What is it?

Circuit board out of an industrial robot

Ron

Actually a CNC machine that I need some service info on the resolver amp, serial to parallel converter and counters/hex inverters/flip flops etc.. Too old and obsolete for any free data archives. I just want to check for the proper resolver stator frequency and voltage level as something is on the fringe of being out of tolerance by the way the motion control is erroring. Cant do that without service info and none seems to be had for free so far.

I can't read the writing on it.

Didja check the optical encoder glass for dirt before you started in with the electronic stuff?

Well when you use a tach generator + resolver for absolute position, speed, and load encoding back to the servo CPU there's no need for glass right? I'm no motion control expert and I didn't see anything resembling a glass encoder inside the box housing the resolver and home/end of travel micro switches. Only other attachment to the servomotor is the tach generator.

I dunno, because I don't know enough about electronics to understand what you just said. Have no idea what kind of machine you're working on or how it knows where it is. We had a couple of older CNC milling machines for a decade or two, and oil and even chips found their way down into the linear encoders. We had to take them apart and clean them every two years or so.

Yeah ok understood. Google --- cnc resolver --- and you'll see how a resolver is used for absolute position.

A resolver is a three phase rotating transformer. One stator is fed a

10kz AC waveform. The resolver is attached to the servomotor via a reduction gear. When the output of the resolver is sent to the resolver processor (extremely simplified explanation) its waveform is compared to a clock and converted to a digital serial out then multiplexed to a parallel out and sent to the servo CPU.

Here is a block diagram of the basic operation

Position and speed is the responsibility of the resolver. Motor load is probably determined via the tach generator, a single phase generator bolted on the end of the servomotor rotor housing.

BTW this machine is a Bayer Acroloc ES chucker with Yasnac/Yaskawa/Singer-Kearfott/Bayer/Getty's guts circa 1982.