This circuit is from a 1968 publication. Here we have several types of resistive sensors with individual adjustments triggering a single SCR. Power depends on the type of sound device to be triggered.
Found in a 90’s Electronics Now, this circuit has its output connected to an audio amplifier. The...
This configuration that appears elsewhere on this website and in this section was suggested by...
This circuit was designed to power the previous circuits of the wireless sound system, but it can...