Found in Motorola documentation from the 90's, this circuit has a high input impedance. The power supply must be symmetrical. The circuit can be implemented with modern operational amplifiers.
This circuit is from an Italian publication from 1988 but can still be easily assembled....
We found this circuit in a Japanese publication in 1967. The circuit consists of a 15 W audio...
This charger circuit provides an initial voltage of 2.5 V and when the current reaches 180 mA the...