Search found 20 matches

by audiomath
Sat Sep 30, 2017 11:41 pm
Forum: CO2 Laser Discussion
Topic: CO2 laser PSU cathode voltage relative to ground?
Replies: 6
Views: 1194

Re: CO2 laser PSU cathode voltage relative to ground?

There is this man named Murphy... After installing the new 60W SPT tube and power supply, I fired the machine up and the chiller came on, but it wouldn't shut off! It turns out the 10K thermistor in the bottom of the coolant tank quit working - for some reason?? (I flushed the coolant twice before i...
by audiomath
Mon Sep 25, 2017 8:48 am
Forum: CO2 Laser Discussion
Topic: CO2 laser PSU cathode voltage relative to ground?
Replies: 6
Views: 1194

Re: CO2 laser PSU cathode voltage relative to ground?

Problem solved -
A search of the LO site turned up a 30mA panel meter with a rectangular mounting bezel.
I ordered two, and will install one and the protection diodes in the sheet metal in the front of the machine.

--jim
by audiomath
Sun Sep 24, 2017 1:27 am
Forum: CO2 Laser Discussion
Topic: CO2 laser PSU cathode voltage relative to ground?
Replies: 6
Views: 1194

Re: CO2 laser PSU cathode voltage relative to ground?

Daniel, You were correct. I got the machine back together tonight, and the cathode voltage relative to ground is essentially zero. Now to decide how to mount the meter. It's currently in a plastic box that attaches to the laser with a cable. I bought a new raw meter from LO to replace the flaky one ...
by audiomath
Thu Sep 21, 2017 10:48 am
Forum: CO2 Laser Discussion
Topic: CO2 laser PSU cathode voltage relative to ground?
Replies: 6
Views: 1194

Re: CO2 laser PSU cathode voltage relative to ground?

Hello, The cathode voltage should be very close to the ground voltage, the only difference is caused by the internal shunt in the current meter. On my system (80W RECI tube, 80W PSU "Jupiter" from lightobject) I use bidirectionnal transil diodes (reference 1,5KE6,8CA voltage 6,8V) wired b...
by audiomath
Wed Sep 20, 2017 1:44 pm
Forum: CO2 Laser Discussion
Topic: CO2 laser PSU cathode voltage relative to ground?
Replies: 6
Views: 1194

Re: CO2 laser PSU cathode voltage relative to ground?

Since this doesn't appear to be common information, I'll measure it at close to full current once the new tube and PSU are installed.
I'll post the cathode voltage value and what safety measures (if any) I used once everything is up and running.

Thanks,
--jim
by audiomath
Tue Sep 19, 2017 3:37 pm
Forum: CO2 Laser Discussion
Topic: CO2 laser PSU cathode voltage relative to ground?
Replies: 6
Views: 1194

CO2 laser PSU cathode voltage relative to ground?

I just ordered a new milliammeter to be permanently installed in my 60W laser cathode circuit. I plan on cutting out the sheet metal and mounting the meter directly in the cabinet. My question is does anyone know the cathode voltage (not current) of (say) a 60W tube, relative to ground? My reason fo...
by audiomath
Mon Sep 18, 2017 11:02 pm
Forum: CO2 Laser Discussion
Topic: 60W Power supply keeps failing
Replies: 9
Views: 1692

Re: 60W Power supply keeps failing

The machine seems to move fine at 400 mm/s. I can scan a 100x100mm rectangle at that speed and it doesn't appear to lose any steps. (it returns to the correct origin when through) I'll have to wait until the tube and PSU are replaced to really tell for sure, though. I suppose I never thought to run ...
by audiomath
Mon Sep 18, 2017 9:02 am
Forum: CO2 Laser Discussion
Topic: 20W~45W or 40W~60W power supply for 40W tube?
Replies: 1
Views: 575

Re: 20W~45W or 40W~60W power supply for 40W tube?

Never mind, Marco convinced me to stay with the 60W. :-)

Thanks,
--jim
by audiomath
Mon Sep 18, 2017 9:01 am
Forum: CO2 Laser Discussion
Topic: 60W Power supply keeps failing
Replies: 9
Views: 1692

Re: 60W Power supply keeps failing

60W is great for engraving. Even 80W is good! 40W sometimes may not get you deep engraving enough with huger speed like 600mm/s That's interesting... I haven't ever tried running the machine faster than 200mm/s. Ok, you changed my mind. I'll stay with the 60W components. You'll see an order in the ...
by audiomath
Mon Sep 18, 2017 8:58 am
Forum: CO2 Laser Discussion
Topic: 20W~45W or 40W~60W power supply for 40W tube?
Replies: 1
Views: 575

20W~45W or 40W~60W power supply for 40W tube?

I've decided to convert my machine back to a 40W tube. After looking at LightObject's listings, I see there are two different power supplies that might work: 20W~45W and 40W~60W . Here are my questions: (1) If I use the 40W~60W supply, will the 40W tube draw more current than it should at higher PWM...
by audiomath
Mon Sep 18, 2017 8:41 am
Forum: CO2 Laser Discussion
Topic: 60W Power supply keeps failing
Replies: 9
Views: 1692

Re: 60W Power supply keeps failing

I think you need to pay closed attention to your laser tube. 3 power supply broken in a year sounds unbelievable. When the laser power supply arcing, either the transformer of LPSU defective or the laser tube is leaking gas! Not sure why you unplugged the current meter. To us, it is one of the most...
by audiomath
Sun Sep 17, 2017 9:48 pm
Forum: CO2 Laser Discussion
Topic: 60W Power supply keeps failing - SOLVED (I think)
Replies: 0
Views: 800

60W Power supply keeps failing - SOLVED (I think)

I believe I've found out why the power supplies (PSU's) keep failing. I made it a new topic because I want it to be clear it isn't the fault of the PSU's. After installing a spare PSU, I noticed the output of the tube was down as compared to before the last PSU failed. I started a job, opened the ba...
by audiomath
Sun Sep 17, 2017 2:17 pm
Forum: CO2 Laser Discussion
Topic: 60W Power supply keeps failing
Replies: 9
Views: 1692

Re: 60W Power supply keeps failing

I think you are just unlucky.. If the environment ain't hostile (moist, dust, very high or very low temperature etc), i can't think of anything that can cause it. If all HV-wires are kept at quite a distance of the metal frame and the connection to the tube is solid, it should be fine. If you read ...
by audiomath
Sun Sep 17, 2017 12:35 pm
Forum: CO2 Laser Discussion
Topic: 60W Power supply keeps failing
Replies: 9
Views: 1692

60W Power supply keeps failing

I just lost another 60W power supply. This makes a total of 3 in one year, 2 of which are the "Jupiter" brand power supplies I bought from Light Object. (the first was a very cheap one I bought from another vendor with the tube) When I install the power supplies I put the anode wire inside...
by audiomath
Tue Jan 31, 2017 12:48 pm
Forum: CO2 Laser Discussion
Topic: Newer 60W power supply went "bang" - now what?
Replies: 5
Views: 1088

Re: Newer 60W power supply went "bang" - now what?

I agree the Jupiter PSU is much better built than the cheap ones, so I'll stay with it. I suppose what I should do is make a chart of the current at different duty cycle percentages, so if I need to change a LPSU I'll know at least approximately what to change in each job to get the same results. I ...

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