Swapping out the arc lamp for Laser diodes in yag laser

[Laserman532]

Hey pat, how much gren would 35 amps of arc get him? If he migrated to a ESKI supply which would run off single phase 220 ?

Steve

I use the single phase Converter Power CWT-600 (now out of business) running single phase and get 45 watts @ 532 at 35 amps with the ceramic cavity. But that is MY laser the average is about 30-35 watts.

Did i mention it is for sale

[weartronics]

Hey pat, how much gren would 35 amps of arc get him? If he migrated to a ESKI supply which would run off single phase 220 ?

I think the Laserscope power supply already runs off single phase 220V, doesn't it?

[Laserman532]

I think the Laserscope power supply already runs off single phase 220V, doesn't it?

some of them do most of them dont. Why do people keep trying to change a good thing...i dont get it.

[mixedgas]

some of them do most of them dont. Why do people keep trying to change a good thing...i dont get it.

Because people think pump diodes will save them money, or they dont have the truck to haul around the gear. Or they cannot bill enough to have a genset on site.

Factoid, pump diodes will NOT save you money on a laserscope class laser.
And they pop if you sneeze. Its just not designed for diode pumping.

The university I used to work for blew 7000$ a year on pump diodes for one laser for 1500 hours per year. The lamp pumped laser ran for 3000 hours a year at a fraction of the price. And you still need the pump for the coolent.

Steve

[Laser Ben]

Why do they blow so often? The are rated for 5000 hours if I remember correctly. Was the laser overdriving them?

[weartronics]

Why do they blow so often?

They don't "blow so often" relative to other long arc lamps. In my experience, the Laserscope arc lamp lifetime is typical for long arc lamps in this service.

The are rated for 5000 hours if I remember correctly. Was the laser overdriving them?

I have never seen a QCW-20BC arc lamp specification, but 5000 hours lifetime would be very unusual, so I suspect you remember wrongly. In my experience, 500 to 1000 hours is much more typical for long arc lamps in this service. It's impossible to over-current the lamps with the medical computer, and I suspect there is probably even a software timer to prevent you from running them beyond their rated lifetime. If you have replaced the medical computer, then naturally the lamp current and lifetime are entirely up to you. The lamp stresses are highest during ignition and varying current. If you run them for long periods (few ignitions) with stable current (ramp slowly), you should get more than the rated lifetime. If you run them at reduced current (e.g. 75% rather than 100% of rated current), they will last even longer.

Edit: I should add, Lee Laser have a good one-page primer on arc lamp lifetime here http://www.leelaser.com/pdf/Arc%20Lamp%20Lifetime.pdf.

[mixedgas]

Lamp. lets take 700 hours lamp life as a compromise:

8 hours x 7 days x 52 weeks /700 Hours = 4 lamps x 175 a lamp = 728 dollars give or take.

1 year worth of diodes for 40 watts green out, 7,000 installed.
Once a year, on average for the past 7 years since installed.
That laser gets ran 1500 hours average per year.

There is one there more expensive then that.
The diodes for the ti-saph cost 22,000$ for 4500 hours rated

Your call.

Steve

[blown350]

Sorry for my slow response, You are all right as it seems there would be no real benefit in swapping diodes for the arc lamp I was thinking there would a space savings in doing the swap, but I wasn't thinking about the power requirements for the diodes, or thier sensitivity to static and such.

As for the power requirements of the stock laserscope setup: I have no problem running the system off of my dryer outlet (240 30 amps), I even made a long extension cord for it so that I could bring it out of the garage.

Also I bought the ktp oven controller that is recommended on another post and I am about to rip out the computer of this beast so that I can have more control of the beam shaping optics and get rid of all that power monitoring stuff. Can anyone give me some hints or words of advice on this operation?

Thanks Sean

[weartronics]

Also I bought the ktp oven controller that is recommended on another post and I am about to rip out the computer of this beast so that I can have more control of the beam shaping optics and get rid of all that power monitoring stuff. Can anyone give me some hints or words of advice on this operation?

For light show use, I recommend you keep the turning mirror, separation prism, and collimating lens - everything beyond these components can be removed from the table. Jon at DSLI is the expert on getting a nice beam out of these things - he recommends replacing the collimating lens with a 400mm or 600mm FL lens to get a beam suitable for use with 6 or 7mm aperture scanners.

Best regards,

weartronics

[mixedgas]

Yeah, with a oscilloscope powered by a isolation transformer, document the signals to the power supply and qswitch before you rip it apart, and make sure before you remove the isolation transformer in the base that you have one of the power supplies that can run un isolated.

Ie find out if the PSU needs 0-5 V or 4-20 ma current or some other weird protocol and messure it, keeping in mind many of those signals can be floating at high voltage to groud, so you use a isolated battery powered meter

document the KTP temp.

whats the q switch freqeuency, and does the driver do the giant pulse suppression or the cpu????????

Note where the water cooling loop turns on and off cooling wise, because its designed for a constant temperature around the rod, you might want to measure that.

and beware of the posted laserscope mod schematics.

In other words, DOCUMENT EVERYTHING. I wouldn't cut the harness until your very sure you can sequence and cool and interlock it correctly.
In fact, keep the harness and trace the signals back. It takes a bit longer, but at least you can recover if you make a mistake.

I've done this a number of times on in similar circumstances, rip the oem supply or CPU out of something and then find I was missing one signal some place and could not find the documentation.

I've read over the years, that many people cant get the docs on the qswitch from the factory, so document all the signals and levels and pulse rates before you snip a single wire.

Steve