Use of Microwave Diodes

On Tue, 09 Jun 2015 07:46:28 -0500, amdx Gave us:

A "MICROWAVE" oscillator does not operate at 60Hz, you absolute idiot.

The HV in one is not at that cycle count either, you clueless idiot.

On Tue, 09 Jun 2015 10:23:47 -0400, krw Gave us:

How are those "20 times a day" cardio readings going, punk?

Bwuahahahahahaahahahahahah!

Yeah, I am laughing alright... at your dying.

I am not so sure the diodes will not work at 20 khz. Way back in the 1960's I know there was a circuit that used regular rectifiers at 81.6 khs. Sure they were not as efficient as diodes that have a faster recovery, but they still worked.

At 20 khz the period is 50 usec or 25 usec per half cycle. The microwave oven hv diodes are almost sure to have a recovery time of 2 usec or less. Sot hey should work well.

Dan

Quite well, DimBulb. Usually about 48bpm, but sometimes lower. Thank you for asking.

They're coming to take you away...

We're all dying, DimBulb. Well, all the living, anyway. I suppose that may not include you.

oven hv diodes are almost sure to have a recovery time of 2 usec or less. Sot hey should work well.

Okay, I did a little diggirg on the internet and found one data sheet for a 1n4007 that specified the reverse recovery time spec as 30 usec max. I su spect current production is much less. That data sheet specified using a T ek 545 scope for the measurement.

And I found another web site that showed testing a 1n4007 and the recovery time was 3 usec.

So try the microwave oven diodes. I think they will work, but it depends o n the diodes you have and the circuit you are using.

Good luck.

Dan

Cheers

Phil Hobbs

A perfect record of being wrong again.

Oh boy, I had stopped clicking on Dec's posts, but when I read your post, I had to go back and see if he really said that. He did. Oh boy! Mikek

On Tue, 9 Jun 2015 13:01:21 -0400, "Tom Miller" Gave us:

The HV rectifier in a microwave does NOT operate at 60Hz.

You are wrong to think it does.

This looks typical:

Many modern ones are switchmode, without big heavy 60 Hz magnetics. They can do better RF power control than on/off.

Only in a microwave oven that uses an inverter HV power supply would you stand a chance at being right. Any oven that has a HV AC transformer operates at 50/60 Hz and the diode would be the cheapest available and not have the reverse recovery time to operate in a faster circuit.

Still, with the OP using a diode from an older microwave oven, puts you "wrong again" and maintains your perfect record of "always wrong".

Perfection is hard to find these days.

On Tue, 09 Jun 2015 13:22:43 -0700, John Larkin Gave us:

Said the idiot who thinks/said that nothing moves in an LCD 'pixel'.

In over 90% of microwave ovens it does

NT

I rather liked the "not that cycle count" wordsmithing, myself. Perfect Dimbulb.

On Tue, 9 Jun 2015 14:44:39 -0700 (PDT), snipped-for-privacy@gmail.com Gave us:

It wouldn't need to be an HV diode if it were that way.

The HV in the microwave isn't made at line frequency.

Nor is it rectified at it.

When you reach the bottom, you should stop digging.

During one half cycle, the capacitor charges via the diode plus transformer secondary. On the next half cycle, the capacitor and secondary act in seri es - doubling the voltage. At some point the magnetron bursts into oscillat ion at 2.4GHz and does a bit of cooking until the voltage falls too low.

Next half cycle, the game starts again.

The transformer's design, value of the HV cap and current drawn by the magn etron are carefully balanced at the AC supply frequency (50 or 60Hz) so the load is the same during both half cycles too.

.... Phil

... Phil

all 3 incorrect. well done.

NT