Re: MOT secondaries

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "David Speck by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dspeck-at-relex-dot-com>

Ben
The first secondary (with the very heavy wire, and 3 or 4 turns) that you
mention is the filament
supply for the magnetron.  It puts out about 5 volts, depending on the tube
used, at a number of amps,
and isn't much use in TC work.  You can tape the ends and ignore it.

The HV winding is made of the finest wire on the transformer.  One end is
grounded to the transformer
core, and the other end usually goes to a 1/4" Faston tab.  This winding is
where you get your HV, but
remember that the tfmr core is hot.  In a standard Microwave application,
the metal chassis is part of
the circuit, and you'll frequently find that the doubling diode also has
one end connected to the
chassis ground.

Most microwaves have their schematic glued to the inside of the case.  You
can study it to figure out
how they implemented the doubler circuitry.  In many more modern ovens, the
diode is inside the case
of the capacitor, and part of the circuit is the grounding of the case to
the chassis.

Just study the schematic of the particular MO that you are harvesting, and
you should be able to
extract the HV doubler circuit without a lot of trouble.  You may have to
supply a wire from the
transformer frame to the cap case to imitate the presence of the chassis,
but that's about all that
would not immediately be obvious.

HTH,
Dave

Tesla list wrote:

> Original poster: "Ben McMillen by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <spoonman534-at-yahoo-dot-com>
>
> Hi all,
>   There's one thing about MOT's that I don't understand.. There seems to be
> 2 secondary windings.. The first is quite obvious.. the two heavy wires
> that connect to the magnetron.. but then there's a second winding, one end
> of which goes to the core and the other to a spade lug.. What's this one
> for? Does it have something to do with the voltage doubler part of the
> setup? Is there anything that can/should be done with this? (As in, does it
> pose any kind of potential hazard and could it be modified to give more
> output voltage?) Thanks for any info..
>
> Coiling in Pittsburg
> Ben McMillen