Is there a position sensor on SpaceLas galvos?

[mbb]

Hi Laser Pointer Forums!

This is my first post to the forum (hope I put my question in the right place)!

I work in a university research laboratory and am working on a project with a shoestring budget. We recently purchased a set of PT-20K Spacelas galvos for a new imaging system we're constructing and need to know the real-time position of the galvo scanner during a scan.

Does anyone know if the PT-20k offers such a signal? Or another method to obtain position information? I've tried to contact the supplier of our galvos but they haven't responded to my queries.

Thanks for everyone's time and help!

 

[ElektroFreak]

I'll have to have a look at one of my sets when I get home, but yes I think they do. Most (if not all) galvo amplifier boards have some sort of connector for a scanfail circuit, which relies on position data to function. I'll see what I can find later on after work.

Also, if you haven't already tried, I would recommend contacting Sam at Spacelas directly at spaceship111@msn.com

 

[mbb]

Hey ElektroFreak,

Thanks for the speedy reply!

I've talked with Sam at Spacelas about this question but it appears our purchasing department ordered the galvos from another supplier (even after we tried to put through a purchase order with Sam!), making Sam become non-responsive to my questions before a solution was found

mbb

 

[carmangary]

I'm sure they have position sensors. All closed loop scanners have them. Finding the signal on the amp board might take some reverse engineering but I am sure it is there. Most of the Chinese scanner amps are clones of well documented Cambridge amps. So Googling and asking of the right people might turn up the schematics for those. Check with MixedGas over on PL. I'd be willing to bet he has some schematics.

 

[mbb]

Thanks for the tips carmangary. If I find anything for schematics I'll add it to this thread.

 

[LSRFAQ]

A friend hosts this for me, and in the back are some Cambridge schematics, but please DO NOT repost them on the net. Depending on what amp the Chinese cloned, you may or may not find help there.

You are concerned with the photodiode inputs from the position sensor, which is IC U4 in the drawings. "position" is the raw feedback signal.

http://www.skywise711.com/lasers/scanner/scanner.html

Steve