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ArcticMyst Security by Avery
Need info on Coherent Innova 20 argon laser
- Thread starter ogoun
- Start date
I have the manual, I THINK, if I do, its on a CD-ROM, 150 kilometers away in storage. I'll have access to it weekend after next.
make sure the passbank transistor strings are not shorted.
A transistor in a large frame fails shorted C to E, and tends to take the rest of the string its in with it. It is therefore imparitive that you know your tube voltage, and tap the transformer correctly, as anything NOT going into the tube goes into the transistors as heat. Low currents are worse for the regulator then high currents on a linear like that. IE you MAY need a tap chart for the transformers. Since I cant get at mine, email Laser Innovations in CA with your model and serial and ask them to tell you your tube voltage and reference current for your laser. Start the tube at moderate to high current to protect the passbank.
Coherent MAY have someone at the factory who remembers.
Also you MAY need to set taps on the cathode transformer. Again, I do NOT have the numbers for I2o in my head, I've seen them run but never worked on one.
Remember tube voltage plus passbank voltage drop = rectified line, as tube current goes down, passbank voltage goes up.
Once you get her lit, and if she appears stable, let her run, setting still is one of the worse things you can do to a tube.
I would not expect ANY stability for the first one to two minutes. It is a INNOVA ceramic tube, and the pressure control system WILL have leaked up somewhat. The good news is you have one of the hottest ignitors in the business, and a good chance of it starting. If it starts, its going to need to reseason itself to the new gas pressure and bury some gas, so leave it
run, for at least a hour. DO NOT shut her down if she's stable, let it run. A quick "OK it works" shutdown is bad if it has not ran for a while. I would not expect lasing, but DO NOT move the front mirror, its the reference for the system. You will probably have to "vert search" the rear mirror, send me a email at (reduce nato phonetics to letters) oscar sierra romeo at ohio.net and I'll walk you through the search procedure for the rear mirror. I think you have the version of the resonator that has the search bar...
For the first few minutes, your going to have to stand back and commit faith... This can be difficult considering the possiblity of catastrophic passbank failure running through your mind. I'd say 25 amps minimum once she starts.
Break it into three decision periods, one at about 2 seconds, one at 20 seconds, and one at 1-2 minutes. A large amount rests on how well the previous owner followed the refill schedule. Expect to see some flashing/fluctuations in the bore light as it gets the cobwebs out of the system. It will take a while for the plasma to pump the gas to where it wants to be, and remember, gas flows inside the tube at high rates.
Start in current mode, NOT light. Light mode will cause you to ramp to max I if the cavity is misaligned, and I'm wiling to bet a serious pile of donut holes that she's not 100% aligned or peaked after transit. Treat the beam port as though it WILL lase, a carbon block or the built in beam bump (or intracavity shutter closed) is wise. If you've never worked around 20 watts of laser light, its stunningly bright for the first time and VERY easy to get stray light levels that are dangerous. Few things hold up well to that much blue green. Beam dumps need to be aligned before firing and in such a way that they direct the scatter to a safe area. One thing most newcomers to large frames miss, is the quality and large amount of cooling water needed. Also cheap rubber hoses actually shrink when warm, I've watched more then a few new setups where the outlet hose shrinks down when warm and cuts off flow. You need to be able to source water indefinately.
When starting BAD = obvious loud audible oscillation in the plasma, Ok is some dimming or random flashing in the first few seconds. OK is a few dips/dropouts of the tube current, BAD = tube current rocketing up to the limit or no response to the control pot. Wait a few seconds before turning the pot to test. ALWAYS keep one hand behind your back when working on one of these.
HEAD LID may be off and interlocks defeated, but make sure your aware of where the stray reflections off the brewster windows may go. PSU doors should be on and closed. On a smaller laser, we would watch for sparks, but at that energy level, it either works or its a mess.
Inspect inside the head and psu for water leaks before applying full pressure and before connecting power.
Inspect inside the head for stray metal where it should not be, ie anode or cathode brewster window covers touching exposed high voltage, etc...
Large frame power supplies HUM, some humming is not bad. Massive humming is bad.
Heck the contacter thunk is downright scary.
Make sure you have a working precharge system, it is BAD to dump raw line into the cap bank.
If anything pops from lack of running, it will be the line rectifiers, and usually just one of the 6 or so diodes used.
Start delay should be on the order of 30 seconds or more before you can ignite.
The usual technique is to rotate the pot to full current before starting and then back off 1/4 of the total travel, thus keeping you high enough to protect the passbank, but out of the overcurrent trip.
IGNORE any fill or low pressure warning lights or low indicated tube voltage for the first minute.
BE prepared to flip the meter switch if so equipped between tube voltage or current.
ONE HAND IS ON THE MASTER SWITCH DURING STARTING. IT IS OFTEN POSSIBLE TO "SAVE" a PSU from destruction during the first few seconds of a bad start by quickly de energizing the contactor.
If the mains fuses pop, something is BADLY wrong in the PSU. And fuses are 70$ or so each....
FULLY expect a safety system to pop a shutdown on you in the first few seconds, usually its overcurrent, back the I pot off a serious bit and try again.
When shutting down, IDLE the tube for a few minutes before turning off. Let the cooling water run a good 5 minutes after shutdown.
DO NOT BE CONCERNED WITH LASING DURING YOUR FIRST RUN.
Running a largeframe is a ARTFORM.
DO YOU HAVE at least OD5 or OD6 goggles for ARGON ION? IF not, run that beam in some form of metal tube to its DUMP.
Steve
make sure the passbank transistor strings are not shorted.
A transistor in a large frame fails shorted C to E, and tends to take the rest of the string its in with it. It is therefore imparitive that you know your tube voltage, and tap the transformer correctly, as anything NOT going into the tube goes into the transistors as heat. Low currents are worse for the regulator then high currents on a linear like that. IE you MAY need a tap chart for the transformers. Since I cant get at mine, email Laser Innovations in CA with your model and serial and ask them to tell you your tube voltage and reference current for your laser. Start the tube at moderate to high current to protect the passbank.
Coherent MAY have someone at the factory who remembers.
Also you MAY need to set taps on the cathode transformer. Again, I do NOT have the numbers for I2o in my head, I've seen them run but never worked on one.
Remember tube voltage plus passbank voltage drop = rectified line, as tube current goes down, passbank voltage goes up.
Once you get her lit, and if she appears stable, let her run, setting still is one of the worse things you can do to a tube.
I would not expect ANY stability for the first one to two minutes. It is a INNOVA ceramic tube, and the pressure control system WILL have leaked up somewhat. The good news is you have one of the hottest ignitors in the business, and a good chance of it starting. If it starts, its going to need to reseason itself to the new gas pressure and bury some gas, so leave it
run, for at least a hour. DO NOT shut her down if she's stable, let it run. A quick "OK it works" shutdown is bad if it has not ran for a while. I would not expect lasing, but DO NOT move the front mirror, its the reference for the system. You will probably have to "vert search" the rear mirror, send me a email at (reduce nato phonetics to letters) oscar sierra romeo at ohio.net and I'll walk you through the search procedure for the rear mirror. I think you have the version of the resonator that has the search bar...
For the first few minutes, your going to have to stand back and commit faith... This can be difficult considering the possiblity of catastrophic passbank failure running through your mind. I'd say 25 amps minimum once she starts.
Break it into three decision periods, one at about 2 seconds, one at 20 seconds, and one at 1-2 minutes. A large amount rests on how well the previous owner followed the refill schedule. Expect to see some flashing/fluctuations in the bore light as it gets the cobwebs out of the system. It will take a while for the plasma to pump the gas to where it wants to be, and remember, gas flows inside the tube at high rates.
Start in current mode, NOT light. Light mode will cause you to ramp to max I if the cavity is misaligned, and I'm wiling to bet a serious pile of donut holes that she's not 100% aligned or peaked after transit. Treat the beam port as though it WILL lase, a carbon block or the built in beam bump (or intracavity shutter closed) is wise. If you've never worked around 20 watts of laser light, its stunningly bright for the first time and VERY easy to get stray light levels that are dangerous. Few things hold up well to that much blue green. Beam dumps need to be aligned before firing and in such a way that they direct the scatter to a safe area. One thing most newcomers to large frames miss, is the quality and large amount of cooling water needed. Also cheap rubber hoses actually shrink when warm, I've watched more then a few new setups where the outlet hose shrinks down when warm and cuts off flow. You need to be able to source water indefinately.
When starting BAD = obvious loud audible oscillation in the plasma, Ok is some dimming or random flashing in the first few seconds. OK is a few dips/dropouts of the tube current, BAD = tube current rocketing up to the limit or no response to the control pot. Wait a few seconds before turning the pot to test. ALWAYS keep one hand behind your back when working on one of these.
HEAD LID may be off and interlocks defeated, but make sure your aware of where the stray reflections off the brewster windows may go. PSU doors should be on and closed. On a smaller laser, we would watch for sparks, but at that energy level, it either works or its a mess.
Inspect inside the head and psu for water leaks before applying full pressure and before connecting power.
Inspect inside the head for stray metal where it should not be, ie anode or cathode brewster window covers touching exposed high voltage, etc...
Large frame power supplies HUM, some humming is not bad. Massive humming is bad.
Heck the contacter thunk is downright scary.
Make sure you have a working precharge system, it is BAD to dump raw line into the cap bank.
If anything pops from lack of running, it will be the line rectifiers, and usually just one of the 6 or so diodes used.
Start delay should be on the order of 30 seconds or more before you can ignite.
The usual technique is to rotate the pot to full current before starting and then back off 1/4 of the total travel, thus keeping you high enough to protect the passbank, but out of the overcurrent trip.
IGNORE any fill or low pressure warning lights or low indicated tube voltage for the first minute.
BE prepared to flip the meter switch if so equipped between tube voltage or current.
ONE HAND IS ON THE MASTER SWITCH DURING STARTING. IT IS OFTEN POSSIBLE TO "SAVE" a PSU from destruction during the first few seconds of a bad start by quickly de energizing the contactor.
If the mains fuses pop, something is BADLY wrong in the PSU. And fuses are 70$ or so each....
FULLY expect a safety system to pop a shutdown on you in the first few seconds, usually its overcurrent, back the I pot off a serious bit and try again.
When shutting down, IDLE the tube for a few minutes before turning off. Let the cooling water run a good 5 minutes after shutdown.
DO NOT BE CONCERNED WITH LASING DURING YOUR FIRST RUN.
Running a largeframe is a ARTFORM.
DO YOU HAVE at least OD5 or OD6 goggles for ARGON ION? IF not, run that beam in some form of metal tube to its DUMP.
Steve
Last edited:
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Hey ogoun! When do we get to see some pictures of this beast of yours ?
- Joined
- Dec 28, 2009
- Messages
- 118
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I use photobucket, which is a pretty good picture hosting site.
