Assorted power supplies? I knocked together this module over the last week, about:
12V input, 150-800V output, about 50W capacity. UC3843 based flyback (the two transistors are in parallel, and the output is +/- flyback, ground referenced for + output only).
Cutesy kits? Learning projects? Oscillator, timer, amplifier, counter, wire up an MCU, sensor, IoT thing, what catches your fancy?
Tim