Machine: Scratch Built Custom Design
Board: Cohesion3D LaserBoard
Firmware: Probably Smoothieware Clustered version
Problem/ Question: Just need a bit more clarity on the whole PWM control side of things.
First off this is a new build, my first laser and I’m diving in at the deep end. I’ve ordered the majority of what I need bar the mechanical side of things that I’m still designing out. So in the meantime while I wait for delivery I’ve been doing a lot of reading and the control of the laser power seems to be an interesting topic! (I have read the PWM Control Pot vs. Digital thread.)
In my ignorance I assumed that the Active High or Active Low connections on the LPSU were binary and simply used to enable the laser, and its power during operation was controlled by the IN connection by a PWM signal. However it seems that the LaserBoard PWMs the Active Low connection, and it is intended that the IN connection is used to set maximum power.
Have I got this correct? (Specifically that the LaserBoard PWMs the Laser Fire pin, which is an active low signal and connects to the Active Low on the LPSU.)
Out of curiosity what period/frequency is this PWM signal?
What’s considered 100% power for a RECI W2 tube that’s rated at 90W with a peak value of 100W?
What controls the Alternate PWM pins on the LaserBoard?
I also read on the PWM Pot. vs Digital thread the suggestion of setting the max power via the Pot to be the maximum that the job at hand requires, which will then give more resolution for varying power requirements when engraving. Sounds like good reasoning to me bar one detail that’s niggling at me. Say you have an engraving job on a given material at 2mm thick that requires engraving and then cutting. You set the maximum power to be whatever is required to cut the material and then the engraving portion is done at a percentage of that value. What if you need to run the same job later on the same material but now 5mm thick? You have to up your maximum power which then screws up your engraving power levels. Or am I just over thinking this and getting way ahead of myself?
Please bear in mind that my only experience with lasers up to this point is annoying the cat with a laser pointer, so I know I have much to learn!