This circuit is from a 1977 Signetics integrated circuit manual. The output transistors can be BD136 and BD237 and the symmetrical supply can be from 6 to 12 V. The voltage gain is 10.
Found on a 1969 EDN this circuit switches a current from a digital control signal. The impedance...
This circuit provides a 5 V negative output with a maximum current of 1 A. The circuit is from the...
This low noise circuit was obtained from a 1980s US RF publication. Transistors used are uncommon...