This simple metronome, from 1985 documentation uses only transistors and has two settings. For voltages above 6 V, up to 12 V, replace the BC557 with a BD136.
This amplifier was taken from documentation from the 1960s. Transistors are germanium types from...
This configuration elaborated with common junction FETs has a characteristic like that of tunnel...
This unusual amplifier configuration is from 1986. The circuit has a high resting current given the...