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James Wilkinson Sword[_4_] James Wilkinson Sword[_4_] is offline
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Default Why do microwaves shut off 15 seconds early?

No, mine will do that too on low power, cycle on and off during the whole cooking time. But this is on full power I'm getting the 15 seconds off, only at the end. I hear the magnetron stop, and I've noticed the power consumption drops to almost zero (just enough for the light, fan, and turntable motor).

Testing.... doesn't do it on 1 minute cooking time. Or 2 minutes. It does do it on 5 minutes and 10 minutes.

Perhaps it's to allow frothed up food to calm down before the user takes it out?

I noticed something else while testing. It uses 1.45 kW to start with, then gradually lowers to 1.25 kW. I thought at first it was being clever and lowering the power as the food got hotter so it didn't boil over, but starting another cooking cycle with cold water or with already hot water changes nothing. It seems to use less power when the oven itself is warmer. The magnetron gets more efficient or tired perhaps?


On Sun, 25 Jun 2017 17:33:20 +0100, Brian Gaff wrote:

I think this only happens on lower than full power settings. This is because
a Magnetron has no power setting and the power is derived from the duty
cycle of ons and offs and often the off time is in work when the timer ends.
Brian