KB Electronics KBIC-125 schematic

[Jester]

Does anyone have or no where I can get a schematic for a KBIC-125 DC motor drive?

The drive I have is OLD dated 1987

It actually works fine, I want to drive the speed with a dc voltage instead of the external POT and seeing how the pot is connected in the actual circuit would be helpful.

Thanks

[jpanhalt]

After a bit of a search, I found an extra, new KBIC-125 that I bought in about 2003.  I never throw away the manuals, but I couldn't find this one. (My stuff is spread currently between 2 houses 42 miles apart.)  But, I did pay $50 for it.
Attached is a picture of the installation on my Prazi miniature lathe.  I also found this online:

The KBIC® can also be operated in a voltage following mode by supplying an isolated analog signal (0 – 9VDC) to the input
terminals P2 (+) and F-.The controls are terminated as standard with Q-D terminals.

As I recall, the KB controls I have can all be operated by a potentiometer or variable DC voltage.  None of them are current controlled.

Maybe that helps.  I will probably go to  the other house Thursday and will look for the manual there.

[Jester]

Attached is a hodgepodge of info and KBIC schematic from various sources. It does give a feel for the circuit if anyone needs to troubleshoot a defective unit.

Regarding controlling speed with an external source, looks to be easy as long as you keep in mind that that bottom leg of the pot is sitting at 1/2 MAINS voltage (178Vp-p), waveforms below.

One observation is that this thing 60Hz hums like crazy, I prefer the silence of a VFD. Tests were performed on an unloaded treadmill motor.