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.
A 25 mVpp applied to the input of this circuit produces in the output a 1 Vpp signal. The...
This current source was obtained from an 80's operating manual. The circuit can be applied to modern...
This excellent amplifier, found in a 1986 documentation, provides good power and is powered by a...