This simple bridge circuit can be used for impedance or resistance measurement using a high impedance earphone as an indicator. The circuit is from an American 80's documentation.
This switching circuit for analog signals is from a 90’s Electronic Engineering. The components...
This circuit triggers a relay when a pulse of light hits the LDR. The potentiometer serves as a...
This circuit acts as a VU-meter when connected at the output of any audio amplifier, triggering a...