Charging System Regulator

[Gregory]

I have a 250 cc Motor bike. the voltage regulator started to smoke .
I have removed the charger and it is burnt out.(Sealed unit)
I have attached specifications sheet to enable you to help me.
I need to build a Bridge rectifier Voltage regulator for my bike.
I do not understand what has to happen to the 3 yellow wires from the generator.
Where on the bridge rectifier the 3 yellow wires go .
Can you help me with this problem so I can design the Rectifier / Regulator

 

[premkumar9]

I have attached specifications sheet to enable you to help me.

There is no attachment.

 

[Gregory]

The attachment failed to load .
I had to edit the post, and load the attachement.
Thank you.
Greg

 

[Gregory]

I need help with this project please

 

[Nigel Goodwin]

The alternator is a three phase one, so you need a three phase rectifier (six rectifiers in total) - but you also need a regulator of some kind, in a car this is done by varying the current to the rotor, but motorbikes usually use a permanent magnet rotor.

 

[Hero999]

I'm surprised the generator puts out >55VAC, be careful that's enough to give you quite a shock.

Providing the generator is connected to the input, it doesn't matter which wat the wires go round.


Have you contacted the manufacturer for a replacement rectifier/regulator?

Replacing it with one specifically designed for your bike is the best option.

 

[Nigel Goodwin]

I'm surprised the generator puts out >55VAC.

Not at all, bear in mind that's off load.

Voltage output is proportional to speed, so if it puts out enough to charge a 12V battery at 1000 RPM, at 5000 RPM it's likely to be exceeding 60V with no load.

 

[Gregory]

I do not understand about the 6 bridge rectifier do they have to connect to each phase then the dc output connects together and then into a voltage regulator.
Could you give me a sketch of the circuit you are talking about.
Thank you greg

 

[Hero999]

That's quite a voltage drop to 14V and I doubt it's a switching regulator so that's a lot of power wasted.

EDIT:
Here's a schematic of a thre phase rectifier and the output waveform.

**broken link removed**
**broken link removed**
The regulator is connected to the output of the rectifier - here's a block diagram of a typical regulator.
**broken link removed**
Op-Amp Based Linear Regulators

The regulator and rectifier are integrated into the same module, either could have failed but it doesn't matter which since you have to replace the whole thing.

The regulator cuts off the ripple and leaves steady DC. A filter capacitor is often added (especially on single phase systems who's output goes through 0V) but this circuit probably doesn't have one as it's three phase and with 55V coming from the alternator the output from the rectifier never drops below 66V.

 

[Nigel Goodwin]

That's quite a voltage drop to 14V and I doubt it's a switching regulator so that's a lot of power wasted.

You're thinking about it entirely the wrong way Hero999, you just bang the output directly on the battery - the battery holds it down to a nominal 13.8V - nothing clever like switchmode.

The regulator may well just be a simple shunt regulator, essentially a huge zener diode, as Triumph used to use years and years ago (mounted on a heatsink under the front forks)

 

[Hero999]

I understand now, the regulator just absorbs the extra voltage when it exceeds the maximum allowed battery voltage.

A three phase rectifier with a 15V power zener connected across the output should do the job, a power transistor and lower power transistor might be more cost effective than a power zener.

Gregory,
Did you try to power the rectifier/regulator with the battery disconnected? That would certainly destroy the regulator because it isn't designed to absorb all the power generated by the motor.