Vfd info

That controller is for a DC motor. My Hardinge lathe uses the same design power supply for the DC carriage feed motor. It feeds full 110 volts to the fields and varies the armature voltage for speed control. With full field voltage the motor can produce more torque at slow speeds than ones that reduce both armature and field power.
The field power should be steady, and I would expect 110 v.
I don't see what I would recognize as a rectifier in the picture or the circuit so it may be AC output.

Greg
 
I didn't know there were controllers that vary the field. But yes normally the field voltage should be steady. Be a simple matter to add rectifiers to it though
then you could use it with a dc permanent magnet motor, or a shunt wound type with a field. Can you post a picture of that Baldor motor you want to use?
Mark S.
 
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That varac xformer should be able to handle about 10 amps. Those two blue round looking things are your SCR's. There's also a fuse in the bottom of the box, according to the schematic is F2. What is the amperage of it? I suspect, this fuse is to the amature, which shoould be a higher amperage than the one on the front cover. The one on the front cover is probably for the field winding. One amp would be just about right on a fractional rated motor, probably not over 1/4 HP. Of course, this is depended on the amp rating of the other fuse. And , yes, you should be able to hook up a PM motor to this controller. Just connect to the amerature connection only. Leave the field connection open and not hooked up to anything.
 
I don't know about 10 amps Ken, I was thinking more like 3; it doesn't look that big. But yes if those are SCRs then it can be used as is
Mark
 
for what its worth, my 2 cents worth
This is not a VFD (variable frequency device)
This was built before SCR (silicon controlled rectifiers) were in wide use
There appears to be something that looks like a full bridge rectifier in the light blue round thing with 4 attachments.
I don't think that the variac is capable of 10 amps
This device was manufactured before the postal zip codes were more than two numbers (before 1963)
I wouldn't trust the large electrolytic capacitor for being any good after all this time

Just thinkin which these days is getting harder and harder'

CHuck the grumpy old guy
 
I was thinking SCR, I thought that they were that time frame.. I guess not.
was looking for the stacked set of disks, certainly not diode at that time.
Enough ranting, I don't have enough knowledge..
 
Corrections
OK SCR's were just getting started by '63 but there appears to be no such thing in the box. They were rather large (large peanut sized (without shell))
looking at the front panel, and the schematic, the blue disk is a 3 way switch not a rectifier bridge.

Grumpy old guy
 
Looks like a DC motor control to me. This control/supply has two DC outputs. One output is for the field (fixed DC). The other DC output is for the armature (variable). Those blue things are bridge rectifiers, CR1 & CR2. The smaller one is for the field and the bigger one is for the armature. That brown cylinder thing is probably an electrolytic capacitor. Sorry, it's not a VFD...Dave
 
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Bridge rectifiers!!! That's what I meant, not SCR's. Thank you Dave.

Mark, yeah, variac is probably good for 3 amps! You are likely correct!

Used to use some about that size that would handle 10 amps. Of course, that was on 240V. Used them to power the field windings on BIG DC motors! Even bigger one's for the field voltage voltage on the M-G sets. Only did this because the owner didn't want to spend the extra $$$$ for SCR controlled motor controllers. We ran motor-generator sets to run those big DC motors.

Getting too old for this stuff!
 
OK! the round blue thing is a rectifier bridge, not a switch, I looked at it and figured out that it was on the other side of the door that had a F-off-R switch on it
switch on it and totally missed the point that the thing was on the back of the box, not the door. Duh.
 
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