Originally this circuit was created to produce synchronism pulses in TV cameras SSTV (Low scan frequency), however it can be adapted for other purposes. The integrated circuits are common TTL.
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...