System for contactless power and data transmission

• US 5,892,300 A
• Filed: 04/28/1997
• Issued: 04/06/1999
• Est. Priority Date: 10/26/1994
• Status: Expired due to Term

• Current Assignee: Infineon Technologies AG
• Original Assignee: Siemens AG
• Inventors: Rydval, Peter
• Primary Examiner(s): Elms, Richard T.
• Application Number:
  US08/848,017
• Time in Patent Office: 708 Days
• Field of Search: 307/104, 340/310.01, 340/310.07, 439/950, 336/DIG. 2, 455/41, 342/51, 331/167, 331/177 V
• US Class Current: 307/104
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier

Abstract

A system for contactless power and data transmission contains a stationary station and a mobile station. In order to tune a resonant circuit of the mobile station to the resonant frequency of the stationary station, a multiplicity of capacitors which can be connected in parallel with the resonant circuit are provided. An instantaneous operating state of the system is included in the tuning. The realization is easy to integrate.

Claims

1. In a system for contactless power and data transmission between a mobile station and another station, the mobile station comprising:

a tunable resonant circuit supplying a signal to be picked off;

an integrable control circuit for driving said resonant circuit, said control circuit having a multiplicity of capacitors and a switching device for connecting said capacitors in parallel with said resonant circuit;

a drive device including a comparison device comparing two time-staggered signal levels of the signal to be picked off from said resonant circuit at two different points in time with one another and generating a comparison output signal, and

a control device receiving the comparison output signal and tuning said tunable resonant circuit by driving said switching device in dependence on the comparison output signal.

2. The system according to claim 1, including a sample-and-hold element receiving the signal to be picked off from said resonant circuit, said control device being an up/down counter to be clocked by the signal to be picked off from said resonant circuit, said up/down counter having an up/down control input to be controlled by the comparison output signal of said comparison device, said comparison device being a comparator having a first input to be controlled by the signal to be picked off from said resonant circuit and a second input to be controlled by the signal to be picked off from said resonant circuit and fed through said sample-and-hold element.

3. In a system for contactless power and data transmission between a mobile station and another station, a mobile station, comprising:

a tunable resonant circuit supplying a signal to be picked off;

an integrable control circuit for driving said resonant circuit, said control circuit having a multiplicity of capacitors and a switching device for connecting said capacitors in parallel with said resonant circuit; and

a device for receiving the signal to be picked off from said resonant circuit and for driving said switching device to tune said resonant circuit in dependence on a relative evaluation between at least two time-staggered signal levels of the signal to be picked off from said resonant circuit, including a sample-and-hold element receiving the signal to be picked off from said resonant circuit, a comparison device for comparing the at least two time-staggered signal levels of the signal to be picked off from said resonant circuit with one another and supplying an output signal, said comparison device being a comparator having a first input to be controlled by the signal to be picked off from said resonant circuit and a second input to be controlled by the signal to be picked off from said resonant circuit and fed through said sample-and-hold element, and a control device receiving the output signal of said comparison device to drive said switching device in dependence on the output signal, said control device being an up/down counter clocked by the signal to be picked off from said resonant circuit, said up/down counter having an up/down control input controlled by the output signal of said comparison device.