Abstract: In this non-contact power feeding system that is capable of transmitting power from a power transmitting device (1) to a power receiving device (2) by a magnetic field resonance scheme, the power transmitting device (1) is provided with first to n-th resonant circuits (TT[1]-TT[n]) which are provided with coils (TL) that are different in size, respectively, and which have a resonant frequency set to a prescribed reference frequency. Prior to power transmission, test magnetic fields are generated in sequence in the first to n-th resonant circuits to detect the amplitude of current flowing through the coils of respective resonant circuits, and the presence/absence of a foreign object is determined on the basis of the obtained first to n-th amplitude detected values, to control execution of the power transmission.

Abstract: An interface circuit, which uses electromagnetic induction to perform a signal transmission, comprises a transmission coil and a transmission circuit that provides a signal to the transmission coil, thereby causing the transmission coil to output a triangular or roughly triangular magnetic field signal.

Abstract: A power transmission control device provided in a power transmitting device of a non-contact power transmission system includes a driver control circuit that controls a power transmitting driver that drives a primary coil, a load state detection circuit that detects a power-receiving-side load state, and a control circuit that controls the power transmission control device. The control circuit acquires a reference value used to determine a power-receiving-side load state after starting normal power transmission in a reference value acquisition period, the reference value acquisition period being a period after receiving ID authentication information from the power receiving device, but before starting the normal power transmission.

Abstract: The invention provides an electronic circuit capable of simplifying a transmitter circuit and yet realizing low-voltage drive and low power consumption where communications between substrates are realized by inductive coupling. As the transmission data Txdata are turned from LOW to HIGH, the transistor T1 is turned from OFF to ON, and at the same time, the transistor T2 is turned from ON to OFF, wherein the current IT is caused to flow to the transmitter coil 14, and the capacitor 15 is charged. As the capacitor 15 is sufficiently charged, the current IT stops flowing. As a result, a pulse current of a triangular waveform is flown to the transmitter coil 14. Next, as the transmission data Txdata are turned from HIGH to LOW, the current IT is inversely flown to the transmitter coil 14, and the capacitor 15 is discharged, wherein a pulse current having a triangular waveform of reversed polarity is flown to the transmitter coil 14.

Abstract: The system of the present invention allows transmission of information and data across a gap, for example, from the steering wheel of an automobile to the steering column, without any physical connection between the information source and the information or data gathering circuit. Furthermore, the information source requires no power. The system of the present invention utilizes the principle that an oscillator circuit is loaded by an inductively coupled circuit tuned to oscillate at approximately the same frequency. Loading the oscillator circuit causes the oscillator L-C loop voltage amplitude to decrease.

Abstract: A data transmission system including a pair of parallel transmission lines, applies data signals to the transmission lines through a transformer and an associated impedance connected across the lines. The transformer is magnetically coupled to at least one of the lines to apply a signal current thereto. The signal current is transferred to the other line through the impedance. The impedance is tuned to the transmission frequency so that it has a very low value during data transmission.

Abstract: 1. The combination comprising a pair of magnetic dipole antennae of substantially equal radiation strength in proximate but offset relation and oriented with their axes extending in a common direction, and an oscillating current source operatively connected to both of said antennae to drive them simultaneously but in opposed phase relationship, whereby the dipole moments of said antennae substantially cancel one another so that the antennae function together to produce a magnetic quadrapole radiation substantially free of any dipole movement.