Powering LED lights.

[golfpaul]

Evening.

Been asked to replace some old halogen under cabinet lights for their LED equivalent.

The power supply is boxed in and not at all accessible, so was going to use this to power the new fittings, but am I right in thinking a standard 12v psu might upset the LED's...
All the ones I've previously fitted have been part of a kit, LED's and driver.

Cheers.

 

[davesparks]

I doubt it will upset them, they aren't sentient so won't have feelings.
They almost certainly won't work though, unless the old psu is outputting DC and the LEDs you are going to fit require a constant voltage supply.

 

[Barry White]

Think it depends if its a transformer or a switched mode psu if its an old setup it could be a transformer (usually heavy and bulky) I have nine 3w led mr16 running 12v ac in my bathroom for 3+ years. Did try them with the switch mode psu and they just flashed unless i put a load on them with one halogen bulb (defeating the object) did the same in my kitchen too worked ok for over 2 years but replaced with gu10 leds when I revamped it.
The correct drivers are DC and the bulbs wont work if inserted the "wrong way"
I recomend using the recomended drivers for longitivity of the bulbs and piece of mind for yourself /customer

 

[golfpaul]

Yeah cheers guys, I did think they were driver specific but just wondered if the existing psu would work.

 

[amlu]

depends on the LEDs. some may need a driver supplying a specific current, some will have resistors/drivers built in and will be happy with any 12v DC applied.