Quote:
Originally Posted by DavidTrap
Les,
My basic understanding of generators (happy to be corrected by those with better knowledge of technical terms, etc):
The cheaper generators have a petrol motor connected directly to a generator that makes the AC power. That petrol motor must run at 3000rpm to produce 50Hz AC power. This is inefficient if you are using a large generator, eg >1kVA generator, but only drawing a small load (most astro setups would draw <0.5kVA (~500 watts). If you switch on a big load, the petrol motor takes a finite amount of time to ramp up it's output, so the voltage and frequency can vary - ie, the AC power is dirty. Because the motor is running at high speed all the time, they are usually noisy.
The expensive (eg Honda) generators use an inverter. The petrol motor turns a generator that produces DC power. This DC power is fed through an inverter to produce high quality, clean AC power. They are more efficient as the petrol motor can run slower and produce just enough power to meet your requirements. If you switch on a big load, the inverter can maintain a stable voltage and frequency of AC power (better than the cheaper generators) while the motor speeds up (not sure how ? capacitors??).
That's my understanding. I don't own a generator as I don't have need for one - fortunately all my observing sites have 240V. I'd definitely buy a Honda Inverter or equivalent if I needed one.
DT
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Sounds about right David. The Eu10i has an inverter to produce the 240V. As a consequence of producing DC power initially this allows a seperate circuit to charge batteries at 12V and 8 amps. With all my gear attached it revs at about 800 -1000RPM, virtually idle. It has an eco throttle setting which adjusts RPM to a given load. Honda have been very clever and the generator itself is part of the engine, not a seperate component and this is why they are so compact. Another clever innovation allows the gensets of the same type to be joined together in paralell to double the output. Mine is only a 1kV job but they also make 2kV and 3kV versions that are only slightly larger but of the same design.
Mark