Constant voltage LED driver != power supply?

[mho_logos]

Hi all.

I am working on replacing some lighting in my home with LEDs, and have found some high quality flexible LED strips, that I want to use for under cabinet lighting in the kitchen.

The strips are rated 24V, and about 10W/m. The 24V design is achieved by having groups consisting of a number of LEDs (6 or 7 I believe) in series, with a current limiting resistor. The strip can be cut for every group (be it 6 or 7 LEDs). In other words, each of the groups are in parallel.

So the current limiting resistors are in the strips, and the strip should be driven by a constant voltage (of course PWM dimming can be used).

The supplier recommends using a "Constant Voltage LED driver", but being constant voltage, I really do not see the difference versus a regular switched power supply (which of course needs to be stable from no load to the maximum LED strip power consumption). Can someone tell me if there is a difference?

If I go to digikey and look for a constant voltage LED driver that suits my needs, the cheapest one I find suitable, is this:
http://search.digikey.com/us/en/products/LED50W-24/1121-1080-ND/2786578

Looking instead for a power supply, I find this:
http://search.digikey.com/us/en/products/ETSA240270UD-P5P-SZ/T1165-P5P-ND/2743486

This one even has a no load power rating of 0.3W, which is perfect, since I want to turn of the LED strip with the PWM controller (0% duty cycle), so a low stand-by consumption is very nice.

Hope someone can shed some light on this.

Kind regards,
Mikkel Holm Olsen

 

[pranam77]

As you are aiming to use LED stips, you can use any SMPS power supply with the specified voltage. Amphere rating must be 20-30% above what is rated. My sugession is to go for 12 volts rated stips as they are common and frequently used in architectural lighting
Cheers

 

[sky_123]

Btw, make sure they really are high-quality (or replaceable). I went down the road of installing such lights (can't remember the mnfr/model),
and despite spending a reasonable amount of money on them, failures do occur. I have one LED failed (luckily near the far end, so not really visible),
although they have been running for several years now.
Also, you way want to have PWM, so you can have multiple settings, e.g. a lower brightness setting in the theory that they may last longer that way.
Recently I've bought some nice Lumidrives (dialight) (for 50k hours down to some brightness level) and their recommended driver, but I've not had a
chance to try them.

 

[vipinsaini]

@pranam77

I am agree with pranam.
So you must not use the power supply of same rating as your load require. You have to use the power supply(cv-constant voltage) and whose rating should be more than your load.
In the market the LED strips operated by 12V are available in the market so you may use those LED strips.