Argon laser - problem with JDSU PSU

Hello guys. Recently I've bought an argon laser and it arrived yesterday I have a JDS Uniphase 2114 power supply and there's some problem with it. Current regulation doesn't work. I checked it with a 230V 2kW kettle as a load and the PSU gives always 7A on output, no matter what the pot is set to. There's no signal on current monitor output so I think that there's something wrong with current measure in the PSU. What I want to ask you is if someone has a service manual of 2110 PSUs series, or a schematic of the power section? I've read argon section of the Sam's Laser FAQ and also found this (link) but it doesn't help me. To run the laser I connected the tube with 15 Ohm heater in series, that limits the tube current to 6,5A.





http://www.youtube.com/watch?v=BYM9LUoK7EQ


[edit]
Just measured how it exactly looks like. The PSU gives always 170VDC on output (tested with 25 and 16 ohm resistant load). The output looks very good, there is only a 10Vpp 12kHz sinusoidal ripple on the output (when loaded), so I think that the inverter works OK. Still no signal on current monitor output, i think that this is the problem (built-in current measure circuit doesn't work), but I don't know yet how to repair it

c4r0 said:

Hello guys. Recently I've bought an argon laser and it arrived yesterday I have a JDS Uniphase 2114 power supply and there's some problem with it. Current regulation doesn't work. I checked it with a 230V 2kW kettle as a load and the PSU gives always 7A on output, no matter what the pot is set to. There's no signal on current monitor output so I think that there's something wrong with current measure in the PSU. What I want to ask you is if someone has a service manual of 2110 PSUs series, or a schematic of the power section? I've read argon section of the Sam's Laser FAQ and also found this (link) but it doesn't help me. To run the laser I connected the tube with 15 Ohm heater in series, that limits the tube current to 6,5A.





http://www.youtube.com/watch?v=BYM9LUoK7EQ

Click to expand...

Why do you have a ballast on the PSU ? Mines always ran at 10.25A and I never used a ballast. Unless your powering the kettle using the PSU !??! I also don't see what you're using the 15 ohm resistor for , if your limiting the current to 6.5A then the PSU isn't going to power the tube past that anyway.



Also, you could be using the wrong value potentiometer.

I use a ballast because the PSU is giving always 170V on output no matter what current is set on a potentiometer. The 15 ohm resistor (two microwave oven's grills connected in parallel, the kettle is 25 ohm) is the ballast and it is for limiting the tube current to 6,5A. I know that the PSU isn't going to power the tube past that, actually this is the ballast for I don't have working current regulation so I don't know what will be the current if I connect the laser without any ballast - I don't want to burn it.

I'm powering the kettle with the PSU for testing. Kettle is a dummy load in this case.

If I connect a potentiometer across some voltage (here it's 15V) I got regulation from 0V to that voltage, no matter what is the pot value. I'm using 1k5 pot.

c4r0 said:

I use a ballast because the PSU is giving always 170V on output no matter what current is set on a potentiometer. The 15 ohm resistor (two microwave oven's grills connected in parallel, the kettle is 25 ohm) is the ballast and it is for limiting the tube current to 6,5A. I know that the PSU isn't going to power the tube past that, actually this is the ballast for I don't have working current regulation so I don't know what will be the current if I connect the laser without any ballast - I don't want to burn it.

I'm powering the kettle with the PSU for testing. Kettle is a dummy load in this case.

If I connect a potentiometer across some voltage (here it's 15V) I got regulation from 0V to that voltage, no matter what is the pot value. I'm using 1k5 pot.

Click to expand...

Try a 10k pot.

Also, the tube should run at about 100V happily. with a cathode voltage of 2.6V @ 25A .

if it's only outputting 170V constantly it sounds like you have a problem with the FET driver or FET. However it might be doing this because it doesn't have the correct load on it, or you may have it wired up wrong. Try a 10K pot and see if that helps.

Regards,

Adam

HAHAHA, It works I took the PSU apart and then put it together and after that it works good. Sometimes such things happens with old equipment. Current regulation is from 4 to 11 amps and there is 100mV/A signal on current monitor output. Problem solved

c4r0 said:

HAHAHA, It works I took the PSU apart and then put it together and after that it works good. Sometimes such things happens with old equipment. Current regulation is from 4 to 11 amps and there is 100mV/A signal on current monitor output. Problem solved

Click to expand...

Good work !

Mines only went to 10.25A

I didn't think it would work with a 1K pot actually, mines would only work with 10k!

Need some beam pics man !

Here you go! More tomorrow

And here's logo scanned using that argon + galvos:


pic removed

Diffraction:


With 532nm 100mW DPSS laser module:


With galvo scanners:


And a video: http://www.youtube.com/watch?v=JvkhvyWH0Js

Very nice ! what galvos and software are you using ?

GSI G100PD galvos with dedicated amplifiers and Popelscan 3.1.

Very nice beam shots, I like the way the LPF logo turned out.

Very nice

I just bought another argon laser ... need a power supply for it, however, there is one I have my eye on that is along with another head, so I may get that


Also have my eye on a HeCd laser, but that's pickup only. So I'll see what happens.

Anyway, have fun !

Regards,

Adam


EDIT: I'd add pics of my old argon, but they are too big and I cannot be bothered to resize them at this time

I fired up my argon today for a while after having it sitting for a few months. She was hard to start but she fired up eventually. It's an Omnichrome 532 and strangely enough my current control doesn't work either. I'm stuck with light control mode, and while I have no problems with that, if I turn it up all the way the tube current goes as high as 11.5 amps! On a tiny air-cooled head! I don't let it run that way for long, but the last time I kept it like that for a while the air coming out of the blower was so hot it would almost burn your hand. And the metal grill that covers the fan got so hot that I scalded my finger on it! Plus even PSU started to get hot to the touch, something it never did before. It's pretty scary when you think about it. I can only imagine how hot the actual tube was!

The tube will likely last less than 1000 hours at that current. If you limit it to 8A, you can get as much as 6000 hours from it.

A thousand hours i a long time unless you are running shows. ENJOY !!!

Mike