Power supply question.

[Locrian99]

Hello,

I found a bunch of these at work while cleaning out a storage area headed for the dumpster.  So I kept them .   




Using these as a regular power seems easy enough.  Get it down to 9V and have 1.3 a to play with. 

I know nothing of power supplies.   If I want it to be isolated.   Is it simply a matter of having a regulator on each output or do I need to use transformer for each outlet (seems like with the regulator it's still sharing ground). 

But what I'm really curious about is there any simple
Way to combine a multiples of these to get over 3A at 18v?

[PRR]

AFAICT: these are NOT isolated even from the power line. You stand a good chance of strong (110V) shock by touching the low-voltage output wires and metal objects or dirt.

These are made for LED lamps, where you can not get your fingers on the low-voltage side. So they do not need to be isolated in the intended use. They are made to be CHEEP, so no unnecessary frills like isolation.

They really are like sticking the butter-knife in the wall outlet or toaster slot. (Or like I saw yesterday: having a shattered incandescent bulb within easy reach.)

https://powerselectinc.com/index.php/products/led-drivers/constant-voltage-cv-led-drivers
https://powerselectinc.com/pdf/PS20U15K.pdf

No, they don't tell you these are dangerous because you are unlikely to find them for sale unless you know just what to do. (They did not allow for dumpster diversion.)

[Locrian99]

makes sense they were located with a bunch of lighting etc the electricians left behind from construction. 

[Rob Strand]

AFAICT: these are NOT isolated even from the power line. You stand a good chance of strong (110V) shock by touching the low-voltage output wires and metal objects or dirt.

These are made for LED lamps, where you can not get your fingers on the low-voltage side. So they do not need to be isolated in the intended use. They are made to be CHEEP, so no unnecessary frills like isolation.

They really are like sticking the butter-knife in the wall outlet or toaster slot. (Or like I saw yesterday: having a shattered incandescent bulb within easy reach.)

https://powerselectinc.com/index.php/products/led-drivers/constant-voltage-cv-led-drivers
https://powerselectinc.com/pdf/PS20U15K.pdf

No, they don't tell you these are dangerous because you are unlikely to find them for sale unless you know just what to do. (They did not allow for dumpster diversion.)

The lack of clear documentation and labeling is just astounding for such a dangerous device.

*If* these things are labelled correctly the isolated ones are supposed to be labelled SELV.  I don't know if that's enough to trust your life with it.  These days you have to assume *everything* unsafe - especially no markings!

[PRR]

....the isolated ones are supposed to be labelled SELV.....

SELV is I think a term from UK-world regulations.

I (ignorantly?) associate SELV with shavers and lights in wet bathrooms, so their output "should" be touch-safe whatever the connections.

As you say, Locrian's units don't even say SELV, or any kind of HI-POT test which is another way to quantify safety isolation.

These actually have a US UL rating and a test-sheet we can't access without a thousand bucks. But inferring from related ratings these are all specific lighting fixture parts so probably not user touchable. (Any simple audio is user-touchable unless extreme cases like lots of audio transformers in radio network repeaters.)

I can think of some oddball uses, like running DC fans inside sealed chassis, _IF_ interlocked to drop power when the chassis is opened.

Or..... lights in sealed fixtures?