# LED power management

I am creating a led grid with 176 cells. Details:

• The size of each cell is 30cm x 30cm.
• Each cell contains two WS2812 LEDs that work under 5 volts.
• The power supply unit has to be placed 10~20 meters away from the led grid.
• To minimize the current value and voltage drop, I decided to use a 350W, 24V power supply unit.

Power management proposal:

• Each led @ full brightness consumes about 0.5W, one row has 16 cells, each row consumes about 0.5w x 2leds/cell x 16 cells = 16W
• At the location of the PSU, split the power into 12 channels: 11 channels to 11 rows and 1 channel to MCU. Each channel is protected by a 2A PTC resettable fuse.
• Each row consumes 16W which is going to be about 16w/24v = 0.66A. Considering the power consumption through the wire. I assume each row uses 24V/1A~0A (Sometimes one row can be all off and another row is on full brightness)
• Each channel feeds the power to one row.
• 24V channels are stepped down to 5V by a buck converter. This is to ensure every LED has the same brightness without voltage drop.

Questions:

• How can I ensure that each signal shares the same ground reference? How should I connect the grounds properly?
• How can I improve the design?