So I'm trying to build an 8x8x8 LED cube according to this Instructables. But I'm using slightly different parts:
- 74HC595 shift registers instead of 74HC164
- 2N2222 transistors instead of 2N3904
I'm still using the same 100 ohm resistors as him for each output on the shift registers.
My question is, what base resistor value should I take for the transistors so that I don't pass too much current through the shift registers?