Given the parlous state of Australia's power systems, I've been
considering buying a standby generator. One marketing point of some of
the inverter bases models is their suitability for 'sensitive
electronics' with computers given as an example. This appears to be
based on the fact that they'll provide a consistent sinewave output.
But given that computers invariably use switch-mode power supplies, are
they actually going to care what waveform they see - from square wave
thru 'modified sinewave' thru pure sinewave?
Sylvia.
Regarding "inverter" generators:
Honda (and possibly others) now offer generators with an inbuilt
sinewave "inverter" in
order to provide high quality power (presumably crystal locked to
50hz) for sensitive
equipment regardless of generator motor speed fluctuations etc.
This would also allow lower engine speeds at low load to save fuel,
without affecting the output frequency
http://mayberrys.com/honda/generator/html/invertgenerator.htm
Another advertised advantage of this system is the ability to link 2
of these
units together in parallel via a special cable (available from Honda)
in order to increase the total output capacity.
This would probably have extra wire(s) to ensure the inverters outputs
are synchronised, their output voltages as close as possible to each
other to keep the load balanced between the 2 inverters/generators ?
http://mayberrys.com/parallel/parallel.htm
this provides 30a @ 120v (equivalent to a 15A 240v socket.) (note -
this is for US use only, there would be an Australian version.)
The other advantage that this dual system MIGHT have is the ability
to keep critical equipment in the home (such as life support) running
in the home if one of the two generators fails, as long as the total
load is sufficient for one unit.
(NOTE: I don't want to go round giving advice on this, or saying its
100% foolproof, or legal, or safe in case Im wrong and someone is
hurt or dies, please seek expert advice from the supplier or
manufacturer or other expert before using or relying on this or any
other method of powering life support)
For most people, I think this sort of unit would be an good choice for
occasional temporary emergency home use of lighting, computers, phone
charges etc etc and you can be sure it will run ANY sensitive
equipment just as well as off the mains. Gas rings would be more
efficient for cooking, boiling water etc.
Trevor's comments on selecting a generator should be noted also.
regarding large loads, fridges air cons etc,
2 problems I can recall with use of non-mains power are :
Note there was a letter from a reader in silicon chip recently
regarding use of a generator powering a battery charger on a boat, the
battery charger wouldn't start at all with one particular generator
(probably because of low quality or noisy power) and worked perfectly
with another.
Another problem I have had personally is with my Dewalt cordless drill
I bought in the 1990s when they first came out.
It charged perfectly on the mains, but wouldnt charge on a modified
square wave inverter (note: true sine wave inverters/generators
wouldn't give this problem) we used in the work van. IT turned out to
be a "series capacitor" type power supply (transformerless).
Fortunately it charged pretty fast compared to the older cordless
drills, and armed with a spare battery we just charged it off the
mains at places where we were doing jobs.
These are examples of where a TRUE SINEWAVE inverter generator would
be of benefit.
I dont think a PC would need this and would work happily off a square
wave or modified square wave inverter (this is what most UPS provide.