Using 80W Laser PSU's 5V for panel meter power

MitchL
Posts: 71
Joined: Fri Aug 23, 2013 4:40 pm
Location: California

Using 80W Laser PSU's 5V for panel meter power

Postby MitchL » Wed Oct 15, 2014 9:09 am

I'm going to install an ammeter in my laser (80W Reci tube + 80W PSU).

The easiest way to go is with an analog meter, no special power requirements, easy hookup. It's got that retro look going for it as well.

If I choose the digital meter (like the Min3 blue 3-digit one here at LO), can I power it from the +5V output from the 80W PSU?

I'm assuming the digital panel meter does not provide any isolation of its own for the inputs (one of the input terminals is probably common with GND). Since I know that the laser return is also common with the GND pin on the control header, powering from the +5V output of the laser makes some sense to me.

Thanks!

/Mitch.

swamidog
Posts: 59
Joined: Mon Feb 03, 2014 3:28 pm

Re: Using 80W Laser PSU's 5V for panel meter power

Postby swamidog » Wed Oct 15, 2014 9:43 am

the digital meter looks cooler (LEDs are oh so sexy), but the analog meter will have faster response time.

MitchL wrote:I'm going to install an ammeter in my laser (80W Reci tube + 80W PSU).

The easiest way to go is with an analog meter, no special power requirements, easy hookup. It's got that retro look going for it as well.

If I choose the digital meter (like the Min3 blue 3-digit one here at LO), can I power it from the +5V output from the 80W PSU?

I'm assuming the digital panel meter does not provide any isolation of its own for the inputs (one of the input terminals is probably common with GND). Since I know that the laser return is also common with the GND pin on the control header, powering from the +5V output of the laser makes some sense to me.

Thanks!

/Mitch.

MitchL
Posts: 71
Joined: Fri Aug 23, 2013 4:40 pm
Location: California

Re: Using 80W Laser PSU's 5V for panel meter power

Postby MitchL » Wed Oct 15, 2014 10:07 am

swamidog wrote:the digital meter looks cooler (LEDs are oh so sexy), but the analog meter will have faster response time.


What I really wanted to do was to have my microcontroller measure the power, then I could show it as a graph on the LCD.

That'd be pretty sexy too :-).

But then I'd need to get into isolation amplifiers and other stuff. I do have a spare analog input, just in case!

Meanwhile, after the "rapidly losing power" episode (solved with the 110/220v switch), Marco's suggestion that I ought to always have some power measurement is a good one. Still haven't cut the skins for my laser yet, so I need to know what size opening to leave (and where to power that meter from).

/Mitch.


Return to “Digital/ Analog Meter”

Who is online

Users browsing this forum: No registered users and 1 guest