create a ground when armed
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=119882
Printed Date: May 02, 2024 at 10:29 PM
Topic: create a ground when armed
Posted By: erusso17
Subject: create a ground when armed
Date Posted: February 03, 2010 at 10:04 PM
Hello, I am looking to install the DEI 508d and 516U in my car. My car (2009 G37 coupe) has the factory alarm and no Ground When Armed that i know of. Im looking to see if there is a way i can find, or create a ground when armed in my car. thank you!
Replies:
Posted By: oldspark
Date Posted: February 04, 2010 at 3:02 AM
Does it have a +12V when armed?
If so, an inverting (polarity) relay see Relays - Converting Polarity on this site. (The alarm turns on a relay which connects ground #30 to #87.)
Otherwise others will have to answer...
Posted By: tedmond
Date Posted: February 04, 2010 at 6:43 AM
if your trying to wire in shock sesors only to a factory alarm, dont even bother. there is no way to trigger the factory alarm with aftermarket sensors.
-------------
Ted
2nd Year Tier 1 Medical School
Still installing as a hobby...pays for groceries
Compustar Expert
Posted By: tommy...
Date Posted: February 04, 2010 at 6:49 AM
tedmond wrote:
if your trying to wire in shock sesors only to a factory alarm, dont even bother. there is no way to trigger the factory alarm with aftermarket sensors.
Why...Are you meaning on this specific car...? We use to install just a shock sensor on factory alarms on toyota,honda,etc...? ------------- M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!
Posted By: erusso17
Date Posted: February 04, 2010 at 11:57 PM
i really dont want this tied into my cars alarm at all. I would just like the 508d to trigger the 516u so if someone comes near my car the voice alarm will trigger. I think this is possible if i can create a simple ground when armed so the 508d knows when my car is off.
Posted By: erusso17
Date Posted: February 04, 2010 at 11:58 PM
off and locked (preferably)
Posted By: oldspark
Date Posted: February 05, 2010 at 12:03 AM
Microwave detector.
Posted By: erusso17
Date Posted: February 05, 2010 at 12:23 AM
im sorry, what is a microwave detector and how can i use it to create a ground when armed? thanks again
Posted By: oldspark
Date Posted: February 05, 2010 at 4:48 AM
A microwave detector is one that doesn't respond to moving air ant isn't too susceptible to false glass breakage triggers (if at all AFAIK).
It is sometimes used as a proximity detector.
I got one so that I can arm my alarm with windows open and detect an intruding torso or part thereof by not air etc (ie, ultrasonic detectors would false trigger).
Although like may detectors they are often a ground output (an "open collector" output), it is merely a detector that can be used for alarms etc.
Posted By: KPierson
Date Posted: February 09, 2010 at 9:51 PM
OK, so I have way too much time on my hands. When I first read this thread I sketched out a drawing of how I thought I could make a gwa output using only transistors and resistors. Tonight I finally built it, tweaked it a bit, and redid it in paint. It works great, toggling the output based on (+) actuator triggers. 
------------- Kevin Pierson
Posted By: KPierson
Date Posted: February 09, 2010 at 9:53 PM
The NPN transistors would be 2n3904 or similar and the PNP is a 2n3906 or similar. The current output is limited to around 150mA. You may add a smaller resistor to increase current output. The diodes are 1A 1n4001s or similar. ------------- Kevin Pierson
Posted By: oldspark
Date Posted: February 09, 2010 at 10:01 PM
Or use 2 relays.
Ha! Here I am suggesting "multiple relays" instead of "one electronic circuit". Ain't that a flip!? (Viz those 4-8 relay switching conglomerations!)
Posted By: KPierson
Date Posted: February 09, 2010 at 11:18 PM
I stayed away from relays due to their current consumption. I guess I could have used reed relays but I thought a transistor based solution would look more impressive in paint!
-------------
Kevin Pierson
Posted By: tedmond
Date Posted: February 10, 2010 at 7:45 AM
Kevin, wonderful diagram. but yes, too much time of your hands ! ahah i kid. i still want to order something from KPT but dont know what  ------------- Ted
2nd Year Tier 1 Medical School
Still installing as a hobby...pays for groceries
Compustar Expert
Posted By: Ween
Date Posted: February 10, 2010 at 9:47 AM
hi, dual coil latching relay, with diodes in series on the coil leads. wire the coils to the door lock motor in the drivers door. the set coil will latch with the lock signal, and reset with the unlock, you'll need to add a relay to 'disable' the output when the doors are locked while driving, otherwise you'll have the 508 triggering unnecessarily. did a setup like such in a Prowler years back. m
Posted By: KPierson
Date Posted: February 10, 2010 at 1:55 PM
yes, that would work as well!
-------------
Kevin Pierson
Posted By: i am an idiot
Date Posted: February 10, 2010 at 6:59 PM
How about a magnet attached to the door lock mechanism, and a magnetic reed switch positioned where the magnet closes the contacts when the door is locked?
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