Converting K40IV CO2 Laser machine to DSP

[fprckq]

Hi Marco,

I got the DSP board installed, homing is good now, arrow keys all work, I owe you for shipping. I installed 2 mechanical limit switches. I had to replace the Laser tube, and attempted to align the optical path today but discovered that whenever the machine is energized, the laser fires immediately at 10 MA and cannot be controlled. When the LP-1 connector is unplugged the laser woint fire unless the small red Test pushbuttoin is pressed on PS.
My PS is enclosed version in a gold colored case. all others I've seen are open frame type, I wanted ot see if there were any changes in DSP LP-1 terminal voltage status with Laser keypress, but didn't see any changes with a DVM. Some terminals were 2.8 to 3 volts but none of them changed states. It might be a short event. I was going to drag out the scope but thought I'd wirte first. I saw the youtube video you made.so I'm confident the board is OK. I am attaching some pictures of limint switches and the power supply that came with this machine.
I tried to upload the pictures but it failed.

[Tech_Marco]

Denis:

When I tested your card I used an "analog" output for the power supply. It seems that you're not using the PS that came with the machine, did you? If not, then you need to change the postition of the jumper from 1,2 to 2,3 and that will switch the output from Analog to PWM.

Marco

[fprckq]

Hi Marco,

I am using the power supply that originallly came with this machine, it's enclosed in a gold colored case, and different from the open frame version PS that I saw in the youtube video. I found the jumper next to the LP-1 connector on the DSP board, it's silkscreened JP5, and I moved the jumper from the 1-2 position to the 2-3 position. Same result though, the laser fires at 10 MA as soon as the power is switched on. Maybe this PS is defective, although it does fire the laser whenever it's Test button is pressed, with the LP-1 connector discnonected from the DSP.
Here's the wiring connections:

DSP Laser 1 terminal block Laser PS terminal block

1 -------------------------------------------------- 3 and 4 3 is water pump, 4 is ground
2
3 -------------------------------------------------- 2 2 is TTL-L input
4 -------------------------------------------------- 5 5 is control input
5
6

Ground is connected to 24 volt negative switching PS, and equipment/case ground, which up here means earth ground/water pipe.potential.
Maybe I should just change out the laser PS and be done with it. I don't know what to get.
Do you think this PS caused damage to the DSP?

cheers,
Denis

[Tech_Marco]

I think it's just a matter of connection issue here. Did you still use the power control (potentialmeter) on the machine? If so, you need to remove it and connect the center tap wire of the potentialmeter to the output port of the DSP card. The ground on that potentialmeter should be connected to the ground of the DSP to establish a 'closed loop' circuit. Remember that you use the DSP to control the power.

From what I think so far, I believe that your output signal from the card was serving as On/Off control rather than power control. That's why you always get a contant 10mA output. By the way, you can adjust the potentialmeter on the card to control the power. What you should do is to set the DSP for max power 100% on both Max and min then adjust the VR (potenitalmeter) to obtain about 18mA ~20mA current. Do not go over 20mA for a 40W tube or it will shorten the life span of the tube. It's not the case of "the more the output current, the more power it output".

One more thing, you should use TH/LH (level high) to triger the power supply if you're not using quality PWM power supply. Those small machine always come with an analog power supply with TH (level high) to trigger the fire.

It's better you post pictures of the power supply and the connection to view here. I really got no idea what PS you have there and the connection to the machine control. Seeing is better than 'imagination'


Marco

[fprckq]

Hi Marco,

here's the Power Supply pictures. The dimensions of PS in picture 4917 are:
3.75" high x 6.625" wide x 5.75" deep

cheers,
Denis

[fprckq]

Hi Marco,
here's 3 power supply pictures. I can't see a nameplate on it.

cheers,
Denis

[TeacDance]

Hi Marco,
here's 3 power supply pictures. I can't see a nameplate on it.

cheers,
Denis

Look like you have same setup what i have i can take pictures for you if you want

why you have that big green resistor connect?

Do you have same power stepper motors and control board?

[Tech_Marco]

Denis:

Your power supply seems is PWM ready. Now you should give a try by using PWM on the DSP card. Simply cap #2,#3 for J4 or J5.
Plus, you shouldn't use the original power control (the potentialmeter) and let the DSP to do the job. You didn't post the control part so I don't know how you control the power so far.

If you can, you may want to open the case of the power supply and take a picture for it as I want to know what PS you have
You're getting closed as now your X,Y motion is doing well, so just be patience and hold on and you will get it!

Marco

[fprckq]

HI Marco,
I am patient, it's almost over.
Sorry, I don't know what you mean by " cap #2,#3 for J4 or J5 "
Original control pottentiometer is not installed, was removed with the old control board.
Sorry, I don't understand " You didn't post the control part so I don't know how you control the power so far "
I haven't been able to control power, it's steady at 10 MA whenever powered up.
I will draw a picture of the wiring connections between DSP and PS and send the picture.
I've enclosed several pictures of the PS and the 50 watt wirewound resistor has been relocated on to the rear panel in the fan airstream # 4959, # 4963
Several PS pictures are # 4962, 4961, 4964
Wiriing diagram between DSP and PS is # 4966, 4967, 4968.

cheers,
Denis

[Tech_Marco]

Denis:

I'm pretty sure that your PS is PWM mode. So, you must change the output signal from Analog to PWM on the card. It's easy, just move the jumper from #1,#2, to #2,#3. You should find two jumper J4 and J5 right below the Laser1 and Laser2 phoenix terminals. I thoughs your PS was analog so I set it to #1 and #2.

If you can't locat the jumpers, download the a pdf from this post: viewtopic.php?f=16&t=746


After the change, try again.

Marco

[fprckq]

Hi Marco,
yes, I had already moved the jumper from 1-2 positon to 2-3 position earlier this week, I think you emailed me about changing it to 2-3 position on August 14, but the condition remains unchanged.
I changed both jumpers J4 and J5 to 2-3 position.

cheers,
Denis

[Tech_Marco]

Denis:

Do the following:

1) Twist the the small blue potentialmeter (VR) under the the Laser1 counter-clockwise see if it can stop the fire. The VR supposed to be used to control output current for analog. But I'm not if it will does same thing on PWM. I tuned it almost 90~95% on your card

2) If the #1 doesn't work, try switch TL<>TL to TH <>TH between the DSP card and the power supply. What it does is to switch from level low to level high triggering.

3) Check the configuration on the PHCad to make sure the change. I believe that there is a place you can do level low or level triggering but not sure if that is related for the laser fire control

4) Make sure you're seletcting CO2 tube rather than RF tube on the manufacturere setting.


Let me know how it goes

Marco

[fprckq]

Hi Marco,
thanks for all the help.
I got the laser PS going OK today, I followed suggestion by Bart Ding of buildlog.net and he gave directions to a schematic.
here's the link to the schematic I followed:

http://www.buildlog.net/wiki/doku.php?i ... nal_blocks
scroll down to below the heading Connectors/Termnial Blocks

I was short 1 wire, the schematic I had was wrong for me. The page heading read:
4. Power supply connection

Now I got to align the optical path and figure out how to use the software, but that's a job for tomorrow, and here's how someone did it with pictures:

http://www.rabbitlaserusa.com/Manuals/B ... nment.html

cheers,
Danis

[Tech_Marco]

I don't see any problem of your connection diagram above. It looks good to me. Which wire was shorted? Are you now using #2 (TH) to enable the Power supply? If so, it means that the either the PS's TL or the DSP TL (level low) has an issue

Anyway, the hardest part has past and the alignment adjustment is considered much easier than anything else.

Cheers!
Marco

[TeacDance]

I don't see any problem of your connection diagram above. It looks good to me. Which wire was shorted? Are you now using #2 (TH) to enable the Power supply? If so, it means that the either the PS's TL or the DSP TL (level low) has an issue

Anyway, the hardest part has past and the alignment adjustment is considered much easier than anything else.

Cheers!
Marco

I connect just like that and it's work direct i don't have to do nothing special?

if i want to that mAh display where i have to connect that?