This 1.5 A circuit has the output voltages adjusted by a selector switch. We found it in a Popular Electronics from the 90s. The integrated circuit must have a heat sink.
Found in a magazine 73 for radio amateurs, this circuit has two settings, one for the interval and the...
This good quality amplifier found in a 1982 documentation has a traditional complementary output...
A low frequency divider can be made using common unijunction transistors as shown by the figure...