I think you are right. However, I think it’s generally restricted to medical devices. If you order enough of this junk, you’ll eventually end up with it being held by customs as a medical laser. I got three of the C series tubes and they got snagged in US customs for an FDA clearance.
There is definitely some very dangerous stuff showing up over here.
I don’t think anyone actually knows how these work. The only current control line is the IN of the lps. Most have a switch for using it or bypassing it.
I don’t recommend using these until someone clears up how they actually work.
I speculate they work the same as a K40 using manual power control like a dpssl, either on/off. This is only speculation, data, like schematics are non-existent.
It’s a small module on a cat5 cable. Check out Cloudray 100w PS. Model: M100.
I don’t see any reason not to trust it, other then Not noticing that it’s on full power.
If you wish to trust it, that’s your call. I think it works like the K40, so I wouldn’t advise using it without further information. Of course that’s my opinion.
Do you have anyway of measuring your tubes cathode current with a scope?
Suggest you use the internal current control and that will sync it up with your percentage power in Lightburn or other software.
Jack, I have no scopes to measure current. I really wouldn’t want to poke around without some guidance on this specific unit. I’ve been using this tube on a 60w PS for a long time so I know how it cuts. I don’t believe I’m over driving the tube. Im using a Cloudray tube and Cloudray power supply.
If it’s not reading correctly the only issue that I could thing of is lower max power, meaning I have more power that I’m not using. Not a big deal from cutting so far because it has plenty of power. I believe it’s cutting great. Can’t think of any problems but I’ll let you know if it blows up or something.
Dpssl (diode) lasers are on at 100% power anytime they lase. We think of varying the power but you are actually varying the power/time or average value.
Glass tube lasers or the lps can control how much current your tube uses via the IN of the lps. This is usually connected to the pwm of the controller.
If you wire a pot to the IN terminal and use it to set your maximum current value with the pot, when it lases, it does so at that current level.
IMHO, I don’t think that’s wise…
In the end, it’s your machine and you can do with it what you want.
A dpssl (diode) is controlled by a PWM signal. This signal is digital. When the signal is on, so is the diode, 100% power.
You can’t dim a regular led, the brightness can be controlled only by it being turned on and off at 100% power. The brightness is related to how long it’s on during the period or pwm cycle.
If you run a dpssl machine at 50% pwm it will lase at 100% power for 50% of the time.
Conversely, my glass tube, lases at 50% power for 100% of the time.
You can dim a regular led with a resistor but that’s probably not what you mean.
So what you are saying is with a diode laser, the power isn’t actually controlled, it’s the active laser time that is controlled, is that what you are saying? So it’s not when (in my case) I have a 24W diode laser, when I use it on 50% power, it only uses 2 6W diodes instead of 4?
You really can’t… ss devices have a certain voltage/current you need for proper operation. For it to operate, it needs to be done within it’s specified operational range.
Properly designed led will be driven by a pwm control for brightness.
Exactly right.
How your module handles this internally, isn’t published anywhere.
I can only speak for the led device itself, not how all the driving circuitry works. However I’m confident, there is no magic involved.
A LED will lase, but you do it by reversing the polarity and using a higher voltage. The current must be precisely controlled and the heat must be removed. Due to the physical constraints of the PN structure, 5.5 watts light power is all you can get out of one. Using PWM to turn it off part of the time, and thus reducing average power out, helps the diode to run cooler. Running a laser diose at wide open throttle will definitely shorten its usable life.
The light output is dependent on voltage. You can vary the brightness with a variable resistance.
I did exactly this using a red, yellow, and green LED. Each required a different voltage for the same apparent brightness. I built a stage light for my granddaughter’s microscope, with the ability to change the illumination color.
Lasing with a solid state device, like these lasers are dependent on current as far as I knew.
As far as I know, only a solid state structure designed to lase with current has this ability… not any regular LED…
How would it conduct any current if the power were reversed?
You can’t drive a solid state 5V device on 1V to get 20% brightness, so you are very limited with what kind of range you can get. This is the main reason pwm is implemented…
A solid state laser … there must be an area within the diode junction for the amplification to occur.
Too much reverse bias. Use your bench supply and sacrifice some diodes.
True, but LEDs are not 5v devices. And the output is not linear. That little circuit board on the top of the laser has all the smarts. And they are not interchangeable between modules either.
I was afraid it would come to this. Most material is about current laser diode structures and physical designs. The closest I could come to showing they are basically the same when physics is involved is in this Wiki article.
It was years ago, back when I was teaching electronics, that I ran across a magazine article (Popular Electronics?) that described how to do it. If I remember right, the circuit pulsed an LED at 12 volts using 1KHz and a really short duty cycle, like maybe 3%. I think that discovery is what led to the development of today’s laser diodes.
I did find this text about the link between the two…
“Have you ever wondered “When was LED lighting Invented?” Well the answer may surprise you…LEDs have been around for more than half a century! In fact, a viable working version of LED technology first came out in 1962. It was invented by 33 year old General Electric scientist Nick Holonyak Jr. Back then, GE called it “the magic one.” Really! On the back of Holonyak’s original device is inscribed: “The magic one, GaAsP.”
GaAsP (Gallium Arsenide Phosphide) is the semiconducting material that was used in the first LED. According to Holonyak, GaAsP was “the material that became the red LED that everyone saw on the elevators and everywhere else.” He added, “They still probably make them because they’re so damn cheap!”
Holonyak recognized the potential of LED lighting technology right away: “If I can generate that kind of light electronically, that is powerful enough and good enough to run as a laser, this is going to become an LED that covers the spectrum.” It seems the biggest surprise is how long it has taken LED technology to take hold in the lighting industry. "
Sorry I could not provide more solid info (evidence), but this is all I have to work with. I guess I have to schedule another project using those surplus LEDs that I have.
P.S. I think we used up all out freebies in this posting.
