Need Laserscope guru. (possibly more..lol) Greenlight HPS

[als1980]

I went though the hoses and found the missing restritor. I can now boot to my home screen.YAY So now everyone, what's next on the list to get this puppy working. I doubt we can save all the great features it has since a service card is out. Basically I want to keep the switch, and entire optic table functional. Any ideas for a full conversion? What can go and what can stay.
J

[Laser Zone]

Jon, You could not find the apartment one with the baby in the high chair down range?

Giving you a example of how poorly documented this laser is on the net. Set the laser to 10-20 watts Qswitched, Goggle up, try to push the fiber through a 2x4. Only do it without a medical fume extractor. The carbonized, pine tar fumes, in a confined space, will easily kill you. Where is the warning for that?

I can give you two more examples.

The KTP532 mod schematic on the net has a major error when implemented on most models. It can kill the lamp psu if not corrected. 2nd. The mod ROM for the older models has a watchdog interrupt that the hacker did not deal with. When the watchdog kicks in at 9 to 20 minutes, the laser rapidly goes to full RF and Full lamp.

That is why we have our little rule. Jon's helping you via PMs, that is fine.

Steve

Wow ! He sure sounds like a total creep.

[Laserbuilder]

Sorry for invasion into this discussion, but here my 5 cents about this unit, based on my personal experience.

It is very good that in my place there are no computer-controlled lasers and so on. Usually they have some interlocks located in the umbilical cable sockets or some cabinet\water flow\laser head cover interlock switches, as in all russian lasers. These are very simple to defeat. If the power unit of the laser has anything more sophisticated and intelligent than a BIG stupid switch to turn it on, or, as in this bad case it has a computer, that controls the work of the laser -- then I throw all these @brains@ away and put a BIG switch to run the power converter section of the laser PSU directly from line. In some cases I add some more hardware switches and regulators if neccesary. If some sections of the PSU require a set of specific voltages to run -- than I make auxillary power supplies to make work the power section that runs a lamp or a discharge tube. So, if I had a need making such Laserscope unit running -- I would simply throw away the computer and power on the neccesary sections of the PSU directly. No computer -- no hacking needed. In the worst case I throw away the original power supply and leave only the laser head or any othe optical setup and make my own one. Also it guarantees that the laser will never look like original medical unit, the use of which can be regulated in one or another way.

[buffo]

I know this is an old thread, but given that it deals with laserscopes, I think it's worth talking about again.

if I had a need making such Laserscope unit running -- I would simply throw away the computer and power on the neccesary sections of the PSU directly. No computer -- no hacking needed.

That might work for some of the really, *really* old laserscopes. However, even the 500 series (late 1980's model) needed a special heater circuit for the KTP crystal that you had to build from scratch if you ditched the computer. And you also needed to enable "first pulse suppression" on the Q-switch or you'd ruin the internals rather quickly. That suppression required a separate, custom circuit board to be attached to the stock Q-switch driver.

Most of these modifications can still be purchased from experienced laserists who own/used to own laserscopes, but due to the danger inherent in these lasers it's not something commonly posted on forums. If someone really wanted to learn more about them, the best thing to do would be to befriend someone who owns one and see if they will teach you.

Conversely, the modern high-power 'scopes are mostly diode-pumped, and the computer controls all kinds of things that are non-obvious and quite counter-intuitive. I really can't get into the specifics here due to an NDA, but I can tell you that bypassing these controls is a sure-fire way to destroy the laser in short order. Poke around on the Internet and you'll find plenty of people who have purchased surplus medical laserscopes, bypassed the computer, powered the diode drivers directly, and promptly smoked the machine simply because they didn't realize everything the computer was doing.

So if anyone is planning to purchase a laserscope to convert for hobbyist use (or for light show use), I would caution them to be sure to do your research first before you buy anything. And please, *PLEASE* remember that these lasers are very dangerous. Q-switched IR is in a league all by itself. You don't get many second chances with these lasers. (Plus if you have a bad accident it will probably make the evening news, which makes everyone look bad.)

it guarantees that the laser will never look like original medical unit, the use of which can be regulated in one or another way.

Here in the US, it honestly doesn't matter what it looks like. If you introduce it into commerce, it's regulated - period. Doesn't matter if it was a medical unit and you now want to use it for some other, non-medical purpose. The CDRH standard applies to all laser-containing products, including medical, industrial, and light show lasers. (Even products that contain a laser that is inaccessible by the user, such as a DVD player, are still covered by the same standard.)

And yes I realize that US laws are often more restrictive than those of other countries. So the above may not apply to you.

Adam

[Laserbuilder]

Thanks for the answer, buffo, I understand now.

It really looks like that in the US there is another reality compared to Ukraine and other ex-USSR states. I dealed with 125 and 250W CW russian YAG lasers that were commercially produced, the power unit of it is as simple as can be to run a crypton arc lamp and it even doesn't have a key switch. A similar laser had a 50W pumping chamber, AO q-switch with a driver that was built on vacuum tubes and a Lithium Iodate frequency doubling crystal without any thermal stabilizing. Unfortunately it could give only 5W of power, but still quite a lot for the rigid technology I like so much. For higher powers in green region large CVLs were produced commercially in quantity.

[buffo]

It really looks like that in the US there is another reality compared to Ukraine and other ex-USSR states.

In many ways I am envious of the legal climate in your region. For someone like yourself who is experienced and can be trusted to work on high voltage gear without injuring anyone, it must be amazing to know that you can obtain a high power surplus laser for a fraction of the original price and actually operate it in your home.

Here in the US, even if I just keep the laser in my basement, I still have to worry about being sued if my friend comes over and accidentally burns his hand by stupidly sticking it in the beam path. And if I wanted to use a surplus laser in a commercial laser show I have to grind through a mountain of paperwork first. (A Laser Product Report is typically at least 100 pages long.)

I dealed with 125 and 250W CW russian YAG lasers that were commercially produced, the power unit of it is as simple as can be to run a crypton arc lamp and it even doesn't have a key switch.

Nice! Here in the US it would be illegal for a company to sell such a laser. But yes, the flashlamp powered YAG designs are fairly easy to understand and operate. And I'm guessing that they are probably over-built (at least with regard to the lamp power supply), meaning that they should run for a long time.

The current trend towards diode-pumped YAGs in the medical industry is likely driven towards reliability and reduced cost of manufacturing. With no flashlamp to fail and no high-voltage power supply required for the pumping circuit, the actual laser can be built for far less money. Of course, they still charge a high price for them though! They just make more money on each one now.

The gradual change towards great computer control is also in part driven by profits. Sure, part of the magic behind the high-power diode-pumped systems lies in the precise control of the diode drivers, but they also *encrypt* all the communications between the control computer and all components in the system. This allows the manufacturer to require the end user to purchase expensive, single-use cards that will enable the laser to operate for a given number of exposures. After that, you have to buy another card to re-enable the laser for another treatment! It sounds crazy, but they've actually added digital-rights-management to a medical laser... (Bastards)

A similar laser had a 50W pumping chamber, AO q-switch with a driver that was built on vacuum tubes and a Lithium Iodate frequency doubling crystal without any thermal stabilizing. Unfortunately it could give only 5W of power, but still quite a lot for the rigid technology I like so much.

Lithium Iodate, eh? Interesting. I'm not very familiar with that crystal. Nice that it doesn't need to be heated to reach optimal efficiency. Although the unit you describe only has ~ 10% efficiency, which seems really low. KTP is between 30 and 40 % efficient at converting 1064 nm to 532, so maybe it's worth the extra trouble of heating it?

For higher powers in green region large CVLs were produced commercially in quantity.

Oh yeah baby... Copper Vapor Lasers (and their baby brothers, the copper-bromide lasers) are really cool. Damned shame that neon is so crazy expensive these days. Well, and there's the issue of having to wait 40 minutes for your laser to warm up before you get a beam. But they certainly do produce a lot of light! You can sometimes find medical CVLs here in the US for cheap, but usually they are out of neon. And with the high cost of neon, they're usually not worth keeping.

Adam

[Diachi]

Sorry for invasion into this discussion, but here my 5 cents about this unit, based on my personal experience.

It is very good that in my place there are no computer-controlled lasers and so on. Usually they have some interlocks located in the umbilical cable sockets or some cabinet\water flow\laser head cover interlock switches, as in all russian lasers. These are very simple to defeat. If the power unit of the laser has anything more sophisticated and intelligent than a BIG stupid switch to turn it on, or, as in this bad case it has a computer, that controls the work of the laser -- then I throw all these @brains@ away and put a BIG switch to run the power converter section of the laser PSU directly from line. In some cases I add some more hardware switches and regulators if neccesary. If some sections of the PSU require a set of specific voltages to run -- than I make auxillary power supplies to make work the power section that runs a lamp or a discharge tube. So, if I had a need making such Laserscope unit running -- I would simply throw away the computer and power on the neccesary sections of the PSU directly. No computer -- no hacking needed. In the worst case I throw away the original power supply and leave only the laser head or any othe optical setup and make my own one. Also it guarantees that the laser will never look like original medical unit, the use of which can be regulated in one or another way.

You should post pictures of more of your stuff on here, I always enjoy seeing them on the Discord!

[Laserbuilder]

Damned shame that neon is so crazy expensive these days.

How much is it in the US? I've bought a 5l 150bar bottle for 50$ in Ukraine, and it is 99.999% pure.

[danielbriggs]

How much is it in the US? I've bought a 5l 150bar bottle for 50$ in Ukraine, and it is 99.999% pure.

The last time I bought it (in the UK)... 50L of CP grade Neon (99.9995% pure) was about £80-85 I recall. ~$100USD

[buffo]

How much is it in the US? I've bought a 5l 150bar bottle for 50$ in Ukraine, and it is 99.999% pure.

That's amazing!

5L capacity (at 1 atmoshpere) is basically a "CL" size cylinder. Roughly 7 inches in diameter and 21 inches tall. If you can get a tank that size filled to 150 bar (2200 psi) with pure Neon for $50, that's a super deal. Here in the USA that would cost somewhere around $1400 - $1600! (Note that when a CL cylinder is fully pressurized, that represents 750 liters of gas when expanded back to 1 atm.)

Example: A while back, Paul Berthot (Clandestiny) had me pick up a medical CVL from a seller here in Charleston and transport it down to Florida for him. When we got it down there and started playing around with it, Paul was *shocked* to see that the Neon tank was more than 1/2 full. (Had around 1300 PSI in the standard CL cylinder.) His comment at the time was: "Holy Crap - that's about $800 worth of Neon right there!" And this was 9 years ago...

The last time I bought it (in the UK)... 50L of CP grade Neon (99.9995% pure) was about £80-85 I recall. ~$100USD

That seems more in line with the prices I'm familiar with here. At $100 for 50 liters, a full CL cylinder (2200 PSI, so 750 liters total) would be $1500.

Adam

PS: Maybe we should start an import business? Buy the gas in Ukraine and sell it here? Of course, I don't know how many people are in the market for the stuff either...