Before I throw out an old microwave....

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A big, 20 year old, quality microwave went kaput....  I think.  Convection,  
all the bells/whistles, GE.
Anything worth salvaging, of diy-er value??   The klystron is proly too  
dangerous to fool around with, but man, what a honkin xsformer in there.  
What's the secondary?  Klystrons need such xsformer poundage??

I have the working innards of another microwave, but don't know enough about  
them to fool with them safely.  Mebbe I'll give it to my neighbor's kid....  
No, No, just kidding.....   lol
--  
EA





Re: Before I throw out an old microwave....
On Friday, January 4, 2013 6:24:48 PM UTC-6, Existential Angst wrote:
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The outer coils ( high voltage windings) will strip off easily leaving a primary
and core you could add a few turns to for a spot welder supply...  

Re: Before I throw out an old microwave....
On 1/4/2013 4:35 PM, Cross-Slide wrote:
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Don't forget to take out the magnetic shunts.

Re: Before I throw out an old microwave....
Transformer $0.34/lb

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Re: Before I throw out an old microwave....
On Fri, 04 Jan 2013 19:24:48 -0500, Existential Angst wrote:

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Secondary voltage is around 1000V.  It's perfect for, well, a microwave  
oven.  Not much else, though -- they're kind of optimized for the job  
they do (see Mike's comments about the shunt).

--  
Tim Wescott
Control system and signal processing consulting
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Re: Before I throw out an old microwave....
Shucks, I have tubes that run that all day long.

But I'm not running TV or radio tubes.

The secondary is easily cut off many of the designs.
It is normally replaced with a high current few turn
winding.  As in the spot welder. Or destructive fuse tester. :-)

I have a 22 amp 5v transformer that I use to heat the filaments
of high current thyatrons.

Martin

On 1/5/2013 10:18 AM, Tim Wescott wrote:
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Re: Before I throw out an old microwave....

Martin Eastburn wrote:
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   Some water cooled UHF tetrodes i worked with had a pair of 1.5, 1000A
filaments.  You had to balance the filaments to minimize hum in the
output, so they used a pair of copper bus bars as resistors.  They had a
stud embedded in each end, and lock nuts to stretch them to raise the
resistance so they could be matched to under .1 Volt difference.  
Probably several hundred dollars worth of scrap copper these days.

Re: Before I throw out an old microwave....
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ction,
out
....

Not klystron, magnetron.  There are two donut ceramic magnets on the
magnetron, sizes vary,  but have fairly hefty pulls.  Can be re-
purposed for a lot of things.  Have one on the 4x6 gearbox as a
particle trap and wrench holder, slap one on the drill press head to
hold the chuck key, I use any number of them for the maggie-in-a-
baggie trick for picking up steel shavings. Newspaper bags are long
enough I don't have to bend over.  Useful for a bunch of things.  My
dad used a bunch of them for holding a windshield cover on during the
winter, saved a bunch of scraping after snow storms.

If you feel destructive, you can pull the magnetron apart.  There's a
solid copper puck with a bunch of holes in it that could go as copper
scrap.

Usually is a small motor or two, one for the stirrer at the top,
another for the turntable at the bottom.  If it had a convention oven
feature, there's a heater element, controls for same, blower/fan.

Only gotcha is that there's a HV cap somewhere in there, put a
screwdriver across the terminals(insulated handle, of course) just to
make sure it's discharged, then pull it.  The unit is now defanged.
Cut the cord off the unit.

Stan

Re: Before I throw out an old microwave....

Stanley Schaefer wrote:
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   Some microwave oven Magnetrons have a high temp ceramic made with
Berilium Oxide. They are safe as long as you don't do anything stupid
and turn it into dust. If you do, it can kill you.

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