Here's a few pictures of my latest project: "Power Playground." It's a PMOS/NMOS H-Bridge with FETs that can handle 3 amps or so, plus a SPI current sensor, some switches & a rotary encoder (not stuffed yet), and a 7-segment display, all controlled by a Teensy-3.1 running FreeRTOS.
I made this because I'm always running into battery, power, inductor and transformer issues I don't have any experience with. The idea is to use the H-bridge configuration and current sensors to experiment with moderate-current PWM, motor control, power-line synchronization, battery charging and discharging, etc.
The positive rails of the left & right half-bridges are separated so that I can run an experiment I've been wondering about: can you transfer charge from a battery at one voltage to a battery at a different voltage using an inductor and some smart commutation? I think you can, but you never really know until you do it, right?