This configuration can be found elsewhere on this website and section. The circuit is from Popular Electronics. The output signal must be applied to an amplifier.
In the circuit that uses a PIC16F84, the audio present at the input will have its level controlled by...
August 2017 - STMicroelectronics' new T850 switches with triacs up to 8 A can be obtained from...
This circuit was found in an American documentation from 1969. The circuit is a multi-indicator with...