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 circuit, found in a Popular Electronics from 1992, is based on an oscillator and a crystal...
This simple electronic organ with a tremolo effect was found in a 1981 publication, but it can be...
This 1969 circuit generates a high voltage that reaches 100 V from 16 V. The power is of the order...