Microwave oven hackery (was Modern Electronics, earlier List charter mods & headcount...)

From: der Mouse <mouse_at_Rodents.Montreal.QC.CA>
Date: Tue Jun 22 22:10:15 2004

[Tony Duell]
>> [failure modes]
> Most of the time it's the door interlock microswitches (one of them
> is _designed_ to short the mains if the others stick closed),

It's been a while since I had it open, but I'm fairly sure my oven's
door switches don't work that way.

[David V. Corbin]
>> 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".

Well, no; I never submitted an example for testing, so it can't be.

> [your solution APPEARS to have bypassed all of the safeties (door,
> etc.)).

I'm not sure where you saw such an appearance, but it is incorrect. I
may be crazy, but I'm not stupid.

I didn't mention them, because they were irrelevant to my story, but I
did not bypass the safety switches. They were not wired through the
PCB I removed; its _only_ connections to the rest of the oven were (a)
a power feed to run the electronics, (b) an SPST relay (or something
else being used as SPST) to control the fan, and (c) a similar relay to
control the magnetron. Oh, and a flexible-printed-cable to the keypad.
(The beeper was on the PCB.)

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Received on Tue Jun 22 2004 - 22:10:15 BST