This circuit was found in an American documentation from the 80's. The components are from that time. It provides a variable output of 18 to 30 V with a current of 200 mA.
The indicator for this circuit is a 0 to 1 mA milliammeter. The operational is from the 70s, when...
We can use this circuit to connect low impedance microphones and even small speakers used as a...
The circuit shown in the figure was found in the Linear Applications Handbook by National...