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looking for a way to trigger the remote s

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=97489
Printed Date: May 17, 2024 at 8:56 AM


Topic: looking for a way to trigger the remote s

Posted By: dasp
Subject: looking for a way to trigger the remote s
Date Posted: September 27, 2007 at 6:42 PM

Here is what I want to do. I want for my remote start to turn the engine when the battery voltage drops below a certain point.  What I was thinking of doing is to use Priority Start, when the voltage drops below 11.7 volts it cuts power to whatever is connected to it. Whoever it cuts power not send a negatice trigger.  I could however wire the Priority Start with some relays and have it send a negative trigger to the alarm when it cuts off power. That's what I'm thinking of doing, but wanted to ask you guys if there is anything else out there.  Thanks in advance.




Replies:

Posted By: KPierson
Date Posted: September 27, 2007 at 8:01 PM

I'm not exactly sure what you are asking here.  What is "Priority Start"?

You could build a little circuit that would output at (-) if the input voltage (battery voltage) drops below a certain point. To my knowledge there is nothing on the market for anything like that.



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Kevin Pierson




Posted By: dasp
Date Posted: September 27, 2007 at 8:46 PM

www.prioritystart.com is a device that prevents dead batteries. It practically disconnects the battery when the voltage drops below 11.7 volts.   All I would connect to it would one or two relays to send a negative pulse to the remote start when the relays loose power.  The reason I want to do this is so that my battery won't die when I'm having a few beers with the buddies or washing the truck and listening to the stereo.  If someone could design me a circuit I could build it.





Posted By: KPierson
Date Posted: September 27, 2007 at 9:34 PM

The circuit wouldn't be that complicated.

Use a 5vdc voltage regulator to power a comparator circuit.  Put a potentiometer on one onf the comparator inputs and put a voltage divider on the the other input.  Select the resistor values for the voltage regulator to be x and 3x (say 10,000 and 30,000 ohms).  Connect the top of the voltage divider directly to battery power.

What this will do, in theory, is send a signal 1/3 of your battery voltage to the comparator.  You can then set the potentiometer to 11.7/3 volts ( 3.9vdc).  When the comparator sees that the process voltage is lower then the set voltage it will output a (-) signal.

That is the theory behind the circuit, now just need to find a comparator (or even op amp) and figure out the specifics.  Hopefully this will help.  I don't have enough spare time to design the entire circuit, but that should give you more then enough info to get it going.



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Kevin Pierson





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