This simple neon lamp oscillator produces a 140 Hz, 40 V peak-to-peak signal. The frequency is given by the capacitor that can have its value changed. Note the high supply voltage.
This interesting circuit from Radio Elecronics from October 1965 shows a flip-flop or bistable with...
The basic idea of the circuit shown in the figure is to increase the brightness of an ordinary...
Found in an American documentation, this regulator supplies a current according to the integrated...