Laser Power Supply (LPSU) Output Current Test Procedure

Laser Power Supply (LPSU) Output Current Test Procedure

Preface: This is a diagnostic procedure to collect data on the output of the LPSU. It is not necessary to perform this unless instructed to do so by Thunder Laser USA Support & Innovation Labs. But you can if you like. This instruction is specific to the Thunder Laser USA Nova series machines only.

Please reply back to your support ticket with your results                                                                                                                                                    

The Procedure:

This procedure runs the lightburn file and allows you to view the LPSU ammeter to record the ma output values at the LPSU. The job will pulse at 10% and pause briefly and then pulse at 20% and pause, and so on up to 100%. While the machine is outputting, the operator should be recording the values from the power supply output.

Your laser will fire during this test. It is recommended to lower the bed down and clear the bed from any materials. Position the laser head so that it is not going to burn anything below it.

Step 1: Download the attached Lightburn file

Two versions are included, both in lightburn formats LBRN2 and the legacy LBRN format. They were updated in Lightburn 1.12.01.

The file should be run as-is, without modifications. It utilizes advance features to create the desired output.

Step 2: Locate Power Supply for your machine

Nova 35, 51, and 63

Located on the back of the machine, behind the blue door to the Left of the exhaust outlet

Nova 24:

Located on the left side of your machine behind the lower blue door.

Step 3: Send and Run Job

Get your pen and paper ready. It would be good to make a column for 10-100% power in increments of 10 so that you will be ready to capture the output ma values.

Send the job down to the machine and run the job like you would run a normal job. Record the results and email them back to your ticket.

Video Run Through:

Using the provided test file attached at the end of this article. Here is an overview of the test file.

Here is how the meter should respond to the test file. Please record the mA value of each pulse in order from 10% to 100%

These resources show our mA meter on the laser near the e-stop button. This is a modification that has been done to the laser in the lab so you do not need to make such modifications.

Sample Results:

Brian's Nova 35-80w


Current Reading in ma:

10%: 4

20%: 5

30%: 9

40%: 14

50%: 20

60%: 23

70%: 27

80%: 27

90%: 27

100%: 27

If you notice, 70% power and above stayed at 27mA. I rechecked the file to be sure it was correct... and i think it is. 

So, we cap our power at 70% in the machine config. This allows us to match the right power supply with the right tube to get our required 10% over published power safely without worrying about current or overdriving the tube. 

The plateau may be attributed to that cap. We are exploring this to be sure.

Now we are going to gather these values the manual way as well and compare the data.

NOTE: Just because the results are different, that does not indicate an issue, just a difference.

Chris L's Nova 51-100w:

His machine has the same controller and LPSU as the first test on the Nova 35-80. The only difference is, the nova 35-80 has a C-90 tube and the Nova 51-100 has a C-100 tube, which is largely inconsequential when testing LPSU current output. However, the current draw of the 2 tubes may differ slightly. Everything else in these machines, as it relates to this test, is identical.

Here are the results of both machines side-by-side:

            NOVA 35-80. C90 TUBE, 100W LPSU                                                                NOVA 51-100. C100 TUBE, 100W LPSU

Machine Comparison for FW and Settings:

Nova 51-100 firmware and laser settings:

It appears that Chris' machine has 99% set for laser 1 max in the config. If the above tests were done with this cap, and not out 70% cap, the comparison is not accurate. We are exploring this and will provide updates.

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