A system for controlling the activation/deactivation of an electromagnetic shielding screen of a porthole or a protective window of an optoelectronic equipment, which includes, a radiofrequency electromagnetic sensor, with a bandwidth adapted to a cut-off band of said shielding screen corresponding to a range of electromagnetic fields to be blocked, connected to a detector-rectifier with a sensitivity higher than a minimum value of the power of an electromagnetic field to be blocked by means of said shielding screen and a device for activating/deactivating said electromagnetic shielding screen, said detector-rectifier being configured, in the presence of the electromagnetic field with a power exceeding said minimum value, to activate said device for activating/deactivating the electromagnetic shielding screen by capturing the electromagnetic energy supplied by said electromagnetic fields with a power exceeding said minimum value.

A switching circuit includes a first switch and a second switch respectively connecting a first terminal and a second terminal of an electrical coil to a positive terminal of a voltage source, a third switch and a fourth switch respectively connecting the first terminal and the second terminal of the electrical coil to a negative terminal of the voltage source, and a controller to control the switching circuit in a current control mode to alternate a voltage polarity of the voltage source to thereby control a magnitude and direction of the electrical current of the electrical coil, and to control the switching circuit in a current hold mode to disconnect the electrical coil from the voltage source and to short-circuit the electrical coil to maintain the magnitude and direction of the electrical current at the transition time when the switching circuit switched to the current hold mode.

Systems and methods for magnetic shielding are described. A magnetic shield formed of a material having a high magnetic permeability may be degaussed using a toroidal degaussing coil. The toroidal degaussing coil may enclose at least a portion of the shield. Magnetic field gradients may be actively compensated using multiple magnetic field sensors and local compensation coils. Trapped fluxons may be removed by an application of Lorentz force wherein an electrical current is passed through a superconducting plane.

One example discloses an electromagnetic device, including: a first circuit, configured to generate a first electromagnetic field; a second circuit responsive to the first electromagnetic field; a damping circuit configured to generate a second electromagnetic field in response to a current induced by the first electromagnetic field; and wherein the second electromagnetic field reduces the second circuit's responsiveness to the first electromagnetic field.

Various circuit board systems and methods of use and manufacture thereof are disclosed. A circuit board system can have a first circuit board including a substrate and a first component susceptible to electromagnetic interference carried by the substrate. The system can also include a second circuit board including a second substrate, and a shield engaged to the substrate of the first component, the shield at least partially covering the first component and being configured to protect the first component from electromagnetic interference, wherein the shield couples the substrate of the first circuit board to the substrate of the second circuit board.

A magnetic field generator includes a plurality of conductive windings comprising a first conductive winding arranged in a first plane and a second conductive winding arranged in a second plane that is substantially parallel to the first plane. The plurality of conductive windings are configured to generate, when supplied with a drive current, a first component of a compensation magnetic field. The first component of the compensation magnetic field is configured to actively shield a magnetic field sensing region located between the first conductive winding and the second conductive winding from ambient background magnetic fields along a first axis that is substantially orthogonal to the first plane and the second plane.

The present invention discloses an electronic device. The electronic device includes a connector and a sensing control unit. The connector includes a metal mask and at least one terminal. The sensing control unit is electrically connected to the metal mask and the at least one terminal. The sensing control unit is suitable for sensing whether the connector is connected to an external device, and includes a proximity sensing circuit connected to the metal mask. When the connector is connected to the external device, the sensing control unit enables the metal mask to be grounded. When the connector is not connected to the external device, the sensing control unit enables the metal mask to be floated, and the floated metal mask is suitable as a sensing electrode of the proximity sensing circuit.

An anti-interference module and a terminal device are provided. The anti-interference module includes a circuit board, an interfering source, a device disposing space, and an anti-interference component. The interfering source is disposed on the circuit board, where the interfering source may generate a changing interference magnetic field; the device disposing space is provided on a side of the circuit board and is used to dispose an electronic device with a first coil; and the anti-interference component is configured to generate a compensation magnetic field that overlaps the interference magnetic field, or to consume electric energy generated by coupling between the interference magnetic field and the anti-interference component to reduce magnetic induction intensity of the device disposing space. This application may be applied to the terminal device such as a mobile phone.

Systems and methods of shielding a hand sensor system in a steering wheel are disclosed herein. An exemplary hand sensor system includes a sensor mat and a heater mat that is disposed between the sensor mat and a frame of the steering wheel. A power source selectively provides a heating current to the heater mat to provide heat to the steering wheel and a shielding voltage signal to the heater mat to provide electrical shielding for the sensor mat when heating is not needed or when sensing takes priority over heating. Alternatively, the system may include a shield mat that is separate from the heater mat and is disposed between the sensor mat and the heater mat. In addition, to isolate the signal carried by individual sensor return wires, a metallic or insulating covering or conduit may be provided around the wires or portions thereof.

The system and method for dynamically reducing the peak electromagnetic interference produced by a group of electrical or electronic switching devices connected to a common communications bus. The system and method includes a fixed range of frequencies that includes frequencies emitted by the group of switching devices during normal operation and subranges of frequencies within the fixed range of frequencies, each subrange of frequencies being associated with a unique bus address of one switching device in the group of switching devices. Each subrange of frequencies being determined by the unique bus address of its associated switching device and characteristic weights dynamically determined and/or assigned to its associated switching device and/or load by a microprocessor implemented algorithm.