Lasos ArIon cooling problem fixed

As I reported earlier, My Lasos ML ArIon started having start-up problems. With the help of Chris and a torch, I got it running again but the tube was COLD with that 235 CFM fan.

I dropped the voltage to the fan to 60 VAC and the tube temperature came up as expected. At full 8 Amp input, I measure about 115 Deg F exhaust temp which is below what Chris indicated that it likely should be. I ran it for 2 hours last night at this "elevated" temp and tonight, It started on the first pulse. I will get a smaller, quieter fan for this laser.

HOWEVER, The uniphase 30 mW SL laser is a different story. With 212 CFM fan, it runs real warm. It always starts first pulse and the heat may be the reason.

If you are going to experiment with this info, have thermomiters on the exhaust and work up to warm slowly. I'm trying to maintain 40 Deg F delta T. May need to watch this in warmer conditions. This sure fixed my Lasos problem. Thanks for the call Chris !!!

HMike

Glad to see you got it working. It would have been a real shame if you hadn't been able to save the argons.

Between a Variac and a propane torch, It woke up! I used VERY gentile heating on the main cooling fins bringing them slowly up to about 120 Deg and that did it. That's where I guessed I had been over cooling the tube. I could hold the cathode end of the tube without pain. Way too cool man.
Big transmitting tubes don't work well untill they are spit burning hot.

Again -- Don't do this with a Uniphase tube. They need all the air they can get.

HMike

It appears that the Uniphase plasma tubes are confined in a small tubular housing with limited air inlets. This may be by design to maintain heat but use at least 200 CFM or more on them.

I'm thinking that these Lasos lasers are just more vulnerable to high pressure. The one that used to "blink" doesn't any more since I started keeping up with my maintenance burns.

Then I had another that sat for a year while Jason and I tried to get it to work with an ML05 PSU. I finally gave up and rewired the plug to the Spectra Physics pinout. It blinked about 60 times before I got it to fire (with the help of my oudin). I ran it for an hour and gave it a rest. After the hour it blinked about 20 times before it started on its own. I ran it for another hour. This morning it started first click. This afternoon the same thing. It still winks out if I crank up the current too fast, but, the starting issue is gone. And yes, they run MUCH cooler than my JDSU lasers

Peace,
dave

Dave --

I've read that it's best to start at full tilt to establish the arc -- then turn it to what you want. With all the circuitry in the PS, I don't know why.

HMike

I've read that, too. But both my little spectra physics and my HGM seem to start on full power anyway. It's just for the first quarter second, but it does seem automatic.

Dave --
As noted elswhere, I have a screeming 235 CFM fan on my Lasos. How big is the fan on yours?

Mike

Hemlock_Mike said:

Dave --
As noted elswhere, I have a screeming 235 CFM fan on my Lasos. How big is the fan on yours?

Mike

Click to expand...

I use a stock (for JDSU units) Dayton fan in a housing. The specs (from JDSU) call for 185CFM (free air) and 115CFM (nominal) for the Dayton. The fan is connected to the lasers via a 4in. hose.

Peace,
dave

The 4" hose may provide some restriction for a big fan. Running my 235 CFM at 60 volts likely cuts it to 120 +/-

Thanks -- HMike