This circuit was found in a 90s Popular Electronics. It also serves for the analysis of microcontroller signals. The power comes from the circuit under test.
This circuit, from the 90's, is intended for operation with vinyl record players of the time, as...
Using a zener diode it is possible to change the linearity of the scale of an analog instrument by...
Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime...