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FrozenGate by Avery

Little trouble with my argon

bobhaha

bobhaha

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So I grabbed a LaserPhysics 50s-488 off timelablasers and it looks great.

I've done quite a bit of searching but can't find any info on this PSU. It seems the filament isn't getting properly heated so it just sits there clicking.

I checked the voltage between the two filament outputs and am getting 0V differential. But checking the voltage on each pin against ground I'm getting ~400Vac (that is a good sign right?).

There are no signs physically of anything being blown and I have checked both fuses.

There was an interesting thing happened though.... When I turned the emission knob to max while it was clicking... it blew one of the resistors on the interlock PCB. I swapped that out for a new resistor, 1/2W if I recall correctly and that seems fine now.

I have pin 1 and 2 shorted and pin 13 and 14. Is there anything else I have to do to get it lasing, in regards to the interlock?

-Adrian
 
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as far as the interlock, that's what i did to mine to get it to work. good luck, they are good little units
 
Find the filament transformer; it should be the biggest one in there. See if it is getting voltage on the primary.
 
I think the filament circuitry is also switchmode:

IMG_1384.jpg
 
I was just gonna post that pic...

Where should I be probing? I can't really get a good spot to probe on either the little square transformer or the toroid..
 
That's weird. The filament needs to be something like 25A @ 3VAC. That is easier and cheaper to do with a transformer.
I guess you could follow the filament leads to the board and check for a break in the cable.
 
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I'm glad my Uniphase has a good ol' fashioned copper transformer!
Do you have the circuit for it? You should be able to get hold of one somewhere.

The most common things that fail in switchmode supplies are the caps, followed by feedback optocoupler. I would change all the caps as a matter of course, especially if its more than 10 or 15 years old. Make sure you use low ESR caps (eg Rubicon) capable of running at 20kHz or so.

Failing all that, you could build a seperate fillament PSU with a BIG transformer. Let me know if you want one, we are scrapping all the analogue TV transmitters and a few FM radio TX's around the place and I could probably get my hands on a very high current 6-7 V transformer with variac (20-50A or so)

Cyparagon, correct me if I'm wrong, but it should be OK to run DC through the fillaments for a short time to test it? If so, as proof of concept I would try and light the filaments by putting a variac in series with a big 25A or 30A x 12V power supply, run the thing at 3V and see if you can warm the fillaments up with that. Make sure you run the fan while the filaments are lit. These things get very warm very quickly.

My whole Argon experience is with the one that I own and that's it I'm afraid, but if you find the circuit I may be able to help with the PSU electronics.
 
If you could hook me up with that kinda gear that would be awesome! A nice 50A power supply could come in handy.

As for the board.. there doesn't seem to be anything physically wrong with any of the components. How can I check if any of the optocouplers pooped them selves?

I might have to remove the entire board from the chassis.. and inspect it from below. Could it possibly be a feedback issue? From what I can see everything seems correctly hooked up.

-Adrian
 
Electrolytic caps can puff up or leak. Vents are either on top, or in the form of a rubber bung on the bottom. If the top or sides are bulging, bad. If the vent has brown dried up crusty stuff, bad. If the capacitor isn't standign straight up, the rubber bung might be pushing out because of gas buildup. Or it might have just been knocked.

For example, that blue one in the pic by the transistor heatsink and square HV transformer is out of focus, but I can't tell if it is bulging or just fuzzy out of focus and that's just the wrapper that looks weird from the angle. Probalby th latter.
bad caps - Google Search
 
Hope you get it going. Argon beams rock! Love the beautiful hues available, and the skinny/tight beam.
 
Have you spoken to Rob about it? Was it sold as working? I bought mine from him too and picked it up from his place, he seemed like a decent guy.

OK maybe have a look at the bottom of the board for arcing.
Check the electrolytic caps, as I said we replace them as a matter of course on older gear- although as I said make sure they are good ones. If you send me the values, voltages and footprints I can get good ones for you.
The opto is basically just an LED shinning on a transistor, you can check both sides with a multimeter on diode check and see if they are sill OK.
Also check the switching transistors on the filament PSU.

It's a bit hard to diagnose remotely though Adrian... Things could do some checks on his (assuming he has it working) and see what the voltages are at various points, bias voltages on the switching FET's and so forth.
 
Mine isn't working unfortunately, and bob bought the unit as non working as well. I'll probably end up giving my PSU to bobhaha with some other stuff he wants, so he can hopefully rip components off it and get his working.
 
i just went to turn my ctl-dc rg laser light on and the UV violet color won't seem to work, the red one is working fine. is there a way of fixing this, or should i get a repair?
 
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