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Discussion Starter · #1 ·
I'm getting ready to install my line lock. I'm using a toggle switch, and an LED indicator light.
I got the LED, but then relized something. I dont know how to hook it up!

This is what it looks like. PICTURE
Coming off the back, there are just those 2 'wires'. What do they go to? How do i get power to this.

Thanks guys.

-Matt
 

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Matt,

The information states:

20mA (max). Typical Voltage is 1.7, with a maximum voltage of 2.0V.

20 milliamps is the absolute maximum forward current (If). This is a factory rating, most "standard" LEDs are rated at 20 mA, but that is under tight, temperature-controlled laboratory situations. You never want to run an LED at max for the sake of longevity and reliability. The current thru the unit is set by a current limiting resistor--which you need. Again, with the voltage, don't run it at max. Typical is what you aim for. That means the LED will have 1.7 volts across it's anode/cathode. That brings me to another point, these are light emitting DIODES they only allow current to pass in one direction. IF you hook-it-up backwards, it will not light. The longer lead is the (+) aka anode connection. The shorter is the (-) aka cathode lead. This is the industry standard.

Now, you must do some math to get the right resistor. This resistor goes in-line (in series) with ONE of the leads, it doesn't matter which one.

Let's begin with worse-case scenario, highest voltage seen by vehicle electrical system, 14.8 volts. That SHOULD be the highest it ever goes, remember we are engineering for longetivy here. 14.8 - 1.7 = 13.1

13.1 volts need to be dropped by the time it "sees" the LED. Now, we also want to limit the current to let's say 15 mA maximum (remember the 20 mA max is the factory controlled rating, we don't want to push it--especially in an automobile where temperature fluxuations are a way of life). So 13.1/.015 amps = 873 ohms. There is no 873 ohm resistor in the standardized electronics world. 820 ohms and 910 ohms are the closest. Use 910 ohms. Not available, Radio Shack DOES have 1000 ohm (1k ohm) resistors. Use that in line with one lead, connect to power, voila!

;)
 

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Discussion Starter · #3 ·
Thanks for the info Coppertop. I have a few more questions for you (or anyone).
How exactly do i connect those leads to the power and ground wires? Just use regluar connectors? (can you tell electrical work isnt my forte?)

Can you give me some advice on how to wire all this. I know i want power going to a terminal on the switch. Then when the switch is flipped, power goes to the line lock solenoid. Where does the LED fit in here? If i put the resistor on the output side of the switch before the LED, that would also reduce power to the solenoid. Or do i want to reduce the power to the solenoid? Argh :mad:

-Matt
 

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Matt,

Duh, probably didn't realize you don't know how to solder (or do you?). That's the best way, you would solder small wires to the leads of the led. These wires would then connect to + and - (or source and ground). The resistor is INLINE with one of the LED's wires, it won't affect the rest of the circuit. Just imagine it's apart of the LED itself once it's in place and don't worry about it, you just have (2) wires when done:

+ ---------->resistor-------->(+)LED
- --------------------------->(-)LED


Tie the (-) to a good dash ground. the positive will then tie to the switched side of the line lock switch--the same side that feeds the solenoid. That way when you flip the switch, the main power wire that feeds the switch, connects to the wire wire that feeds the line lock AND the led at the same time, LED comes on, and line lock activates.

P.S. Where are you getting power from?? I'm not familiar with line locks so I don't know how much current they draw--you don't want to tie into something that can't handle the extra load.



If you can't solder, you could *cringe* use butt connectors to connect to the LED leads, but they are sort of fragile. You could also just "wrap" wire around the leads and then be sure to tape the heck out of them, but again that's not really the best way. If you have acess to old computers/pars, the older models have power/hard-drive activity LEDs on the front. Inside you could steal the slip-on connectors, those would be great, they have a socket that just slips on the LED leads and have wire to-boot!
 

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Matt...

-12V source to your toggle switch
-wire from toggle to solenoid
-splice into wire going to soleniod with wire going to resistor, then to led.
-ground other terminal on led

Should be good to go

Can you check that coppertop?
 

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Discussion Starter · #8 ·
Thanks guys. Yes, i know how to solder but it never entered my mind. Long day i guess


I cant find a number anywhere on the net and the solenoid wont be here for 2 days, so i cant be sure, but i think i remember reading that it only draws 1 or 2 amps.

-Matt
 
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