US 6,272,328 B1 · System for providing audio signals from an auxiliary audio source to a radio receiver via a DC power line

Abstract

A system is provided for detecting the presence of an FM-modulated audio signal from an auxiliary source, and operating a switch to provide that audio signal to a tuner in lieu of the radio frequency signal received at the tuner antenna. The tuner can be a vehicle tuner. The system also comprises a modulator unit for modulating the audio signal and an output plug for insertion into a cigarette lighter receptacle or power receptacle of a vehicle. A radio frequency transmission line, such as a coaxial cable, connects the cigarette lighter receptacle or power receptacle to the vehicle battery and to an antenna switch unit and transports both DC power and the FM-modulated audio signal. The antenna switch unit comprises switched inputs for the vehicle antenna and the output from the modulator unit, and a radio frequency signal detection device for detecting when the FM-modulated audio signal is present. The antenna switch unit provides the output from the modulator unit to the tuner whenever it is detected.

Claims16

Dependent claims

An apparatus for providing audio signals from an auxiliary source to a radio receiver, said radio receiver receiving a broadcast signal via an antenna, the apparatus comprising:

a modulator unit for modulating an audio signal generated by said auxiliary source onto a radio frequency to which said radio receiver can be tuned;
an antenna switch unit having an output connected to said radio receiver, a first input connected to said antenna and a second input;
and
a conductor connected at one end thereof to an output of said modulator unit and connected at the other end thereof to said second input, said antenna switch unit comprising a switching device for selectively switching between said first input and said second input for providing the corresponding one of said broadcast signal and said modulated audio signal to said output, and a radio frequency detection and switching control device for controlling said switch device to automatically provide said modulated audio signal to said output in response to said modulated audio signal being provided to said antenna switch unit.

1 more element

A method of providing an audio signal from an auxiliary source to a radio receiver for playback in lieu of a broadcast signal received at said radio receiver comprising the steps of:

modulating said audio signal, onto a radio frequency to which said radio receiver can be tuned, for transmission via a conductor;
providing said modulated audio signal to an antenna switch unit via said conductor, said antenna switch unit also being connected to an antenna for receiving said broadcast signal;
detecting when said modulated audio signal is being provided to said antenna switch unit;
and operating a switch to provide said modulated audio signal to said radio receiver in response to said modulated audio signal being detected at said antenna switch unit and to provide said broadcast signal to said radio receiver when said modulated audio signal is not detected.

1 more element

Dependencies are inferred from the claim text.

System for providing audio signals from an auxiliary audio source to a radio receiver via a DC power line

Life of this patent

System for providing audio signals from an auxiliary audio source to a radio receiver via a DC power line

Life of this patent

Abstract

Claims16