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Finally!!! Argon goodness!!

GooeyGus

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Hoooly crap. So I got everything wired up to run it in current mode. With the setup that I wired up, it will go up to about 10.6A. This is perfect because I didn't want the pot to be able to push the current WAY past acceptable limits. I used a 10kohm pot and two 10kohm resistors in parallel (so 5kohm resistance total) to achieve 10.6A at the least resistance. Let me tell you, this is BRIGHT now. It looked about three times as bright, so I got the power meter out and did some measurement. At first my reading was about 160mW but after about 15 minutes it was pretty steady at 180mW. Also remember, the head of my power meter is 15 feet away from the head of the laser, as this is the only way I could get an accurate reading because of all the air moving around close to the laser. I'm sure with the meter up close and personal with the head, it would be over 200mW. I'll try to get some more pictures and post them up!!

I keep blowing the breakers at 10.6A, so I'll have to turn it down a tiny bit  ;D
 

Tallaxo

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GooeyGus said:
[quote author=Tallaxo link=1214412765/36#43 date=1214663799]Hi Gus.

My Spectra physics has the same output modes as yours. Light and current mode. Light mode uses a photo diode in the beam attenuater shutter on the front output coupler (it is part of the black block on the laser aperture ) and uses a small optic that bounces a part of the beam into a photo diode to control stability and power output.

Current mode is just that. You manually adjust the current to the tube. You say your tube is pulling about 6.5A? Well these tubes are designed to pull 10A at full load and 12A at a low duty cycle. A 6.5A draw is a good indication of a "high pressure" tube. What this means , is that the tube has not been operated as often and as long as it should be.

When I received my SP tube, it would only accept 8A max by the power supply , any more amps added would make it brighter for a second or two but then it would drop back to 8A. To cure this, you must normalise the tube argon pressure. Sounds painful but is actually easy.

When a tube is not used for some time or infrequently, Argon that has been buried into the tube walls and cathode, due to the lasing action, starts to leak back into the tube . This increases the gas pressure and inhibits full current flow. to achieve the correct tube pressure, you must run the laser at max current (6.5A) for at least 3 hours a day for a few days. Just switch it on and leave it run. After each run you will notice that the tube will accept higher and higher currents as you "bury" more of the Argon into the cathode and the tube walls and reduce the tube pressure. If you are successful, after a few days your tube should be able to accept the max 10A and give you maximum output. Some power supplies can give up to 12A , but please use that in brief bursts.

The worst thing you can do to a tube is constantly switch it on and off using the emission key on the PSU. Your laser head contains an ignition coil that ignites the plasma at several KV . This ignition stage is very tough for both tube and power supply so once you switch it on, leave it on for as long as you can (No duty cycle ;) ).

Hope this helps.

Jase

I've actually heard quite the opposite to this, even mentioned a bit in the users manual of the laser. (This is for light mode ONLY, I haven't been able to run it in current mode) The manual says that over time, as the tube degrades, the power supply will keep increasing current as much as it needs to to get the amount of expected light when one turns the knob all the way up. So from what I've read, the LOWER the current is when cranked all the way up in light mode, the better. Because the tube is producing the correct amount of light without having to add a lot of power. I was told 6.5A is a pretty good reading for being all the way up in light mode. The person who gave me this info has seen tubes with a reading as high as 10A in light mode, but remember, its still making the same amount of light. I would compare it to two of the exact same cars racing, but one with 2000lbs of concrete in the back. The heavier car will have to work much harder to get the same speed.

SOOO In conclusion, from what I've read on Sam's FAQ and the users manual of the laser itself, a reading of 6.5A > A higher reading in light mode.

Now, If I get it into current mode and it falters as I turn the current up, then I probably have a high pressure situation. But I've ran it for about 3 or 4 hours every night for the last 4 nights so I think its alright. Remember, I've only been using light mode not current mode, which is why I cant get the current over 6.5A (again, because it only increases the current until it sees the amount of light that it is programmed to see)[/quote]

Light mode is just for stabilization. Current draw on the tube and it's condition has nothing to do with this mode. Light mode tranfers control of the output to the power supply to produce a super steady power output for what these lasers are used for (Lithography and high quality graphic reproduction).
In Light mode, you should still be able to draw the max current from the tube. As you cannot, I would suggest wrong wiring or a faulty psu.

Jase
 
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GooeyGus said:
Hoooly crap. So I got everything wired up to run it in current mode. With the setup that I wired up, it will go up to about 10.6A. This is perfect because I didn't want the pot to be able to push the current WAY past acceptable limits. I used a 10kohm pot and two 10kohm resistors in parallel (so 5kohm resistance total) to achieve 10.6A at the least resistance. Let me tell you, this is BRIGHT now. It looked about three times as bright, so I got the power meter out and did some measurement. At first my reading was about 160mW but after about 15 minutes it was pretty steady at 180mW. Also remember, the head of my power meter is 15 feet away from the head of the laser, as this is the only way I could get an accurate reading because of all the air moving around close to the laser. I'm sure with the meter up close and personal with the head, it would be over 200mW. I'll try to get some more pictures and post them up!!

I keep blowing the breakers at 10.6A, so I'll have to turn it down a tiny bit ;D
Gus - an idea regarding your power meter....take the lead from Coherent on this one......grab a KOOZIE - one of those personal can cooler thingies...that wrap around the beer can/bottle ? Yup - those ! Use one to insulate the sensor on your thermal meter - you can even use the hole in the bottom of it to shoot your beam through :) Coherent ships out the $0.50 Koozie with a small paper template to place on it - so you can trim it up to fit around the sensor head on their $2100 package....kinda cheesy, but makes perfect sense ! ALL of you folks out there with the DIY meters should give that a shot - it would most likely stabilize your meters more, and increase accuracy - as it would prevent interference from the outside environment :)
 

GooeyGus

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Tallaxo said:
[quote author=GooeyGus link=1214412765/36#46 date=1214698028][quote author=Tallaxo link=1214412765/36#43 date=1214663799]Hi Gus.

My Spectra physics has the same output modes as yours.  Light and current mode.  Light mode uses a photo diode in the beam attenuater shutter on the front output coupler (it is part of the black block on the laser aperture )  and uses  a small optic that bounces a part of the beam into a photo diode to control stability and power output.

Current mode is just that.  You manually adjust the current to the tube.  You say your tube is pulling about 6.5A?  Well these tubes are designed to pull 10A at full load and 12A at a low duty cycle.  A 6.5A draw is a good indication of a "high pressure" tube.  What this means , is that the tube has not been operated as often and as long as it should be.

When I received my SP tube, it would only accept 8A max by the power supply , any more amps added would make it brighter for a second or two but then it would drop back to 8A.  To cure this, you must normalise the tube argon pressure.  Sounds painful but is actually easy.

When a tube is not used for some time or infrequently, Argon that has been buried into the tube walls and cathode, due to the lasing action, starts to leak back into the tube .  This increases the gas pressure and inhibits full current flow.  to achieve the correct tube pressure, you must run the laser at max current (6.5A) for at least 3 hours a day for a few days.  Just switch it on and leave it run.  After each run you will notice that the tube will accept higher and higher currents as you "bury" more of the Argon into the cathode and the tube walls and reduce the tube pressure.  If you are successful, after a few days your tube should be able to accept the max 10A and give you maximum output.  Some power supplies can give up to 12A , but please use that in brief bursts.

The worst thing you can do to a tube is constantly switch it on and off using the emission key on the PSU.  Your laser head contains an ignition coil that ignites the plasma at  several KV .  This ignition stage is very tough for both tube and power supply so once you switch it on, leave it on for as long as you can (No duty cycle  ;) ).

Hope this helps.

Jase

I've actually heard quite the opposite to this, even mentioned a bit in the users manual of the laser. (This is for light mode ONLY, I haven't been able to run it in current mode) The manual says that over time, as the tube degrades, the power supply will keep increasing current as much as it needs to to get the amount of expected light when one turns the knob all the way up. So from what I've read, the LOWER the current is when cranked all the way up in light mode, the better. Because the tube is producing the correct amount of light without having to add a lot of power. I was told 6.5A is a pretty good reading for being all the way up in light mode. The person who gave me this info has seen tubes with a reading as high as 10A in light mode, but remember, its still making the same amount of light. I would compare it to two of the exact same cars racing, but one with 2000lbs of concrete in the back. The heavier car will have to work much harder to get the same speed.

SOOO In conclusion, from what I've read on Sam's FAQ and the users manual of the laser itself, a reading of 6.5A > A higher reading in light mode.  

Now, If I get it into current mode and it falters as I turn the current up, then I probably have a high pressure situation. But I've ran it for about 3 or 4 hours every night for the last 4 nights so I think its alright. Remember, I've only been using light mode not current mode, which is why I cant get the current over 6.5A (again, because it only increases the current until it sees the amount of light that it is programmed to see)[/quote]

Light mode is just for stabilization.  Current draw on the tube and it's condition has nothing to do with this mode. Light mode tranfers control of the output to the power supply to produce a super steady power output for what these lasers are used for (Lithography and high quality graphic reproduction).
In Light mode, you should still be able to draw the max current from the tube.  As you cannot, I would suggest wrong wiring or a faulty psu.

Jase[/quote]

You are correct about the light mode putting out super stable light, but super stable for long periods does not equal max power. The photodiode inside the head is set from the factory to see a certain amount of light, as soon as that amount of light is reached, it stops adding current. You can open the head of the laser and adjust the sensitivity on it to operate at higher currents, but with the factory setting (on a healthy tube) it should produce the amount of expected light at far below 10A. If it takes 10A to produce the amount of light that the photodiode is expecting (provided its the factory setting) then its more likely that the tube is getting tired.

From what I've read, and from what Sam has told me (author of sams laser faq) everything seems just fine in light mode on my laser. I switched over to current mode earlier today and it has no problems with close to 11A  (until I blow the breaker in my house  ;D )

EDIT: Oops, almost forgot, I'm talking specifically about the cyonics/uniphase 2101-40MLA. I'm not sure if it is the same on other makes/models, but this is how the C/U light mode works.
 

GooeyGus

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SenKat_Stonetek said:
[quote author=GooeyGus link=1214412765/48#48 date=1214735086]Hoooly crap. So I got everything wired up to run it in current mode. With the setup that I wired up, it will go up to about 10.6A. This is perfect because I didn't want the pot to be able to push the current WAY past acceptable limits. I used a 10kohm pot and two 10kohm resistors in parallel (so 5kohm resistance total) to achieve 10.6A at the least resistance. Let me tell you, this is BRIGHT now. It looked about three times as bright, so I got the power meter out and did some measurement. At first my reading was about 160mW but after about 15 minutes it was pretty steady at 180mW. Also remember, the head of my power meter is 15 feet away from the head of the laser, as this is the only way I could get an accurate reading because of all the air moving around close to the laser. I'm sure with the meter up close and personal with the head, it would be over 200mW. I'll try to get some more pictures and post them up!!

I keep blowing the breakers at 10.6A, so I'll have to turn it down a tiny bit  ;D
Gus - an idea regarding your power meter....take the lead from Coherent on this one......grab a KOOZIE - one of those personal can cooler thingies...that wrap around the beer can/bottle ?  Yup - those !  Use one to insulate the sensor on your thermal meter - you can even use the hole in the bottom of it to shoot your beam through :)  Coherent ships out the $0.50 Koozie with a small paper template to place on it - so you can trim it up to fit around the sensor head on their $2100 package....kinda cheesy, but makes perfect sense !  ALL of you folks out there with the DIY meters should give that a shot - it would most likely stabilize your meters more, and increase accuracy - as it would prevent interference from the outside environment :)[/quote]


Can you take a picture of how it sits on yours exactly? I'm having a hard time visualizing this  ;D

Oh yeah... I'll get some new ACTUAL full power pics and videos up soon. It lights matches almost instantly... pretty cool!
 

GooeyGus

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Cyparagon said:
[quote author=Tallaxo link=1214412765/48#49 date=1214747170]
Light mode is just for stabilization.
and to minimize the occurrence of plasma oscillations and prolong tube life.
[/quote]

And prolonging tube life is probably not running 10A all the time :eek:

The air coming out of this thing gets HOT when running at 10A
 

GooeyGus

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here's another picture.... MUCH brighter, this time running at about 9A. It gets even brighter up to 10.5A but my room mate was on his computer, and the argon needs the breaker all to itself so it wont throw it at full power  ;D

You can see my shadow on the wall, and the beam isn't even hitting a white surface! Its hitting dark wood. When the beam hits a white surface, the entire room get covered in the crazy aqua color.

 

diachi

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Wow, thats amazing, cant wait to see some videos.

Btw whats your breaker rated at, they should be higher rated than 10.6A ...

Diachi
 

GooeyGus

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Diachi said:
Wow, thats amazing, cant wait to see some videos.

Btw whats your breaker rated at, they should be higher rated than 10.6A ...

Diachi
15A. Its fine when its the only thing running on the circuit, but with laser + TV or computer it will blow the breaker :(

I'm going to put in a 20A this week sometime.
 

diachi

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Well that could be good atleast you wont have to turn everything else off to run your laser, I wonder how much mines can take.
 
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Standard house wiring in north America limits breakers to 15A. More then that needs thicker wiring, as it could present a fire hazard otherwise. The laser tube is drawing 10 amps, but also remember other parts of the laser are drawing power as well. Fans, indicator lights, and general inefficiency in electronics all contribute to the power draw. Hell, the cathode draws 3 or 4 amps of current by itself, albeit at a very low voltage.

I had a brand new 20A circuit installed into my bedroom just for my argon. And I'm getting like 50mW on all lines combined and I paid twice as much as you did. What a piece of crap!

*throws it out the window*

Also, where did you find out how to set yours to current mode? I want to do it to mine but I am not sure how, it's also a cyonics uniphase.
 

GooeyGus

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Event Horizon said:
Standard house wiring in north America limits breakers to 15A. More then that needs thicker wiring, as it could present a fire hazard otherwise. The laser tube is drawing 10 amps, but also remember other parts of the laser are drawing power as well. Fans, indicator lights, and general inefficiency in electronics all contribute to the power draw. Hell, the cathode draws 3 or 4 amps of current by itself, albeit at a very low voltage.

I had a brand new 20A circuit installed into my bedroom just for my argon. And I'm getting like 50mW on all lines combined and I paid twice as much as you did. What a piece of crap!

*throws it out the window*

Also, where did you find out how to set yours to current mode? I want to do it to mine but I am not sure how, it's also a cyonics uniphase.
Exactly... the power supply says 17A @ 115V... so at full power I'm assuming its close to this. How much did it cost you to have the 20A outlet put in? I'm debating if I should do it myself or not. It's in a pretty easy location, but I always hate climbing under my house  ;D

Also, before I figured out how to wire mine for current mode, I was getting about the same output as you. I was getting around 60mW @ 6.4A, which is as high as the amperage would go while using the knob on the power supply (light mode)

As far as current mode, I learned how to wire it by reading SAM's faq, along with the user manual for the laser (which has a complete pin-out for the power supply). Do you know what model it is? Most of the cyonics/uniphase power supplies (for the lower powered argons at least) should be the same. I know climbak's power supply has the same pin-out as mine, as I told him how I wired mine into current mode and it worked for him.

Anyway, here's how I did it (the quoted part is from Sam's FAQ):

Pin 23 connected to CCW terminal of pot, pin 25 via 5K ohm [I used two 10k in parallel] resistor connected to CW terminal of pot, pin 6 connected to wiper of pot, pin 36 connected to pin 37.
Also, to enable current mode, you have to have light mode disconnected (which is pin 12 & 13, so make sure they aren't jumpered together) AND the current control shunt must be enabled, to do this just connect pin 14 to 15.

Also, to monitor current while its running, connect your DMM to pin 26 (+) and 27 (-)   the calibration is .1v/A

Hope that works!!  :D :D
 

Cyparagon

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Just put a new breaker in. There's no fire hazard unless you're entirely reckless (like 40 or 50A). It may heat up insignificantly but the wire in the wall is 12AWG and can handle 20A just fine. I was running mine (spectra physics) with an 18AWG cord for a while. It became hot to the touch, but still worked.

If nothing else, consider this: you'd run a laser diode a little (perhaps even a lot) over spec, but why not robust wiring?
 

daguin

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Cyparagon said:
I was running mine (spectra physics) with an 18AWG cord for a while. It became hot to the touch, but still worked.
LA LALA LALA . . . .NOT LISTENING . . . . . .not listening

Peace,
dave
 

GooeyGus

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Cyparagon said:
Just put a new breaker in. There's no fire hazard unless you're entirely reckless (like 40 or 50A). It may heat up insignificantly but the wire in the wall is 12AWG and can handle 20A just fine. I was running mine (spectra physics) with an 18AWG cord for a while. It became hot to the touch, but still worked.

If nothing else, consider this: you'd run a laser diode a little (perhaps even a lot) over spec, but why not robust wiring?
That's what I figured. I have a spare 20A breaker here that should be up to the task. I'll check out the wiring to make sure there's nothing ridiculously small (I think the house was built around 30 years ago, so who knows what kind of mickey-mouse jobs have been done since then) and if it all checks out I'll put the other breaker in and make sure the wires don't get too hot with a high current draw. What is the specified gauge that 20A breakers/outlets are supposed to have?
 




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