Step-by-Step DIY Rectifier Instructions

I just recently built one of these.. I was planning to run a small led flash light with a small 3 led side marker as a taillight. i wired everything up and It seems to work but will only run one of the lights at a time. Maybe my engine doesn't put out enough volts to run both? but i though that was the point of making this in the first place.... . . MEH
 
Bmoney, did you make sure you connected the LEDs with the correct polarity? The only other solution I could think of is lowering the values of the resistors.
 
****, this is a great thread and am going to build the rectifier. I see that the dates are about a year old but hear goes. On old motorcycles there was a zener diode on the positive leg of the mangeto that kept the voltage below a certain point this would work on the positive leg of the rectifier to maintain a constant 4.5v etc small LED flash lights have a 3 AAA battery cartridge and if you put in rechargeable batteries used it as your battery you could tap off of 4.5v, and 3v as needed this could power your old bike headlights and one of the turn signal, brake light, and horn kits that you can get for 10 bucks. if you switch it off of the common leg you would use only one on/off switch. what do you guys think? will it work? maybe even adapt the leds from the flash light into a retro bicycle headlamp?
 
If you have a zener diode which does that, I don't see why it wouldn't work. It may be easier, however, to use a regulator circuit. Radioshack sells a few 1amp 5v 7805 regulators, and similar regulators can be found in a lot of old electronics if you want to salvage something. Both my headlights and taillights seem to run fine directly from the rectifier without a regulator, though I think the headlight (led flashlight) has one built in.
 
the rechargable aaa battery idea is a great one.could use it to power the rear as well.
i may try a 12v marker lamp for the rear of my bike,i have a headlight ,but would like something on the back.
 
Pilotgeek said:
If you have a zener diode which does that, I don't see why it wouldn't work. It may be easier, however, to use a regulator circuit. Radioshack sells a few 1amp 5v 7805 regulators, and similar regulators can be found in a lot of old electronics if you want to salvage something. Both my headlights and taillights seem to run fine directly from the rectifier without a regulator, though I think the headlight (led flashlight) has one built in.
Click to expand...

You can run as many of those those regulators in a parallel arrangement as you need to get the correct amperage necessary for the power you intend to use.
5 amps = 5 7805's, ect. At $1.99 each they are a good deal.
It is very important to wire it up correctly though. Do a google search for more info.
 
tooljunkie said:
the rechargable aaa battery idea is a great one.could use it to power the rear as well.
i may try a 12v marker lamp for the rear of my bike,i have a headlight ,but would like something on the back.
Click to expand...
A Happy Time China Girl 2 stroke motor will not support a 12 volt bulb of that watt and voltage requirement off the white wire..
 
I am tagging into this thread so as to keep track- as some of you know, I have R&D into this realm and will gather any intel I can find. I have figured the 6-volt LED system (for the most part) and am now working with the charger/battery standpoint of the beast- will keep developements posted, but currently have to move (again) :army:
 
How many amps does the white wire produce at max rpm? I have a battery that can take about 3 to 3.5 amps. I want to charge it off the white wire.
 
I already answered that in chat for you, but for anyone else that's reading and would like to know it's about 0.5 amps.

It can actually put out a little bit more, but it may cause the ignition to not fire.
 
Yeah, it's about .5 amps. You could charge a 6v battery with a capacity of however many amp hours you want from it, it will just take a longer time.
 
tried introducing a 7.2v nicad into my lighting circuit after rectifying it. I didnt install any resistors or caps. battery kills engine at idle.
 
You'll need some resistors, or else a low battery will try to pull in too much current maybe. The resistors will make it so it can only charge at a slower rate.
 
I am not worried about using the battery if I dont need to, so lets set that aside for the moment. Here is the main issue. I have a headlight I got from wonderful creations on ebay. its 6v, 3w with built-in voltage regulator. The bike cant start with the light on, nor can it idle. The engine will shut off at idle if the light is on. it works fine under power. The light runs off the white wire. I rectified the current to charge the battery. is there a way to get the engine to run the light while idling without using the battery?
 
Well, I have a few doubts about charging a 7.2 battery from a 6v source. The white wire does go above 6v *sometimes* but I'm not sure that's enough to consistently charge. If it were a lower voltage battery, it may work. For some reason I wasn't thinking about the whole 7.2v part of your battery.

6v 3w light is about the limit of what could be run off the white wire. You could try to limit the current a bit with resistors. In my circuit I used two 10 watt resistors in series. The light may be a little dim at idle, but it may not kill the bike. I can't guarantee it will work though. You could play around with resistor values, resistors aren't that expensive.
 
took the battery pack out of a black and decker power ratchet that I no longer use. its only 3.6v, but I tried it on my light last night and it does work. I am a little worried about overheating it, since the light is 6v regulated, and also a little concerned about charging it off the white wire, since the wall unit for the charger is 6.5v 250mA. any thoughts?
 
Be careful with what battery TYPE you're using. Lead acids, NiMH and NiCD are pretty tolerant to just connecting to a power supply. Lithium Ion are not. 3.6v sounds like it may be a lithium ion battery, which have a tendency to start on fire without very special charging circuits to limit the way they charge. If it is Lithium Ion, it may have the circuits in the battery itself, or the wall charger. The 6.5v off the wall unit may get regulated down elsewhere. It also may just be a 3.6v NiCD pack, not sure.

Why not do some Google searches so you understand how battery charging works a little more? Wikipedia has some nice information.
 
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