Help! K40 board upgrade laser control line issue

Lasers
1

Hi all! :waving_hand:

I tried AI help but I got conflicting advice!

I have a K40 laser with an analog current gauge and a type 1 power supply.

I bought the Monport GRBL board. There is no ribbon connection as the original board didn’t have it.

There is no connector block on the power supply for the laser control line.

1/ ChatGPT said leave existing wires in place. Then connect the black wire of the control line to G of the G|P|L|G|IN|5v block and the red to L on the PSU

2/ GoogleAI said connect black to G and red to the IN on the block. Leaving existing wires in place.

The first option caused the laser to fire as soon as the machine was switched on.

It works with the Google advice. The red PWM wire to the IM socket and black to GND.

Trouble is the retained power control seems to be doubling up the voltage. So a minimal setting on the dial and 0.5% setting in Lighburn produces 2mA. 4% will likely produce 16mA.

Any better solution? Thanks in advance.

Can you please help me with regulating the laser power?

Thank you

Chris

2

Ok so I did look at a similar thread but my head exploded.:exploding_head:

My current set up >

PWM to the PSU IN

GND to G

The pot is set to minimum

I get 2-3mA @ 1% power

15mA @ 50% power

______

Monport’s solution >

PWM to IN

GND to G

Jumpers on psu between G & P and L & G

__________

ChatGPT’s solution>

PWM to PSU’s L

GND to G

Invert signal of PWN by coding in LightBurn console

Or invert the signal using 2N2222 inverter

______

Any input will be appreciated as I’m struggling here