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please help

Posted: Mon Sep 17, 2018 6:46 pm
by pedropinedacas
I have a problem with my laser
AWC708C 80W tube
It does not cut, it does not record, it's very weak. the ammeter jumps sharply.
Does anyone know what may be happening?
Thanks for the help

Re: please help

Posted: Tue Sep 18, 2018 6:33 am
by Techgraphix
Normally i would expect the tube to be broken: The current you measure is way too high.
When tubes degrade you will notice a rise in current and a decrease in outputpower.
But you still will see the plasma inside (as in your video)
The HV-powersupply can't deliver that current all the time. That's why you see it collapse
Yours is an extreme example of this..
Is the tube new?
Did it work well before?
Did you connect it the right way?
No airbubbles in the coolingliquid (that might have destroyed the tube)?
Do you use a decent cooling (like CW5200 or similar)
No arcing near the HV-connections?

Normally the return-wire, that is connected to the mA-meter, is attached to the side of the tube, where the beam comes out.
Did you do so?

Re: please help

Posted: Tue Sep 18, 2018 6:53 am
by pedropinedacas
thanks for your help
the laser worked well. The tube has only 50 hours of use
the machine was not working for 18 months it is possible that the tube had
Appreciate your help

Re: please help

Posted: Tue Sep 18, 2018 1:04 pm
by Techgraphix
Tubes do get worse in time, even when stored.. but 18 months is a bit short to get this.. Normally i won't use a tube that is older than two years of storage.
It's a guess, but i think when you replace the tube for a fresh new one, your laser will work fine again..
That is, ofcourse, when you have not damaged the HV-supply..
Some (radio-)tube collectors are very happy with a real BIG lasertube ;)