Got my new mA meter

[Brian Leavitt]

At 85% power, the China Special is running at 24mA. In fact, from 74% all the way up to 100% power, it's running at 24mA. I don't know if that's normal or not, but that's what it does.

Best I can find, my laser tube is supposed to run at 20 mA, which is at 63% power. At that level, it's outputting 42 watts.

Nice to have a proper meter on there. :)

[Scott Marquez]

At 85% power, the China Special is running at 24mA. In fact, from 74% all the way up to 100% power, it's running at 24mA. I don't know if that's normal or not, but that's what it does.

Best I can find, my laser tube is supposed to run at 20 mA, which is at 63% power. At that level, it's outputting 42 watts.

Nice to have a proper meter on there. :)
Im guessing that your readings are at the final output, now you can work backwards and see how much loss you are getting after each mirror.
Dont run your tube past its prescribed limits, it will really degrade the life.
Enjoy, Scott

[Ron Gosnell]

do you have max power set somewhere. That would keep the amps from climbing.
The min max settings also change how the amperage works.

[Brian Leavitt]

The max power is set to 99 in the vendor settings. I don't know where else it could be set to less than that.

[Matt McCoy]

The max power is set to 99 in the vendor settings. I don't know where else it could be set to less than that.

You might check your power supply for adjustment.

[Brian Leavitt]

Do they have a potentiometer on them? I've briefly looked mine over because I've seen that there is some kind of adjustment, but I didn't notice anything that looked adjustable. I didn't spend a lot of time going over it, though.

[Matt McCoy]

Some do, yes.

This might help (Step 11):

http://www.instructables.com/id/How-to-test-and-set-a-Chinese-China-made-CO2-Laser/?ALLSTEPS

[Bill Carruthers]

Do they have a potentiometer on them? I've briefly looked mine over because I've seen that there is some kind of adjustment, but I didn't notice anything that looked adjustable. I didn't spend a lot of time going over it, though.
On many of the Chinese power supplies there is a small hole on the side of the box that you can use a small screwdriver to adjust the potentiometer output it.s usually not marked as such especially on the cheaper ones.

[Brian Leavitt]

On many of the Chinese power supplies there is a small hole on the side of the box that you can use a small screwdriver to adjust the potentiometer output it.s usually not marked as such especially on the cheaper ones.
Thank you. I noticed that in that instructable link as well. I was looking for something more obvious, I suppose. I'll have another look tonight.

[Doug Fisher]

>>>At 85% power, the China Special is running at 24mA. In fact, from 74% all the way up to 100% power, it's running at 24mA....Best I can find, my laser tube is supposed to run at 20 mA, which is at 63% power. At that level, it's outputting 42 watts.<<

If I had that tube and power supply, I wouldn't take a chance messing with the power supply and screwing it up. What do you have gain? You are able to get 24 mA which is more power than your tube should be driven.

>>at 20 mA, which is at 63% power. At that level, it's outputting 42<<

If this is on a blue and white 50 watt Chinese labor, your output is right at or a little better than average reported real-world performance on those machines.

[Dave Sheldrake]

How long is the tube?

[Brian Leavitt]

If I had that tube and power supply, I wouldn't take a chance messing with the power supply and screwing it up. What do you have gain? You are able to get 24 mA which is more power than your tube should be driven.


It's the red and black Redsail knockoff.
I want to turn the power supply down because I have no self control and will always have the temptation to run it at a higher power than it should be run at.

[Brian Leavitt]

How long is the tube?
It's approximately 1050mm long.

[David Somers]

Brian! Put a yellow sticker or label on your mA meter about where the maximum power rating is for your tube. On it write the cost of a replacement tube.

he he.