Medical Argon Lasers???

[buffo]

The pedal is part of the safety interlock. It has to be connected or the tube won't fire. (There are multiple pins on the connector. Some are part of the interlock, while others are for triggering a high power treatment pulse.)

I'll have a look at my connector later this weekend and let you know which pins you'll need to short.

Adam

[gottaluvlasers]

(refering to "arms lasers")

i am not an ion king but i think you are going to need to supply A LOT more info than what you just said.

power supply?
water cooled?
multi-line?
single line?
220v at what amperage?

in my opinion it is probably just an interlock issue. but again i am in NO WAY an authority on argon lasers.

when you turn the key do you hear anything? see anything? does the cathode glow? do you smell anything? does time travel backwards?? lol..??

help us HELP YOU!!!

-Marc

[ams-laser]

Hello,

It is a HGM model 5 laser unmodified
220V 60Amps

pretty much that is what i know about it

any help would be apreciated,

is there something i could take pictures from and post them so i can get a better help

Thanks

Eduardo

[buffo]

Eduardo;

No need for pictures just yet... Until you get the footswitch interlock bypassed (or you get your hands on an authentic HGM5 foot pedal) you will *not* be able to fire the laser. It won't even idle unless the foot pedel is connected.

When you depress the footswitch, the tube current will ramp up to whatever you have the max pulse power set at, and it will stay there for the duration of the pulse you have selected on the front of the panel. Then it will drop back to idle.

But like I said, without the footswitch connected to the face of the PSU, the ignitor won't fire and the tube will never light.

I'll have some time on Saturday to ring out the connector on my HGM5. I'll be able to tell you which pins to short to get the tube to light. If after you do that, the tube *still* doesn't fire, then we can troubleshoot from there.

Adam

PS: Here's a few pictures of one of my HGM5's. (I have two of them. These pictures are of my first one, before I replaced the tube.)

[Xytrell]

I have a copy of the schematics, but not the entire unit. If the pins are labeled, J and K need to be shorted according the the interlock string section.

[buffo]

I tested my foot pedal this morning. In order to satisfy the interlock, you need to short pins 2 and 3, and you also need to short pins 12 and 14. That should allow the ignitor to fire. The tube should light and be running at idle current. You can adjust the idle current by turning the aiming beam intensity pot up or down. (It's located on the face of the unit to the left of the output aperture.)

When you want the laser to ramp up for a treatment pulse, you need to connect pins 3 and 7 together. (This is the same thing as stepping on the foot switch.) Now, depending on how you have the face plate controls set, you'll get a pulse lasting from a few milliseconds to 10 seconds. (Some HGM5's even have a "continuous" mode where the beam will stay on until you let go of the pedal or the thermal interlock kicks in...) You can adjust the power of the treatment pulse using the dials on the faceplate.

Note that you still need to defeat the fiber launch interlock for the laser to light. The easiest way to do this is to cut the top off the cap from a Bic pen. (You know, the cheap ones that cost like $2 for a pack of 10...) Shove the cap into the fiber connector. (Cut end goes in first.) That will leave the little pocket clip sticking out so you can grab it easily to remove it. It should slide into the fiber launch about 1/4 of an inch or so. Turns out that the cap from a Bic pen is exactly the right diameter; it will push the switch out of the way and the laser will think the fiber is attached.

I took a picture of the connector on my foot switch and labeled the pins. I've posted it in the gallery, but here's a copy of the picture for you to reference:



Note that there are no pins at position 5 or position 10.

This should be everything you need to get your HGM5 to fire. Let us know how you make out!

Adam

[GooeyGus]

Sorry to resurrect from the dead, but this seems like the perfect thread to post in.

I recently bought an HGM 5 (this unit: http://cgi.ebay.com/ws/eBayISAPI.dll...:X:RTQ:US:1123) and I was wondering a bit about shipping.

Are these units, when complete (without the stand though), fairly robust in shipping, in comparison to other ion lasers? Any tips on how to keep the unit nice and safe while it's on it's way to me? The guy says it works great so I'm just hoping that it stays that way in shipping!

[buffo]

You're in luck. That laser is local to me. In fact, I was trying to get in touch with the seller on behalf of another PL member here to check into that laser and some other stuff he supposedly had for sale. However, the seller hasn't contacted me yet.

I've got 2 HGM5's. They are reasonably stable when shipped. They need to be packaged extremely well, however, and they *can't* be dropped.

When I had my first one sent to me, it was packaged using the expanding foam stuff. (You know, where they put the unit inside a plastic bag and then shoot liquid foam between the box and the bag.... It expands and hardens in seconds... That stuff.) It worked pretty well, considering the laser had to be shipped from Minnesota to South Carolina!

Unfortunately, when it arrived, the tube was up to air. No joy. Now, the guy I bought it from didn't know jack about lasers, so it's possible that the tube was always dead and he didn't know any better. As it was, he refunded me the purchase price and let me keep the laser. (I had to eat the $90 shipping charge.) That worked out OK though, as I was able to get a different tube for it, and it's lasing now.

Make damn sure the guy packages it well, and have him insure it for $800 or so. One drop onto a loading dock, even from a height of 3-4 feet, can be enough to kill the tube forever.

If you want, I'd be happy to check it out for you before he ships it. Send me a PM and we can trade contact info.

One thing about HGM5's. They absolutely can *not* be run continuously at any significant power level unless you drastically upgrade the cooling. They are designed for 3 watts output for 30 seconds, with a 5 minute cool-down period. If you bypass the computer so it will run CW, you can run it for about 90 seconds before the thermal interlock shuts it down. Bypass the thermal interlock and you can probably run it for another 3-5 minutes before the thing melts. (And I'm not kidding...)

Realistically, if you add a lot of extra airflow, you can get 1.5 to 2 watts reliably out of them for several hours. I know of a few people that are getting nearly 3 watts CW out of them, but tube life is *drastically* shortened if you do that, and you need a pair of 6 inch diameter blowers to suck all the heat out of the head. (Plus you've got to deal with two large ducts spewing 170 degree air in your face!)

The good thing is that you can run it off a standard 30 amp 220V drier outlet all day long. Pretty neat to get a couple watts of argon running off single phase AC without any water for cooling!

Adam

[mixedgas]

my HGM factory tech friend rates them at 500-750 CW all lines with the stock PSu and cooling.

Steve

[buffo]

Hey Steve;

Yeah, that's what I meant by not reaching "significant power level" with stock cooling.

Running a 3 watt tube at 500 mw is pretty pathetic. But with a little extra cooling, you can easily get 1.5 watts out of them. Even 2 watts isn't all that hard.

However, the monster that we had at SELEM 2007 was making just north of 3 watts. That required extensive modification of the cooling system, including those two 6 inch blowers that were mounted on the extended sled behind Jeff's laser. Even so, he can only run it for an hour or two like that. Once he tried to do a 5 hour rave, and he completely *melted* the plastic fan shroud around one of the blowers!

My smaller 903 tube makes around 900 mw at 18 amps of tube current. Wide open, the power is a lot higher (don't know how much, as my power meter maxes out at a watt), but the outlet air from the pair of blowers reaches 165 degrees in about 4 minutes with the tube maxed out. I don't want to melt it though, so I run it a lot lower.

Adam