This isn't audio related but the principals should still apply.
The application is a lighting coil on an engine which uses a single diode, half wave rectifier, with a shunt regulator to produce pulsating DC for the lights. I would like to switch to LED lighting but with LEDs the flicker at lower rpms is very pronounced so I was thinking of modifying it to use a high speed bridge rectifier. What I'm wondering is how that would affect the load on the lighting coil? I don't want it to overheat and burnout.
The application is a lighting coil on an engine which uses a single diode, half wave rectifier, with a shunt regulator to produce pulsating DC for the lights. I would like to switch to LED lighting but with LEDs the flicker at lower rpms is very pronounced so I was thinking of modifying it to use a high speed bridge rectifier. What I'm wondering is how that would affect the load on the lighting coil? I don't want it to overheat and burnout.
As this is an audio site some further explanation would be beneficial to those not familiar with lighting coils.
I had to Google it.
So I guess you have a motorbike which generates a low voltage for lighting directly from crankshaft rotation?
And no battery?
LEDs use much less current which is good.
I'd be inclined to try a 4-wire 6/12v Regulator Rectifier. It should be more efficient than the shunt rectifier.
I'm no expert on these motorcycle things and the suppliers don't give out a lot of detail but it is certainly safe to try - you won't fry anything.
If the generator does not put out sufficient voltage at low revs then you may still have poor lighting.
I had to Google it.
So I guess you have a motorbike which generates a low voltage for lighting directly from crankshaft rotation?
And no battery?
LEDs use much less current which is good.
I'd be inclined to try a 4-wire 6/12v Regulator Rectifier. It should be more efficient than the shunt rectifier.
I'm no expert on these motorcycle things and the suppliers don't give out a lot of detail but it is certainly safe to try - you won't fry anything.
If the generator does not put out sufficient voltage at low revs then you may still have poor lighting.
Half wave rectification means dc through the coil. It could be that this is needed propértie, and a bridge rectifier would prevent any dc to flow through the coil. Maybe better to keep the halfway rectfier and shunt reguator as is, and use a large timeconstant RC filter to smooth out the LED flickering. For the RC filter you can try either the lightbulb as serial R, or a similar value resistor and a big enough eectrolytic cap, and feed the smoothed voltage to the leds.
Just n idea
Just n idea
Thanks. I did actually pick up a regulator rectifier module. Guess I'll start with a basic RC filter first and see how that goes. I'm just being careful because it's old and parts are hard to come by.
I know a bit about this. Is the regulator the stock one on the bike or are you adding? Are you sure the regulator is for lights only? Do you know if the ignition is AC or DC? Is it really a lighting coil, or is it shared with ignition? Is it grounded in the middle or at one end?
If you are flickering at low rpms only it likely means you are dropping below the regulator's min voltage. Your fix is likely to be a well filtered voltage doubler.
Also this is the wrong forum, should be in Everything Else.
If you are flickering at low rpms only it likely means you are dropping below the regulator's min voltage. Your fix is likely to be a well filtered voltage doubler.
Also this is the wrong forum, should be in Everything Else.
I managed to locate a wiring diagram. It's an old Yamaha snowmobile of a friend of mine.
It does have a battery but curiously the head and tail lights are off the coil but the brake is off the battery. The simplest solution would be to move the head and tail light to the battery as well? Not sure why the mfgr didn't do that. Maybe too much load with an incandescent bulb to keep the battery charged? Shouldn't be a problem with LED though.
Sorry for not posting in Everything Else.
It does have a battery but curiously the head and tail lights are off the coil but the brake is off the battery. The simplest solution would be to move the head and tail light to the battery as well? Not sure why the mfgr didn't do that. Maybe too much load with an incandescent bulb to keep the battery charged? Shouldn't be a problem with LED though.
Sorry for not posting in Everything Else.
Ok, well as I read that you likely have hybrid 6V and 12V electrical system. The center tap of the "big" coil on the alternator goes to battery, starter, and brake light and is presumably 6V, and the end tap goes to other lights and is presumably 12V. You should be able to verify this by checking if it's a 6V battery and if the original light bulbs are 12V. Take care figuring out what the brake light is.
If this is right, they your fix is likely just adding some capacitance to the 12V lighting circuit.
If this is right, they your fix is likely just adding some capacitance to the 12V lighting circuit.
He sent me a pic of the battery and it's indeed12v. Not sure how i missed this because it's so obvious, but the lights aren't rectified at all, they're just regulated AC. Surprised the LED bulb worked at all but it explains why it was flickering.
I think the solution is to disconnect the wire marked L going to the voltage regulator and move it down to the Br connection on the ignition switch. Then all the lighting will be DC.
I think the solution is to disconnect the wire marked L going to the voltage regulator and move it down to the Br connection on the ignition switch. Then all the lighting will be DC.