I have problem with minimum power being too strong. I know about the $30 value vs. device S- value. Both got the same value. I would like to “throttle down” more, but can not. Difficulty is that burning texts etc. on wood, is carving too much. I can compensate to some degree by increasing speed, but this is less then optimal. Additional backround is that prior I changed to Monport, the original board enabled very lower power settings. Laser was firing, but not doing much anything. Here at minimum level it is really already burning considerably.
Here are my symptoms:
-laser fires with above zero power setting, so even with 1% laser is firing. Obviously nothing happens with zero.
-When increasing powers from 1% to lets say 15%, there is no difference in mah meter, as if now change was made to percentage.
-at around 35 or so percentage I am nearing full allowable milliamps i.e around 13-15
-at 100% I am shooting way too much power through the tube
So to summarize. I can not have low enough firing power, and percentage control at bottom end is not really allowing finer control. As if some additional setting is forcing some higher minimum power. I am guessing this is Lightburn related problem. I have googled and tried altering various $ values, mainly $30, but to no result.
If you ask for 50% power, you should get a 50% pwm output from the controller. You can measure this with a voltmeter and ensure the controller is providing to the lps the proper signals.
A normal ttl pwm will read 1/2 the ttl voltage with a 50% pwm signal. 100% would be 5V, 50% would be 2.5V and 20% would be 1V. You don’t needs to actually allow it to lase to test this. It depends on your setup.
Do you have a knob to adjust maximum power with your configuration?
I don’t now of any glass tube co2 that will lase at 1%.
Have not had time to measure voltage. Few notes though.
First off. Monport is in full control of the laser. There is no Knob or test button that would shoot the laser. I detached two connection from the power and attached one 3 pin connection with two wires coming from Monport. See picture.
After my first post I have now found out interesting detail. If I am lasering “line” layer type of work with laser, I will need to be below 35% throttle, in order to keep laser not going above around 13 mA. BUT if I am doing picture engraving “image” layer type, the throttle is acting differently. Laser is shooting light even with 1%, but with a weak power. Very low ma measurement, something like 1-2 mA. If I want to get somewhere around 4 mA, I will need to raise power % to about 45.
This to me suggests that:
Monport is capable of outputting very low power from the lasertube, not as it seemed to be initially shooting at least with 4-5 mA level, regardless of power setting
Something in Lightburn/and/or Monport is making them interact differently with Monport depending on layer type
For the most part I do not need lower power setting elsewhere except when engraving text. So if I could set text to be as image layer, that would solve my problem. But based on short study I have not found that possibility.
Most K40 have some kind of maximum current control on the console… It’s apparent in this photo of a Monport K40. It’s in the white area. Newer models have a digital display with up/down buttons for maximum current control.
Forgot the picture. Here it is. Black/blue two wires end up in Monport motherboard and to my knowledge is in complete control of the lasertube. No auxiliary control mechanism exist.
I believe the white unplugged wires would enable the original control mechanism on my K40. But the wiring as intructed completely disregards the original panel/controls. Obviously with the 3 pin slot being taken, the original white 3 pin/3 wire can not be plugged. I have not tried what the two pin single wire would do, since this was intructed to unplug.
Looks OK… from what I can see… took me a minute to see the jumper in the P-G connector. The three pin G-IN and 5V which is usually used to power the board, so it must be getting power from the right hand connector… I don’t use/reference these supplies much, so I tend to forget the what pins are what.
There are only two signals that control the lps… the L (laser enable) and IN (tube current limit)
Most K40 do have the front panel connected some way, so thanks for mentioning it doesn’t on yours. Does this mean there is no display or current meter?
At this point I’ll have to wait to see what the pwm or IN terminal reads at different percentage power levels…
I have separately installed mA meter, which is showing the power.
About measuring the pwm. Do I understand correctly that I could measure this by unplugging the 3 pin, 2 wire connector in the picture and just by measuring the voltage accross the pin when software is commanding firing? Meaning I would disconnect that single wire controlling the laser and seeing what voltage Monport mother board is sending throught those black/red wires?
The idea is to follow the signal to where it’s failing. If you get the proper control voltage readings, then it eliminates the pwm control coming from the board and is, likely further down the line such as wiring or lps itself.
The only other control line is the L input of the lps… Might check that voltage also…
While you do this, keep an eye open for faulty connectors that haven’t seated or the pin has been pushed out of it’s seat… Probably a good idea, to reseat these control connectors.
