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.
This circuit appears in several configurations in this site. This is from American documentation from...
Using two LM377s, this amplifier provides a few watts of audio in a low impedance speaker and the power...
Found in a 1969 EEE, this circuit converts input pulses into linear sawtooth signals, as shown in...