This circuit is from the 80's but uses common components today. The relay is voltage sensitive according to the power supply used. Transistors may be general purpose types.
This 1 MHz oscillator was found in the February 1992 issue of Radio Electronics magazine. The...
This circuit is from an American publication of 1978. It can be assembled with modern transistors, since...
This traditional oscillator uses two complementary transistors to produce low frequency signals....