Questions before building from LED strips

Other Types of Lights LED Light Bulbs
1

Hi,

I’d like to built some lamps from LED strips around my home. The most important thing would be High CRI / low blue and very nice “area” light, not point like from a single lamp.

I am planning to buy Auxmer 2835 2400K light, but I’m not sure in a couple of details:

- voltage: 24V or 12V

  • power: 38.4W/m, 19.2W/m, 14.4W/m, 9.6W/m, 4.8W/m

I like the 4.8 W because it doesn’t need cooling and I can just put it on wall, wood, etc. and be done with it. As I understand after 9.6+ I’d need some kind of cooling design with aluminium, etc, right?
So this looks promising: 14.26€ 2% OFF|Low Power 2835 60 LEDs/m LED Streifenlichter, CRI95/90, IP20, 4,8 W/m,LED Streifen warmweiß, rot, grün, blau, bernsteinfarben, gelb, rosa, lila LED Band|LED-Streifen| - AliExpress

What power supply should I use? Can I use a 20V Lenovo adapter with a 24V LED?

I’ve seen that there are special power supplies for LEDs with PWM, I don’t understand that. Why would I need PWM from a PSU? Isn’t that one for dimming?
For example these ones from Meanwell:
IDLV-25A-24 - https://www.meanwell-web.com/en-gb/ac-dc-constant-voltage-led-driver-cv-input-range-idlv—25a—24
ODLV-45A-24 - https://www.meanwell-web.com/en-gb/ac-dc-constant-voltage-led-driver-cv-with-pfc-odlv—45a—24

On the other hand there is the simpler:
LPV-60-24: https://www.meanwell-web.com/en-gb/ac-dc-single-output-led-driver-constant-voltage-cv-lpv—60—24

Also, how is the dimming of these? What kind of dimmers can I use? I’m looking for simple, wired dimmer which is compatible with LEDs.

2

For the PSU I decided I’ll just buy a Meanwell. I’m confused about range though: there are LED specific models, like LPV-35-24 and the normal range like LRS-35-24, GS25E24, GST25E24-P1J or GST40A24-P1J.

Now for dimming I’m trying to understand the different option.
Option 1: don’t dimm. I’d buy 4.8W/m strips and put 2 next to each other, so I can have 4.8 vs. 9.6 Watts. I like that it’s simple and guaranteed flicker free.
Option 2: I’d need a very high kHz dimmer to make sure it’s flicker free and also hopefully over the audible range, so 25 kHz+. I’m confused here, I don’t want anything smart or wireless, but the only one I found are:
QuinLED-Quad - I’d need SMD soldering for this, which I have never done
Waveform FilmGrade™ Flicker-Free LED Dimmer - I’m not going to spend $79 on a LED dimmer for a single lamp.

Something like this is supposed to be 10 kHz and is super cheap: https://www.aliexpress.com/item/32845855679.html

So is there nothing at 25 kHz which doesn’t need SMD soldering or cost $79?

3

I see, I’ll definitely not buy those then. So is there any option for a 25 kHz+ PWM dimmer which is not a DIY PCB with SMD soldering required?

4

What about the constant current PSUs from Meanwell? Would that also be an option with a constant voltage LED strip?

5

If you want just rough dimming you can supply lower voltage to LED strip, it will dim. No need for PWM. Vf of LEDs will limit current.
LED strip is just LEDs in series with resistor. 3 + resistor for 12V strip and 6 + resistor for 24V (simple strips at least), repeated as many times as needed.

Sry, don’t know how to embed video not from YT

6

So what is wrong with supplying less than specified voltage to a LED? For example if I supply a 24V LED strip with 18…24V? I’ve read something here like that the color / CRI change compared to the same luminosity with PWM?

Also, if I understand correctly this is how the CCCV LED PSUs work from Meanwell, isn’t it? When you set the current it actually supplies less voltage right?

Update, I’ve read it here: High CRI LED Strips from China - #16 by L4M4

7

I found the specs for a CC/CV Meanwell PSU: https://www.meanwell.com/Upload/PDF/ELG-100/ELG-100-SPEC.PDF

This can be dimmed with a simple pot and it adjusts the CC part. So if I understand it right, this works for most LED applications but it’s not good for High CRI because color changes in the CC / under-voltage part?