| Author |
Message |
Patrick Turner
Guest
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 Posted:
Thu Oct 27, 2005 5:14 pm Post subject:
Re: OT: Transformer from a microwave oven |
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Engineer wrote:
| Quote: | "Patrick Turner" <info@turneraudio.com.au> wrote in message
news:435B01B4.B1A50DE8@turneraudio.com.au...
Engineer wrote:
Hi, vacuumlanders.
(snip)
Can anyone think of something useful to do with this this
transformer.
All I can come up with is:
(snip)
After many years scrounging for parts for experimental circuits,
I found no useful purpose for microwave trannies.
Patrick Turner.
I've come to the conclusion that you are quite right! They don't
even have a usable primary since the magnetising current is far too
high at about 3 amps (120 VAC in and shunts removed.) I'd say it has
about a 30 VAC primary for about 2 1/2 turns per volt, hence a 500 VAC
secondary..
And too ugly even for an "object d'art"!
Cheers,
Roger
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Do you have a boat?
Do you need an anchor?
But against Wilma, not even old trannies are any good.
Patrick Turner.
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Andy Cowley
Guest
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| Posted:
Mon Oct 31, 2005 7:40 pm Post subject:
Re: OT: Transformer from a microwave oven |
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Patrick Turner wrote:
| Quote: |
After many years scrounging for parts for experimental circuits,
I found no useful purpose for microwave trannies.
|
3CX800 power supply? There must be a few other RF triodes or
pentodes that would like a couple of kV for the anode. A big
microwave x-former or two might be the core of a good linear?
They would also do audio but the output Xformer will cost.
best
Andy |
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Patrick Turner
Guest
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| Posted:
Tue Nov 01, 2005 7:58 pm Post subject:
Re: OT: Transformer from a microwave oven |
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Andy Cowley wrote:
| Quote: | Patrick Turner wrote:
After many years scrounging for parts for experimental circuits,
I found no useful purpose for microwave trannies.
3CX800 power supply? There must be a few other RF triodes or
pentodes that would like a couple of kV for the anode. A big
microwave x-former or two might be the core of a good linear?
They would also do audio but the output Xformer will cost.
best
Andy
|
Well perhaps but I would rather wind a new tranny.
And i have yet to build anything with a HV supply.
Maybe one day though...
Patrick Turner. |
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Guest
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| Posted:
Fri Nov 04, 2005 5:44 am Post subject:
Re: OT: Transformer from a microwave oven |
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Engineer wrote:
| Quote: | Hi, vacuumlanders.
I posted this to the NG "sci.electronics.design" but I think this
group may well have some good ideas, so here it is....
This may seem an odd post but I'm an avid re-user and recycler of old
and/or scrapped electronic stuff (especially tube equipment), so I
hope all will be clear...
I have just picked over the carcass of a dead microwave oven (free
junk from a church sale) to get a thermal switch to repair our main
unit, but that's another story...
I pulled out all the usable bits (not many!) but also the power
transformer. It has a 1.75 x 1,25 inch core, weighs 9 1/4 lbs, and is
120 VAC to a scary 1,925 VAC (measured off load.) The core has two
magnetic shunts between the windings to give, I think, a degree of
voltage regulation (I may be able to press or knock them out, but I've
not tried yet.) The 120 volt primary resistance is about 0.3 ohm; the
2 KV secondary is 115 ohms.
Can anyone think of something useful to do with this this transformer.
All I can come up with is:
1. Use two of them back to back as a bench isolation transformer (but
watch the 2 KV floating around!)
2. Use as the OPT for a weird single-ended tube amplifier with 3.8
Kohm plate impedance (rather low) to a 15 ohm speaker (forget about 8
ohm speakers - too low; also need to isolate the secondary from the
frame (easy enough to do).)
3. Use it with a voltage doubler or tripler for an electrostatic
filter (would not fit inside most units so serious safety engineering
required.) Much too big, though.
4. Run it off a suitable battery and interrupter (NOT AC mains!) to
power an electric fence.
5. Use it as a choke in a tube power supply. I'm not sure of the
secondary winding inductance or current rating. Again, isolate the
secondary.
6. Use to replace another failed one <g> Do they ever fail?
That's it. Thanks for all ideas.
Cheers,
Roger
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How's about a high current power supply?
http://www.users.qwest.net/~ptaylor/Electronics/MOTpowersupply/MOTPSpage.html |
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Guest
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| Posted:
Fri Nov 04, 2005 10:30 pm Post subject:
Re: OT: Transformer from a microwave oven |
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Jacob's Ladder......
Peter Wieck
Wyncote, PA |
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