Ford Motor Company Limited

Visteon Global Technolgoies, Inc.

Sylvester P Porambo

John Elliott Whitecar

Yao H Kuo

Gregory Roger Hamel

John Michael Dicky

Robert D Plowdrey

John D Cotner

Gael D Lindland

An oscillator circuit having an expanded operating range includes an amplifier portion amplifying an oscillating signal. A gain controlling portion controls the gain of the amplified oscillating signal. A switching circuit electrically connected across the gain controlling portion provides a low impedance electrical path in parallel with the gain controlling portion in response to a switch input signal. The switching circuit further includes a switch signal generator portion producing the switch input signal to switch the switching circuit ON or OFF when power supplied to the oscillator circuit reaches a first predetermined voltage level and to switch the switching circuit OFF or ON when power supplied to the oscillator circuit reaches a second predetermined voltage level. In this circuit design, the initiation of an oscillating signal by the oscillator circuit is unaffected by supply voltage variation or, in other words, fluctuation in the power supplied to the oscillator circuit.

Oscillator circuit having an expanded operating range

A method and apparatus for determining the connection status of a communication system speaker connection to the amplifier includes digital signal processing (DSP) circuitry contained in the system receiving a clip detect feedback loop from the amplifier in response to a tone signal delivered to the amplifier from the DSP microprocessor. Preferably, the diagnosis is initiated by actuation of a predetermined plurality of controllers on a face control unit, each of which is otherwise actuated individually to control portions of the communication system. Preferably, a tone signal generated for diagnosis is generally inaudible to the human ear but the front control unit includes a display screen for illustrating the condition of the speaker-to-amplifier connection after the diagnostic function has been completed.

Method and apparatus for diagnosing amp to speaker connections

An RF shielded electronic module is formed of stamped sheet metal in the form of a wrap having four side walls. A sheet metal cross-member extends between opposed walls and is welded thereto. A printed circuit board is soldered to the cross-member and to the wrap such that the cross-member provides an RF shield between separate areas of components on the printed circuit board. A pair of sheet metal covers are joined to the wrap substantially enclosing the circuit board. The wrap and covers provide an externally shielded enclosure. The wrap, covers, and cross-member provide internal shielded compartments.

Shielded circuit module

An automotive radio system employs a plurality of corrective actions in response to the detection of multipath interference to reduce distortion audible to a listener. The speed of the vehicle is determined since the number of multipath events per unit time and the expected duration of each multipath event vary according to vehicle speed. The corrective action taken in response to detection of multipath interference depends upon the vehicle speed. In a diversity antenna system, antenna switching is suspended at high vehicle speed while filtering of the audio output to reduce noise is suspended at lower vehicle speeds.

Automotive radio employing multipath correction strategy based on

A digital signal processing automotive audio system uses an analog audio source providing stereo output signals. One of the stereo signals is mixed to a distinct frequency band and summed with the other stereo signal to form a composite signal which can be digitized in a single analog-to-digital converter. Separate digital stereo signals are recovered using digital signal processing.

Composite signal generation and decoding in digital signal processing

A variable frequency RF passband filter is aligned or calibrated to maximize the sensitivity of a radio receiver using reference frequencies obtained using a fixed frequency oscillator present in a different band tuning section of a multiband receiver. The intermediate frequencies of the various band sections of the multiband receiver are selected whereby a fixed frequency source in one band corresponds to an intermediate frequency employed in the band for which the tunable RF filter is being aligned.

Growing community of inventors

Canton, MI, United States of America

Sylvester P Porambo