General scanning m3 pinout psoted here.

[mixedgas]

In case you ever need to hook up a big, clunkly M3 or just pick one up on Ebay for 15$ and want to see what it does.

The color code is not intuitive.

The Galvo has two cables extending from its base.

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The DRIVE cable is easy, two wires in a shielded cable, terminated in a 3 PIN connector.

WHITE and BlACK are the drive coil, GREEN is the shield on the drive coil cable.

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The feedback color code however, is not so easy. The traditional GSI color scheme is not followed on this galvo.

POSITION FEEDBACK SENSOR CABLE, a four or more wire shielded cable terminated in a RJ45 style connector.

GREEN is Sensor Ground

BLACK gets plus 12 volts at about 70-80 mA to power the sensor.

RED Sensor output side one

WHITE, Sensor output side two.
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RED and WHITE are the sensor outputs, which consist of a few microamps of differential currents riding on about 5 volts of RF noise. Use a 500 Khz Pi section LC RF lowpass on each feedback lead, then run into a transimpedance converter or differential amplifier like all traditional capacitive feedback GSI amps use. Hanging a 10X attenuator probe off a sensor output will let you see the feedback signal, if your scope has a wide enough analog offset control and good DC coupling. This is one case where a digital scope will not serve you well.

DO NOT pop the cover off and then remove the allen screws holding the sense board, you risk cracking off the ceramic sensor butterfly higher up in the galvo.

DO NOT stick your finger on the sensor card while operating, unless you LIKE getting stung by 100 volts or so of RF.

For your reading pleasure, after popping the bottom off one for Reverse Engineering. Some day, some one will use this information, I hope. If not, I don't care.

Steve