Step-by-Step DIY Rectifier Instructions

GoldenMotor.com

Edd

New Member
Jan 25, 2012
19
0
0
Cypress, TX
Here is the schematic for an adjustable voltage regulator (see attachment). It is comprised of a LM317, with a potentiometer to adjust the voltage the regulator limits at. It can be set anywhere between 0V to Supply Voltage (you guys said that was around 4 to 6V, right?).
 

Attachments

Bmoney

New Member
Apr 20, 2011
25
0
0
Sterling, Ma
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
 

Edd

New Member
Jan 25, 2012
19
0
0
Cypress, TX
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.
 

jats

New Member
Mar 13, 2012
38
0
0
oregon
****, 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?
 

Pilotgeek

New Member
Apr 6, 2011
403
0
0
Green Bay, WI
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.
 

tooljunkie

Member
Apr 4, 2012
663
5
16
Manitoba,Canada
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.
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
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.
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.
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
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.
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..
 

Sgt. Howard

Active Member
Sep 28, 2010
186
58
28
69
Okanogan, WA
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:
 

Pilotgeek

New Member
Apr 6, 2011
403
0
0
Green Bay, WI
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.
 

Pilotgeek

New Member
Apr 6, 2011
403
0
0
Green Bay, WI
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.
 

bigbutterbean

Active Member
Jan 31, 2011
2,417
3
38
Lebanon, PA
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?
 

Pilotgeek

New Member
Apr 6, 2011
403
0
0
Green Bay, WI
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.
 

bigbutterbean

Active Member
Jan 31, 2011
2,417
3
38
Lebanon, PA
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?