Re: [CAD_CAM_EDM_DRO] Pittman Servomotor

Mike Haughton wrote:

> Hi,
> Thanks for your info.
> The HP encoder board has a serial (part?) No 07470-60110 and HP 711?5. No
> mention of HEDS.
> I assume the 4 output leads are ground, supply, pulse and direction. But
> which is which?

Gee, 7470 sounds real familiar. I think there might be a HEDS7470 encoder.
Check the HP web site (might be agilent, now).

Anyway, the 4 connections would be _5, Gnd, A and B. These are quadrature
encoders, and output two pulse trains, with a 90 degree phase shift between them.
Any quadrature encoder counter will know how to read these. If the encoder is
held together by molded plastic clips, you can tease these open with a small
screwdriver and look inside. There should be a small circuit board, and it may
have symbols marked on the PC board. If not, there may be a capacitor for
power supply decoupling, and if lucky, it will be an electrolytic with polarity
marks on it. That's how I figured out the power connections on an odd one I had.
Once I had the power worked out, I could use a scope to determine what other
signals were.

Jon