Galvo Driver

[polishedball]

This it for a cheap Y PT-30 galvo driver, but hoping someone will have some ideas.

Real odd problem where the Y axis will just bounce up and down almost like a noise on a power supply. I have proved this to the driver as swapping X Y drivers the bounce is moved to the X side. Also have swapped DACs.

What is interesting is if I run it single ended with half signal it is fine. The problem is also intermittent on the diff side sometimes it will work but most of the time it is failed. Single ended is always OK.

Any ideas guessing a little tiny surface mount op amp is beginning to die but would like to hear other thoughts.

[mixedgas]

Um, check the grounding on the diff cable and the wires to +/- . Bounce is usually a bad diff input amp or bad diff input wiring, lack of of a weak ground return some place to center the diff voltages. Then replace the opamp. Also check the diff signals from the GALVO for magnitude.

Steve