Projector Power Supply?

Well I got 4 diodes each with 1 P3 to control their brightness (for a projector)

Reds: LPC-826 (400mA), Mits-110mW (300mA)
Green: 200mW Module (500mA)
Blue: M-140 (800mA)

As for the power supplies, I guess I'll get a 24V 1A power supply and a 24V 5A.

I would get one of those +/-24V Meanwell-style power supplies for your galvos, and use a second 12V power supply for everything else. You don't want to share the same line as your motors on your signal/laser power lines, and anyway you'd have to do more stepping-down for your lasers and other equipment. Many can't handle something like 24V inputs.

The important part for the galvo power supply is its voltage differential for the motors (galvos), not so much the current. That's why they're +/- 24V instead of +/- 15V like other cheaper galvos.

A 12V is a good PSU for lasers and other electronics and you'll be stepping-down the power anyway. You can get one from DTR's site from an A140. They can supply tons of current. Otherwise just get a regular 12V PSU and it should run those lasers fine, especially since you don't use much current anyway.

Agreed, easier and less wasteful to run your lasers from their own PSU closer to the proper voltage. If you have fans though, you can run 24V ones right off the galvo PSU, or put 2 12V ones in series, or just run them off your laser PSU. Lots of options that don't require stepping any power down.

As I suspected. The tiny TO-220FP package can only dissipate 15W of heat or something like that. For a 445 diode running from 24V, that's at least 20W of heat.

You'd be much better off getting a 7V power supply to run the lasers.

Yeah I've noticed that heat was a problem when I used 24V. I found this MPD-65B, Mean Well MPD-65B power supply with 5V(6A) and 24V(2.6A). Could I use that and another 24V(1A) power supply? Also, why would you not want to use the same power supply to power the galvos and the lasers? Thanks for all your help so far.

Apocalypse said:

why would you not want to use the same power supply to power the galvos and the lasers?

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Because it is wasteful and decreases the reliability of your system. Power supplies are cheap, just get a 7V and be done with it. 5V doesn't allow for enough voltage drop on the blue.

Galvos are a type of motor, an inductive load. They also change direction all the time so they won't reach a steady state. The net result is that your galvos will be causing voltage spikes and EMI on the power lines which can affect your other devices. You don't want excess current or voltage spikes surging through other devices like laser diodes or your control circuitry.

Another thing Cyparagon pointed out is how much energy (as heat) you'll be wasting with all that extra voltage, especially if you're using a P3 directly. From my understanding, those P3s aren't switching supplies--which are efficient in converting between different voltages; rather I believe the P3 is uses a linear regulator, or a transistor. Those devices just "burn off" the excess voltage like putting a well-regulated resistor in line. It'd be like hooking up a DDL driver to 24V.

A 7V supply or something like that would reduce power and stress on your circuits. They're not that expensive anyway, and then you can separately power down different circuits as needed.

Also think about it this way: you've already put hundreds of dollars into your other equipment. Don't ruin them because you bought some cheapo power supplies or tried to force some of the devices to use too much voltage. Even those cheap Reke projectors use multiple power supplies in them.

Alright, I'll use 2x 24V power supplies just for the galvos and a 7.5V power supply for everything else. 7.5V should be enough to power the M-140 diode right? Just wondering, I found this 24V supply NFM-20-24, Mean Well NFM-20-24. Are these isolated so that I can use 2 of them for -24V, 0V and +24V?