Re: [TCML] freau phase adjuster

[Futuret <futuret@xxxxxxx>]

Hi Bob,

The resonant rise is measured right across the motor leads.  As you turn the phase
shift variac, the voltage across the motor will change.  At some point the
voltage will reach a peak.  You want this peak to be above the 120V input
voltage by 5 or 10 volts (5 to 10 volts of resonant rise).  As you rotate the
variac knob, the voltage across the motor will start out at 120V, then it should
rise to 125 or 130 volts at some point, then it will fall below 120 volts as you
continue to turn the variac knob.  You may lose phase lock if you turn the
knob too far.  Some set-ups stay locked for the entire variac-knob range.
If you lose lock, then just install a mechanical stop, so you can't turn the variac that 
far during use.  Or just be careful not to turn the knob too far.  You may be
able to get by without any resonant rise, but it's more likely the motor will
loss sync-lock sooner as you rotate the knob.  More capacitance will give
more resonant rise.  Probably around 130uF to 200uF is what you need,
but I'm not sure about that.... needs trial and error to find out.  

Yes you'll see the disc pattern move using the flourescent or LED as
you rotate the phase variac knob.

http://futuret.110mb.com/index.htm

Cheers,
John

 

 

 

-----Original Message-----
From: robert massa <massahbob@xxxxxxxxxxxxx>
To: tesla <tesla@xxxxxxxxxx>
Sent: Sat, Jan 14, 2012 4:46 pm
Subject: [TCML] freau phase anjuster


   Have fabricated a mechanically sound srsg. 
Used a 1/3 hp 1750rpm 120v motor and milled 4 flats and it runs 1800 dead on. 
Can see it with flourescent and LED light.
 Figured that the phase shifter would be a snap as the schematic looked simple. 
Have a propeller type rotating 1/4" tungsten rod and 4 stationary 
contacts,120bps.  Hooked it to smaller TC and through trial and error got the 
prop indexed on shaft close. Due to the motor available there is no cradle to 
rotate in so will be slotting bolt holes in mounting to accomodate 1/8 of 
rotation. 
  Have been adding run caps 25uF to 250uF in various combo's 5 to 7.5uF at a 
time. I have white mark and can tell when in sync. 
  1) I'm not sure where the resonant V rise is measured and compared to what ? 
  2)  Should I be able to see the phase moving using fl. lighting or led ? 
  3)  Any suggestions on the amount of capacitance needed to make it shift ?
  Am using a 120/140v 5a variac in circuit.
                                         Thank you, Bob
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