This circuit was found in a 1975 documentation. The SCR can be of any type and in this case, we have the horn activation. The relay must be a 12 V type with high contact current.
This circuit uses an unusual electromechanical component: a mechanical blade resonator. The...
This circuit from a Japanese publication in 1968 uses germanium transistors from the time like the...
Found in a 90s Electronic Design, this circuit can provide a relatively high-power output. The basic...