EEVblog #643 – Mailbag

Mailbag Monday

Spoilers:

Dual voltage source selection circuit

Casio FX-7000G the world’s first graphing scientific calculator, circa 1985.

A 1989 vintage analog ohmeter.

Teardown of a 450W electronic dimming module.

Forum HERE

from EEVblog - The Electronics Engineering Video Blog http://ift.tt/1o4NbRY

via Yuichun