Abstract: A rotary transformer includes a resonant circuit and a coil drive circuit. The resonant circuit includes a resonating capacitor connected to a power MOS transistor, coupled across the primary coil of the transformer. The coil drive circuit includes a diode connected to a power MOS transistor coupled across the primary coil of the transformer. A microprocessor detects changes in the voltage across the primary coil. The resonant circuit is connected and disconnected from the transformer during a power transfer mode and a data transfer mode, respectively. During the power transfer mode, stored energy in the leakage inductance of the primary coil is used for power coupling, via the resonant circuit, instead of being dissipated as heat. The resonant circuit is disconnected from the rotary transformer during the data transfer mode to maximize bandwidth for two-way data transfer between the primary and secondary sides of the transformer.

Abstract: A rotary transformer includes a resonant circuit and a coil drive circuit. The resonant circuit includes a resonating capacitor connected to a power MOS transistor, coupled across the primary coil of the transformer. The coil drive circuit includes a diode connected to a power MOS transistor coupled across the primary coil of the transformer. A microprocessor detects changes in the voltage across the primary coil. The resonant circuit is connected and disconnected from the transformer during a power transfer mode and a data transfer mode, respectively. During the power transfer mode, stored energy in the leakage inductance of the primary coil is used for power coupling, via the resonant circuit, instead of being dissipated as heat. The resonant circuit is disconnected from the rotary transformer during the data transfer mode to maximize bandwidth for two-way data transfer between the primary and secondary sides of the transformer.

Abstract: A loosely coupled rotary transformer includes a resonant circuit, such as a resonating capacitor connected to a power MOS transistor, coupled across the primary coil of the transformer. The resonant circuit is connected and disconnected from the transformer during a power transfer mode and a data transfer mode, respectively. During the power transfer mode, stored energy in the leakage inductance of the primary coil is used for power coupling, via the resonant circuit, instead of being dissipated as heat. The resonant circuit is disconnected from the rotary transformer during the data transfer mode to maximize bandwidth for two-way data transfer between the primary and secondary sides of the transformer. Including the resonant circuit in the loosely coupled transformer optimizes data and power transfer without requiring the use of high-cost, high-efficiency magnetic structures in the core of the transformer.

Abstract: The disclosed invention comprises an electronic control circuit for transferring power and data signals between an electronic circuit associated with a vehicle steering column and an electronic circuit associated with a vehicle steering wheel. Communication between the column circuit and the wheel circuit is accomplished by a rotary transformer having a primary and a secondary magnetic coil, wherein the primary magnetic coil is associated with the steering column and the secondary magnetic coil is associated with the steering wheel. The column circuit and the wheel circuit both include data signals that are transferred to the other across the rotary transformer. The column circuit also includes a power supply which provides power to the wheel circuit across the rotary transformer.

Abstract: A controlled torque steering system 10 for use in an on demand hydraulic assist steering system for a vehicle allows a user to engage a controller 18 for employing a signal processor 16 to delay or ramp down a control output signal for providing a stable controlled torque steering system. Controlled torque steering system 10 allows for the selection of a determined amount of desired assist in steering, including none if so desired.

Abstract: A passive keyless entry system is specifically adapted for use with automotive vehicles. The system includes a portable beacon that is carried by a vehicle operator, a receiver/controller located in the vehicle, and an antenna connected to the receiver/controller for receiving an encoded transmission from the beacon. The system is designed to automatically unlock the vehicle as the operator approaches the vehicle. The system is further designed to automatically lock the vehicle as the operator, carrying the beacon, moves away from the vehicle. The beacon includes a motion sensor to conserve battery life when the beacon is stationary. Transmission between the beacon and the receiver/controller is characterized by a magnetically coupled radio frequency signal embodying differential phase encoded data with error correction coding of the data to enhance noise immunity and signal discrimination. In addition, the transmitted signal between the beacon and the receiver is continually changing in order to deter theft.

Abstract: A molded pressure ring adapted primarily for holding the peripheral marginal portion of a diaphragm in a tone generator under uniform light pressure so that the tone does not change significantly under normal changes in ambient conditions of temperature and pressure; more particularly the ring comprises an outer annular body having circumferentially equi-spaced, radially inwardly extending, generally U-shaped, independently movable, flexible and resilient cantilevers provided at the free ends thereof with pressure applicators arranged to engage and hold the diaphragm under pressure exerted by torsion-stressed portions of the cantilevers.

Abstract: An electromagnetic tone generator having a pole piece adapted to be mounted on a circuit board and to be incorporated in the circuitry thereof, an electromagnetic coil sub-assembly adapted for mounting on a coil carrying portion of the pole piece and to be separately fastened electrically and physically to the circuit board, and a sound transducer sub-assembly including a housing defining a sound cavity and a diaphragm closing the latter and held by a retainer ring detachably fastened to the housing, the sound transducer sub-assembly adapted to be tested for sound prior to assembly and for mounting on and detachable connection with the pole piece, the retainer ring being detachably fastened to the housing so that in the disassembled condition of the sound transducer sub-assembly the ring is readily removable for replacement or servicing of critical parts of the sub-assembly, and in the assembled condition of the sound transducer sub-assembly the latter is held by the pole piece spaced from the circuit board t

Abstract: A control circuit for a tone generator that is adapted to cause the tone generator to produce a plurality of readily distinguishable audible sounds, including a chime sound, a pulse tone and a steady tone. The control circuit has particular application for use on an automobile to monitor such conditions as "seat belts buckled", "headlamps on", and "key in the ignition". The control circuit includes three oscillator circuits that are adapted to produce square wave output signals at three different frequencies. The chime sound is generated by pulse width modulating the highest frequency signal and "restriking" the decaying sound at the frequency of the lowest frequency oscillator. The steady tone is produced by driving the tone generator directly with the output signal from the highest frequency oscillator. To generate the pulse tone, the highest frequency oscillator is repeatedly enabled and disabled in accordance with the output signal from the middle frequency oscillator.

Abstract: A driver circuit for a tone generator that is adapted to cause the tone generator to produce a pleasant sounding chime. The circuit comprises high and low frequency oscillator circuits whose decaying sawtooth type outputs are summed and modulated to produce the desired chime effect.

Abstract: A tone generator having a diaphragm and an electromagnet for vibrating the diaphragm to produce sound, the bobbin of the electromagnet being held in a fixed, predetermined relation to the diaphragm and connected to the retaining ring which holds the diaphragm by resilient spring arms that are stressed automatically by assembly of the tone generator to clamp the diaphragm, the pole piece of the electromagnet being held by flexible and resilient supports that are flexed automatically to retain the pole piece when the generator is assembled and to hold an end of the pole piece precisely spaced with respect to the diaphragm.