Help needed with wiring and electrical project...

Ok, what I'm trying to do is hook up some 12v LEDs to work in conjunction with my alarm LED. I won't say where or what these other LEDs are I'm refering to, as I'm trying to keep an original idea here, at least while I can. So the LEDs I have, when I tap them into the circuit for my alarm LED, they light up, but barely. The alarm LED curcuit operates at 3.2 volts roughly (tested it with a multimeter), and I need a way to get the other LEDs I have to flash with my main alarm LED, but I need the power going to them to be somehow boosted up to 12 volts for them to light up bright and properly. How would I go about doing this? Would I use a relay of some sort, or a switch, or what? Electronic gurus out there, PLEASE help! :bloated:

yes you could use a relay. Hook the relay to be triggered by the alarm LED to connnect the ground for the other LEDs. Those you will just hook directly to the battery. Just make sure you've got 12v flashing leds, otherwise you need resistors and voltage regultors and the like to keep the LEDs flashing bright and consistently.

Why don't you go to Radio Shack and get different voltage LED's. Don't they make 4 or 5 volt LED's?

Yeah, they make other voltage LEDs, but I'd still use a relay so you can hook them directly to the battery. I remember burning a couple of LEDs cause I wasn't using the right voltage in the past...

I think JDMFan.com has a basics article on relays. I can't access their site at the moment for some reason...

Might help ya out..

Originally posted by luti
Why don't you go to Radio Shack and get different voltage LED's. Don't they make 4 or 5 volt LED's?

I would, but these LEDs I have, are premounted into something which is why I got them in the first place, so that wouldn't work, not to mention Radio Shack LEDs suck, they aren't very bright, and the ones that are brighter than others they have, don't come in the color I'm looking for, and aren't as bright as I'd like them to be.

I had originally bought the 2600mcd blue LED they sell there to replace my red alarm LED with, but before I even got around to installing it, I sprung for a twice as expensive Varad hyperbright LED in blue, to use because it's WAY brighter, and made specifically for what I was gonna use it for anyways.

if you figure out that voltage problem lemme know. i had tried hooking a pair of washer led's to my alarm, but had the same problem. so i just got lazy and tossed them aside.

This is simple electronics. Nothing hard about it. I just wont tell you because i want to keep this original idea in a dumpster where it belongs.
BTW your relay idea wont work because relay needs 12v to turn on.

Originally posted by kane2g
BTW your relay idea wont work because relay needs 12v to turn on.

Who said anything about 12v relays?:confused: You know relays of different voltages are readily available just like 12v ones. He just needs a 3.2 volt relay, which he can get here:

http://www.allelectronics.com/cgi-bin/category.cgi?category=500&item=RLY-395&type=store

Originally posted by CXHatchback


Who said anything about 12v relays?:confused: You know relays of different voltages are readily available just like 12v ones. He just needs a 3.2 volt relay, which he can get here:

http://www.allelectronics.com/cgi-bin/category.cgi?category=500&item=RLY-395&type=store

But how would I get 12v of power to the LEDs, since they can't run off 3.2v? I need them to get 12v of power when they light, but to ONLY light when my alarm LED wire sends a signal to them.

Originally posted by kane2g
This is simple electronics. Nothing hard about it. I just wont tell you because i want to keep this original idea in a dumpster where it belongs.


You think you could maybe email or PM me how to go about doing this (your idea)? :bloated: I'm desperate.

Try going to this page --> http://www.linearpower.com/html/installcc.html Might give you a better idea on how to do it...

Originally posted by SilverY2KCivic


But how would I get 12v of power to the LEDs, since they can't run off 3.2v? I need them to get 12v of power when they light, but to ONLY light when my alarm LED wire sends a signal to them.

I know this!! Here, I took the time to draw out this schematic, hopefully you can understand it, I know it's not the greatest. Any problems let me know, but it should work.

http://www.villagephotos.com/pubimage.asp?id_=251566

Originally posted by CXHatchback


I know this!! Here, I took the time to draw out this schematic, hopefully you can understand it, I know it's not the greatest. Any problems let me know, but it should work.

http://www.villagephotos.com/pubimage.asp?id_=251566

Great drawing, man. :) I'm kinda confused as to what goes where though, so from top to bottom, you think you could explain it to me? :bloated:

Alright here we go. I'll do my best. The relay has 4 contacts. 2 of them are connected to the coil, to activate the relay. The other two are basically parts of a switch, that when the relay is activated, they connect so the current passes through.

Starting from the bottom of the pic...

1.You want the signal from the 3.2V alarm LED to activate the relay. Connect the positive end of the coil to the positive on the LED so the current from it triggers the relay.

2.The negative end of the coil must be connected to chassis ground, because that's the way DC circuits work. :D

3. Now up at the top, you've got your 12V LED. Connect the positive lead on this to the 12V power source, i.e. your battery.

4.The negative end of the 12V LED must be connected to the switched part of the relay, so that when the coil is engaged, the ground line will be connected, and the 12V LED will light. Thus, connect the negative on the LED to one terminal on the relay switch, and the other part of the switch to chassis ground.

THat seemed a little redundant in the end, but that should be it! Now pat yourself on the back and tell us what you're doing! :D Just kidding. But one more thing:

This is assuming that the alarm LED is constantly grounded and is connected to a power source onyl when the alarm is activated. IF it's the opposite, that is, it's constantly connected to the positive end, and is only grounded when the alarm is activated, then you have to switch the terminals on the coil. Instaed of grounding it, connect it to 12V+, and the other end connect to the 3.2V LED negative. :)

Hope this helps

But how would I get 12v of power to the LEDs, since they can't run off 3.2v? I need them to get 12v of power when they light, but to ONLY light when my alarm LED wire sends a signal to them.

Let me try to answer your question according to the simple but clearly understandtable schematic CXHatchback drew (great job CX !!). However, CX made a tiny mistake on the description on the schematic. The terminal on the "coil" side that connects to the alarm LED should be the negative side instead of the positive.

A relay in this case is connected in series with the 3.2V alarm LED and used as a singal (or power) to electrically charge a coil of wire.

When the coil wire is electrically charged, it will create a magnetic field that pulls down on the "common" terminal metal plate and connect to the normally open terminal which carries negative (ground). This way it will provide ground to the 12V LED that connects to the battery voltage and turns on the LED.

http://www.villagephotos.com/pubimage.asp?id_=251566

Do you mind telling us what is your project with the LED?

You must have missed this part, I covered that.

Originally posted by CXHatchback
This is assuming that the alarm LED is constantly grounded and is connected to a power source onyl when the alarm is activated. IF it's the opposite, that is, it's constantly connected to the positive end, and is only grounded when the alarm is activated, then you have to switch the terminals on the coil. Instaed of grounding it, connect it to 12V+, and the other end connect to the 3.2V LED negative. :)

CX--You beat me on the post right after SilverY2KCivic ask about the explaination.:eek:

There seems to have a problem on the power supply to the project LED that silver is working on.

This is assuming that the alarm LED is constantly grounded and is connected to a power source onyl when the alarm is activated. IF it's the opposite, that is, it's constantly connected to the positive end, and is only grounded when the alarm is activated, then you have to switch the terminals on the coil. Instaed of grounding it, connect it to 12V+, and the other end connect to the 3.2V LED negative.

In this case the relay will be connected in a parallel circuit and will only allow the 12V LED that you are working on to light up when the alarm LED lights which will turns on and off the power to your project LED (flashes).

Acctually the flashes will occur on my theory also (assuming your alarm LED is the constantly connected to ground type).

If you want your project LED to have constant power when you turn on your alarm, you should not connect it to your alarm LED wire. This will require another way of wiring and different voltage of relay.

Let us know if you need constant power to your project LED when the alarm is activated.

I think it all depends. I know what you're saying, but sometimes there are flashing LEDs. We just have to find out if it's a flashing LED or if power is being turned on and off to the LED. Most likely it's a flashing LED and the schematic will work well. Has he tried it yet?

Originally posted by CXHatchback
I think it all depends. I know what you're saying, but sometimes there are flashing LEDs. We just have to find out if it's a flashing LED or if power is being turned on and off to the LED. Most likely it's a flashing LED and the schematic will work well. Has he tried it yet?

Ok, screw it, it'll be better figured out if I just tell what it is. I'm trying to hook up a pair of washer nozzle LEDs to flash with my alarm. These LEDs are meant to be constantly on, and not flas that I know of. But any LED can be made to flash, because I used to have a pair of screw LEDs attached to my mesh grill, and they flashed with my alarm (but worked when tapped into my alarm LED line) and they were also made to just be on constant, but they flashed just fine. I have a Clifford G4 alarm, so I dunno how the LED for it works, weather it's constantly on till the signal is to it, but when my alarm is off, the LED is off, and when it's armed, the alarm LED blinks. Wait, so that means it DOESN'T get a constant signal. :D LOL! I'm such a doof. Ok, so it's only constantly on when I have my alarm in valet mode, but that's irrelivant since the washer LEDs would be activiated when my alarm LED is activated to light up. So alarm LED blinks when armed, off when disarmed, and constant on (no blinking) when in valet mode. :cool: Damn I hope this info helps you all out to help me figure this mofo out. :alien2:

That's perfect. So you need to use regular LEDs (not flashing) for your washer nozzle things, and since the alarm LED is regualr too, just connect them like the diagram shows and you should be fine.

Originally posted by CXHatchback
That's perfect. So you need to use regular LEDs (not flashing) for your washer nozzle things, and since the alarm LED is regualr too, just connect them like the diagram shows and you should be fine.

Cool then, thanks d00d! :D

It would be really cool to get an inverter and somehow hook it up to one of the lights so they blink like a railroad crossing.

I'll have to figure that out :thinkerg:

Originally posted by 93speed
It would be really cool to get an inverter and somehow hook it up to one of the lights so they blink like a railroad crossing.


That's not an inverter you want, it's a relay. Or possibly series of.

I just used the word inverter to keep it an original idea :devil:

I'm in an electronics class at school so I'm sure we could figure something out. :flipa:

CXHatchback:

I sent you a PM< but not sure if you got it or not.

For the relay that I need to get, do I need a specific kind, or type, or will any 4 prong 12VDC automotive relay work for this? Thanks. :)

I already replied to your PM, you don't need a 12V relay, you can't use it. You need a 3.2V relay, or something close, that matches the voltage on the alarm LED.

Originally posted by CXHatchback
I already replied to your PM, you don't need a 12V relay, you can't use it. You need a 3.2V relay, or something close, that matches the voltage on the alarm LED.

Ok, I'll get the one in the link you posted up then, I was just thinking 12v relay because of the 12v line that will be going into it. But you're the expert here. :)

Hehe, cool. Yeah, as far as I know, that should be perfect.