[bigbrosxx]

This 650 watt wolf generator has worked perfectly for two years. Engine runs aok as normal but no 230 volt output on socket after running for one hour with load of two 100w and one 60 table lamps, just went dark, no noticeable change in engine note. Checked powerfactor condenser by swop from similar generator, checked winding continuity, dc ohms, leakage and compared with other generator no problems, seem comparable both units. Took off end cap of generator. Brushless type rotor with two windings and each terminated by diode. Diss ends and check diodes. Both test okay. Re-assemble and still no output on AC socket. Is driving me crazy. Please help.

[crigby]

Hi,
Did it work before with the same load? Your stated load uses almost half the available wattage so I am wondering if a circuit is unavailable with other loads \.
Peace,
Clarke

[giv_meabreak]

Crigby, I'm thinking he meant 6500W. A 230v socket with a 2.5A fuse wouldn't be much use!

Do you have 115v one side to Common and 0v on the other, or are both 115s browned out?

Got your 3 lamps all on one side, or one on one side, 2 on the other? Which side goes brown?

[bigbrosxx]

Crigby, I'm thinking he meant 6500W. A 230v socket with a 2.5A fuse wouldn't be much use!

Do you have 115v one side to Common and 0v on the other, or are both 115s browned out?

Got your 3 lamps all on one side, or one on one side, 2 on the other? Which side goes brown?

Thanks both for replies. No it is just 650 watts at 230 volt outout, no tap for 120 volt and the only earth to three pin output socket is from gene case. Whilst running check shows zero volts with multi meter, try different loads such as 230v to 13.6v power supply or small 400 watt heater element and same result. Point is it has been aok up until now, ran aok for one hour then just lost AC volts, no change in engine sound, no overheating. Overload reset aok all windings check out okay so what ? One suggestion is it lost permanent magnetism required to kick start the rotor field but what would cause this in normal operation. I'm at a loss to understand.

[crigby]

Hi,
The only time I have seen what you describe happen is a stuck brush.
As far as the field goes, there is supposed to be some residual magnetism to allow the generator to build its field. Loss of it is generally only a result on sitting for extended periods unused. That is cured by flashing the field, which putting in voltage rather than taking it out.
Peace,
Clarke

[bigbrosxx]

Hi,
The only time I have seen what you describe happen is a stuck brush.
As far as the field goes, there is supposed to be some residual magnetism to allow the generator to build its field. Loss of it is generally only a result on sitting for extended periods unused. That is cured by flashing the field, which putting in voltage rather than taking it out.
Peace,
Clarke

Hi there, thanks again, it is brushless gene, guess that I shall try your tip, flas by putting 12 volt across rotor winding, but have to be careful as to diode polarity. Wiil try out tomorrow and let you know, thanks again.

[KISS]

Me confused. You do you end up with a brushless rotor?

Schematic?

Is it an inverter based design?

You really need to check if the control winding is generating any small amount AC voltage which would be turned into DC and applied to the rotor as a control signal.

If the control winding is not generating, then it might be time to re-flash the generator.

[bigbrosxx]

Me confused. You do you end up with a brushless rotor?

Schematic?

Is it an inverter based design?

You really need to check if the control winding is generating any small amount AC voltage which would be turned into DC and applied to the rotor as a control signal.

If the control winding is not generating, then it might be time to re-flash the generator.

Hi there, no inverter , here basic two stator windings similar dc resistance one connected to power factor capacitor only and the other is AC 230 volts output to socket. Rotor is two windings each connected across its own diode and nothing else to it. Have tried flashing as suggested elsewhere, putting 12 volts across power winding then giving ten sharp pulls to starter cord. Did of course remove plug and switch off fuel and ignition first. Results still no output when all connected back again.

[bigbrosxx]

hi there, no inverter , here basic two stator windings similar dc resistance one connected to power factor capacitor only and the other is AC 230 volts output to socket. rotor is two windings each connected across its own diode and nothing else to it. have tried flashing as suggested elsewhere, putting 12 volts across power winding then giving ten sharp pulls to starter cord. did of course remove plug and switch off fuel and ignition first. results still no output when all connected back again.

Further to above, ALL modern small alternators use brushless rotor technology. Power taken from winding on stator, with another similar winding on stator to couple to power factor capacitor, in this case 34 microfarad AC working. Seems that "remanent" magnetism in rotor is enough to kick start the two rotor windings to produce enough magnetism in rotor windings. This I got from encyclopaedia.

[KISS]

OK then, what's the rotor good for?

True. Output is taken from the stator. So, I'm asking you:

Where does the regulation come from?
Where does the magnetic field come from?

[bigbrosxx]

OK then, what's the rotor good for?

True. Output is taken from the stator. So, I'm asking you:

Where does the regulation come from?
Where does the magnetic field come from?

Hi only regulation appears to be mechanical on engine, is adjustable for speed, to give 50 or 60 hertz. Magnetic field, well so far as I can make out there is some remaining (remanent) permanent magnetism in rotor iron which is built up into sufficient for generation by the two windings on the rotor. They produce AC which is rectified by the diodes connected across ends of each winding. Let me try a word picture okay? You have the two pole "H" type of rotor, on each arm of this "H" is wound a separate winding the ends of each winding connected across a silicon diode. When rotated inside stator the small permanent magnetism remaining is built up by these two windings to a level sufficient for normal operation. BUT you must have that essential small amount of remaining magnetism there in the first place for the building up effect to take place. THERE IS NONE THERE as a check with screwdriver tip tells me. It is driving me stark crazy as checks according to suggestions received seem to indicate, both rotor and stator windings are okay for continuity and no leakage. Capacitor is okay, diodes are okay engine runs correct speed too so what else can there be ? Have tried now "flashing" as suggested by putting twelve volts across stator winding and pulling over with starter cord, after disabling ignition. The result is still no AC output. Thanks for patience.

[KISS]

I think your missing the operation. Look closely for brushes on the rotor. The rotor must have residual magnetism. There usually is another stator winding that provides the DC for the control circuit.
The control circuit once excited by the residual magnitism is able to then modulate the voltage of the Generator by changing the rotors magnetic field. This gives you voltage regulation.

The rotor must be flashed with a pulse of DC. Usually low voltage like 12 V or near the operating voltage of the control winding is.

You don't flash the stator. You must have movement in magnetic lines of flux which was done in the old style DC generaors of very old cars. The permanent magnet was outside and the generated voltage came from brushes.

In an alternator in modern cars, the stator is wound three phase and rectified to produce CD. The rotor's magnetic field is changed by the voltage regulator. There is no residual magnetism. There is no frequency control.

With an AC generator (Alternator) you need?

1. Frequency control - RPM of engine
2, Voltage control - change magnetic field of rotor
3. Residual magnitism - to get the process started.

Some generators idle the engine low until it dectects what it thinks is a load and then the generator idles up to the proper frequency.

Power is taken from the stator, usually multiple windings. 120, 120, 12,

Voltage regulation is done by varying the magnetic field on the rotor

Frequency by engine speed.

Residual magnetism on the ROTOR gets the process started.

I hope this makes sense.

[crigby]

Hi,
There should be some rectifier assembly built into the rotor to create the field that builds in the stator(it actually does not do that, it just enables the building of the field by creating the one in the rotor!) My guess would be bad diodes in the rectifier(there are usually four, ful-wave bridge.)
Peace,
Clarke

[Tyremist]

Hi, I have a wolf 980 too. It just stopped putting out volatge. It was the big 8uf cap under the pertrol tank (rectangular black block with a screw holding it to the front). Its £7 from wolf's website wolf.tv. Took a few minutes to fit.

[Tyremist]

Hi, I have a wolf 980 too. It just stopped putting out volatge. It was the big 8uf cap under the pertrol tank (rectangular black block with a screw holding it to the front). Its £7 from wolf's website wolf.tv. Took a few minutes to fit.

[Tyremist]

Hi, I have a wolf 980 too. It just stopped putting out volatge. It was the big 8uf cap under the pertrol tank (rectangular black block with a screw holding it to the front). Its £7 from wolf's website wolf.tv. Took a few minutes to fit.

[rohmell]

RE-ENERGIZING DEAD GENERATORS