rising edge pulse?

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=101765
Printed Date: July 05, 2025 at 8:07 AM

Topic: rising edge pulse?

Posted By: avc8130
Subject: rising edge pulse?
Date Posted: February 01, 2008 at 8:47 AM

I am trying to hook up my Astrostart 2205 to control my Check Corp heated seats. The Astrostart can generate a negative pulse (of programmable time). My heated seats are controlled by a membrane switch. I am told by Check that they require a rising edge pulse to signal. I am told this should be negative. I tried just using the Astrostart directly and it didn't work. I also tried a relay. Any suggestions?

Anthony

Replies:

Posted By: KarTuneMan
Date Posted: February 01, 2008 at 9:56 AM

Pardon my stupidity... but what is a rising edge pulse?

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Posted By: Chris Luongo
Date Posted: February 01, 2008 at 10:16 AM

I've never heard of a "rise edge pulse," either.

Regardless, before making any type of electrical configuration in a car, you should be testing the wires you're interfacing with.

Information from the seat heater manufacturer (or one of us forum members) is not a substitute for testing.

Posted By: avc8130
Date Posted: February 01, 2008 at 10:33 AM

I have been probing the wires.

The Astro Start wires do exactly what they are supposed to.

I probed the signal wires on the membrane switch. It seemed like the switch momentarily broke the connection. I setup a relay to break the connection when the Astrostart gave its ground pulse. That didn't work.

I have been working with the seat manufacturer. They are seeming to be worthless and I am sick of driving around with no dash board or center console. It has been a week of them "waiting to talk to the engineer".

Posted By: Twelvoltz
Date Posted: February 01, 2008 at 1:12 PM

KarTuneMan wrote:

Pardon my stupidity... but what is a rising edge pulse?

X3

When you do get to talk to someone there, could you find out what a 'rising edge pulse' is? Sounds to me it could be like a flux-capacitor type device. posted_image

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Installer, IT support, and FFL. I need less hobbies.

Posted By: Mark Mizenko
Date Posted: February 01, 2008 at 1:17 PM

Do they mean a "Leading Edge" trigger?

Posted By: KPierson
Date Posted: February 01, 2008 at 1:49 PM

Rising edge pulse would be the transition from negative (or 0) to positive voltage.

12vdc _____________
00vdc______| |_____________

^ that is the rising edge

I've never heard anyone use the term quite like that though. Typically in car electronics switch on the falling edge, as most car electronics run the ground signal out to the switch, but either way works.

If it truely is a rising edge that is needed you'll need to send battery voltage (or perhaps 5vdc, depending on how the unit works) to the switch output.

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Kevin Pierson

Posted By: KarTuneMan
Date Posted: February 01, 2008 at 6:02 PM

Well the astro outs rest @ open, when triggered go to ground.

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Posted By: Twelvoltz
Date Posted: February 01, 2008 at 10:14 PM

Kpierson wrote:

Rising edge pulse would be the transition from negative (or 0) to positive voltage.

12vdc              _____________
00vdc______|              |_____________

        ^ that is the rising edge

Thank You! Explained it so that us non-engineer's can understand it.

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Installer, IT support, and FFL. I need less hobbies.