40W laser loosing power

[jbailey19]

I have a 40W tube and power supply bought in Dec of 2011. They have about 900 hours on them. I am currently having to run at 60% speed rather than the usual 80% speed and it is barely cutting. I just read today that I should not be running 100% power but should limit to 18ma so I think that I may have used up my tube.
In order to trouble shoot I finally hooked up my 100ma meter and am showing 11ma at 100%. I then hooked up a 10k pot to (+5v/IN) but it does not limit the power. It just stays at 10ma no matter what. Should I use a 5k pot?
Back to the tube. I have a spare tube so I hooked it up and am still showing 10ma. Could the power supply be the issue? I think I might have a spare for it as well but I need to find it.
Any ideas?
Thanks.
Mike

[Things]

Are you sure it's the laser itself loosing power? Your machine could be out of alignment, or your optics could be dirty too.

[Tech_Marco]

Mike:

All our laser come with 3 months warranty. But the power supply it comes with 1 year warranty. If it's the laser power supply issue and if you buy from us, you can send it back for exchange. If you can't set power over 10mA, check the power input: AC 110v/220V

For our 40W PS, there is a switch at the back for 110V/220V selectable. In general, you should get full power by tapping the +5v to the "In" terminal. For a 40W PS, the output current could be as high as 24mA! A 40W laser tube should be limited to 18mA while a 60W tube can take 22~24mA.

Regards,
Marco

[waltfl]

Hi mike
did you try the test botton on the laser supply and watch the ma meter? the test botton should fire at the full power.
the next is did you check the power settings ( glass laser - 20,000 cycle- max power 98%)?
also check the HV connection on the tube and if maybe there is a jumping of the HV inside the housing.
thats also a bit crazy but check the connection to the laser supply that they are right ( TL - in - 5V etc)
greetings
walt

I have a 40W tube and power supply bought in Dec of 2011. They have about 900 hours on them. I am currently having to run at 60% speed rather than the usual 80% speed and it is barely cutting. I just read today that I should not be running 100% power but should limit to 18ma so I think that I may have used up my tube.
In order to trouble shoot I finally hooked up my 100ma meter and am showing 11ma at 100%. I then hooked up a 10k pot to (+5v/IN) but it does not limit the power. It just stays at 10ma no matter what. Should I use a 5k pot?
Back to the tube. I have a spare tube so I hooked it up and am still showing 10ma. Could the power supply be the issue? I think I might have a spare for it as well but I need to find it.
Any ideas?
Thanks.
Mike

[jbailey19]

The laser had been working properly until a month ago when it started to not cut as good. I made up for it by reducing the speed. I finally had time last night to play with it and got the results that I posted. I had been running 100% and as I did not have the ma meter installed I do not know how much power I was putting through the tube. I have a spare power supply. I will hook it up and if that fixes it I will send the bad supply in for replacement. I doubt it is the tube as the new tube shows the same 10ma.

Where is the manual for the 40w puwer supply? I cannot find it anymore.

What size pot do I use to control power and does it go between +5v and IN?

When the tube is old will the ma reduce or just the cutting performance?

Thanks.
Mike

[Tech_Marco]

Can't just do In and 5v. You need to connect one lead to the ground. The pot must be three legs type.
See it here : download/file.php?id=32

‘By the way, chech the focus lens. It could be dirty and may need to replace

Marco

[jbailey19]

Thanks for the manual.
I will hook up the ground. That makes sense. Is the 10k pot ok to use?
Mike

[Tech_Marco]

10K or 5K is fine.

Marco

[waltfl]

hi
just sort if the tube is gone it still will work for sometime in engraving but will not cut as usually.
one sign that the tube is gone is when the corona inside the tube has a whitisch color it should be purple.
maybe something else what I just found out and is interesting and actually logic is that the manufacturer of the laser tube
say the cooling water should enter the tube on the ray exit site mirror chamber ( negative wire) and should exit on the positive wire site
greetings
walt

The laser had been working properly until a month ago when it started to not cut as good. I made up for it by reducing the speed. I finally had time last night to play with it and got the results that I posted. I had been running 100% and as I did not have the ma meter installed I do not know how much power I was putting through the tube. I have a spare power supply. I will hook it up and if that fixes it I will send the bad supply in for replacement. I doubt it is the tube as the new tube shows the same 10ma.

Where is the manual for the 40w puwer supply? I cannot find it anymore.

What size pot do I use to control power and does it go between +5v and IN?

When the tube is old will the ma reduce or just the cutting performance?

Thanks.
Mike

[jbailey19]

Well I got the negative wire hooked up on the POT and now I have control.
I also found that the ac switch was set at 220. Not sure how that happened as it used to work fine. Must have gotten bumped.
Once I was able to get 18ma out of the supply I did find that the tube was bad. It would barely cut at 10ma and would not cut at all at 18ma. The color of the arc was white so I that tube must be shot. I installed a new tube and set it to 18ma and it is cutting great.
Thanks for all the help.
Mike