Microwave circuit diagram?

Harry Bloomfield presented the following explanation :

Forget that one, it's sorted. The PCB tracks to the relays had been vapourised due to the fault current. All now soldered up and working again.

Incidently, it is the first modern microwave I have had to probe deeply into and try to fault find, with the unit both live and in cook mode - amid concerns of the microwaves leaking out all over the place. For future reference, the easy way to shut off the microwaves on this particular unit was to simply pull the mains feed onto the magnatrons primary winding of the transformer. That left all the control circuit working, which had its own separate miniature mains transformer mounted on the PCB.

To be honest I'd be very wary if the magnetron transformer was running given the voltage and stored charge in the voltage doubling capacitor and the power behind it!

I presume the circuit hasn't changed much over the years. I thought they might now be using switch-mode supplies.

Some are. It allows for proportional heating control, rather than cycling the magetron on and off, although proportional heating control was not found to produce better cooking results.

I once had an oldie with HT power switching, giving uncycled low power setting - ISTR it being an advantage only with things that bubbled up and set frothy (trying to remmeber what theyre called!)

NT

Scrambled Eggs?

Joking. Some microwave ovens had a low power setting, where an inverter magnetron reduced the radiation to the cooking cavity. I think Toshiba called it "Slow Cook" setting. It was good for scrambled eggs and actually baking sponge cakes, although the cake needed browning under a grill or in a conventional oven to make them look nicer.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember snipped-for-privacy@care2.com saying something like:

Soufflé.