Patent ID: 6590982
Filing Date: 2003-07-08
Classification: H04H,H04R,H04S

Abstract:
A wireless concealed transmitter center speaker system including a concealed transmitter unit installed in a center speaker cabinet, and two receiver units installed in two rear speaker cabinets, wherein:said concealed transmitter unit comprises: an automatic audio level regulating circuit comprising an audio regulating IC, having an input terminal connected to the output terminal of said audio equipment to regulate the audio level of the output signal of said audio equipment to a predetermined range to a signal processing circuit; said signal processing circuit having an input terminal connected to the output terminal of said automatic audio level regulating circuit and output terminal connected to an external and internal dual adjustable oscillatory frequency regulating circuit; said external and internal dual adjustable oscillatory frequency regulating circuit comprising an oscillator transistor, and dielectric resonator, a first variable capacitor and a second variable capacitor diode; an inductance antenna connected to the output terminal of said external and to internal dual adjustable frequency regulating circuit, said inductance antenna being a matching device; and a power control circuit controlled by the output signal of said audio equipment to provide the necessary working voltage to said concealed transmitter unit, said power control circuit comprising a signal amplifier, a comparator and a transistor switch, when said signal amplifier receives an input signal from said audio equipment it drives on said comparator and transistor switch hence permitting external power supply or battery supply to be connected to said concealed transmitting unit.