Pin 11 PWM remains after image completes

[kn4ud]

As I stated back earlier , I think the wires (white & Gray) go to diode. If their is any current limiting on the board it is most likely a simple smd resistor. I took a paper clip bent it 90 degrees , stuck it through the hole and tried to feel around and I feel where the wires go through but not much of anything else other than what I think is epoxy . I check the input 12v line and wires to diode and they to be directly connected . I diode check the diode wires and from all indication that is what is on the end of these wires. The Banggood board has everything needed to run this laser that is why I am going to completely remove it from the picture and just use the board I have ordered. I think if their was anything connected in the diode circuit wires it would show up in the diode test function of the fluke meter, I know it has before when checking diodes in some of my ham radio builds. I am going to fix up a simple test bed using another arduino to feed PWM to the banggood board and laser to check it out. We will all find out what is on the bottom of this board when I get my banggood board because I am going to completely remove it.

[Agastar]

I suspected your forum name might be your call sign

Yeah that board seems to just be there for connections. My meter reads .855v as the forward voltage of the diode but that seems a bit low to me.

My L7 board doesn't do any current limiting other than for the weak laser switch which is why I figured it had to be in the laser module. I was planning on doing the same with my Arduino and a mosfet as well. What power laser do you have again?

[kn4ud]

KN4UD is call sign. My laser is a 2.5w or that is what banggood said it is. I did not write it down but the best I remember my forward was higher than .855v , I have it all back together now but I will check it again later tonight. I am playing with firmware some. I am not shure but to me their is something that is not right with jtech and my setup. With jtech I have to be around 215 on the power to get it to burn birch plywood . I know it has been said that the problem is a linear problem with the laser. I can load .9i firmware and I get burn below 50 and from their it goes up . From 215 to 255 for a full scale I agree is not much linear but 50 to 255 is more linear and it was just changing the firmware. This is why I would like to find a copy of the source code for the jtech firmware . I would like to see the difference. I have noticed that some of the jtech upgrade kits some are using the ramps 1.4 boards ( or set up to connect to the ramps 1.4 ) with a driver board much like the driver we have ordered. I have found several diagrams on the IE of this board being used in conjunction with a ramps 1.4. So that causes me to question  the firmware . I am trying to find out all I can and will ask a lot of crazy things but , LOL, I learning.

[Zax]

That's probably because most versions use the standard Grbl frequency, whereas J Tech modified it for a true 1kHz to support their PWM circuit.

[Agastar]

Any Eleks board that has the mosfet and cap driving the diode is going to be affected by frequency since the resistance between the diode and cap will form an RC filter. I'll try to get some pictures from my o'scope for the two frequencies I've seen (1Khz and 7.8Khz). This supports what Zax has been saying about the different GRBL versions.

[Lob0426]

I found this picture of what is in the diode cartridge buried in the heatsink

https://images-na.ssl-images-amazon.com/images/I/41plBeudKIL._AC_UL320_SR320,320_.jpg

[Agastar]

That looks a bit different than what's in mine. Where did you find it?

[Agastar]

I really want to take the laser apart and see what's inside that heatsink. I don't have anything I need to use it for right now but I'm sure as soon as I pull that laser out of the heatsink (and most likely break it) I'll need it for something lol.

What to do, what to do lol.

[kn4ud]

Just below the circuit board in mine it is filled with white epoxy. I could pour it full of xylene but with my luck it would seep down into the focus lenses. My L5 board will be here on the 15th and possibly the ttl driver board and I will play with it using the gray & white wires. If I fry it then I will get it all apart , if it works then I will be happy. I am now playing with the grbl master file learning what is going on in the firmware.

[kn4ud]

LOL, Agastar, I know exactly what you are talking about WHAT I IN THERE just a diode , some circuit?? I want to get in it too. I am going to take the gamble based on what the Fluke meter tells me. If it fails then I will put the thing in the mill and mill a slot the full length of the thing and find out what is in there taking care not to damage the optics.

[Agastar]

The white stuff in there is the only thing I'm really concerned with. if it is hard epoxy then it is going to be tough to get that out, if it is that soft rubbery stuff i've seen used elsewhere, it should be easy enough to pull it away from the threads enough to get it out.

I don't know if you have taken your focusing lens off yet but under mine is two pin holes for removing the retaining ring (well, that's what I'm calling it anyway). The diode host is a different metal and based on some similar heatsink housings I've seen I don't think it is a part of the actual laser diode or its housing (or host as others are calling it).

now that I have my laptop fixed I'm going to get some pictures with my USB microscope. After that I'll be more comfortable with the question of "can it come out from the other end".

I'll post some pics tonight.

[Agastar]

Well, no pics. I couldn't really see much down in there so I didn't bother taking any pictures. Maybe when I get brave enough I'll do a tear down.

[kn4ud]

I was in hopes your scope was smaller than mine , my Celestron just would not do it. I thought I posted it back at the time you were having computer trouble but I guess I didn't. Do you have any good news to when you will get your driver board? Mine is showing it is in transit but not on U.S. soil yet.

[Agastar]

I thought I had ordered it but I had ordered the 3 axis board instead. That came in yesterday though lol. Guess I need to go place that order and wait for 3 weeks lol. Man! I should have just gone ahead and ordered one instead of trying to design one lol. At $10 its hard to beat.

[kn4ud]

LOL, I was in hopes that you would get yours before I get mine where you would have the bugs worked out and all I would have to do is follow your lead. My driver board is somewhere setting in China, dang, not moved since the 11th. Really wanted to work with it this weekend, Zax may get a chance to check it out.