Reci Laser powersupply and Arduino ramps 1.4

I have a little challenge and am busy with it for weeks and can't figure this out.
Maybe your minds are better. I'm so close but missing something.

I have a Reci power supply P12
The specs are not important but the connection is.

It came with this instruction, kinda simple you should say...
Wiring instructions
① Footer 1 is 5V power supply. (Not needed when connecting the cardinal plate. It is used when regulating the power with potentiometer and the 5V current should be less than 20 mA.
② TH. TL refers to high and low power level respectively, and WP refers to water protection.
③ Footer 5 G refers to ground, and 6 refers to input end.
④ When connecting the control plate, connect the light signal with footer 2 in the case of high power level light~emitting, (footer 3 for low power level light~emitting), connect the ground~wire with footer 5, connect footer 6 with power control analog signal, and make short circuit for footer 4 and 5.
⑤ For testing: 3, 4 and 5 are in short circuit (or 4, 5 are in short circuit and 3, 5 are connected to switch), the potentiometer center is connected with 6 IN, and the two other ends are connected to 5V and ground (1 and 5) respectively.
⑥ PWM can also be used in footer 6, but the pulse peak is required to reach 5V, and the frequency should be above 20K. When the pulse peak signal can't reach 5V, please rotate the current regulator button clockwise for adjustment.
⑦ The high power level controls the light, 1 and 2 are connected, and 4 and 5 are in water protection.
⑧ It is not proposed to control laser power with high~frequency modulation, because it will have impact on the service life of the laser.
⑨ The model is applicable to Z2 laser tube, it is necessary to regulate and use the current according to the laser instructions.
⑩The ammeter is concatenated to the cathode line.



So fist I made the test scenario. Connected 4 and 5 this is the WP with the Ground, no check if there is a waterpump.
Then connected 3 and 5. TL and ground. Low power and ground with a switch. When trying this you see the L on the powersupply going on and off.
Then connected 1, 5 and 6 to a potential meter. 5V and ground, middle pin to 6, the IN port on the powersupply.
Clear picture to me, switch for putting on the laser and the potential meter for the power from the laser.
That works. Great!


Then the challenge was there:

PWM can be used from D9, but that port gives 12V so i used a LM7805 getting it back to 5V. Trying this with the arduino with the commands half powered S120 it gave indeed 2.5V, connected the pin to the D9+ to 6(IN) and D9- to 5(ground). Leaving the 3, 4 and 5 connected. The powersupply is protected and gives errors when stuff is not connected the right way. So I gave it a try but it was a nogo.

I also gave it a try from D4 pin that gives me 5V same way... but still nothing, only error.

What am I missing? How should i connect the Arduino with Ramps 1.4 to the Reci Laser.
Any idea's?

The only difference I see in the pictures is, the 5V are not coming from the PSU anymore ( Pin 1 ) which might confuse the PSU. Maybe you can trigger a transistor with the arduino pin at the base of the transistor and pullup resistor in series with the transistor.

I made a basic sketch for inspiration. Follow on your own risk!

Maybe you'd need a pullup resistor on the transistor base too?
To make sure, the IN pin is low, when you power up the PSU

Edited 1 time(s). Last edit at 01/06/2017 05:36AM by o_lampe.

Today I got it working with this setting:


The first try it failed. Error:
Protection: Short Circuit
Fault analysis: The high voltage wire connected to ground wire or connected to the machine.

The second try it worked. But only for this attempt. He did some drawing I stopped it.
All attempts after that failed... strange...