Generator trials (by alaric)
Yesterday, my friend Mike (who is interested in generators) was around, so we tested the generator out with the cable I made.
It could run the computers, or the fridges and freezers, without straining; I couldn't try running everything at once since I don't have the spur in my cable yet to reach both bits of the house.
We tried running the kettle on it, since it's a 2kW kettle and a 2.1kW generator, and when the kettle was switched on you could hear the generator rev up to deal with the load, then when the kettle clicked off, the generator settled down again.
I wonder how the generator actually outputs AC - the revving up and down would imply that it's not just a synchronous generator. Also, when I hooked it up to an oscilloscope, it showed some kind of spiky noise at a few hundred Hz (nicely synchronised to the 50Hz sine wave) - so perhaps it's a DC generator running an inverter with voltage and frequency regulation?
The computers ran fine with the noise - but the UPS was suspicious of it and thought the incoming frequency was fluctuating between 50Hz and 80-90Hz, so kept switching to battery and back again. In the long run this would probably run the battery out, so I may have to build some kind of low-pass filter (at scary mains voltages and high currents!), just to stop it panicking.