The Stovebolt Site Forums The Shop Area The Electrical Bay LED Lights - New Tech Tip

We just added another new Tech Tip from Jim "Caroline\'s truck" Wilson.

Convert a single LED light to function as two different lights. So if you do have some sort of newer LED tail lights, this might be of consideration for safety. This is made for a 12 volt system.

Thanks to Jim for taking the time to do this. Thanks to John for doing the drawing ... I've had this tip for a long time, and I just couldn't draw those lines on the computer.

So ... there it is ...

Peggy

Maybe I am a little dense, but I can't see how the lower intensity portion could be wired to the turn lght wire and the direct connection to the brake light wire and accomplish anything. Applying the brakes while trying to indicate a turn would just swamp out the turn signal. If he meant tail lights instead of turn lights to be wired to the lower intensity circuit and the turn/brake lights wired to the high intensity circuit, it would make sense to me; that would make it work like a standard two filament incandecent bulb.

I'm also trying to figure out how this works.

I'm with Baldy. That's the only way that I can see this working.

If you are installing a later model GM steering column the brake lights and turn signals use the same wires, so wouldn't it work if that were the case? I don't think it was completely explained on how it was setup.

If you don't wish to have extra lights in the back of your truck or
have limited space and you have upgraded to 12V LED's,
this may be a tip for you.

You can use any two light functions using one 12V LED light, using any combination below.
It's that simple.

brake
tail
blinker
parking
side marker

This uses a simple diode (a one way circuit, so a ''cross'' from the other function does not bleed-over) affect the second function, installed on each function and a resistor used on one of those functions. one light gives you 100% voltage, while the other gives you about 90% +/- depending on the type resistance the resistor you buy is.


a ''cross'' is when one wire has a path of higher reststance to another (or touches the other wire) thus affecting the second circuit. aka bleedover.

the simple LED lights refered to in the tech are a simple clearence light as shown.
the above number for the diode is this, a zener ! ..... 1947RBT you're looking at this way to hard.

http://images.google.com/imgres?img...6svnum%3D10%26hl%3Den%26lr%3D%26sa%3DNPs
There IS nothing complicated about the tip. :confused:

The problem with the low intensity circuit wired to the blinker and the high intensity path wired to the brakes is that the light will flash as it should until the brake comes on, then the light will be at full intensity and the flashing of the blinker won't be visible. That's what I meant by being swamped out. With the light at one diode drop (~.7V) below V+, adding another line to the light at one diode drop plus a resistor will not affect the light at all.

I would like to add that it is a great tip, just the listed application was faulty.

there are many things not right about this tip but the thery is almost right
1) A LED only reqiers 1.5 to 2V way not a 6V
2) resisters will vary with evry application
3) there is a beter way of doing it with zeener diods and a 555 and if any body rilly onts to know how that way will work let me know.

1947RBT,

The LED taillights have current limiting resistors as part of the assembly and are sold as either six or twelve volt units. The additional diodes and resistor are only used to give close to the effect of a dual filament incandesent bulb. A 555 timer and the capacitors and resistor to accompany it would require a power sorce and would be more complex than the solution in the tech tip, and would only be useful if you wanted the light to go out completly when the flasher was in the off mode between flashes. A relay would do the same thing without another power sorce.

yes there are but if you use a 12 volt on a 6 volt sys not muchof a difrants and no you would not need an aditional power sorce to use a 555 it is all a mater of wireing all you have in a car or truck is 2 power sorce and thay act as one. and no you can do it with a 555 and a zener. the aplication is simple the hardist part is the 555 pine lay out.