REDUCE THE POWER BY REDUCING THE DUTY CYCLE BY VARYING THE ON-OFF TIMES.
YOU SHOULD NOT BE PLAYING WITH MICROWAVE OVENS IF YOU DONT UNDERSTAND PULSE
OPERATION. WHEN YOU DROPPED THE VOLTAGE, YOU ACTUALLY HURT EFFICIENCY. IF
YOU HAVE LIMITATIONS ON THE MAINS SUPPLY, GO WITH A SMALLER MAGNETRON. I.E.
CHECK THE LABELS BEFORE YOU BUY. MOST CONSUMER MODELS PULL BETWEEN 8-15
AMPS DURING THE ON CYCLE. i SAW A CLAMP ON AC AMMETER FOR 20 BUCKS
RECENTLY. TRY BEFORE YOU BUY.


JIM, ac6tk
Technical Consultant
http://tekstuff.freespaces.com


"Scott Dorsey" wrote in message
...
WD=?ISO-8859-1?B?2A==?=HCO wrote:
OK I NEED HELP - REALLY I DO ...

I AM PLAYING WITH A MICROWAVE OVEN -

WOULD LIKE TO REDUCE THE POWER OUTPUT OF THE MAGENTRON -

AS IT IS - IT IS SETUP FOR 600 WATTS PULSED ERP - THAT IS SHE PEAKS AT
600
WATTS 60 TIMES A SECOND -

ANODE VOLTAGE IS 4500 VAC THROUGH A 125 VAC STEP UP TRANSFORMER.

I WANT TO KEEP THIS VOLTAGE BUT WANT TO REDUCE THE CURRENT TO REDUCE
POWER.

You can't do that. From the supply side, the magnetron is basically a big
diode. There is no grid. All you can do is adjust the voltage across it,
and the current will follow.

ANY IDEAS ? ALREADY TRIED A VARIAC ON THE PRIMARY - IT REDUCED VOLTAGE
BUT
DID NOT REDUCE POWER UNTIL THE MAGNETRON STOP OSCILLATING COMPLETELY.

Right. It's not really intended to operate over a very wide range.

There _is_ an article from Radio-Electronics in the mid-nineties on
those things... they give some methods to modify them and to get them
operating well out of their normal regime. Detuning it may be the
easiest way to reduce the output level.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."