Another Idea For Lights

Discussion in 'General Questions' started by yamaslo, Jul 22, 2008.

  1. yamaslo

    yamaslo New Member

    I read a lot of lighting threads but not really impressed by any. Here is one that should work but need somebody that knows some electronics .
    The 50+ led lights put out plenty on 3 aa cells ( thats 4.5 v ) & will burn a long time - longer than most of us ride a night anyway. We could hook the white wire to the + terminal & ground to the - post, & use 2000 mah nickel metal hydride cells. need some kind of diode to get the dc & some kind of cut off so at low rpm the batteries won't discharge. How about it?

  2. sjackson

    sjackson Member

  3. relaxxx

    relaxxx Member

    Here's what I did for LED lighting:

    White wire goes to a 6v filament light bulb from a flashlight, this is to act as current limiter and fuse in case of short circuit and is wired in series with the circuit as any fuse would be. From the bulb to a diode to prevent reverse current from the 6v NIMH battery connected after the diode. Then there is a switch after the battery running to 10 LED's in front and 5 in back. I decided not to add a switch before the battery to prevent overcharge because the battery is a rusty old part pulled from an RC UFO toy. The front LED's are 20000 MCD ultra bright with 2 resistors limiting voltage to about 3.8v. I think they were 47 ohm 1/2 watt, each powering 5 LED's in parallel. The red rear LED's have a 100 ohm resistor. Plenty bright for my needs. Total power draw is about 0.7 Watts.
  4. hi there

    i have tried this and failed, here is what i did:

    1. Built a rectifier circuit (converts the AC from white wire to DC) .. note this is pretty essential as backwards charging a battery .. well i wouldnt advise it! and also could destroy LED's as they are only supposed to work one way.

    2. Build a Voltage Divider (Using two resistors to create a lower voltage) .. I used two 2.5Ohm resistors, which makes an output of 6v

    3. Modded my 52 LED torch the have a removable plug so i can dissconnect it easily.

    Looks good on paper! however here are the problems:


    The main problem is that, or whatever the strange thing that the ignition box creates .... the same effect that why bike speedos generally don't work on my bike, it gets scrambled.

    If you put the 52LED torch (powered by batteries only) and put it CLOSE to the running engine, the lights will come on by themselves ...

    now with my circuit in place, this is amplified along the wires making it 10 times worse!!

    so it constantly flickers and basically isnt great ... i wired in a capacitor to even the current flow but to no avail.


    So no i'm going to make version 2, which will comprise of a small 12v battery which is charged slowly by the white wire, then a switch to disengage charging and engage the LED light (using a voltage divider circuit).

    This will remove most of the EMI interference


    If that fails! Them i will have a 6v tail light, which will act as part of the voltage divider, and then run that to the LED light, but this will probably have the same effect ... SO i will resort to a filament bulb, 12v, 2.5watt, and all will be well

    I'll post pics sometime of my fails if you wish!