Matronics Email Lists :: View topic - TCAD IAS Switch (with link to sketch)

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

TCAD IAS Switch (with link to sketch)

Matronics Email Lists Forum Index -> AeroElectric-List

View previous topic :: View next topic

Author Message

nuckollsr(at)cox.net
Guest

Posted: Wed Nov 15, 2006 7:07 am Post subject: TCAD IAS Switch (with link to sketch)

The circuit is just a ground to tell my TCAD that it is on the ground.  A

pressure switch ( I can only find NO in the range I need) is in the pitot

system.  The switch closes at roughly 50 knots.  I have access to both ends

of the switch.  The switch is a micro pneumatic logic 503.  Maybe you know a

supplier that would sell me one that is NC.The closing of the switch is

supposed to open the ground on the TCAD.  I can easily convert the no to nc

by using a relay, but, I thought a transistor may also work??  Just making

an attempt to learn more electric stuff.  I hope that this explanation

works.



   If we knew more about the internal wiring of the TCAD system, perhaps

   the solution could be as simple as the first sketch below.



   (I didn't get the attachment here . . . I've posted the sketch

    at:  http://www.aeroelectric.com/temp/TCAD_Switch.pdf



However, the second sketch is 99.9% certain to work. All the parts are

available from Radio Shack.



Bob . . .

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

      < What is so wonderful about scientific truth...is that >

      < the authority which determines whether there can be   >

      < debate or not does not reside in some fraternity of   >

      < scientists; nor is it divine. The authority rests     >

      < with experiment.                                      >

      <                            --Lawrence M. Krauss       >

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

- 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

dsvs(at)ca.rr.com
Guest

Posted: Wed Nov 15, 2006 8:55 am Post subject: TCAD IAS Switch (with link to sketch)

Bob,

Thanks for the help.  I now have one more question.  I am looking at the second sketch and the two resistoirs look to be in series with the second resistor going to ground.  The resistors appears to half the volltage going to the transistor when the switch is open with the other half going directly to ground. With the switch closed the voltage that would have gone into the transistor would now go to ground ? with no voltage going into the transistor?  If you have time I would like to hear a little explanation of the actual workings of this circuit.  I am not doubting it will work, I just want to understand what and why it does what it does.  Thanks for all the help.  Don    

---- "Robert L. Nuckolls wrote: 

 	  Quote: 	
		   

 

 

 

 The circuit is just a ground to tell my TCAD that it is on the ground.  A

 pressure switch ( I can only find NO in the range I need) is in the pitot

 system.  The switch closes at roughly 50 knots.  I have access to both ends

 of the switch.  The switch is a micro pneumatic logic 503.  Maybe you know a

 supplier that would sell me one that is NC.The closing of the switch is

 supposed to open the ground on the TCAD.  I can easily convert the no to nc

 by using a relay, but, I thought a transistor may also work??  Just making

 an attempt to learn more electric stuff.  I hope that this explanation

 works.

 

    If we knew more about the internal wiring of the TCAD system, perhaps

    the solution could be as simple as the first sketch below.

 

    (I didn't get the attachment here . . . I've posted the sketch

     at:  http://www.aeroelectric.com/temp/TCAD_Switch.pdf

 

 However, the second sketch is 99.9% certain to work. All the parts are

 available from Radio Shack.

 

 Bob . . .

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

       < What is so wonderful about scientific truth...is that >

       < the authority which determines whether there can be   >

       < debate or not does not reside in some fraternity of   >

       < scientists; nor is it divine. The authority rests     >

       < with experiment.                                      >

       <                            --Lawrence M. Krauss       >

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

- 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

dsvs(at)ca.rr.com
Guest

Posted: Wed Nov 15, 2006 7:32 pm Post subject: TCAD IAS Switch (with link to sketch)

Bob,

Thanks for the information.  I sent a previous response that I do not think

made it.  In that one I asked about how and why the resistive portion of the

circuit was there.  I figured it out and think that I actuaslly learned

something today.  Thanks again.

Don

--

- 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

dsvs(at)ca.rr.com
Guest

Posted: Thu Nov 16, 2006 2:22 am Post subject: TCAD IAS Switch (with link to sketch)

Bob,

I sat down and examined the resistors and finally figured out that they are a voltage divider and that the total amperage down any leg in the circuit would 0.007A.  I think I understand how it works now.  Thanks.  

Don

---- "Robert L. Nuckolls wrote: 

 	  Quote: 	
		   

 

 

 

 The circuit is just a ground to tell my TCAD that it is on the ground.  A

 pressure switch ( I can only find NO in the range I need) is in the pitot

 system.  The switch closes at roughly 50 knots.  I have access to both ends

 of the switch.  The switch is a micro pneumatic logic 503.  Maybe you know a

 supplier that would sell me one that is NC.The closing of the switch is

 supposed to open the ground on the TCAD.  I can easily convert the no to nc

 by using a relay, but, I thought a transistor may also work??  Just making

 an attempt to learn more electric stuff.  I hope that this explanation

 works.

 

    If we knew more about the internal wiring of the TCAD system, perhaps

    the solution could be as simple as the first sketch below.

 

    (I didn't get the attachment here . . . I've posted the sketch

     at:  http://www.aeroelectric.com/temp/TCAD_Switch.pdf

 

 However, the second sketch is 99.9% certain to work. All the parts are

 available from Radio Shack.

 

 Bob . . .

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

       < What is so wonderful about scientific truth...is that >

       < the authority which determines whether there can be   >

       < debate or not does not reside in some fraternity of   >

       < scientists; nor is it divine. The authority rests     >

       < with experiment.                                      >

       <                            --Lawrence M. Krauss       >

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

- 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