Need help - regulator/rectifier problems

[ca1987]

I put a 12-volt engine in a 6-volt bike.

I have a 12-volt reg/rec and a 6-volt reg/rec.

I put the 12-volt on, and when I tested the hot DC wire not connected to anything, I got about 3 volts. When I plug it into the battery, I get 12.

I put a 6-volt DC regulator between the 12-volt rec and the battery, but it only gave it 3 volts out of the reg/rec and a little less out of the regulator. So when the reg/rec is connected to a regulator its output is the same as when it is not connected to anything.

So I put the 6-volt reg/rec on and tested. Not connected to anything, it gave 3 volts. Connected to the battery, it gives either about 2 volts or absolutely nothing depending on if the key is on or off on the bike. (There is a separate system for ignition and charging/electrical.)

Is there a way I could get this 6-volt regulator to put out 6 volts when connected to the battery?

If not I'll use the 12 and swap out the battery and bulbs. At this point (almost a year into this project), I'll just be happy to have lights!

 

[AlphaDogChoppers]

Your post is confusing and impossible to follow. It seems to me that you don't know how the charging system works or how to diagnose it. You need to read the factory service manual for the engine's charging system, use the 12 V regulator, and convert the bike to 12V. Read and understand the troubleshooting procedures and follow them. That will give you enough information to give us some useful information to help you. Include what the engine is so that we have a clue what hardware you are working with.

 

[ca1987]

It's a Lifan 200cc. There is no support or instructions with these Chinese engines. Yes - I don't understand it that's why I'm asking someone else for help. If I understood it it would be fixed and I wouldn't be posting here. It is confusing to me that the 12-volt reg/rec gives 12 volts but the 6-volt gives 3 unless it is faulty. If there is a specific part that you're having a hard time following please let me know because otherwise I have no clue how to elaborate any further. As far as I can see, unless the two have different internals, the 6-volt has to be faulty. I'm going to swap the battery and bulbs tomorrow when the rain clears up unless someone can help me get the 6-volt working or the 12-volt to send 12 volts to the regulator before then. Thanks.

 

[crazypj]

I put a 12-volt engine in a 6-volt bike.

I have a 12-volt reg/rec and a 6-volt reg/rec.

I put the 12-volt on, and when I tested the hot DC wire not connected to anything, I got about 3 volts. When I plug it into the battery, I get 12.

I put a 6-volt DC regulator between the 12-volt rec and the battery, but it only gave it 3 volts out of the reg/rec and a little less out of the regulator. So when the reg/rec is connected to a regulator its output is the same as when it is not connected to anything.

So I put the 6-volt reg/rec on and tested. Not connected to anything, it gave 3 volts. Connected to the battery, it gives either about 2 volts or absolutely nothing depending on if the key is on or off on the bike. (There is a separate system for ignition and charging/electrical.)

Is there a way I could get this 6-volt regulator to put out 6 volts when connected to the battery?

If not I'll use the 12 and swap out the battery and bulbs. At this point (almost a year into this project), I'll just be happy to have lights!

I used to teach motorcycle mechanics, I've heard loads of strange explanations, you have me baffled?
You need to do some basic testing, then, if you doing the tests correctly, ask for advice.
If your using a DC voltmeter you shouldn't be getting any volts with battery disconnected, generator output will be AC volts and should be around 18~20+ @2,000rpm (fast idle)
The motor is basically a Honda CG125 bored and stroked, you can use probably use CB/CM 200 twin manual as the generators are almost identical on small Honda's and the wire colours will probably match up (CG or CB125 singles are usually 6v so numbers won't be close)
The regulator doesn't 'put out' any voltage, it shunts it to ground when it gets above a pre-determined level
I think your confusing regulators and rectifiers, you may want to edit first post so it makes a little bit of sense, engine ISN'T 12v, it's petrol (gasoline)
Generator may be 12 v but really it doesn't care as AC output could be as high as 110v (@9,500rpm)

 

[ca1987]

I know a little more than that. I'm not confusing regs and recs. Regulators regulate voltage and rectifiers turn AC to DC.

Don't know what to tell you, I am still measuring positive voltage coming out of the reg/rec (both of them) with the hot wire not connected to anything but my meter.

Generator output is fine, it is a bit above 20 AC.

The regulator does put out voltage.. It goes like this: stator -> reg/rec (12-volt) -> 6v regulator -> battery. The strange thing is, when it is reg/rec (12-volt) -> battery, it gets 12. But when I put a regulator between the 12-volt reg-rec and the 6-volt battery, the measured voltage from the reg/rec comes out to 3 volts (same as when the reg/rec is only connected to my meter), so the voltage then coming out of the regulator and going to the battery is something like 2. I'm not sure why putting a regulator between the reg/rec (12-volt) and the battery causes the reg/rec to act like it isn't connected to anything (putting out 3 volts instead of 12, as it does when it's connected directly to the battery), or why when I hook up the 6-volt directly to the battery it is putting out 3 volts, as the 12 volt reg/rec puts out its full 12 under the same configuration.

Anywho, I've decided since the only thing that works is putting the 12 directly to the battery, I've gone ahead and bought new 12-volt lights, battery and horn.

Thanks.

 

[crazypj]

Regulator is never connected directly to battery, it should be connected through a switched wire.
Rectifier IS connected directly to battery
You will have red wire with white tracer on rectifier plus 3 wires (either all yellow, or, pink, white, yellow) and a green wire for ground.
Regulator will have a black wire and a green wire, possibly a yellow or yellow with white tracer.
It doesn't 'put out volts', it 'bleeds off' excess
How are you getting a voltage with battery disconnected?
If your running engine and trying to measure you will get false results (plus probably burn out internal components)

 

[Speedshop]

Theres plenty of funny charging systems out there. These CG/mopeds things often run a split AC/DC system IE regulated AC is fed to the headlamps and regulated 12 volts DC to the battery for the stop lights, horn and indicators. The CG Brazil models run this system along with the Yamaha Roller. Because these are the bikes the Chinese copy there are many others out there with the same set up.

The Lifan engines run a conventional 3 phase 12volt DC system with CDi ignition.

Its fairly easy to convert one type to another - BUT you need to find out what systems you have so you can work out what modifaction is requied.
If you have split AC/DC, you need to feed the lights from The DC system when running 100%DC. A simple jumper wire is often all thats needed added to the loom.

 

[crazypj]

Yep, A lot of the early Honda's used AC 'load balanced' headlight and DC tail light/indicators, etc
They used load balance on a lot of the XR's, some had an AC regulator.
I never checked one but it was probably a zener diode used to 'short out' half the wave?

 

[Speedshop]

Nope its a brilliently simple system. Way better then a plain zener. Basically they regulate the AC with 2 scrs back to back - then feed the regulated AC into a bridge rectifier to give the DC portion. So long as the regulator is in circuit the Ac is always controlled so it doesn't blow the bulbs.