LEDs and the infamous White Wire (Questions)

[Scotchmo]

@Scotchmo,

Hooking up a 1N4007 series rectifier cathode to ground, and engine keeps running...

Good. That shows you can set up a negative ground system without robbing power from the CDI. That is what works on my HT engine. Does the engine die when you do anode to ground instead?

Hooking up lights after it (a prebuilt to test with), and lights work at 50% duty cycle...

We leave the other 50% of the duty cycle alone so as not to hamper the CDI.

If I add a battery pack into the system, I get 100% cycle on the lights. Will draw up a schematic when I get on my desktop later...

Exactly

Thoughts on lighting are this. If I go to 3.6/3.7 volt system for lights, it means I will be able to use the three cell lights that are re-wired/nodded to be driven off magneto/battery pack combo. I am curious, will have to wait till next pay day to replace meter and Check voltage output, but think this will give battery a charge half the time, and power lights. Might have to add voltage limiter to keep it from going to high, but easy. Lower voltage LEDs will mean less power draw, which should allow more lights to be powered off system.

Thoughts on this one?

Just use a zener diode to limit the peak voltage. Simple. It might not even be needed but it will insure that you don’t blow a lithium cell. I would test it without an regulator first and monitor the voltage to see if it ever gets critical. It is not needed for a 6v system but may be needed for a 3.7v system.

 

[Scotchmo]

@Scotchmo,

This is what I have come up with so far. I put in a full wave rectifier and voltage regulator. I should be able to use any LED or prepackaged lights that use two to three standard 1.5 volt batteries for power.

WRONG! That looks like a schematic for a desktop power supply. It is not what we were talking about. You can go ahead and try a full wave rectifier but you will have to isolate it because grounding either pole will kill the engine.