This relay triggered by voice or by another sound was found in an Elektor from the 90's. The circuit uses a 12 V sensitive relay and has no sensitivity control.
This circuit generates 5 notes in sequence, which are programmed in the connections of the 4017...
This configuration appears on our website obtained from several sources. This is from English...
This zero-crossing switch circuit triggers an SCR when the input voltage goes through zero. The...