This Linear Technology circuit can measure currents from 100 pA to 100 uA. The circuit is from the 80's, using a component of the era. Transistors are general purpose types.
Originally this 2000 circuit was designed to be a switch to the parallel port, but with 5 V or...
This circuit using a SIDAC is suggested by ON Semiconductor in its thyristor manual. The circuit...
This interesting multivibrator was found in an Italian magazine that no longer exists. This is...