A control device includes a moving portion, a magnetic element coupled to the moving portion, at least one magnetic sensing circuit responsive to magnetic fields, and at least one magnetic flux pipe structure. The magnetic element may comprise alternating positive and negative sections configured to generate a magnetic field. The magnetic element may be any shape, such as circular, linear, etc. The magnetic sensing circuit may be radially offset from the magnetic element, and the magnetic flux pipe structure may be configured to conduct the magnetic field generated by the magnetic element towards the magnetic sensing circuit. The magnetic element may generate the magnetic field in a first plane, and the magnetic sensing may be responsive to magnetic fields in a second direction that is angularly offset from the first plane. The magnetic flux pipe structure may redirect the magnetic field towards the magnetic sensing circuit in the second direction.

A proximity sensor and a proximity sensing method are disclosed. The proximity sensor includes a sensing element and a sensing circuit. The sensing circuit is coupled to the sensing element and transmits a first driving signal and a second signal to the sensing element, respectively. The sensing element receives the first driving signal and the second driving signal, respectively, and generates a first sensing signal and a second sensing signal, respectively. The sensing circuit generates a proximity signal according to the first sensing signal and the second sensing signal. The accuracy of sensing the proximity of the human body whether near to the sensor is improved. In addition, the sensing circuit is further coupled to a radio-frequency circuit, and the sensing circuit transmits a driving signal or/and receives a sensing signal according to the state of the radio-frequency circuit, thereby reducing interference of the sensing circuit to the radio-frequency circuit.

An inductive proximity switch comprising signal oscillating circuit and a reference oscillating circuit; multiplexer circuit designed to alternately activate the signal oscillating circuit and the reference oscillating circuit; driver circuit having an oscillator designed to operate the activated signal oscillating circuit and the activated reference oscillating circuit with an oscillator frequency, respectively; detection module designed to determine a number of oscillations of the activated signal oscillating circuit measured within a predetermined gate time and a number of oscillations of the activated reference oscillating circuit measured within the predetermined gate time; and an evaluation module designed to determine a difference signal on basis of the determined number of oscillations of the activated signal oscillating circuit measured within the predetermined gate time and the determined number of oscillations of the activated reference oscillating circuit measured within the predetermined gate time, and to generate a control signal depending on the difference signal.

A coil system for an inductive proximity switch for flush or non-flush installation in a housing includes a coil board. At least one first receiver coil and one transmitter coil are arranged on the coil board, wherein the first receiver coil includes a coil designed in a polygonal form. A method for producing a coil system for an inductive proximity switch includes forming at least one first receiver coil on a coil board in a layered arrangement and forming a transmitter coil on the first receiver coil in a layered arrangement. The first receiver coil includes a coil with a polygonal form.

The flat-type proximity sensor detects a detection object in proximity to a plate-shaped member, and includes a head body, a cable, and an amplifier. The head body includes a case member, a coil, and a head board. The case member has a first surface and a second surface. The coil and the head board are accommodated in the case member, the first surface includes a detection surface, and the second surface is installed on the installation surface. The coil generates a magnetic field by applying a pulse-shaped excitation current. The head board includes a head circuit through which a detection current flows due to a change in a magnetic field. The cable guides the detection current from the head circuit to the amplifier. The amplifier includes a processing circuit that performs processing related to detection of the detection object based on the change in the detection current.

Techniques are disclosed relating to sensing an object using an inductive proximity sensor. In an embodiment, an apparatus includes a transmission coil having turns formed on a first circuit board and including a first primary winding having a first winding direction. The apparatus further includes a first sensor coil having turns formed on a second circuit board and including a second primary winding having a second winding direction and a second sensor coil having turns formed on a third circuit board and including a third primary winding having a third winding direction opposite to the second winding direction. The coils are spaced apart from one another in a common axial direction and at least one of the coils includes a compensation winding having at least one turn, where the compensation winding is arranged radially outside of, and has a winding direction opposite to, the same coil's primary winding.