I'm the solo dev on an industrial training website. We have a short lesson about the basic electrical units (voltage, current, resistance) that might serve as an approachable introduction or handy reference: https://www.lunchboxsessions.com/materials/basic-electrical-...
Your site is really amazing. Well done! I was a mechanical engineer for a bit and it's fun going through your lessons and reacquainting myself with that world.
