Some help required please Coherent 315m

[Grayham]

Hello

I need a little assistance please. I have a coherent 315m and I want to measure the power setting in the dongle. The manual says you can check the pot voltage between pins 10 and 13. I was expecting to see a voltage between 0 and 5 volts but I'm seeing zero. I expect I'm doing something wrong.

The dongle has a 14 pin chip in it and I can't find it on Sams FAQ. Could someone point me at or offer some advice please.

I can provide a pic if need be.

Thanks
Grayham

[laserbiker]

Hello Grayham

I believe that the power set voltage is on pin 5 of the dongle. Pin 9 should be your ground connection.
I am not sure of the range or linearity of the input voltage to actual laser output. Measuring the voltage on pin 6 of the
dongle will give you the actual measured laser power as monitored by an internal silicon sensor. There is calibration pot for
setting it when you have known, measured output from your laser.
If this was the laser you purchased from me recently, and you have not adjusted anything, your laser should be outputting almost exactly
100mw as I set it and tested it prior to sale. If this is the case, than you can just measure the voltage on pin 6 and this should be the 100mw power point.

Laserbiker
as

[Grayham]

Hi Laserbiker

It is the laser I bought from you. I've just finished building it on to a heat sink. I've also added a shutter an built a control box for it.
I'm reading about 92mw from the laser which dropped from 95mw when I got it. I turned the pot less than .5mm to the right and if now locks at 99mw but I want to check
the correct voltages etc.. as I don't know if my laser check is in calibration and don't want to overdrive the laser.

I know you set the laser already but if it's got a pot I'm going to twiddle it. It's to much of a temptation not too

I did look on the faq for that specific adaptor but could not find it. If you have a link it would be appreciated.

Kind regards
Grayham

[laserbiker]

[URL="http://www.repairfaq.org/sam/laserscl.htm"]http://www.repairfaq.org/sam/laserscl.htm[/URL
]Hello Graham

This schematic should help you out in operation of your laser. It is copied from with all due respect from Sam's Laser FAQ.
I also suggest you go to Sam's Laser FAQ site and get familiar with your laser there. Just about everything you want to know about
this laser is there...
The little autostart dongle is not well suited for interfacing with the laser due to the tiny cheap 270" pot used to derive the setpoint voltage.
I am glad to see that the laser is working for for you. Good luck with your holography. It appears to me that you are quite experienced and
knowledgeable in holography. I would love to do that but I do not really have the room.
Regards
Brian

[Grayham]

Hi Brian

I've managed to track down the correct section in the FAQ and now and have all the information for pins on the dongle. I'm running at 100mw as per my laser check and am at 4.47v of 5 (pin 14 to gnd) which if I read everything correctly puts me at approx 90% power which is good. Nice to have some reserve.

Thanks again for your assistance and patience

Grayham

[URL="http://www.repairfaq.org/sam/laserscl.htm"]http://www.repairfaq.org/sam/laserscl.htm[/URL
]Hello Graham

This schematic should help you out in operation of your laser. It is copied from with all due respect from Sam's Laser FAQ.
I also suggest you go to Sam's Laser FAQ site and get familiar with your laser there. Just about everything you want to know about
this laser is there...
The little autostart dongle is not well suited for interfacing with the laser due to the tiny cheap 270" pot used to derive the setpoint voltage.
I am glad to see that the laser is working for for you. Good luck with your holography. It appears to me that you are quite experienced and
knowledgeable in holography. I would love to do that but I do not really have the room.
Regards
Brian