How can I make a 16x16 led pannel without losing the brightness intensity of each single led?

Question

So, this is my first question here in this forum and I don't know if I'm doing this right. Then in fisrt place, I'd like to apologize myself if I'm doing something wrong or if my english is a little ununderstandable. I also don't know much about electronics, but even so I want to do this project and because of that I'd be extremely grateful if someone could help me.

What I'm trying to do is a 16x16 (= 256) led panel with 5W leds that need a 700 mA current each. The leds have differents wavelenght and beacuse of that, I want to divide these leds in two differents groups so that I can control the brightness of each group independently with its correspondent dimmer. The main point is, I want that when the dimmers allows the maximal current flows, each led must bright with the full intensity.

So, having said that, I'd like to ask 3 questions:

• Would I need to use something else than a heatsink, transformer, the leds, and the dimmers to do this? (of course things like wires and plugs are already implicit).

• Wich transformer suld I use ?

• How should I set those things to not lose any brightness intensity of each led ?

Answer 1

The most common solution to driving large numbers of LEDs at (approximately) equal brightness is to use constant current drivers. A common size driver is 250W. If you used that size, you would set up about 5 series circuits, each consisting of about 50 LEDs. You would then choose a driver with 700mA current and 360V maximum voltage. This is a common voltage/current range from vendors such as Meanwell (e.g. HLG-240H) and many others. Dimming is usually included. Alternatively, if you wanted lower voltage, you could put two parallel strings of 25 LEDs and use 1400mA.

It should go without saying, but take care that your wiring is properly isolated. High voltages keep the current reasonable, but they can be very dangerous if you come into contact with them.