Mike wrote:

"Ian Stirling" wrote in message
...
(If you manage to kill yourself or burn down your house as a
consequence
of this posting, I reserve the right to point and laugh).

Well I've designed a kW audio amp before and that could fry you without
thinking about it.

So what's the problem?
All you need is a 50Hz sine-wave oscillator, some lead-acid batteries, and
a charger

Actually inverters are nasty to design, because you never know what
somebodies going to plug in.
For example, a large series universal motor being repeatedly switched
from backwards to forwards, ...

And the load keeps changing unlike the amplifier. But I've already sketched
out what I think I'm going to build. Next stop the scrappy for some
batteries.

A car 'immersion heater' in a jamjar of water can make a usefull load to
test batteries with.