(failed posting with longer title) This will be the first time I have built a project like this and would like someone to review it before I wire it up on a breadboard to test. The goal is to control a cluster of LEDs with a Raspberry pi. Idea is to power the LEDs with a 8v 1A wall wort via a constant current circuit switched with a PNP BJT hooked to one of the Pi GPIO ports (3.3v 16ma max). I looked around and didn't notice a circuit that did exactly what I needed. I took an example constant current circuit and modified the component values a little to fit my needs and added an extra BJT transistor to switch the circuit on and off with. Falstad (image also attached) R1: 100k-ohm 1/4 watt R2: 5 ohm 1w R3: 550 ohm (4 2200 ohm 1/4 watt) Q1: Fairchild FQP50N06L Q2: Fairchild 2N5088BU Q3: Radio shack MPS2222a LED: ~1.5v 100ma cont. V1: 8v 1a V2: 3.3v 16ma Since the LEDs are only running at about half rated constant current, I think it should be fine even if I had an open in one of the pairs. Does the power handling look reasonable on all the transistors?