On Sat, 14 May 2011 19:19:28 -0400, "Michael A. Terrell"
wrote:


mm wrote:

On Sat, 14 May 2011 16:35:53 -0400, "Michael A. Terrell"
wrote:


mm wrote:

Can a microwave oven have its output controlled, limited, by something
like adjusting the AGC on a TV? Or on combo devices, radio,
cassette, CD, tv, there is usually a pot on each of those, adjusted so
the volume stays the same when one changes functions.

I didn't like my old small microwave oven because it was so small, and
I also had to cook longer than instructions said, because it was low
power. (So I was in the habit of mulitplying the time given by 1.1 or
1.3, but I was hoping not to have to do that anymore.)

Now I have a new, one-year old, full-size Sharp microwave -- I can
provide the model number if it matters -- and it is too powerful.
Things cooked in their packages according to instructions have their
water boiling over and taking some of the food with it, and I presume
other food is being cooked more than instructions or recipes call for.

It has a power control that will lower the power by 10% for every push
of the button, but I would have to use that button every time.

I can see how this is ambiguous.

Is there any chance I can turn the full power down by 10%, for every
use?


Can you write code for the microprocessor in the control panel? The

No.

power function is hard coded into the controller.

I didn't have in mind changing the power function, but changing the
circuit that makes the microwaves. Maybe at the stage at or just
before the microwave tube. So they would be weaker. By changing
the bias on the output transistor, or something like that. I was
hoping there might be a pot there already.


Magnetrons don't work that way. They run at full power over their
useful life. That's why they have to use PWM to control the average
power level.

Makes sense. Okay. I'll give up the plan. That's one more thiing I
don't have to do.

Thanks again.


The power function would still work, turning the radiation on X% of
the time and off 100-X% of the time.


(As an aside, it's interesting that on 90% power, for example, I can
tell when the microwave part is functioning because it makes more
noise during the 90% than the 10% of the time.


That is a form of 'Pulse Width Modulation'.

Good to know.

Thanks.