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Saturable transformer works!
Gang!
I have been working in a frenzy today, to see if this Saturable
transformer works, or not, and to find out wether it is possible to make
it as I described.
Having no machineshop to instruct how to cut the cores ,-) I did that
with a hacksaw, and the resulting transformer can be seen on the url`s
below. Really lashed up, but who cares?
Http://home5.inet.tele.dk/f-hammer/setup.jpg
Http://home5.inet.tele.dk/f-hammer/sattrans.jpg
The transformer works great!
Since I didn`t have the gumption to cut whole cores, I did the
modification on 1/2 cores, so that the crossection got halved. This of
course alters the turns per volts of the core, but this doesn`t matter
in a experimental situation: I just give the 2 seriesed primarys enough
voltage till the transformer starts to draw current, and let that settle
the matter. This transformer is for 120 volts AC max. operation, because
at this voltage, the current draw starts to get big real quick :-).
This is no surprise, since the core area is halved and the primary turns
are doupled.
This also means that the stepup ratio of the transformer is halved, so
that 120 volts in gives me 500 volts out.
The shunt coil is a primary, positioned around both choke cores, which
in turn are made from 1 MOT core slit right down the midle of the center
leg.
Both power coils are the original secondaries.
The transformer does deliver power into a short , It doesn`t shut
completely down, after all, and I guess this is due to some leakage
inductance btwn the primary and the secondary.
Secondary open i get:
Primary current 0.3A -at- 120 volts
Secondary voltage 500 volts
Secondary shorted:
Secondary amperage: 0.130 A (this would probably drop to round 0.006 A -at-
10000 V unloaded primary.
To cater for my limited variac supply I made measurements at 100 pri.
voltage:
Secondary shorted:
Secondary amp: 0.08 but increasing to 0.4 with 10 amps into the choke
coil.
This is a 1:5 variation of the output current dialed in real nifty with
a knob on the lab supply: Great feeling :-)
So the consept works, but a special secondary has to be made, to get
voltages in the tesla coil league.
This has been a fun day, where my knowledge of transformers has been
increased tremendously.
Cheers, Finn Hammer