LED’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=20052
Printed Date: June 06, 2024 at 5:13 PM
Topic: LED’s
Posted By: fireman1321
Subject: LED’s
Date Posted: October 13, 2003 at 6:18 PM
I wired 2 green 2v leds to my dei alarm in a series... one of the leds dont work... what do y-ou think might be the problem???
-------------
Future Fire Man
Replies:
Posted By: auex
Date Posted: October 13, 2003 at 6:43 PM
Well, the wire going between the wires could be grounded out somewhere. It probably is unlikely that the led is bad, if it where then the led's probably wouldn't work at all.
-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.
I've been sick lately, sorry I won't be on much.
Posted By: misterjimbo
Date Posted: October 13, 2003 at 9:43 PM
i wire my LED's in parallel configuration with no prob, on audiovox/pursuit/prestige units
-------------
Posted By: Ocelaris
Date Posted: October 14, 2003 at 6:47 AM
The DEI alarm is probably putting out only 2 volts, meaning it will only have power to run 1 LED in series. You need to run them in parallel like misterjimbo said above. or if you haven't tested them individually yet, I would reccomend that also...
Posted By: HamiltonAudio
Date Posted: October 17, 2003 at 7:38 AM
if you're only wanting to add LED's to add to the "flashing light" theory inside the car, why not get 12V self-flashing LED's? Use the starter disable output to trigger a relay, and turn on 10,000 of these if you want. I've been using em for years with great success. b
Posted By: auex
Date Posted: October 17, 2003 at 5:24 PM
Ocelaris: Even according to dei, you are supposed to wire led's in series and you can have upto five. If you wire them parrallel then they will try to draw to much current and burn the led output out. Also I have 5 led's wired in my car and they are in series and have worked fine for the last 3 and a half years.
-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.
I've been sick lately, sorry I won't be on much.
Posted By: misterjimbo
Date Posted: October 17, 2003 at 7:46 PM
auex... very good. sometimes we forget basic elec. laws. you are correct.
-------------
Posted By: fireman1321
Date Posted: October 20, 2003 at 9:31 PM
How can I wire in led's through a relay??? I want to use the pos and neg of the output of the led and out them to 85 and 86 then have constant go to 30 and series 6 LED's from 87.... anyone think or might know how I can do that???
-------------
Future Fire Man
Posted By: auex
Date Posted: October 20, 2003 at 10:14 PM
You cannot use a relay for this application. If I remember, you have a dei alarm and they only put out two volts to the led and it won't energize the coil in the relay. Not saying it can't be done just not with a relay.
-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.
I've been sick lately, sorry I won't be on much.
Posted By: fireman1321
Date Posted: October 21, 2003 at 7:03 PM
How can I get my LED's to work??? just do it in series?!?! it doesnt work...
-------------
Future Fire Man
Posted By: xetmes
Date Posted: October 21, 2003 at 7:17 PM
if you want to isolate it and allow for as many LEDs as you want use a transistor and some resistors the whole setup (if you bought the stuff at radioshack) would run about $2 or less... A relay is a horrible idea, it would draw way too much current (even without changing state) plus if it did work the thing would not last too long until the contact broke off lol
Posted By: fireman1321
Date Posted: October 21, 2003 at 7:26 PM
Can you please tell me or show me a wiring diagram??? I would really apprecieate it. Thanx!
-------------
Future Fire Man
Posted By: xetmes
Date Posted: October 21, 2003 at 8:28 PM
Posted By: xetmes
Date Posted: October 21, 2003 at 8:30 PM
man that picture is larger than i expected it to be..  ohh well at least it is easy to read
Posted By: xetmes
Date Posted: October 21, 2003 at 8:36 PM
ohh man I dont know what i was thinking that is completly wrong, I ment to use an NPN transistor, sorry its been a long day.. here is the correct diagram: 
Posted By: tcool
Date Posted: October 21, 2003 at 11:57 PM
Correct me if I'm wrong, but some LED's have built in diodes and can't have the polarity reversed. Just switch the wires on the LED that doesn't work. I believe most LEDs are around 3 volts, I seriously doubt 4 volts is going to damage the alarm brain... ------------- bzzzzttttt
Posted By: xetmes
Date Posted: October 22, 2003 at 5:23 AM
All leds function as diodes as well, although they can not handle the same amounts of current and reverse bias voltages because they are not made to. LEDs do not really operate on voltage, they operate on current. the only reason they have such a high voltage drop is because they are based on gallium arsenide, not silicon. A resistor is used to limit current because the PN junction will not. Not sure what you mean about 4 volts damaging the brain?
Posted By: auex
Date Posted: October 22, 2003 at 8:17 AM
Tcool, LED= Light Emitting Diode
-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.
I've been sick lately, sorry I won't be on much.
Posted By: tcool
Date Posted: October 22, 2003 at 1:25 PM
Oh yeah, Duh. I didn't think about that. I am still confused, first of all, what is a PN junction? Secondly, if they cannot handle reverse bias voltages, how can you hook them up in series? I understand that if the alarm puts out 3 volts, no matter how much stuff you hook up to it, it will only put out 3 volts. It's the amount of current the LED's draw, right. So the limiting factor would be how much current the alarm puts out, vs. how much current the LEDs draw combined, right? I do know that if you hook up a 3v LED to a 12V battery, it will fry the LED, and I know that if you hook up too many LEDs to an alarm output, the LEDs will not get enough voltage (because of voltage drop, I assume) to operate. Can hooking up too many LEDs to an alarm damage the brain?
-------------
bzzzzttttt
|
