I'm doing a large photostudio automated lighting setup and I'll need a lot of light so it will be 1000W of LED strips and I need them to be controlled by Arduino. The strips are gonna be on about 20% of power most of the time and then for a photo capture (about 2sec) they gonna light up to 80-100%. I have some electrical skills and I've done this before in smaller scales but I'm worried about controlling 1000W with PWM. So please can anyone confirm if following setup will work?

  • Power supply: 1000W 24V Mean Well (RSP-1000-24)
  • Arduino Uno with 6 PWM outputs
  • MOSFET modules from Ebay:

https://www.ebay.com/itm/MOSFET-Switch-Module-Four-Channel-4-Route-MOSFET-Button-IRF540-V2-0-For-Arduino/122680439778

https://www.ebay.com/itm/3D-Printer-hotbed-MOSFET-expansion-module-inc-2pin-lead-Anet-A8-A6-A2-Black-H5M9/253328731753

I need to drive 5 channels. 4 of them with 3Amps each and one channel with up to 30Amps. This channel can be split into multiple channels driven by single Arduino pin. So I would use that 4 channel module for those 3A channels and then use two of those 3D printer powerful MOSFETs to drive that 30A channel split to two 15A channels.

Question 1: Will it work? :)

Question 2: Will the power supply be OK with driving the whole load with PWM? Are the PWM outputs from Arduino synchronized? Because if they are the power supply will be switching between 40A and 0A constantly. If I could offset phase-shift the PWM outputs the load for the power supply would be more spread. This is what I mean:

Synchronized PWM channels vs offset ones

Question 3: The MOSFETs - will that 3D printer MOSFET switch at 5V from Arduino? Do I need some extra cooling? I think I should be OK, because the PWM load should be at 20% most of the time and then just about 2sec of full load. Right? Oh and is it a good idea to put multiple MOSFETs in series paralel to spread the load - will it spread evenly? I guess better option is to split them into multiple channels right? Thank you.

closed as too broad by Andy aka, laptop2d, Dmitry Grigoryev, Bimpelrekkie, Dave Tweed Jul 14 at 22:56

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • Have you considered getting a power supply that intrinsically supports 0-10V dimming? Then you just have to switch the <1mA dimming current, and the driver will control the full load. – Someone Somewhere Jul 6 at 11:46
  • I need to drive 5 separate channels.. – LuigyCz Jul 6 at 11:49
  • 5 separate LED drivers? – Someone Somewhere Jul 6 at 11:54
  • Too expensive in compare to MOSFETs which are really cheap. – LuigyCz Jul 6 at 11:56
  • Thats as easy as changing your code, just modify the output of the timer – laptop2d Jul 6 at 18:10
up vote 0 down vote accepted

I see no reason this wouldn't work. If you're concerned about the effects of a PWM load on your power supply, I'd suggest adding some extra capacitors on its output (I don't know how well the output is filtered already, but more capacitance never hurts in a power supply). Your MOSFETs seem appropriate for the job; the HA210N06 on that board is a new one to me, but this datasheet suggests that they will be fine. However thermal dissipation could be an issue: at 5V gate voltage, the channel resistance will be about 6mOhm, so power dissipation for 15A will be about 1.5W. Even at 20% duty cycle, that small heatsink will struggle to dissipate an average of 300mW. I'd suggest fitting a larger heatsink or a small fan. And if you can use a smaller MOSFET to boost the gate voltage up to 10V the channel resistance will halve, which will help a lot. I certainly wouldn't trust the ebay vendor's description that the board is stable up to 25A: there's just no way that tiny heatsink can handle close to 2W.

The Arduino Uno board has 6 PWM outputs, which can be set to run on different duty cycles, phases, and IIRC and up to 3 different frequencies, so arranging for appropriate power sharing between your circuits should be possible.

Multiple MOSFETs in parallel (not series) works in theory, but in practice variations in manufacturing etc will likely cause one of them to take a lot more of the load than the other, so one will get hotter than the other. If you can arrange to split your load into two separate 15A channels, that would be much more reliable.

  • Well yeah the MOSFETs are usually pretty powerful according to datasheets but the thermal dissipation seems to be the issue. Can you tell me or point me out to a source where I can learn how to calculate the thermal thing? Do you think that if I split the 30A channel in two it still won't be enough with that heatsink? I'm definitely thinking about a big fan for a whole box with power supply and the MOSFETs. MOSFETs in parallel - that's exactly what I thought. I'll split them in two separate channels. Thanks! – LuigyCz Jul 6 at 11:37
  • I tend to use celsiainc.com/heat-sink-size-calculator whenever I need to check heat sink sizes - estimating the heat sink on that board as about 3cm x 2cm x 0.6cm it's close, but not quite enough. A small fan should be enough to keep it down to an acceptable temperature. – Jules Jul 6 at 11:40
  • Oh and the PWM thing - the power source is from Mean Well which should be really high quality one. Do you think I need to worry about stressing it with PWM? Should I try to implement some kind od phase-shift between the PWM channels? Or different frequencies? – LuigyCz Jul 6 at 11:40
  • I wouldn't worry too much about it if it's a good supply, but using a phase shift should be easy enough to achieve, and should reduce the instantaneous load variation which may make the power supply last longer. – Jules Jul 6 at 11:42
  • 1
    Famous last words: more capacitance never hurts in a power supply – Andy aka Jul 6 at 11:51

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