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 battery circuit provides a charging current of 500 mA depending on the solar panel. The...
This circuit was found in an Analog Devices manual and can supply a 3 mA current or drain a 10 mA...
This circuit has its application suggested in an alarm system. The circuit is from an old RCA...