danger setting max laser power in manufacturer settings

[waltfl]

Hi all
I just wana point out again the max power setting for the laser in manufacturer setting should not be more then 60%
to avoid destroing the laser tube due to overpower.
I am just experienced a tube destruction because I was not aware that the DSP actually does not take the real current to the lasertube and does not stop a overpowering.
like a few other guys have experienced this too and damaged or destroid ther laser tube ( see tim wehr etc)
after I have added a mA meter I saw whats happen if I did choose 70 or even 80 % especially for cutting 1/4 material the curent did go over 20mA and measured with a bigger mA meter it did shoot up all the way to 40mA thats what destroid my laser tube.
my recommendation:
put a analog mA-meter in the return circuit from the laser tube . a digital mA meter will not help due to the high fluctuation.
set the max power in the manufacturer settings to max 60% not the 98%.
order early a replacement tube if you have use the original settings and a job setting higher then35% like I did my tube lasted only about 250 hours engraving with around 10 to 15% and about 5hours cutting at 75%.
now I am waiting for the replacement tube .
marco this should be changed from the software to avoid maybe liabiltiy question.
greetings
walt

[Tech_Marco]

PLEASE DO NOT MAKE ANY WRONG ACCUSE TO THE DSP CARD IF YOU DON'T KNOW OR IF YOU'RE NOT 100% SURE. EVEN 150W POWER SUPPLY WON'T GO OVER 38mA! DON'T JUST BLAME ON THE DSP, THE RESPONDING TIME VS PWM FROM THE POWER SUPPLY NEED TO BE TAKING INTO ACCOUNT. PLUS, LP DISCHARGE TAKE TIME.

If you don't have a proper power supply for a proper rating tube, you're running on your own risk. Even a 40W PS can driver a 50W laser tube easily. Or, our 80W PS can driver a 100W without any hesitage. If you don't have a current meter to monitor the output, sure you're walking on a string.

I'm going to post a few screen shots per rating setting. It's true that if you set full power 100% on manufacturing and anything over 80% (not 60%) make no significance. But Idon't think this is a "life or dead" suituation.

True, CO2 laser always dangerous. It doesn't matter 20W, or 100W or 50% or 100%.

Note: Even though you power off the system and hit "Laser", there still a little fire possible. You can't discharge PS in micro seconds. Live with that or don't use it.

Marco

[Tech_Marco]

System power:100%
PWM frequency: 20KHZ (20,000)
LaserCad setup: 3% to 100%

In general, system power by default shouldbe 90%. Anything over that really make too much significant as high voltage PS won't respond to high speed enough to discharge.

Marco

[waltfl]

hi marco
I dont blame the dsp card just the setting for the 40W in the manufacturer settings is wrong you can ask tim too he has the same experience.
if the power settings in the manufacturer settings are at 90 % and the job power setting are at more then 65% it will output more then 20mA.
thats what I have measured this with the mA meter what I have installed but to late for my tube ( see picture)
I have the 40W PWM power supply from you also nothing wrong with the power supply.
acording to the manufascturer every current over 20mA will damage the Lasertube sure if it is used for maybe 1 time for cutting the damge would not be so fast but like me I used the setting of 75% for many cuttings and the result is ( like tim wehr has experienced it too not just me ) that my tube is gone.
I measured them output with a 200mA analog meter and it was 40mA by manufacturer settings original 98% and 95% job settings.
pleas keep in mind that I dont make aquasitions if I can not back it up!!
I am in contact PM with a few other guys who just starting and they had the same understanding with the settings.
greetings
walt

PLEASE DO NOT MAKE ANY WRONG ACCUSE TO THE DSP CARD IF YOU DON'T KNOW OR IF YOU'RE NOT 100% SURE. EVEN 150W POWER SUPPLY WON'T GO OVER 38mA! DON'T JUST BLAME ON THE DSP, THE RESPONDING TIME VS PWM FROM THE POWER SUPPLY NEED TO BE TAKING INTO ACCOUNT. PLUS, LP DISCHARGE TAKE TIME.

If you don't have a proper power supply for a proper rating tube, you're running on your own risk. Even a 40W PS can driver a 50W laser tube easily. Or, our 80W PS can driver a 100W without any hesitage. If you don't have a current meter to monitor the output, sure you're walking on a string.

I'm going to post a few screen shots per rating setting. It's true that if you set full power 100% on manufacturing and anything over 80% (not 60%) make no significance. But Idon't think this is a "life or dead" suituation.

True, CO2 laser always dangerous. It doesn't matter 20W, or 100W or 50% or 100%.

Note: Even though you power off the system and hit "Laser", there still a little fire possible. You can't discharge PS in micro seconds. Live with that or don't use it.

Marco

[Tech_Marco]

More Proof.

[Tech_Marco]

Morec to come... stay tued

[Tech_Marco]

Sorry my last post won't be a solution. After I press 'Reset', it lost that capability.

Sorry my last post won't be a solution.

I discussed that matter with the programmer Li after spending two days for testintg and trying to dig out more info with my troubsome Tektronix Scope. Then I did some tests with him for several hrs (chatting by typing, pain as ...). In fact, the card was actually performing it was supposed to be. 70% 3.778V, 95% 5V. So logically, it worked the way it designed. But in reality, it's hard to see much difference after the Max_Power setting is set over 80% . I guess the PS was in saturated mode.

So, my suggestion to the programmer is to rewrite some code to 'fool' the controller. Pretending that 65% was as 100% and add non-linear adjustment to the code. That way, we should be able to see current changing via 65%~100% adjustment, hopefully.

Looking forward to see his new code

Marco

[Ruud Hogenberg]

Hello ALl,


On my card 68% is 18mA.

Indeed strange, I also should expect 98% is 18ma for the awc608 card and the pwm supplied by lightobject in combination with a 40w co2 laser tube.

As i have read all the remarks on this forum.. (days) i could prevent by changing the 98% manufacturer setting to low and upscale by measuring the mA
Maybe a solution so set the manufacturer setting to 50% for safety..

Thanks for that..
Ruud

[Tech_Marco]

Please make no assumption. A quality 40W PS can output as much as 26mA and a true 40W laser tube should take no more than 18mA in general. The controlling from the DSP is perfect if you have a scope to monitoring the output. It output pefectly waveforum in the proportional to the power rating setup. Say 50% power and I could get a 50/50 squre wave. That's very making sens output. The true is that the power supply doesn't response fast enough to the signal (or non-linear) and if power is set over 75% or above. The slope of the curve go rapidly than the region at 20% to 60%. Plus, the PWM frequency does have some effect on the output as well.

I hope you guys wont get panic about it. Once you understand the logic behind it, you should be able to make good adjustment on the power setting. I talked to the programmer about that issue (it's truly not the fault of the DSP card), it's compatible issue and the law of physics. To deal wit that, I asked him if he could extend the range of the zone from 70%100%, make it like triple long. So, that you can see the difference (human eyes issue) more obviously.


Marco