[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

John Freau's phase adjuster- a few questions



Original poster: Tesla729-at-cs-dot-com 

Hi all, (esp.John),

I have been putting together a Freau phase adjuster for my big coil
system, since I have a salient synch 3600 RPM Wysock rotary gap.
The motor is 1/2 HP and I am using a 140 volt, 10 amp variac that I
modified so that the variac is simply a series inductance with the mo-
tor/capacitors inastead of the 120 VAC in, 0-140 VAC out setup. Any-
who, I am using (2) 100 uFD, 370 VAC run caps plus a single 15 uFD,
240 VAC run cap for 200 or 215 uFD. I put the voltmeter to the terms
of the motor input and looked for the resonant rise in the range of the
variac's knob. At first the voltage does decrease a bit after the variac's
inductance is added to the circuit (about up to 20 on the 0-140 scale
of the knob) but then does begin to increase slightly between about
25 and 60 ( w/ 200 uFD - about 70 w/ 215 uFD) on the knob. I never really
got a 3 to 5 volt increse in this range, more like a 1.5 to 2.5 volt increase
(it was kind of hard to get an exact voltage change amount as my
lines voltage constanly varies by a couple of volts). Anyway, is a 1.5
to 2.5 volt increase good enough or does it need to be at least 3 volts?
I can hear the motor changing phase a little by its sound, so I must
assume that it's at least partially working. Even increasing the cap
to 230 uFD (I have about (25) of those 15 uFD, 240 VAC caps) didn't
seem to change the voltage from resonant rise by more than 2.5 volts
or so, but the higher capacitance did seem to extend the phase adjust
range on the variac knob as well as not allow the voltage to drop as low
from the initial adding of variac inductance in the 0-20 range of the knob.
If I turned the variac knob up too high (past 110 on the knob) the motor
would suddenly start slowing down and bringing the variac knob back
toward lower inductance would cause the variac to make an awful hum-
ming sound until the motor finally reached back up to it's full speed. Is
this the "self braking" that John was referring to?)

Also, I placed a 10 amp fuse between the capacitor(s) and the line hot
from the line voltage supply to the motor and it worked fine when just
running the voltage from the phase adjuter to the motor via an extention
cord (100 ft), but blew the 10 amp fuse twice in a row when I ran the voltage
via the grounded shielded nomex (18 ft) from the cap to the motor. I wonder
if the "Blumline effect" is possibly causing this? I finally placed some foil
around the fuse since I didn't have any more 10 amp fuses handy. Funny
thing, though, the 10 amp (or maybe 15 amp?) fuse in the variac itself
nevre tried to blow, even after defeating the phase adjuster fuse w/ the foil.
Any help/expertise would be greatly appreciated :^)

David Rieben