Finding pinout of a servo encoder?

[Glenn Ashmore]

Building an XY stage with Buhler 1.13.043 servos salvaged from an old HP
ink jet plotter. Documentation is nil. The encoders have 5 pins. There
are two rows of holes on the disk, one coarse and the other fine, so I asume
there are two sensors. How would you go about figuring out the pinout
without doing any damage?

I am thinking that if I can find which pins go to the LED I can use the
'scope to figure out the output. I am reading 32 meg between pins 1 (+) and
4 (-) but that seems mighty high. All other combinations are open circuit.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

 

[colin]

"Glenn Ashmore" <gashmore@cox.net> wrote in message
news:OKP7e.6120$Z73.2376@lakeread04...

Building an XY stage with Buhler 1.13.043 servos salvaged from an old HP
ink jet plotter. Documentation is nil. The encoders have 5 pins. There
are two rows of holes on the disk, one coarse and the other fine, so I
asume
there are two sensors. How would you go about figuring out the pinout
without doing any damage?

I am thinking that if I can find which pins go to the LED I can use the
'scope to figure out the output. I am reading 32 meg between pins 1 (+)
and
4 (-) but that seems mighty high. All other combinations are open circuit.

asuming the info cant be found, if it was me id use my fluke 77's diode
tester. puts out 1 ma I think, cant do much damage, a normal led would show
up 2-3 volts. of course the sensor might be harder to determine what it is,
maybe its a simple photo diode or photo transistor or some integrated device
if its fairly new.

Colin. =^.^=