  From: Robert L. Nuckolls, III (nuckolls.bob(at)aeroelectric.com) 

 Sent: Tuesday, June 21, 2011 7:52 PM

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

 Subject: Re: push to test circuit for differing  loads

  



 At  06:01 PM 6/21/2011, you wrote:

  	  Quote: 	
		  --> AeroElectric-List message    posted by: "pmnewlon" <philn(at)toosan.com>



I posted on VAF    yesterday and got a partial answer to my question there, which caused me to    have more questions so I thought I better get to the right place!



I    have seven annunciator LEDs on my panel; as it turns out all but one switch    the positive side of the LED but one switches the ground.  I understand    how to arrange diodes in a push to test circuit if all the LEDs are switched    the same way but cannot find an example of a circuit where there is a mixture    of ground and positive switching with a single push to test button.  The    response to my post on VAF suggested a double pole push button but I have not    found a suitably small DPST (ON) device.  I'd really like to make the    circuit with a small SPST (ON) pushbutton but am short on the circuit    knowledge.



Does anyone have a reference diagram of such a circuit that    I could 'borrow'? 	


    You betcha. Did this in  some airplane wayyyyyyy back when.

    The annunciators were  light bulbs instead of leds but

    the principal is the  same.



    You can get the parts at Radio Shack . .  .



http://tinyurl.com/3lu334y 



     The transistors operate saturated so given

    the  intermittent duty service, will not require

    heat-sinks.  Wire 'em up and truck on. You could

    probably get it to  work fine with physically

    smaller transistors but these  TO-200 devices are

    robust and easy to mount to a piece of  perf-board.



 

  Bob . . .  	  Quote: 	
		  



href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-List

href="http://forums.matronics.com">http://forums.matronics.com

href="http://www.matronics.com/contribution">http://www.matronics.com/c

	
   

No virus found in this  message.

Checked by AVG - www.avg.com

Version: 10.0.1382 / Virus  Database: 1513/3718 - Release Date: 06/21/11

   [quote][b]

- 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

JLuckey(at)pacbell.net
Guest

Posted: Tue Jun 21, 2011 9:00 pm Post subject: push to test circuit for differing loads

Ok – devil’s advocate here…  

   

Bob’s schematic parts count: 2 transistors, 4 resistors = 6 components – or -- ONE small, 2-amp, DIP DPDT relay.    

   

Which way is stronger/better/faster/easier?  

   

   

         

  

From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Vern Little

 Sent: Tuesday, June 21, 2011 20:29

 To: aeroelectric-list(at)matronics.com

 Subject: Re: AeroElectric-List: push to test circuit for differing loads  

  

         

Check out the IL-4A or IL-12A on this site:  

    

http://vx-aviation.com/page_2.html  

    

   

    

The datasheet has the schematic for what you want if you feel like building your own.  

    

   

    

Thx,  

    

Vern Little  

    

Vx Aviation  

        

   

      

From: Robert L. Nuckolls, III (nuckolls.bob(at)aeroelectric.com)   

    

Sent: Tuesday, June 21, 2011 7:52 PM  

    

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

    

Subject: Re: push to test circuit for differing loads  

  

  

    

   

  

    

At 06:01 PM 6/21/2011, you wrote:

 

   

--> AeroElectric-List message posted by: "pmnewlon" <philn(at)toosan.com>

 

 I posted on VAF yesterday and got a partial answer to my question there, which caused me to have more questions so I thought I better get to the right place!

 

 I have seven annunciator LEDs on my panel; as it turns out all but one switch the positive side of the LED but one switches the ground.  I understand how to arrange diodes in a push to test circuit if all the LEDs are switched the same way but cannot find an example of a circuit where there is a mixture of ground and positive switching with a single push to test button.  The response to my post on VAF suggested a double pole push button but I have not found a suitably small DPST (ON) device.  I'd really like to make the circuit with a small SPST (ON) pushbutton but am short on the circuit knowledge.

 

 Does anyone have a reference diagram of such a circuit that I could 'borrow'?  



     You betcha. Did this in some airplane wayyyyyyy back when.

     The annunciators were light bulbs instead of leds but

     the principal is the same.

 

     You can get the parts at Radio Shack . . .

 

 http://tinyurl.com/3lu334y 

 

     The transistors operate saturated so given

     the intermittent duty service, will not require

     heat-sinks. Wire 'em up and truck on. You could

     probably get it to work fine with physically

     smaller transistors but these TO-200 devices are

     robust and easy to mount to a piece of perf-board.

 

 

     

  Bob . . .    	  Quote: 	
		    href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-Listhref="http://forums.matronics.com">http://forums.matronics.comhref="http://www.matronics.com/contribution">http://www.matronics.com/c 	
      

  

No virus found in this message.

 Checked by AVG - www.avg.com

 06/21/11  

  

  

   	  Quote: 	
		     	
0 	  Quote: 	
		   	
1 	  Quote: 	
		   	
2 	  Quote: 	
		   	
3 	  Quote: 	
		   	
4 	  Quote: 	
		   	
5 	  Quote: 	
		   	
6 	  Quote: 	
		   	
7 	  Quote: 	
		   	
8 	  Quote: 	
		   	
9 	  Quote: 	
		  href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-List 	
0 	  Quote: 	
		  href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-List 	
1 	  Quote: 	
		  href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-List 	
2 	  Quote: 	
		  href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-List 	
3 	  Quote: 	
		  href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-List 	
4

       [quote][b]

- 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

pmnewlon

Joined: 20 Jan 2011
Posts: 21

Posted: Wed Jun 22, 2011 2:30 am Post subject: Re: push to test circuit for differing loads

Thank you guys for your excellent input! Phil

- 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

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