I'm planning on hooking up 3x6 LED array to a USB port that only turns on at night, but I have no idea how to do that last part. I'm just dabbling in electronics and have barely even wet my feet. SO, I have a 5v DC source, 18 IR LEDs(1.5 forward voltage, 140 mA), and 6 3.9 ohms 1/4 Watt resistors.
My diagram so far:
Will this work? What do I need to get/do to have this only run at night?
My diagram so far:
Will this work? What do I need to get/do to have this only run at night?