This circuit was found in a 1980s American documentation. The circuit is based on integrated CMOS 4001 that are common today. The load is a relay according to the power supply from 6 to 12 V.
This circuit, which can be used on percussion instruments, has the oscillation point adjustment made in...
Equivalent transistors, like the BC548 and BC558 pair can be used in this circuit that we find in an...
Any general-purpose germanium or silicon PNP transistor can be used on this receiver. The handset...