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Microwave oven PWM frequency
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NiHaoMike:

--- Quote from: tom66 on June 25, 2020, 03:10:48 pm ---I've not, actually.  Is there a specific one I should use?

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Just plain JB Weld is rated to quite high temperatures.

--- Quote from: Yansi on June 25, 2020, 05:14:53 pm ---It already appears as a busy network channel already. It doesn't matter how did a packet got corrupted.
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Wifi has a mechanism for APs to tell each other that they're going to transmit in order to avoid collisions. If the microwave could act like an AP and tell nearby networks to avoid transmitting for some time, they'll wait until the microwave has finished outputting its pulse before trying to send data, thereby avoiding retries.
tom66:
I recall an industrial (i.e. chef's) microwave that used 915MHz RF.  I don't know if that's common in industrial ovens or not, or if it's any better at heating food, but it was interesting.  Probably only legal in the USA as 915MHz is protected in Europe.
David Hess:
900 MHz works fine for heating food and probably even better than 2.4 GHz.  Early microwave ovens in the US were 900 MHz.

The problem with 900 MHz is that there is no room for a choke ring in the door so metal finger stock is used instead to seal the door from RF leakage.  But the metal finger stock proved to be too easy to damage, especially in a kitchen, leading to problems with leakage.
tom66:
I've never heard of a choke ring.  I'm assuming that's a tuned antenna of some kind inside the door that helps reduce the emissions by shorting leakage?
David Hess:

--- Quote from: tom66 on June 28, 2020, 06:24:59 pm ---I've never heard of a choke ring.  I'm assuming that's a tuned antenna of some kind inside the door that helps reduce the emissions by shorting leakage?
--- End quote ---

It is something like that.  There is an open quarter-wave or shorted half-wave channel along the door seam which causes an out of phase reflection of the 2.4 GHz energy canceling out leakage.  Since it only works at 2.4 GHz and harmonics, this is why microwave ovens are not cheap substitutes for Faraday cages.
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