DC Generator

I used to do something like this back in the 50s through 60s. For the old car DC generators in use before alternators, often one needed to polarize it. This was especially needed if it wasn't used for a long time, or it had been taken apart to be fixed. This polarization was done by quickly zapping it with a battery directly on the generator output terminal to ground. I used the same polarity as was to be generated. This zap would provide enough residual magnetism in the right direction, in the iron field to get the generating process started with the correct polarity. Once rotation started any current generated would then strengthen the field coil magnetism and thus generate more current. The result was the DC generator back in operation. This process is not needed for permanent magnet generator-motors.

Your attempt at describing how to polarize a generator is appreciated, but it lacks the specific information necessary to do it correctly. For instance, "zapping" is non-descript, "zapping with the battery to ground" says nothing about what connection goes where or when.

Susan

Do not use this technique on alternators. Alternators generate their own field when in operation by use of 3-4 amps of battery flow. So it is not necessary for these. This technique can be used only on the old fashioned DC generators (used in cars earlier than 1960-1970's). One quickly flashes the battery across the generator using the same polarity as is normal in charging. What you are doing is bypassing the voltage regulator circuit. Some charging circuits use a positive ground and some use negative ground so I can not say what polarity you have. The result is a small residual magnetization of the iron in the field coils and armature, that allows the generator to start producing power once it starts to turn.

Offered by Mike.