Matronics Email Lists :: View topic - SPDT momentary push-button switch (comm flip-flop)

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

SPDT momentary push-button switch (comm flip-flop)

Matronics Email Lists Forum Index -> AeroElectric-List

View previous topic :: View next topic

Author Message

nuckollsr(at)cox.net
Guest

Posted: Thu May 10, 2007 8:10 pm Post subject: SPDT momentary push-button switch (comm flip-flop)

At 08:44 AM 5/10/2007 -0700, you wrote:



 	  Quote: 	
		  



At 07:50 5/10/2007, you wrote:

>I did touching the wire to ground and the frequency toggled ONCE. It was

>necessary to then touch this wire to aircraft power to get it to toggle

>a second time.

>

>Bill



I don't have the 155 service/installation manual, but looking at the SM 

for the 155A there are some internal pull-up provisions for the external 

switch.

A momentary to ground should be all that is required.

By means of whatever type switch you choose to use.



Perhaps there is some issue within your 155?


	


    Aha! good data sir. How big are the resistors and to

    what voltage do they pull up? The snipit from the

    install manual suggests that pulling to ground is

    the expected resting condition with the lead being

    pulled up to +14 to effect a "flip".



    If the radio has internal pull-ups, then a NORMALLY

    CLOSED push button would be expected to provide the

    necessary function but without a need for external

    resistor. A Grayhill 30-6 illustrated at:



http://embrace.grayhill.com/embrace/IMAGES/PDF/E-17-20.pdf



    and available from digikey at:



http://tinyurl.com/2nqymz



    for about $2.65 should do the job.



    Looks like you have a little bit of homework to do

    Bill but I'm 90% certain that you can make a single-throw,

    two-wire push button do this job.



    I'm going to take the sketch referenced in the

    earlier post down from the website. Given Ron's

    new information, I'm not sure we want the signal

    lead to "rest" in the low state.



    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

wgill10(at)comcast.net
Guest

Posted: Fri May 11, 2007 2:49 am Post subject: SPDT momentary push-button switch (comm flip-flop)

Hello Bob,



Thank you for the reply. I understand connecting a normally closed SPST

switch to 14V, but how does opening that circuit cause a toggle when the

radio is expecting a ground once the 14V is removed? 



 Bill

 



--

- 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