Mod Reactors from HV PS Xfmrs?

[wavebourn]

Microwave transformers have a magnetic short-cut, so they are acting as a transformer with a series choke.   ...They usually have one side of a secondary high voltage winding grounded, so it's problematic to use them instead of just ordinary chokes.

Magnetics and magnetic coupling are interesting subjects.  I am guessing that magnetic shunts produce a current limiting effect in these transformers, and possibly a voltage limiting effect as well.  It certainly makes them tricky to use.

Not exactly like a current limiting, just as a higher output impedance, like a transformer with a choke in series already connected. One full wave rectifier may be made from 2 microwave ovens. I suppose, they will supply with half of a kilowatt of a plate voltage. :lol:

[Bacon, WA3WDR]

Not exactly like a current limiting, just as a higher output impedance, like a transformer with a choke in series already connected. One full wave rectifier may be made from 2 microwave ovens. I suppose, they will supply with half of a kilowatt of a plate voltage.

Hmm, really high leakage inductance.  Or maybe a choke input?  It might give poor regulation with a varying load, but the idea of a cheap high voltage transformer is appealing.  I could use two, and put one primary winding on one side of 220VAC, and the other winding on the other side.  If I can't make the amplifier work, I could at least cook two TV dinners!

[Ian VK3KRI]

I helped a guy design a C.V. transformer once. The Shunt and resonant winding with cap had a big effect ot voltage regulation dynamic range.
Then we had to make it work at 50 Hz. Very interesting stuff.

Hmm. Thats interesting. I have a 250Watt 50 V DC supply here (good for testing MOSFET amps!) that has some sort of regulation that is frequency sensitive. It certainy seems to regulate pretty well for no active components, but Ive always wondered if it should draw as much current as iit does with no load. Is that normal for these CV transformer thingies

                                    Ian VK3KRI

[WA1GFZ]

I have a big lorain 48 volt supply on  my test set up for the 75 meter final.
They all want to see a minimum load to stay in regulation. I'm sure your unit has an internal load resistor. A bigger cap will also help regulation. fc

[WD8BIL]

I have a big lorain 48 volt supply on my test set up for the 75 meter final.

Hey Frank. What's the model number of that Lorain supply ?

Lorain Products is now Emerson Network Power.
My employer !

http://www.angelfire.com/blues/wd8bil/WORK.html

[w3jn]

I picked up a mambo-jambo regulated DC supply at Dayton last year 0-175V at 20 amps (!) - takes 220V input and uses a saturable reactor for regulation.  THing I don't like about this unit (other than its 100+ pound weight) is the talkback from the reactor.  I have no skizmatic and the voltage jumped all around... found that putting a load between the remote sense input and ground stabilized it somewhat.

Would make a superb class E supply, which is what I bought it for.  It's even fairly compact, only 6" high rackmount.

Anyone know why the reactor and/or xformer talks back so much?  There's a FB 2 KHz squeal that's pretty annoying.

73 John

[WA1GFZ]

Bud,
I will have to check at home but would like a schematic.
It was used in a phone system C.O. to charge batts. 48V 30 A.
Very well built! I use it as a test supply for the class E 75 meter final.
I've had the final making 1200 watts carrier so DC power was up around 1400 watts. The output is fairly stable in CW mode.  fc