22 Jun
2004
22 Jun
'04
5:54 p.m.
So I yanked the whole
thing, wired the fan and magnetron together (I almost always used it on
high anyway, and lower power settings worked by imposing a <100% duty
cycle on the magnetron), and controlled it with an ordinary wall light
switch, on the principle that it's too simple for much to go wrong.
A classic example of where a little knowledge can be very dangerous.
Definitely NOT "UL Approved" or "CE Marked".
Lack of detailed core issues, presents a situation which is potentially
dangerous. I would hate to think of the law suit you could face if someone
comes over to your house and a fatal error occurs [your solution APPEARS to
have bypassed all of the safeties (door, etc.)).
Very unlikely. At least in the UK, the interlocks on the microwave oven
door don't operate on inputs to the cotnroller board, they directly
switch mains to the magnetron transformer. That way, even if the
controller crashes (or the relay sticks, or...), the magnetron won't turn
on if the door is open.
My view (but I would wan to trace out a schematic to be sure) is that
it's perfectly safe to repalce the controller with a suitably-rated switch.
However, to tie this into the rest of the thread, I've seen some totally
lethal things by people who should know better (i.e. people with EE
degrees) and who didn't realise they were dangerous or that there was a
better way to do it. I am not talking about the sort of thing we've all
done on the workbench (mains on bare tags, etc while testing), I am
talking about finished devices with no earth, with earth and neutral
connected, with no isolation between mains and output, and so on.
-tony