OK, I just ran several test on my Trail King MB that has the twin single wire coils. The engine idles at 650 RPM and maxes out at just over 3,000 RPM by a stop.
I started out with the engine warm, and idling.
Here is the idle AC output:
At at max RPM for my engine:
As you can see, even if running to an AC head light bulb, this would mean death to the bulb in very short order. The rising and falling VOLTAGE would be very hard on the filament as Ohms law states.
Now running through A 30 Amp Full Wave Rectifier ( 5-50 volts rated) You can see the slight drop in voltage as expected due to the Diodes firing at idle:
A now at max RPM. As expected the voltage is way too high for a DC bulb and will burn it out as well:
Now for something no one ever talks about Hertz. This is how many pulses of energy per second is being generated,both positive and negative pulses.
If you live in the USA the Hz are 60, and most of the rest of the world is 50 Hz. ( 120 pulses in the USA / 100 pulses outside the USA per second)
Now since the engines flywheel,if you have the Lighting flywheel with three magnets, changes speed as the engine speeds up, the Hz are uncontrolled.
These pulses are going through the bulbs filament and vary with engine speed. ( think firing a single shot shotgun to pulling the trigger on a MiniGun. One shot per second or 100 shots per second) It's no wonder bulbs fail so fast if un-regulated. an expensive lesson to learn.
Now lets look at the wave form on a O-Scope. I have combined both legs of the single wire coils (2) and grounded the probes to the engine chassis.
As you see off to the right of the display we are getting some sort of distortion. While this may be called noise,what you are really seeing is the development of Counter Electromotive Force or EMF ( not EMP that's in nuke weapons going bang) This is a force countering the voltage and current being generated by the faster and faster spinning magnets. It is what governs electric motor RPM's by design.
Anyway, it too is not a good thing for light bulbs as now the filament has to deal with this noise as well.
So far we are just looking at the AC output. Now it has to be rectified to DC and then regulated to prevent an Over Voltage.
Here are some O-scope displays on various voltage settings:
Engine is running at 2,800 RPM
OK, now that you a bored to tears, lets run the varying AC from the coils through a Rectifier and Regulator. The rectifier changes AC to DC, the Regulator does all the magic You need to know about. It keeps a constant VOLTAGE ( at normal running engine RPM) to your lights or Cell Phone charger,etc. It also keeps a constant current ( amps) to the devices as well. How it does this is very complicated. In the US Navy we called this PFM.
( Pure Fuc%&*g Magic) Just know that it does work very well.
OK, so the new Harbor Freight LED Spot Light is hooked up to the Rectifier/Regulator and the engine is idling.
As you can see it is too low to run the LED head Light at maximum brightness. Adjusting it here at idle MAY,depending on how well the device regulates provide way too much voltage at max RPM and burn out the LED's. I like to adjust at the "normal" running rpm which on my engine is about 3/4 throttle. You decide what you want to do. The regulator does a pretty good job of keeping the voltage to 12VDC or so.
I will re-adjust to 13.0 VDC as most car batteries provide that under load,perhaps a little more. By adjusting to lets say,13.5 VDC,you will never hurt the LED's but get max brightness and a little more Current to power other lights,cell phone charger,etc as well.
Now what about the killer HZ? There are none. The Rectifier/Regulator provides pure D.C power. 'It don't get no better than this.
Here is the LED Head Light running at 2,500 RPM and the Rectifier/Regulator is doing it's job very well. The head light is bright with no flickering what so ever. Current ( Amps) was just under the rated 1.25 ( one and a quarter).
The Rectifier/Regulator even,through stored energy in the large capacitor ( large black can looking thing) kept the Head light on full brightness at idle for over 5 seconds! then it dimmed down to about 1/3rd output,still enough on a dark night to be seen by others. A slight increase in RPM brought the Head Light up to full power again. By adding a battery/ battery pack the HL will stay at full brightness.
The Heat Sink never go over "warm" to the touch after a ten minuter run at high speed ,full load.
At idle it stayed cool.
I hope you found this info helpful in using the power your Flywheel and coils addition you have done to your engine.
There is a lot of helpful info here from others as well. Use what you think is best for your devices you wish to power.
This is what woks for me.