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 two-transistor circuit features excellent gain operating with low impedance microphones. The...
In the figure we have a circuit to excite a piezoelectric capsule taking advantage of its resonant...
The integrated circuit used in this 70's application is not common today. The circuit consists of a small...