This is a calculator I wrote in Python for doing various electrical calculations. It calculates things such as volts, and amps, LED resistor values, voltage dividers, 555 timers, etc.
It is basically a collection of different calculations I have needed all gathered into one program.
It runs on Linux, Mac OSX, and even Windows, It’s open source, licensed under a GNU GPL license.
You can download My Electrical Calculator if you want to try it out. If you want to change anything, it’s open source so you can.