1

We have a "Tsong LED Panel":

Model: SRPL60X120-60WH
Type: 4014 - 4000K
Input DC27-42V/1350mA - 60W

With the LED driver:

Model: SR60-01N-042V1350
Input Voltage: 200-240VAC 50/60Hz
Input Current: 380mA Max
Power Factor: Ø 0.9
Output Voltage: 27-42VDC (Max 49VDC)
Output Current: 1350mA
Maximum Output Power: 54 watts

And I also have a HUE compatible LED driver of 12-36V (Constant Voltage).

But I feel that it's incompatible with the panel and driver; as the panel expects Constant Current, I feel it will burn out.

I also believe that a 230VAC wall dimmer will just 'mess up' instead of actually dimming; as the driver is 'constant current' changing the input voltage wouldn't have effect.


Does anyone know how to dim such LED panel, preferably with a HUE compatible dimmer (or 230VAC wall dimmer)?

enter image description here

11
  • Actually; it appears a driver like this: ltech-led.eu/en/cc-01-10v-dimmable-driver/… expects a 0-10V input from an unit like this: ledtechnologies.co.uk/0-10v-cct-touch-wall-panel-white-992.html ?
    – Paul
    Jan 10 '20 at 18:49
  • 2
    When working with bare LEDs like your panel seems to be, the dimming capability really needs to be built into the driver (and it will usually include some kind of control input, like a 0-10V, or PWM signal). I can't find a datasheet for your driver to know if it already has this, but if it doesn't, I'd suggest replacing it with one that does, with otherwise similar specs.
    – Nate S.
    Jan 10 '20 at 18:59
  • @NateS. that makes sense I found a driver that has similiar (constant) current, but lower voltage (in the comment above); it's a bit hard to tell if it's going to work?
    – Paul
    Jan 10 '20 at 19:18
  • 1
    @Paul, that part is easy; Phillips makes such a device: docs.lighting.philips.com/en_gb/oem/download/xitanium/… . I believe there are third party solutions as well.
    – Nate S.
    Jan 10 '20 at 19:32
  • 1
    I'm not concerned with the points, so feel free to do the writeup if you wish :)
    – Nate S.
    Jan 10 '20 at 19:38
3

Since your product has actually cleared all the EU safety standards and then some (TUV follows UL's standards generally), I recommend keeping your safe product all-safe. That precludes using the cheap Asian junkstream coming out of Alibaba and blasting onto AliExpress, eBay, Amazon, banggood and other turdmeister outlets.

You want drivers which either have a listing from an NRTL, or component listings such as Underwriter's Laboratories ЯU mark. You can make do with the "CE" mark if and only if the driver was shipped in a container to a bricks and mortar manufacturer in the EU, and then distributed to EU electronics distributors or to you.

Dropshippers like Amazon's warehouse do not count; anything from Prime equals direct ship from China. That means the CE mark is no good.

The CE mark is a promise by the manufacturer or importer that the item complies with EU safety standards. It has no bearing on anyone outside the EU. So the manufacturers simply fake the mark, and direct-ship it (including via dropshippers). That makes YOU the importer.

Dimming LEDs

LED drivers do not naturally dim. They consider triac dimming to be line noise, and they do their level best to ignore it. This could fatigue and burn out a non-dimming-rated LED driver.

Triac dimming uses a cheap hack that makes the dimmers cheaper, but was only ever expected to work on incandescent lights. A "dimmer-friendly" LED driver is generally one which is hardened and also has some intelligence to listen to the AC waveform and "reverse-engineer" what the triac dimmer is trying to do. It then commands the LEDs to dim to that level, such as with PWM or current limiting. This scheme is tomfoolery.

Triac dimming is cheap residential grade nonsense. Commercial lighting requires more efficiency, so it has always used better tech such as fluorescent, which couldn't possibly use triac dimming. So they have had a standard, for decades, called "0-10V" - principally used on fluorescents at the time. A signal is sent on separate wires from the dimmer controller (which need not be the light switch) to the LEDs. The separate wires run in a separate cable that may or may not need to be part of the AC mains wires. You have to follow your local electrical code's rules for low voltage wiring.

All that to say, if you're unequipped to run additional wires in the walls, you might not be able to use 0-10V dimming. But it is definitely the more "pro" way to do that thing.

Matching your spec

LEDs are driven "constant-current" because they are not linear; they have a very steep voltage-current curve that is influenced by age and temperature. (hotter = higher current at same voltage, causing a thermal runaway situation). Constant-current is essential to best performance.

"Constant-current" (or to be more precise, varying current) is also the best way to dim LEDs.

So, the critical spec on your LED driver is the 1350 mA figure. You could use a driver with a lower figure, but the LEDs will be dimmer if you do.

It will take a certain voltage range for that to happen; the voltage changing based on temperature, age, etc. The manufacturer believes that happens in the range of 27-42 volts. You need a driver capable of functioning in that voltage range.

I generally go to electronics supply houses like Mouser or Digi-Key for LED drivers. Not sure who the players are in your country.

6
  • Good writeup, I use a lot of hobby-electronics for low-voltage Arduino projects. But I agree this must not be in a 'professional' home installation. Also; I feel you're trying to say that your driver should do the dimming and not use anything to dim the 230VAC to the driver itself?
    – Paul
    Jan 10 '20 at 20:55
  • I'm thinking of leaving the 230VAC wall switch as-is and putting in an "Hue constant current Driver" or "Hue 0-10V controller" with an "0-10V constant current driver". Can I loop the 0-10V to multiple drivers in the last case?
    – Paul
    Jan 10 '20 at 20:57
  • 1
    Me too, I'll use all sorts of cheap on the low side of the wall-wart. I'm saying nothing on the 230V side is capable of dimming an LED driver by brute force; only the driver can do that. The driver can only a) listen to the weird waveform shape from the triac dimmer and reverse engineer what the dimmer is trying to do; or b) use separate wires for a 0-10V scheme. Yes, in the 0-10V system you can distribute 0-10V to any lights you please. Jan 10 '20 at 20:57
  • Good, I agree with you on not dimming the 230VAC, it will bring noise on your net. We once tried it with multiple 24VDC halogen, with all their own drivers... But can I control multiple 0-10V constant-current drivers using a single 0-10V 'wall knob'? My source states I would need 1-10V for that?
    – Paul
    Jan 10 '20 at 21:09
  • I'm thinking that for multiple lights, I need the 1-10V controller (with built-in relay for off) + 1-10V drivers or DALI drivers + DALI controller. (0-10V wouldn't work, but not sure why)
    – Paul
    Jan 10 '20 at 21:36
1

To properly dim an LED, you need the following info:

  • What type of LED you're trying to dim (integrated IC or 'bare')
  • What type of dimmer you need to use
  • What type of controller you need/want

LED strip (or integrated driver IC)

LED strips usually have a driver built-in and operate at 12 or 24V. They are easily powered by a regular (Constant Voltage) power supply and controlled by an PWM (Pulse Width Modulation) driver.

Below is an example of a constant voltage driver.

Constant Voltage driver

Do note this Constant Voltage driver is powered by a power supply with the same voltage (NOT HIGHER) as the LED strip's operating voltage. The current drawn by the LED strip (dependent on length) should NOT exceed the maximum power output of the driver or power supply.

It depends on the internal driver IC if the LED light is dimmable.

For 110-230VAC LED lights with integrated IC, dimming is often achieved by a "Phase Cut" dimmer, this is often applied on the "Trailing edge" (to avoid high switch-on surge) of the A/C wave. This is different

One thing to note is the minimal and maximal power/current (for example 3/50W) a dimmer may not function properly if a too low load is applied and can break if the load is too high.

'Bare' LED

An LED will forward (~ exponentially) more current if more voltage (at least above it's forward voltage; otherwise it stays off) is applied. LED's are thus often only driven by Constant Current drivers. This constant current should not exceed the LED's maximum rated current.

You will need a "Constant Current" driver which output current is lower as the maximum current for your LED. Also; mind how this driver is controlled. Control options include 0-10V, 1-10V and DALI (digitally addressed lights).

Controller

In my case I wanted to use a Philips HUE system with the panel (using a 1-10V driver) and was pointed that there is an HUE compatible controller box by Philips.

Though; the most simple controller would be an 0-10V wall dimmer like this: 0-10V wall controller

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