I ended up taking a 10K linear potentiometer, connecting the DAC output to the top terminal, GND to the bottom terminal, and the wiper to IN1 on the LPSU. Test-fired the laser at 100% and adjusted the pot for 17mA. Now I get 0-100% and the scaled power settings are as linear as they were before.
I was hoping that the user that posted it is still on here and can share a wire diagram of how they added the 10K linear potentiometer. I am trying to figure out how to add it as a limiter to what my ruida is sending to the LPS. I would like to set my ruida min and max to 0/100 and have the LPS limited.
Right now, I have it set to 15/50. But it is very confusing when sending jobs from Lightburn. If I send a cut file of say 30% power, it shows correct on the ruida controller. But if I send a cut file at 75%, it shows as 50% on the ruida controller. It is just very confusing on what I am actually getting for an output.
I know at 50% limit on my ruida, that is 15ma on my meter which should be 80 of the tubes rated power.
I have yet to find an internal pot on the actually K40 LPS to limit this internally.
The proper connections for a Ruida is for the LPWM1 → IN of the lps and L-On1 → L of the lps.
If it’s wired correctly, then you can adjust the internal pot of the lps for a 50% output at 50% power from Lightburn and then your 0 to 100% power will be synced up. I don’t know if the K40 lps is adjustable… that could be an issue.
If you have a pot wired to IN feed by the control voltage, you’re just limiting the variable voltage (pwm) to the IN terminal… so instead of it going from 0 to 5V it goes 0 to some lesser voltage. This restricts the current control range and limits control.
I suggest you measure the tubes length and see how much power it has based on the length. Wire the controller up correctly.
Yes, I think that is the issue I am running in to. There is no internal pot on the LPS. I have been looking for a new 40 watt lps with an internal pot, but have yet to find one. I see them a lot on the high power lps. Right now I have the old k40 pot disconneted and just using the Ruida.
It is confussing with setting up jobs with one power setting and not knowing what you are actually getting at the laser.
