Siemens Aktiengesellschaft

Continental Automotive Gmbh

Herbert Zimmer

Peter Turban

Herbert Froitzheim

Dieter Sass

Thomas Roehrl

Mark Elliott

Hans Schreiber

Udo Frinzel

Ludwig Binnewies

Robert Murr

Wolfgang Reiml

Dieter Saβ

Christoph Kleiner

Maximilian Loeffler

Bernhard Foerstl

Roman Turba

Andreas Noichl

Manfred Trefalt

The transceiver features a fast de-excitation circuit, by means of which the transceiver can be very quickly de-energized or de-excited after sending of signals. The fast de-excitation circuit can be realized in the simplest case as a controllable switch with series-connected resistor. The transceiver is thus ready to receive signals again very fast, i.e. in the range of a few oscillation periods. With bidirectional data communication between transceiver and transponder the danger of malfunctions is avoided or at least reduced to a minimum level.

Transceiver and method for operating the transceiver

A transponder has a transponder tuned circuit, an energy store or energy supply and a starter device. The transponder tuned circuit has a tuned circuit capacitor and a tuned circuit coil with an inductive coupling to a base station for inductive energy and/or data transmission. On transmission the energy store provides a discharge current Ice. The starter device is arranged between the transponder tuned circuit and the energy store such as to generate an adjustable reference voltage Uref, which, on transmission, controls the transmission voltage Us-TSK such that an envelope curve H for the transmission voltage Us-TSK is constant over a transmission duration ts, giving a constant discharge current Ice from the energy store to supply the transponder tuned circuit and a discharge voltage Uce dependent on the reference voltage Uref for the energy store falls linearly to the reference voltage Uref at a transmission end tE.

Transponder

The device has a primary circuit () that transmits energy or data via an intermediate circuit () to a secondary circuit () by means of induction. The intermediate circuit () has a very low quality factor. The inductive coupling between the intermediate circuit () and the secondary circuit () is reduced by inserting an additional leakage inductor (L) so that energy or data is transmitted from the primary circuit () to the secondary circuit () as effectively as possible. This has the effect of lessening the damping effect of the intermediate circuit () on the secondary circuit ().

Device for the inductive transmission of energy and/or data

A device and a method for contactless transmission of data or power include an impedance which is connected into an LC resonant circuit only in a phasewise manner, in order to match a resonant frequency of the resonant circuit to an excitation frequency. This is realized by measuring a difference between the resonant frequency and the excitation frequency and connecting the impedance into the resonant circuit as a function thereof in a manner controlled by a charging current. In this case the charging current is phase-gating-controlled, and consequently only an effective component of the impedance is connected into the resonant circuit.

Device and method for contactless transmission of power or data

A transmitter unit generates a carrier signal in the form of a periodic bipolar signal. The carrier signal has intrapulse periods between two pulses of different polarity. A transmission antenna is operated with the bipolar signal. To prevent the harmonic oscillations of the transmitted signals from having excessively great amplitudes, the intrapulse period is defined such that the amplitude of the first harmonic of the transmitted oscillation, ascertained by Fourier analysis, is greater than 90% and the amplitude of the third harmonic oscillation is less than 25%, in comparison with the amplitude of the fundamental oscillation of a rectangular oscillation without intrapulse periods.

Transmitter unit for an anti-theft system of a motor vehicle, and method

An antitheft system for a motor vehicle includes a transponder having a charging capacitor which is wirelessly charged by energy signals from a transceiver. The level of the energy being transmitted depends on the quality of an inductive transmission between the transponder and the transceiver. Too little energy is transmitted if the exciting frequency of a transceiver oscillating circuit does not correspond to its resonant frequency due to component tolerances. In order to ensure that the charging capacitor is always quickly and properly charged, the exciting frequency is varied within a predetermined frequency range during a charging phase so that it passes in the vicinity of the resonant frequency at least once.

Antitheft system for a motor vehicle

A transceiver with an antenna oscillating circuit generates a magnetic field which inductively charges a charge capacitor of a transponder through a transponder oscillating circuit. A frequency-modulated oscillation is thereupon generated in the transponder and that oscillation is transmitted back to the transceiver. In order to ensure that the transceiver will receive the highest possible amplitudes of the frequency-modulated oscillation, the resonant frequency of the antenna oscillating circuit is adapted to the oscillation frequencies of the transponder oscillating circuit. To that end, an impedance is connected, automatically weighted, to the antenna oscillating circuit.

Anti-theft system for a motor vehicle

An anti-theft system for a motor vehicle includes a transceiver disposed in a motor vehicle and a portable transponder. If a magnetic alternating field of the transceiver is turned on, energy signals are transmitted inductively to the transponder, where they charge an energy storing device. As soon as the alternating field is turned off, a transponder oscillating circuit oscillates at its resonant frequency. This oscillation is transmitted inductively back to the transceiver. In the process, the resonant frequency is measured. Then, the exciter frequency of the alternating field is adapted to the resonant frequency of the transponder, so that the inductive energy transmission is as effective as possible in subsequent charging operations.

An anti-theft system for a motor vehicle includes a portable transponder carrying an item of code information. A stationary antenna has a resonant circuit with components and a resonant frequency being determined by the components. An oscillator oscillates at an oscillator frequency and has an output variable being used as an exciter variable with an exciter frequency for compelling an oscillation of the resonant circuit. The oscillation is amplitude-modulated as a function of the code information of the transponder. An evaluation unit receives the oscillation of the resonant circuit. The evaluation unit detects the modulated oscillation and demodulates the code information out of the oscillation. A comparator compares the code information with command code information and supplies an enable signal if a match occurs. A security unit receives the enable signal. The exciter frequency or the resonant frequency of the resonant circuit is varied if initially no code information is recognized by the evaluation unit.

A converter includes a feed source furnishing a medium-frequency feed voltage of constant frequency and amplitude, a coupling element and a scanning head for producing an output signal as a function of a position of the coupling element relative to the scanning head. The scanning head includes a shell core of magnetic material having a middle leg and a cup-shaped jacket concentrically surrounding the middle leg, the cup-shaped jacket having an outer surface; a primary winding being wound around the outer surface of the jacket and connected to the feed source; and a secondary winding wound around the middle leg. The primary winding and the secondary winding are connected in opposite directions in series for supplying alternating voltages at the windings forming a differential voltage having a phase relationship relative to the feed voltage determining the output signal. A load having constant, accurately reproducible properties is coupled to the magnetic flux by means of the middle leg.

Converter for generating an output signal as a function of the position

In a safety system for a stepper-motor drive, a stepper motor for operating a throttle valve has poles with windings. Each pole winding is divided into part-windings, each of which is driven by a dedicated output stage. As a result, in the event of a failure of a part-winding or an output stage, it remains possible to control the stepper motor.

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Wuppertal, Germany

Herbert Zimmer