# Most efficient and cheapest way to drive a high power and consumption giant dimming LED matrix

I'm building a giant LED matrix for an art project.

Each "pixel" is a 12V RGB LED strip consuming ~23W, and has to be fully dimming controllable.

We're talking about 768 pixels with a total current draw near to 18kW at max power (RGB fully ON for white color). That's a lot so it needs to be "efficient" with a component cost that keeps it relatively economical.

What would be the best way to drive that thing? The project will be controlled by Arduino via shift registers. The mains is 3phased 380AC or AC230V (Europe).

In a small circuit I would use BJT transistors or any MOSFET I have lying around (TIP120 for example) after any suitable AC to DC transformer/driver in a configuration like this:

1. What parts could I use in "C" to not waste too much energy? MOSFETS, BJTs, Buck Converters, what?
2. Do you recommend me a power supply format like the one pictured in part A? I've used meanwell led drivers in other projects (I'm assuming they're more efficient) and they have a different form.
3. What would be the best DC voltage to power this? (I'm assuming 12V for cheaper led strips, but perhaps 1€/1US\$ extra for every 5meters of 24V is better in the long run)
4. Do you have any Shift register (part B) model recommendation? This project needs only 2304 channels haha :_) (768"pixels" *3 channels).
• The units of power are Watts, abbreviated W. Not 'Wh' or 'W-h'. Feb 1 at 12:09
• a total current draw near to 18kW·h at max power shouldn't be that much with multiplexed driving. One "pixel" will be on at a time, am I correct? Feb 1 at 12:16
• Using some programmable LEDs, like WS2812, you may avoid using of lot elements. Feb 1 at 12:27
• You might want to find yourself an electronic engineer as there will be legal and safety issues that need to be complied with as well as the significant cost of the parts. Note that DC current is DC current. There is no ‘best’. Feb 1 at 13:17
• @MakerCult Even if you go for building everything yourself, look at DMX. to multiple microcontrollers responsible for zones. It looks more complex than shift registers on the surface, but the RS-485 differential signalling makes it a lot easier to transform you system into 18-36 subunits, which means that the power consumption per unit becomes a lot more manageable (12v AC-DC adaptors are a lot more common than 18kW ones, and 36 500w units will probably be a lot cheaper, and you dont have to deal with a 1500A power rail). Once you have the subunits, with 12v supplies, PWM dimming isn't to bad. Feb 1 at 13:38