anyone still running the front headlight on there modified engines?

#24
Are those twilight bulbs? They are 12v car bulbs correct?
all i know is that there led, they are 12v 80w light-bulbs.
they were marketed for a motorcycle headlight (not sure for what reason, but i returned then so i dont have them anymore)
they have 3 leds on each side (total of 12 leds)
i dont think there twilight bulbs, but im not sure (not that big into light bulb types lol)
here is the link to what i had bought
https://www.amazon.com/gp/product/B078W1T9L2/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
 
#27
Tomorrow I’ll go into my stash and get one of the ones I use. Pm me your address and I’ll send it to you. I’ll send along a full wave rectifier. Wire it up first using the rectifier and verify it works ok on dc. Then remove the diode and see if it burns out. The bulbs I buy are a couple of bucks each with free shipping from China.
 
#28
Tomorrow I’ll go into my stash and get one of the ones I use. Pm me your address and I’ll send it to you. I’ll send along a full wave rectifier. Wire it up first using the rectifier and verify it works ok on dc. Then remove the diode and see if it burns out. The bulbs I buy are a couple of bucks each with free shipping from China.
I've sent it. Check your conversations tab.
 
#30
Here are the cheap bulb assortment from ebay/China. I have used all of them in my various minibikes with only the bigger taillight bulbs giving me any trouble. The larger taillights on the left would break the 3 tiny solder grounds after a while from vibration. The other taillight bulb next to the two big ones hold up just fine as there is not enough mass to break the solder grounds between the case and the PCB. I am going to wire one up to a full wave bridge and send it to merc20 to test it and if it works OK and after a while does not blow, he can remove the diode and try it with AC and see if it blows then. If it works OK both ways there must be some electronics in the bulb that he was having trouble with that does not like AC.
 
#32
Here are the cheap bulb assortment from ebay/China. I have used all of them in my various minibikes with only the bigger taillight bulbs giving me any trouble. The larger taillights on the left would break the 3 tiny solder grounds after a while from vibration. The other taillight bulb next to the two big ones hold up just fine as there is not enough mass to break the solder grounds between the case and the PCB. I am going to wire one up to a full wave bridge and send it to merc20 to test it and if it works OK and after a while does not blow, he can remove the diode and try it with AC and see if it blows then. If it works OK both ways there must be some electronics in the bulb that he was having trouble with that does not like AC.
Thanks! :scooter:
I got a voltage meter that's accurate now
My idle volts are 8.5-9v
My mid rpm voltage is 16-18v
My WOT voltage is <24.6v (I didnt want to blow up my motor, it read 30v but I dont push beyond that) sorry that some are upside down. 20181221_130014.jpg 20181221_125842.jpg 20181221_130035.jpg
All are ac voltages
 

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#33
OK I made the test fixture. When you get it attach the two yellow wires to your alternator output. That will convert AC to DC and then see if the bulb survives some reving of the engine. If it works OK then cut off the red and black wires from the rectifier and connect to the minibike AC wires and again try to blow the bulb. If it blows then it is because of the AC, if it still works fine there was something in your bulbs that did not like your alternator output. Here it is working off of 12volts AC to verify it works before sending it to you.
 

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#34
OK I made the test fixture. When you get it attach the two yellow wires to your alternator output. That will convert AC to DC and then see if the bulb survives some reving of the engine. If it works OK then cut off the red and black wires from the rectifier and connect to the minibike AC wires and again try to blow the bulb. If it blows then it is because of the AC, if it still works fine there was something in your bulbs that did not like your alternator output. Here it is working off of 12volts AC to verify it works before sending it to you.
Alright, I'll do that!
Will see how it goes!
 
#35
Ole, if you get bored, look up FC in an XC environment. Those diodes show reactance in that AC circuit, which increases 90 degrees before peak voltage. Not only is he seeing the maximum recommended voltage at WOT, he's probably doubled the frequency from his minimal reading.
 
#36
Never thought about the frequency but you are correct faster motor goes more AC sine wave frequency increases. My setup on a clone still has the governor although I have the screw all the way out so it goes about 4600 rpm but because of cheap china flywheel I would not remove the governor. That bike has a cap across the dc but it has never blown a bulb, same setup as mark. My rupp continental has the two lighting coils each going thru a single diode not fullwave so I don't have the to coils fighting each other but that one does not blow bulbs either and it revs mid 5K . Probably a lot less voltage than the poster. Tried to look up what you said (FC in a XC environment) but it does not give me anything electrical, what search argument did you use?
 
#37
what search argument did you use?
Dim memories from my electronics schools in the late 70's. What I did not know is that LED's look reactive because in this case, they are operating in an AC environment. XL=2×pi×f×L. Inductive reactance increases proportionally to frequency. Add to this, we do not have accurate numbers for voltage drops on "white" (blue and yellow mixed) LED's in whatever configuration the MFGR has decided to sell us.

That is why at face value, it is better to work with DC (or rectified AC) with LED's in general, and in high RPM (frequency) specifically. Thus that $8 Voltage Regulator on the end of a full wave rectifier would result in a solid system without worrying about resistor legs turning cherry red beneath electrical tape shoved in a head lamp assembly. (grin) I know I am preaching to the choir, but I see people all the time, spending serious money on engine guts, then turn around and get the cheapest crap possible to make the rest of the machine work. As it is, he is already turning the maximum voltage for either of his lamp selections.

I'm sure the set up you are sending him will work out just fine. You will never match sine waves with your dual coil mag set up. (Called paralleling in the generator world, if it happens, things explode)
 
#38
So, conclusion
I used the light with and without the resistor, and it didnt blow up (even at WOT)
It got a bit brighter with out it but, really not much of a difference. So, my.guess it I was just using the wrong light bulbs for my application. Thanks ole4 for sending it!
 

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#40
That is a full wave rectifier to make it DC. Should not have flicker as bad as with straight AC. Here are some very cheap bulbs you can use if your headlight takes this kind.
http://rover.ebay.com/rover/1/711-5...0001&campid=5335845805&icep_item=401669285191
That is a full wave rectifier to make it DC. Should not have flicker as bad as with straight AC. Here are some very cheap bulbs you can use if your headlight takes this kind.
http://rover.ebay.com/rover/1/711-5...0001&campid=5335845805&icep_item=401669285191
It flickers about the same, ther really wasn't a difference. I'm just going to play it safe and keep the recitifyier on there. But thanks agian!
 

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