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 circuit provides a negative supply for circuit biasing. The current is very low. The voltage...
This very low voltage circuit with the LMV321 was obtained from its own datasheet. The circuit can be...
This circuit was found in a Modern Electronics from 1990. It activates an old electromechanical pulse counter,...