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Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
lpfthings wrote ...
Yeah I realise that, but it still could be some fun to play around with while I wait to play with the HV and convert it.
Would I need any ballasting? or is that only hen you are doing something like directly shorting the HV windings?
you don't need any ballast if you don't trip the fuses from inrush current. Just be aware of not coming close to it while its running, the HV output will be "active" nonetheless...
Registered Member #1630
Joined: Sat Aug 09 2008, 11:36AM
Location: Seoul Korea
Posts: 115
Dr. Kilovolt wrote ...
Well.. this is the sort of thing I would expect to c in a 1000W microwave (and I do NOT call this a big MOT )
Yours really looks like its of the smaller kind.. but anyway it COULD be good for 1000VA with fan cooling.
You'll be surprised how much these can draw.. it is only 1000W because there is a cap that prevents it from pulling the amount of current. ( most ovens use the capacitor to ballast. Yes there are shunts in the xmfr but they aren't good enough alone. TRUST ME .. I know a lot about MOTs, and have taken apart many! That is a large MOT from a old early 90s Microwave oven. Output of those one is around 2.5Kv @ 650-800mA without the cap. With the cap you will pull around 2.5Kv ~500mA There are larger mots but they are from early -mid 1980s, and these ovens had a diode inside the capacitor which is connected to the case of the oven. capacitor is grey and has a diode symbol on the case.
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
I know how much they can pull, this particular one will draw up to 25A from 230V. But this does not have anything to do with the thermal rating of the transformer, meaning it will overheat within 30 seconds.
Registered Member #1630
Joined: Sat Aug 09 2008, 11:36AM
Location: Seoul Korea
Posts: 115
Dr. Kilovolt wrote ...
I know how much they can pull, this particular one will draw up to 25A from 230V. But this does not have anything to do with the thermal rating of the transformer, meaning it will overheat within 30 seconds.
right.. but that's the other part I wanted to say.. they will overheat quickly because of the shunts, the core can handle the Amps as you have observed (25A).. that's why the shunts alone won't help. When I made my PSU these were under several Ls of Shell Dialex oil... I popped all the shunts out the XMFRs and took out the filament windings. I could run 6KVA with a 5 stack no problem. Very little heating.
Registered Member #1408
Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679
Be smart and make a nice long chicken stick and see what she throws out with the cap. The really big ones come from the commercial units. THOSE occasionally have caps beyond 2400Vac.
Is that a rabid dog with fangs or the estrogen enraged elephant? I can't remember ? Either way they go have the ability to "move".
Registered Member #1630
Joined: Sat Aug 09 2008, 11:36AM
Location: Seoul Korea
Posts: 115
quicksilver wrote ...
Be smart and make a nice long chicken stick and see what she throws out with the cap. The really big ones come from the commercial units. THOSE occasionally have caps beyond 2400Vac.
Is that a rabid dog with fangs or the estrogen enraged elephant? I can't remember ? Either way they go have the ability to "move".
Or, older big microwaves from 80s. some of those have XMFRs up to 3-4Kv. You more than likely WILL NOT find any of those around anymore.
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Help with dissecting a MO?
(and I do NOT call this a big MOT 
)