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Re: ganging up cheap generators

Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>

At 08:44 PM 1/7/2007, Tesla list wrote:
Original poster: <davep@xxxxxxxx>

> I notice that there has been a recent influx of very inexpensive
> imported generators.  Today's Sunday LA Times has ads for 2kW
> generators for under $200 and 3kW for $250.  Sure, these aren't
> electric start, they're probably noisy as all get out, and are not
> necessarily the most durable and rugged things.
> BUT, for those folks looking for a (portable) power supply for a
> bigger coil, and worried about zapping their home electronics by
> interconnecting to the mains power, this is interesting.  When the  coil
> is running, you'll probably not hear the generator.
> Another intriguing possibility is that one can conceivably
> interconnect 2 or 3 of these to make 3 phase power if you're running  a
> big DC coil.  Yes, one could go do a REAL 3 phase 9-10kW generator,  and
> get better performance, but I'll bet it would cost more than the  $750
> it would take to buy 3 of the 3kW imports.
> OTOH, maybe there's also cheap imported 3 phase generators.
      Paralleling power sources, especially ac sources, needing
      phase, frequency AND voltage all to track is very
      tricky.   Getting three of them to run stably 120 degrees
      away from each other is trickier yet.

Actually, with a suitable zigzag transformer, apparently synchronization is no worse than just paralleling them.

Frequency/phase takes care of itself (the generator that wants to run a bit fast takes more load, slowing it down). There IS an issue when throwing the switch to connect them. Amplitude is a matter of regulators and throttles.

      For three phase, I'd go with option OTOH....