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.
This circuit is from the 1977 RCA Linear Integrated Circuits Manual. The circuit has a...
This circuit was found in 1980's Radio Electronics. The circuit produces a 1500 Hz modulate 35 kHz....
The maximum power of the controlled load depends on the triac used. The circuit is from a Radio...