175 dynamo question

[coxy]

g day all
what would be the best way to test a dynamo for charge when its not in the bike ?

any suggestions cheers

[coxy]

cool

[Bikenstein]

I would set up a drive mechanism with a variable speed drill to rotate it and check the voltage output. Other than that I would take resistance readings on the coils and compare with a known good one or factory parameters if there are any published. You can also just check for continuity in the windings and possible ground fault of the windings but that won't tell you anything but whether it has a definite problem. I think you have to have the rpm above 3000 before you read an amperage output. I believe I read somewhere that you have a negative output below 3000 which could cause your battery to discharge if drive too slow

[Jon Hardcastle]

Does anyone have those readings?  I would like to test mine as well.

[Bikenstein]

If you are spinnin the generator to test, hook your meter to the wire that goes to the battery of course and if you turn it fast enough you should get it to read a few amps. This would probably require wiring in a rectifier circuit. Does anybody have knowledge of testing these generators out of the bike?

[coxy]

thanks dave i was wondering about the rpm .i spun it by hand ,thats about 1/2 a turn and got aprox 2v so there is life in it