Adjusting power supply for max power?

[DanoInTx]

Hello Forum,

I recently upgraded my Chinese blue/white "50 watt" machine with the following 2 products from Lightobject:

https://www.lightobject.com/Laser-Power ... wer-Supply

and

https://www.lightobject.com/Laser-Tubes ... er-Tube-1M

I have added an ammeter to my system and adjusted max power to 16mah within the controller (Ruida 6442?).

I am currently using Lightburn software and also sent max power of 45%, which is 16mah, to the controller. The problem is that 45% is more of a choke on the laser, if I set my cut at 45% in my designs it's 16mah, if I set at 80, 90, 100% it's still 16mah. I'd like to be able to set say 50% and get 8mah. So I was wondering if there's some manual way (like a potentiometer on the power supply) to actually turn down the max power so I have more fine control? I don't really see anything in the manual on here specific to this power supply. Or if maybe someone runs a similar setup, is there some way in the software that I'm missing?

FWIW, the new tube and power supply work fantastic, I've been cutting a ton of 1/16"-1/4" ply and hardwood as well as 1/8" and 1/4" acrylic with nice clean cuts. I've also upgraded the mirrors and lens to the Lightobject brand just prior to tube/PS install, and even with my original tube I saw a good increase in cut speed. Thanks!

Dan

[Tech_Marco]

What you need to do is to add a three prongs potentiometer to the input of your laser power supply and you may able to do 100% at 16mA and 50% at 8mA (roughly)
https://en.wikipedia.org/wiki/Potentiometer

Marco

[DanoInTx]

So could I set it up like as described in this article?

https://k40laser.se/diy-how-to/upgrade- ... ower-knob/

I realize I don’t have a K40, but would the setup be the same even though I use a Ruida controller?

Thanks,

Dan

[DanoInTx]

Still trying to get my head around this. Doesn’t the power supply in take PWM from my Ruida controller? Will a simple pot wired in series be able to do what I’m asking? I’m handy, but not super electronical. It sounds simple enough, but I don’t want to fry anything while I’m testing this out.

Thanks,

Dan

[Tech_Marco]

Let me draw you a simple diagram and will post it once done

Marco

[Tech_Marco]

See this:

[DanoInTx]

This is perfect Marco, pretty much how I pictured it except I didn’t have the 3rd leg to ground. I’ll give it a shot and report here if it works out.

Thanks again!

Dan

[DanoInTx]

I finally got around to trying this, but it doesn't seem to work. I don't know that limiting voltage from a PWM output works this way, PWM is the width of 5v pulses, not the actual voltage, so I either get nothing or full power. Pretty sure I have it wired as per diagram above, but I think somewhere in there the PWM needs to be converted to voltage 0-5V from PWM (5 volts with variable width), with this I think I'm just limiting the height of the pulse. My background is not electronics, so I could be wrong here? Thank you.

Dan

[DanoInTx]

Found that my controller actually has an analog output as well as PWM. Some images of the Ruida RDC 6442G-B (EC) show a 24V in this location, while others show L-AN1 on the same spot on the controller (different pictures even in same manual, gotta love it). I also found I had a bad potentiometer which wasn't helping me figure this out. New pot, connected to L-AN1 and I'm in business!

Dan