Found in Maxim's documentation from the 90's, this circuit uses an integrated from the time providing a 12 V output from 10 to 12 V inputs.
This simple metronome, from 1985 documentation uses only transistors and has two settings. For...
This circuit is suitable for modulating AM transmitters. The circuit is from a 1977 radio amateur...
This flasher was found in an old Hands On, but uses common components. The optocoupler can be...