I recently wrote a post concerning the possible early failure of my 60 watt tube. The discussion eventually got to making adjustments to the power supply output. In these responses I saw “pwm” which I interpret to mean Lightburn layer power %. What does pwm stand for? Same as “lps” which I believe refers to the power supply, right? What does lps stand for?
I understand the convenience of an externally mounted milliammeter but the adjustment of the power supply output is inconveniently located.
You could think of PWM as a loose analogue of laser power % but it’s not strictly so. PWM stands for pulse width modulation which is a standard or method by which digital signals are used to represent variable measurable states by modulating the width of the digital pulse. In the case of the controller, the signal for power level is encoded with a PWM signal. In practice, the voltage of the PWM signal should reflect the requested power level (although the actual digital signal isn’t constructed that way). So 0-% power will map to 0V PWM signal. 100% power will map to 5V PWM signal. All other power %s map linearly across that range.
LPS stands for laser power supply. This refers to the high voltage supply that drives the laser tube.
It’s not strictly necessary in the sense that equipment will work without the adjustment. It’s only necessary if you want a hardware limit imposed on the output of the LPS such that you can safely request 100% power from LightBurn and the LPS will provide the maximum safe current to the tube. Without the adjustment you’d have to be aware of the upper limit and adjust power levels accordingly in LightBurn. Let’s say that you know that 85% power in LightBurn achieves max safe current for the tube, then you’d have to always keep power levels below that threshold.