Hello, people and/or extraterrestrials. I made a 3x3x3 led cube and have let it sit for a while. I got it working pretty well, but it was much dimmer than I when it was all turned on.
I am going to be powering 9 columns of 3 LEDs. Each led will running at 3.2 volts and 30mA, so each column will be at 9.6 volts and 90mA then this times 9 would be 86.4 volts and 810mA.
Would this mean that I need an 86.4 volt power supply, that also provides 810mA?
I have an old printer power supply that provides 32 volts and 844mA, could this provide adequate power and moderate brightness to the cube?
I guess that is it, I think I already know the answer, but any tips on powering something like this would be appreciated.
Cubes are multiplexed tho - so only 9 max would be on at a time.
Most LEDs have a max continuous current rating of 20mA -running higher can burn them out sooner.
9 x 0.02 = 180mA.
5V supply will work.
(5 - 3.2 - transistor driver (say 0.7V)/.02 = 55 ohm per column.
In theory, if he has a 32V power supply, could he not chain 9 LEDs in series with a single current limit resistor? All assuming the LEDs are ideal at 30mA and all the same.
Then run sections of 9 LEDs in parallel, each section would 'add' 30mA to the load. In theory could run ~25 (nice round number for safety) sections of 9 in parallel.
Personally I would shy away from 32V. For me that voltage is starting to get too high, in my mind I don't think higher than 24V.
Each led will running at 3.2 volts and 30mA, so each column will be at 9.6 volts and 90mA
If each column has three leds in it, they are connected either in series or parallel, and you will be tripling up the either the voltage or the current, but not both.