Hello all, Recently my k40 stopped drawing as much current as it did before.

Lasers
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1

Hello all,

Recently my k40 stopped drawing as much current as it did before. I have the digital percentage control board and I added a current meter. At 85% it used to draw 20ma. Then, my machine dropped to 10ma max. I thought it was the power supply so I replaced it. With the new power supply installed, max current draw is 5ma. What’s going on?

I bridged the 5v to the laser control in and it draws 5ma max. I thought it was the power connection to the tube so I removed the wire and cleaned it. I soldered it to the tube to ensure a good connection and re-insulated the connection. It still only draws 5ma. I tried a dvm and got the same reading.

Did I get a bad pws? Is my tube going bad? The tube is less than. 30 days old. Or, is there something I’m missing? Suggestons?

2

What kind of coolant are you using?
What is temp of coolant?

3

The temp is 22c. I’m using distilled water with a little chlorox to keep it clear.

4

Possibly the same problem RDWorks ran into? Poor quality laser. Here are some youtube vids of him testing it.


5

I’m going to go back to the old power supply and see if it goes back to 10ma. I’m also going to change my water.

If that doesn’t work, what’s a good 4ow laser tube?

6

Thanks. I’ll check out the videos. I’ve seen some of his already.

7

Why not upgrade to the 50W while you are at it? :wink:

8

Sounds like the gas in the tube is depleted. Not shooting for long periods, or running at max for too long without a rest can do that. Replacing tube is usually the fix. The input is PWM for power, so bridging it to 5 volts makes it shoot max…in our case 10ma. Your new power supply may have slightly lower voltage out, or not matched to your tube which can affect end current.

9

I am running into a similar issue… Did you ever pin down the exact cause?

10

yes, my ammeter went bad and was giving me false information. I also suspect the digital control board that controls the 5v pwm signal wasn’t reliable either. I’ve replaced the ammeter with a combo Volt Meter/Milliampmeter and the digital control with a simple high resolution pot. I now have much greater control of my laser power for cutting and engraving.