I am looking at fixing a small generator for a friend. It's running off a little 49cc 2 stroke engine and has a 0.7kW brushless 2 pole generator.
The history is that the bearing at the generator end had failed so he pulled the cover off and replaced the bearing. From that point forward it hasn't produced power.
I had a look yesterday and put a meter on the output. It seems to be producing between 5-30 VAC, but at something like 400Hz to 700Hz and bouncing round a lot ! (the meter is working correctly, verified on another genny).
I pulled it apart yesterday. I cannot see any physical damage and resistance readings for the rotor seem to be consistent with a similar machine I own. The capacitor is rated at 300V / 15uF, and tests to within 5% of that value.
I removed the leads from one of the diodes to test, there's a ~ 7.5kohm resistor in parallel with the diode. Using the diode setting on the DIMM is shows 0.95 V one way, nil the other, but doing the test the old fashioned way it did seem to allow current to pass both ways, but at very high resistance. That might be the difference between a DIMM and analogue meters ??
Any ideas or suggestions as to what might be wrong or for further checks to carry out?
Thanks in advance for any help
The history is that the bearing at the generator end had failed so he pulled the cover off and replaced the bearing. From that point forward it hasn't produced power.
I had a look yesterday and put a meter on the output. It seems to be producing between 5-30 VAC, but at something like 400Hz to 700Hz and bouncing round a lot ! (the meter is working correctly, verified on another genny).
I pulled it apart yesterday. I cannot see any physical damage and resistance readings for the rotor seem to be consistent with a similar machine I own. The capacitor is rated at 300V / 15uF, and tests to within 5% of that value.
I removed the leads from one of the diodes to test, there's a ~ 7.5kohm resistor in parallel with the diode. Using the diode setting on the DIMM is shows 0.95 V one way, nil the other, but doing the test the old fashioned way it did seem to allow current to pass both ways, but at very high resistance. That might be the difference between a DIMM and analogue meters ??
Any ideas or suggestions as to what might be wrong or for further checks to carry out?
Thanks in advance for any help