Safety volume control for car audio equipment - reduces volume when warning device emits audible signal

摘要

The control reduces the danger of accidents by ensuring that the driver can hear audible warning signals without delay even when the reproduction equipment is in use. When the warning device outputs an audible signal a detector provides a control signal to an element which reduces the vol. of the electroacoustic reproduction equipment or sets it to zero. The detector contains a microphone connected to the input of a bandpass filter which drives an averaging circuit. The output of the averaging circuit is fed to the input of a threshold switch whose output provides the signal for the control element.