anatech said:
It's gone almost 'throw away' now, the main faults are failure of the cheap and nasty chinese LCD displays, usually they go blank or lose some of the digits or segments. The only thing you can do is change the entire module, and it's really too expensive to be cost effective! - so only warranty ones get done.
Microwave repair is only a minor part of my job, mainly it's TV's etc.
Over the years I have probably dragged almost 100 discarded microwave ovens home and parted them out. The magnetrons are a terrific source of two awesome fridge magnets and the transformers make good weights for woodworking, or a cores for low voltage filament transformers (except for the eddy current heating issues, the cores are welded).
I even built a working radar telescope that can bounce an echo off the moon with the magnetron from one of these ovens. I formed an organization called MOMMBA (Microwave Oven Magnetron Moon Bounce Association), and as someone suggested, yes they are great for tesla coil power supplies. I used one to get a big furry 22" discharge of RF plasma from an 833A tube operating with a bright orange spot on the plate. http://www.area31.org/833mag01.html
I even built a working radar telescope that can bounce an echo off the moon with the magnetron from one of these ovens. I formed an organization called MOMMBA (Microwave Oven Magnetron Moon Bounce Association), and as someone suggested, yes they are great for tesla coil power supplies. I used one to get a big furry 22" discharge of RF plasma from an 833A tube operating with a bright orange spot on the plate. http://www.area31.org/833mag01.html
Heh,ya mean somebody actually found my website? 
Don't Fool with MOT's -seriously!
1500V+ and 500ma+ is NOT a toy.
The MOT power supply works great!
I've run several car amplifiers from it at once,jumpstarted the car,charged batteries,etc. It's a great little high current supply!
Crude,and ugly,but it works nicely!
The shunts in the core cause it to run warm,you could remove them if you like,But I decided to leave them,thinking it might help add a bit of crude regulation.Ohh,the welds too.
The voltage is fairly steady,but it does sag under heavier loads. The massive cap bank pretty much takes care of any hum issues.
I don't have a fan on mine,but a small 12V fan wouldn't hurt.
I left the old filament winding on there,since it was over the 120V primary.Plus,since it was wound with like 6 or 8-gauge solid wire,it could be kinda hard to remove!
This particular transformer came from an Oolldd microwave,with the timer and bell.(I think the tag on the back said 1976?) It's MUCH larger than most MOT's I see around today,and I think the micro it came from was rated 1200W.
Ohh,and be careful of the capacitors in microwaves!
They *usually* have a built in bleeder resistor,BUT-Do Not Trust It! it may have gone "open"....test with a meter,or resistor discharge lead,etc. before putting your hands inside! BE SURE it's discharged before you touch anything!
Don't Fool with MOT's -seriously!
1500V+ and 500ma+ is NOT a toy.
The MOT power supply works great!
I've run several car amplifiers from it at once,jumpstarted the car,charged batteries,etc. It's a great little high current supply!
Crude,and ugly,but it works nicely!
The shunts in the core cause it to run warm,you could remove them if you like,But I decided to leave them,thinking it might help add a bit of crude regulation.Ohh,the welds too.
The voltage is fairly steady,but it does sag under heavier loads. The massive cap bank pretty much takes care of any hum issues.
I don't have a fan on mine,but a small 12V fan wouldn't hurt.
I left the old filament winding on there,since it was over the 120V primary.Plus,since it was wound with like 6 or 8-gauge solid wire,it could be kinda hard to remove!
This particular transformer came from an Oolldd microwave,with the timer and bell.(I think the tag on the back said 1976?) It's MUCH larger than most MOT's I see around today,and I think the micro it came from was rated 1200W.
Ohh,and be careful of the capacitors in microwaves!
They *usually* have a built in bleeder resistor,BUT-Do Not Trust It! it may have gone "open"....test with a meter,or resistor discharge lead,etc. before putting your hands inside! BE SURE it's discharged before you touch anything!
Annoying it?
It will run warm even with no load due to the shunts/welds in the core.
It will also buzz a little bit,but not too much.
They'll heat up and buzz more with a heavier load.
100-200W is a breeze!
I've drawn several hundred watts for fairly long periods from the one I rewound for 12V..I'd suggest a fan if you're attempting this though,the core gets pretty toasty after a while.
Not the most efficient way to get (up to) a kilowatt of 12Vdc,but it works.
It will run warm even with no load due to the shunts/welds in the core.
It will also buzz a little bit,but not too much.
They'll heat up and buzz more with a heavier load.
100-200W is a breeze!
I've drawn several hundred watts for fairly long periods from the one I rewound for 12V..I'd suggest a fan if you're attempting this though,the core gets pretty toasty after a while.
Not the most efficient way to get (up to) a kilowatt of 12Vdc,but it works.
Tekko said:
Yes, but only a very small number - they also tend to be very expensive, both to buy, and to repair! - if the magnetron fails it very often wipes out the SMPSU as well!.
It's easy to tell which you've got, a SMPSU one will have it clearly labelled as such on the front (no good buying a very expensive oven if people don't know what you have!). Or you could just pick it up!, the weight difference is amazing!.
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