Lightobject.com Support Forum

Hey folks,

The simple question is:
To which end of the laser tube does the red positive high voltage line attach?
40W tube
LSR-JN40W-1V

The manual online is for the 80W and I want to verify that the Red Positive High Voltage line goes to the rear and that the Negative return wire attaches to the front with the 40W

The second question is:
What happens if one reverses this?

The back story:
Back in 2005 or 2006, I bought one of the early HK40 style 40w laser cutter/engraver. It came with useless Moshi draw and I immediately gutted the thing and made a slightly larger cutter. In the original machine, the positive was wired to the front of the tube and the negative to the rear of the tube. Not knowing any different, I thought "that must be how it is..." Occasionally there were flashes of lightning from inside the old laser power supply due to inadequate insulation. I could add silicone caulking to areas where arc would occur and it would fix the problem.

Now I am building a 48" by 24" machine.

At some point, I realized the old tube was dead from just sitting. I ordered a new tube and connected it (to the old power supply) just like it had been: Positive to the front and negative to the back. I did a test fire and all seemed good. Then the power supply started with the lightning again.

So, I ordered a new JN40W from LightObject. Of course, the manual (if it is correct) says to put positive in back and neg up front.

So, once again..
Which way is correct?
What happens if it is reversed?

Thank you

Steve

the anode (+/red wire) is the electrode by the gas return tube. the cathode (-/black wire) is the electrode by the output coupler.

StevoLaser wrote:Hey folks,

The simple question is:
To which end of the laser tube does the red positive high voltage line attach?
40W tube
LSR-JN40W-1V

The manual online is for the 80W and I want to verify that the Red Positive High Voltage line goes to the rear and that the Negative return wire attaches to the front with the 40W

The second question is:
What happens if one reverses this?

The back story:
Back in 2005 or 2006, I bought one of the early HK40 style 40w laser cutter/engraver. It came with useless Moshi draw and I immediately gutted the thing and made a slightly larger cutter. In the original machine, the positive was wired to the front of the tube and the negative to the rear of the tube. Not knowing any different, I thought "that must be how it is..." Occasionally there were flashes of lightning from inside the old laser power supply due to inadequate insulation. I could add silicone caulking to areas where arc would occur and it would fix the problem.

Now I am building a 48" by 24" machine.

At some point, I realized the old tube was dead from just sitting. I ordered a new tube and connected it (to the old power supply) just like it had been: Positive to the front and negative to the back. I did a test fire and all seemed good. Then the power supply started with the lightning again.

So, I ordered a new JN40W from LightObject. Of course, the manual (if it is correct) says to put positive in back and neg up front.

So, once again..
Which way is correct?
What happens if it is reversed?

Thank you

Steve

Thank you. I shall rectify the situation. What happens if anode and cathode are reversed? Does laser fire other direction, bounce off of the rear mirror and fire out the front anyway?

Thank you again for the quick reply

Steve

It will fire too!
But, I think it may cause some delay firing because of reversed electronic charge movement. The effect may not obviously in small tube but should be an issue on a longer tube.

Some day I will test a longer tube and post what I found

Marco

typically photons in the lasing medium make multiple passes between the OC and the HR mirrors. direction is not an issue.

there are super-radiant lasers that don't require mirrors because the gain in the lasing medium is sufficiently high for coherent output, but that is not the case here.

StevoLaser wrote:Thank you. I shall rectify the situation. What happens if anode and cathode are reversed? Does laser fire other direction, bounce off of the rear mirror and fire out the front anyway?

Thank you again for the quick reply

Steve

I doubt my "cheap" 40w laser is super-radiant anything. It is already way more coherent than I am...