Re: microwave power settings

[brian whatcott <inet@intellisys.net>]

At 11:00 1/30/98 -0500, you wrote:
> A new thread:
>
> For a microwave oven, when one selects other than 100% power for cooking or
> defrosting, what is changed in the oven cavity?  
>
> Is the power level 100% for a smaller fraction of the duty cycle? i.e. does
> the magnetron spend less time "on" than at "full power"?
>
> Or, is the duty cycle a fixed fraction of run time but at a lower
> intensity?  i.e. is the magnetron "on" for the same time but emitting fewer
> photons?
>
> George Spagna           **********************************************

It is the former option.
The power supply to the magnetron is a rather rough and ready device
of a transformer rectifier combination, I believe.
 In appropriate "radar ranges" you can hear the ventilation fan and mode 
stirrer sag during the on phase, and recover during the off phase.
 It is in general cheaper to provide on-off (bang-bang) control rather than
proportional control in electronic devices - a question of the average
power expended in the control device.

 
brian whatcott <inet@intellisys.net>
Altus OK