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PWM causes lockup

Rather than keep piling on, figured would start a clean thread.

When attempting PWM control via the Gerbil, the whole thing stops (and locks Inkscape) a second or so after the laser fires and x/y start moving. The test jobs for this are all via default settings in the Inskscape plugin on WIN10.

Here are the scenarios I have been through:

1:Original panel current control and laser switch on: all is fine for cutting (since no Gerbil Current control this way, I cannot engrave)

2:laser switch off, Gerbil PWM connected: the routine will run through the x/y and return to home.

3:Laser switch on, Gerbil PWM connected: locks once x/y and laser go at same time (it will x/y to the cut start location, just lock as soon as the laser fires)

4:0.1uF cap across PWM as was suggested here, but the behavior is the same as without (see #3)

I am thinking this may be due to having an entirely digital panel (no manual POT). Does this seem reasonable? Can someone tell me the specs on the POT so I can try to wire one in place of the digital panel?


Any thoughts are greatly appreciated.




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The pot is a 5kOhm and connects to 5v, In (middle of the pot) and gnd. These three laser power supply connections sit next to each other on the second connector (middle one) and these three screw connections start counting from the right. When the pwm wire is connected, you should not have the output of the stock digital control panel connected. You can add a switch in between so you can choose between the stock digital control or gerbil pwm control for controlling the tube current.

Thanks for the info.

I will give the analog POT a try and report back with the findings.



unfortunately, same behavior with the analog POT as with the digital panel (works fine without PWM connected, locks up with PWM connected)


Any thoughts on what else I might be able to test?



Hi Nick PM me so we can establish what the issue is. cheers, Paul

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