Misc: Charging Systems Regulator for MZF-12A dynamo

[Paul Coene]

My Rapide has a Chinese dynamo type MZF-12A. The fuse was burned out and after replacement, the battery didn't charge any longer. I cleaned the commutator and tested the dynamo. It seems to work well now, so I think the (electronic) regulator is broken. (I don't know how to test it though). Is it possible that a malfunctioning dynamo blows the fuse and/or the regulator ? And does anybody know what type of regulator is required or advised for this kind of dynamo ?
There's not much information on it:

Thanks in advance,
Paul.

 

[mercurycrest]

You need to look at how the field leads and armature leads are connected to the brushes so you can determine if the field is internally, or externally grounded. Then you will know which type of regulator you need. To make the generator "motor" did you ground the "F" lead from the generator? That would be an externally grounded generator. "F" to "D" is internally grounded.

 

[Marcus Bowden]

I've always tested with D & F together to the positive battery terminal, negative to earth and should motorise in direction of driven rotation and will be polarised for negative earth at the same time, it's now good to go.
bananaman.

 

[Paul Coene]

@ mercurycrest and Marcus: I found some information on internet:

Chang Jiang

When I connected both terminals W and AW together to the +terminal, and the -terminal to the earth, the dynamo was running fine.
Next, I mounted the dynamo to the engine again and measured the tension between A+AW and earth (battery disconnected) at "fast" tickover: 7 to 10 V. Is this test good enough to decide that the dynamo is ok and that the regulator must be faulty ? Is there an easy way to test the regulator ?
(Sorry, I don't know much about electronic equipment)

 

[Marcus Bowden]

Sorry, I'm no expert on electronics although had to get to a certain standard when doing my engineering tickets of competency that has gone the same way as the majority of stuff I learnt at school & college. Sucket and see is the advice I give now but be ready to pull the plug when you see insulation leaking smoke.
bananaman.

 

[Simon Dinsdale]

Sorry, I'm no expert on electronics although had to get to a certain standard when doing my engineering tickets of competency that has gone the same way as the majority of stuff I learnt at school & college. Sucket and see is the advice I give now but be ready to pull the plug when you see insulation leaking smoke.
bananaman.

When I started my electrical apprenticeship the first two rules I was told by the instructor called Jeff was:
1. When you see smoke it too late
2. Getting the smoke back inside the wires is the tricky bit.

Simon

 

[stu spalding]

I believe that genuine Lucas wiring smoke was available, in tins, on ebay a while back. Cheers, Stu.

 

[Paul Coene]

here we go again.

 

[vibrac]

There is a good piece on dynamo testing etc here https://www.matchlessclueless.com/

 

[Paul Coene]

Thanks Vibrac, but I've found that article already. Very good information indeed. What should I do without internet nowadays ? Actually , it is not the first regulator I'ld have to replace and, asking for advice about testing methods, I never got any other advice than: try a new one and you'll find out if the old one was faulty.