laser power supply voltage transients

[burkard99]

I have just got my 40 W CO2 laser cutter up and running but immediately ran into problems. First the UC-2000 laser controller connected between the 'H' and 'Gnd' connections of the power supply (bought from LightObject) stopped working. I discovered that the output buffer stage was toast: I can measure 5V PWM in and nothing out. I switched over to gating the output from Mach3 via C10A break-out board. Shortly after, when running the laser, I heard a soft 'pop' and every thing stopped working. I discovered that the output stages on the breakout board are similarly dead (I can't even run the motor controllers).

I believe this happened due to high voltage transients from the laser power. Has anyone had similar problems? I plan to return the power supply to LightObject but don't know if they will find anything. Has anyone tried adding voltage suppression diodes to their system?

[daniel.macke]

Hello,
I have a 80W system running from linuxcnc with a NETMOS parallel port card. I use bidirectionnal transil diodes (reference 1,5KE6,8CA voltage 6,8V) wired between each PSU input and GND to prevent any high voltage return (in case of arcing for example). I have had no problem so far.

[burkard99]

Thank you! I found these diodes on Digikey and have ordered them