Abstract: An actuator for opening the separable contacts of a circuit interrupter integrates a Thomson coil arrangement into the movable and stationary conductor assemblies. A movable separable contact is coupled to one end of the movable conductor, and a stationary separable contact is coupled to one end of the stationary conductor. The movable and stationary conductors are each formed with a collar positioned near the respective movable and stationary separable contacts. The actuator further includes a coil seated within a coil housing, and the coil housing is coupled to the stationary conductor collar. A conductive member shaped as a cup and structured to be actuated by the coil is coupled to the movable conductor collar, such that the rim of the cup faces the coil. A housing is positioned around the conductive member cup body with bellows and coupled to the coil housing, forming a vacuum chamber around the separable contacts.

Abstract: One variation of a keyboard system includes: a substrate including an array of inductors; a tactile layer arranged over the substrate defining an array of key locations over the array of inductors; an array of magnetic elements, each arranged within the tactile layer at a key location configured to inductively couple to an adjacent inductor and configured to move relative to the adjacent inductor responsive to application of a force on the tactile layer at the key location; and a controller configured to read electrical values from the inductors. In response to detecting a change in electrical value at a first inductor, the controller also configured to: register a first keystroke of a first key type associated with a first key location defined over the first inductor; and drive an oscillating voltage across the first inductor to oscillate the tactile layer over the substrate during a haptic feedback cycle.

Abstract: A control device for a push bar latch, comprising: a base frame having a sliding slot; a control connecting rod, the outer end is combined with an unlocking return unit of the push bar latch and the inner end has a positioning pin, the positioning pin is set through the sliding slot; a locking hook, the outer end has a hook portion relative to the positioning pin; an electromagnet, used for holding the inner end section of the locking hook, so let the hook portion enter a hooking state for the positioning pin; and a release element, used to release the hook portion from the hooking state for the positioning pin when the electromagnet is powered off. Whereby the push bar latch has the enter control function.

Abstract: A 5G/6G network can include a modulation scheme for uplink and downlink messaging using a special zero-power modulation level, in addition to the regular amplitude modulation levels of, for example, QAM. The receiver can demodulate each message element by comparing the amplitude to the various amplitude levels, including the zero-power level, and thereby increase the bits per message element, and hence the communication throughput, at no increase in transmitted power. In addition, the zero-power states can reveal intrusive noise and interference in the proximate message, enabling correction before the demodulation. The zero-power amplitude may be added to conventional modulation schemes, such as an additional zero-power amplitude level in QAM, PSK, and amplitude-phase modulation schemes, thereby providing greater versatility at little or no cost and no additional transmission power.

Abstract: The present invention relates to an energy storage device, comprising a switchgear cabinet housing in which a plurality of receiving spaces are provided, in which receiving spaces at least one control device and a variable number of electrical storage blocks are accommodated in an exchangeable manner, wherein the storage blocks can be selectively interconnected in series or in parallel and are connected to power connections by means of a current controller. Therefore, it is initially proposed to form the control device which is installed in the switchgear cabinet housing and the associated power electronics components themselves in a reconfigurable or variable manner in order to allow the controller and power electronics to be matched to another mode of operation or another application, without having to exchange the control and power electronics module and provide corresponding wiring for this purpose.

Abstract: An integrated circuit thermal management system includes an enclosure, a heat exchanger, an integrated circuit, a slide having a moveable slide body, an electromagnetic coil, a magneto caloric material and controller circuitry. The heat exchanger is positioned on a first side of the enclosure, and the integrated circuit is positioned on a second side of the enclosure with a temperature sensor configured to generate a temperature signal indicative of a temperature of the integrated circuit. The slide is disposed in the enclosure extending between the heat exchanger and the integrated circuit. The electromagnetic coil and the magnetocaloric material are included on the slide body. The controller is configured to control energization of the magnetic coil and movement of the magnetocaloric material on the slide body between the heat exchanger and the integrated circuit based on the temperature signal.

Abstract: One variation of a system includes: a substrate including an aperture and a multi-layer inductor; and a cover layer arranged over the substrate and cooperating with the aperture to define a housing. Additionally, the system includes a fingerprint reader arranged within the housing and configured to permeate through the cover layer to scan a fingerprint applied over the cover layer. A magnetic element is arranged facing the multi-layer inductor and configured to inductively couple the multi-layer inductor. The system further includes a controller configured to: read electrical values from the multi-layer inductor; and register a fingerprint input on the cover layer based on the electrical values. Additionally, the controller can: read fingerprint values from the fingerprint reader to generate a fingerprint image; and trigger a first oscillating voltage across the multi-layer inductor to oscillate the cover layer in response to the fingerprint image deviating from a target fingerprint image.

Abstract: One variation of a keyboard system includes: a substrate including an array of inductors; a tactile layer arranged over the substrate defining an array of key locations over the array of inductors; an array of magnetic elements, each arranged within the tactile layer at a key location configured to inductively couple to an adjacent inductor and configured to move relative to the adjacent inductor responsive to application of a force on the tactile layer at the key location; and a controller configured to read electrical values from the inductors. In response to detecting a change in electrical value at a first inductor, the controller also configured to: register a first keystroke of a first key type associated with a first key location defined over the first inductor; and drive an oscillating voltage across the first inductor to oscillate the tactile layer over the substrate during a haptic feedback cycle.

Abstract: The present disclosure relates to a device and method for forming skyrmion in a magnetic thin film. A skyrmion forming method comprises aligning the surface of the magnetic thin film and a horizontal magnetic field to be applied to the magnetic thin film and applying the horizontal magnetic field and a vertical magnetic field to the magnetic thin film. Accordingly, it is possible to form the bubble skyrmion easily even in the case of a wide width of a stripe formed on the magnetic thin film.

Abstract: An electromagnetic actuator device includes an actuator having an actuator coil and a tappet that can be moved in and against a longitudinal direction. The actuator device includes a sensor device having a transmitter element arranged on the tappet and a sensor element for generating a measurement signal, containing information about a current actual position of the tappet, depending on a magnetic field generated by the transmitter element. The actuator device includes a control unit with a controller, which applies a control voltage to the actuator coil for generating an electromagnetic field during operation in dependence on a position signal based on the measurement signal, so that the tappet moves into a target position. During operation, a stray magnetic field is generated by the at actuator coil, an adaptation of the measurement signal is performed to compensate for the influence on the measurement signal caused by the stray field.

Abstract: A transformer is provided which includes an insulating sheet separating the primary-side windings and portion of split magnetic core from the secondary-side windings and portion of split magnetic core. Thin layers of conductive and semiconductive material are deposited on areas of the insulating sheet surfaces facing the primary and secondary sides. These layers are electrically referenced or tied to the potentials of the respective primary or secondary sides. This ensures that the high electric field due to primary-to-secondary potential gradient is substantially placed across the insulating sheet dielectric and avoided in the air gaps or voids in the transformer, thus reducing undesirable partial discharge effects. The two core sections on the primary and secondary side are also electrically referenced or tied to the potentials of their adjacent windings, thus reducing high electric fields and partial discharge in the space between the core sections and the windings.

Abstract: An exemplary method generally relates to operating an access control device including a motor, a locking member, and a target component operably connected with the locking member. The motor may be operated to drive the locking member in a first direction from an initial position toward a desired position. When the locking member is blocked from moving beyond a blockage position, a target location of the target component is detected. The motor may then be operated to drive the locking member in a second direction opposite the first direction. The motor may then be operated to drive the locking member in the first direction toward the blockage position while monitoring the location of the target component. As the target component reaches the target location, the motor is supplied with a boost current to drive the locking member beyond the blockage position and toward the desired position.

Abstract: An integrated switching device in which a contactor unit which is capable of controlling a continuity state of an electric circuit, a blocking unit which is capable of cutting a contactor and blocking a current when abnormality is generated in the contactor or a current having a size exceeding a permitted current range of the contactor is generated, and a current measuring unit which is capable of measuring a current by using shunt resistor are integrated into one device, thereby performing various functions only with one device.

Abstract: An input method and a smart terminal device. After a processor in the smart terminal device determines, based on a first detection solution of a first infrared sensor, that a target object enters or leaves a first space range from a first plane, the processor starts or stops displaying a cursor based on distances measured by ultrasonic sensors; and after the processor determines, based on a second detection result of a second infrared sensor, that the target object enters or leaves a second space range from a second plane, the processor starts or stops performing a confirmation operation based on a location of the cursor.

Abstract: An injection control device controls the opening and closing of a fuel injection valve by performing peak current drive and constant current drive with respect to the fuel injection valve and controls injection of fuel from the fuel injection valve to an internal combustion engine. The injection control device includes an energization control unit that performs constant current switching control of an energization current to the fuel injection valve. The energization control unit is configured to, when the energization current to the fuel injection valve is to be stopped, controls an energization stop timing of the energization current such that a flyback period is equal to a first predetermined time period.

Abstract: A magnetic bearing device includes a magnetic bearing including a plurality of electromagnets, a displacement sensor configured to output an output signal in accordance with a displacement of a shaft, and a controller configured to control the electromagnets. The controller compensates for a change in levels of the output signal, the change occurring in accordance with a change in ambient temperature around the displacement sensor, based on one or more reference values correlating with the change in levels of the output signal. The one or more reference values are detected for use in controlling the rotary electric machine, a fluid machine system including the rotary electric machine, or an apparatus including the fluid machine system.

Abstract: A magnetic switch sensor is provided having a magnetic field sensing element configured to generate a magnetic field signal in response to a magnetic field indicative of a distance or angle between the magnetic field sensing element and a target, a first circuit coupled to receive the magnetic field signal and having an output to provide a comparison signal, and a debounce circuit coupled to receive the comparison signal and having an output to provide a debounced signal. The sensor can include a second circuit having an input coupled to receive the debounced signal and an output at which is provided a toggle signal that transitions between first and second levels every other time the magnetic field signal crosses a threshold level.

Abstract: A system for actuating a vacuum bottle of an electrical device, the vacuum bottle being connected in a circuit shunting a main circuit of a phase of the electrical device and comprising a movable electrode and a fixed electrode. The actuating system comprises a shunt contact which is connected to a movable contact of the main circuit during a movement of opening the electrical device, and an electromagnet whose coil is connected between the movable electrode and the shunt contact, and whose core is mechanically linked with the movable electrode, such that the core drives the movable electrode to the open position only when the value of the current which passes through the coil reaches a predetermined threshold.

Abstract: A method is provided for determining the operating status a MV switching apparatus. The method includes providing a test signal to the test winding for an observation period of time, the test signal having a waveform capable of exciting the magnetic element; obtaining first measuring data indicative of a voltage at first terminals of the capacitor bank during the observation period of time; obtaining second measuring data indicative of a voltage at second terminals of the test winding and indicative of a current circulating along the test winding during the observation period of time; and, calculating estimation data indicative of the operating status of the capacitor bank at the end of the observation period of time on the basis of the first and second measuring data, the first estimation data comprising a first estimation value indicative of the capacitance of the capacitor bank.

Abstract: To provide an electromagnetic bad driving device capable of performing failure diagnosis of a relay more frequently. The electromagnetic bad driving device according to the present invention, interrupts the relay while an electromagnetic induction bad is under control, and diagnoses the relay on the basis of a surge voltage occurring at the interruption.

Abstract: Some embodiments provide irrigation valve control apparatuses comprising: a solenoid configured to cooperate with a plunger; an input stimulus source coupled with the solenoid and configured to apply an input stimulus while a plunger drive signal is not being applied and that is sufficiently small to not cause the plunger to move; sampling circuitry configured to measure one or more voltage measurements corresponding to one or more voltages across the solenoid, wherein the one or more voltage measurements are dependent upon the current position of the plunger relative to the solenoid; and control circuitry cooperated with the sampling circuitry to receive the one or more voltage measurements from the sampling circuitry, wherein the control circuitry is configured to determine whether the plunger is in one of the open and closed positions based on the one or more voltage measurements.

Abstract: A magnetic bearing vacuum pump comprises: a first displacement signal generation section configured to amplify, by a resolution multiplying factor K of K>1, a displacement modulated wave signal modulated according to a displacement of the rotor from a predetermined position to generate a high-resolution displacement signal in a first displacement region including the predetermined position; a second displacement signal generation section configured to generate a low-resolution displacement signal in a larger second displacement region including the first displacement region; a selection section configured to select either one of the high-resolution displacement signal or the low-resolution displacement signal based on an unsteady-state response signal obtained by excluding a steady-state whirling displacement component from the high-resolution displacement signal or the low-resolution displacement signal; and a bearing control section configured to control the magnetic bearing based on the displacement sig

Abstract: A driving device for multi-axis common-mode voice coil motor is provided, which includes a control signal processing interface and a plurality of drive-stage circuits. The control signal processing interface generates a plurality of control signals and a plurality of command signals. The drive-stage circuits receive the control signals and the command signals respectively; each of the drive-stage circuits is connected to one end of one of the coils of a voice coil motor and includes a half-bridge switch circuit; the drive-stage circuit controls the half-bridge switch circuit to generate a driving current to drive the coil according to the control signal. The drive-stage circuit compares the feedback signal of the feedback elements of the coil loop with the command signal to generate an adjustment signal and adjusts the driving current according to the adjustment signal, such that the driving current can track the command signal.

Abstract: A relay control device is provided configured to reduce the amount of power supplied to a coil in an electromagnetic relay. The relay control device includes a control unit for generating and outputting a PFM signal to control the voltage-drop DC/DC converter unit, a filter unit allowing passage of the PFM signal, and a circuit unit controlling the operation of the voltage-drop DC/DC converter unit in accordance with the output signal of the filter unit. If the filter unit does not allow passage of the PFM signal, the circuit unit prevents the voltage-drop DC/DC converter unit from dropping the voltage, and performs control so as to output the power supply voltage to a coil in the electromagnetic relay. If the filter unit prevents the PFM signal from passing, a current path from a power supply potential to a ground potential within a circuit unit is cut off by transistors.

Abstract: Provided an active suppression controller with an adaptive algorithm capable of tracking the fluctuation of multi-fundamental frequencies and correcting them while the deviation is divergence based on the DXHS (Delayed-X Harmonics Synthesizer). It includes a controller's architecture, an adaptive frequency tracking & correcting algorithm and its FPGA implementation structure in real-time.

Abstract: A magnetic electronic device includes a first body and a second body. The first body includes a first case and a magnetic member inside the first case. The second body includes a second case and includes a magnetic sensor, a magnetism guiding member and a switch control component inside the second case. The second case is connected to the first body to be movable relative to the first body. The magnetic sensor is disposed on the magnetism guiding member, and the switch control component is electrically connected to the magnetic sensor. The magnetism guiding member guides the magnetic field caused by the magnetic member, and the magnetic sensor detects the magnetic flux caused by the magnetic member. When the magnetic flux is larger than a first value, the switch control component switches a component's switch.

Abstract: An electromagnetic valve includes a valve body, a valve core, and an electromagnetic drive device. The valve body has an operation chamber, wherein the valve core is movably arranged in the operation chamber. The electromagnetic drive device is arranged in the valve core and is suitable for being electrically connected with a power source. The electromagnetic drive device is arranged, when driving the electromagnetic valve, to provide the valve core with a starting drive so as to drive the valve core to enter a running state. After the valve core is driven to enter the running to state, to provide the valve core with a maintaining drive so as to keep the valve core in the running state.

Abstract: A scalable, highly dynamic electromagnetic linear drive with limited travel. The linear actuator is distinguished by low transverse forces.

Abstract: Some embodiments provide irrigation valve control apparatuses comprising: a solenoid configured to cooperate with a plunger; an input stimulus source coupled with the solenoid and configured to apply an input stimulus while a plunger drive signal is not being applied and that is sufficiently small to not cause the plunger to move; sampling circuitry configured to measure one or more voltage measurements corresponding to one or more voltages across the solenoid, wherein the one or more voltage measurements are dependent upon the current position of the plunger relative to the solenoid; and control circuitry cooperated with the sampling circuitry to receive the one or more voltage measurements from the sampling circuitry, wherein the control circuitry is configured to determine whether the plunger is in one of the open and closed positions based on the one or more voltage measurements.

Abstract: A method for controlling a piezoelectric actuator of a fuel injector of an internal combustion engine of a vehicle, the actuator acting on valve elements to open or close the injector, respectively enabling or stopping the injection of fuel into a combustion chamber of the engine, includes the steps of: applying to the actuator a first nominal electric charge required to open the injector in accordance with the torque requested and the engine speed, to open the valve elements for fuel injection, instructing the closure of the injector to stop the fuel injection, by applying an electric discharge to the actuator to close the valve elements, the method applied from an on-board engine control unit during operation, and including applying to the actuator between these 2 steps at least one second electric charge to polarize the actuator during an opening phase of the injector and during fuel injection.

Abstract: A relay circuit includes a power supply to apply an AC input line voltage to the relay circuit, a relay coil and at least one pair of contacts actuated by the relay coil. A zero cross detection circuit and a control logic circuit for the relay circuit are also disclosed. The control logic circuit determines a zero crossover point in response to an output signal from the zero crossover detection circuit, and controls a relay coil to actuate the relay contacts to switch a load at the zero crossover point of a load current when the load is connected to the at least one pair of relay contacts, such that the voltage and current across the relay contacts is zero.

Abstract: A vibration device includes a touch panel, a vibrator that is arranged on the touch panel, a frame that is separated from at least a part of the touch panel and is arranged to surround the touch panel in a planar view, and a first connecting member that is arranged on the touch panel and the frame to cover a space between a part of the touch panel and the frame in a planar view and that connects the touch panel and the frame. Furthermore the first connecting member includes a first member positioned on the operation panel, a second member positioned on the frame, and a third member covering a space in a planar view. The thickness of the third member is smaller than those of the first and second members.

Abstract: A magnetic bearing device includes a first carrier generation section which generates a first carrier signal, and a second carrier generation section which generates a second carrier signal whose phase differs by (?/2+?) radian from the phase of the first carrier signal. In addition, the magnetic bearing device includes a first demodulation section which performs demodulation by sampling the first modulated signal at sampling timing shifted by a phase ? from timing at which the first carrier signal becomes a peak. A second demodulation section performs demodulation by sampling the second modulated signal at sampling timing shifted by a phase (??) from timing at which the second carrier signal becomes a peak. A controller controls current in each of the first radial electromagnet and the second radial electromagnet, based on a result of the demodulation by each of the first demodulation section and the second demodulation section.

Abstract: A gyro sensor includes a vibrator and a drive circuit. A PWM drive signal is applied to a pair of electrodes of the vibrator. The drive circuit outputs a high level signal and a low level signal to the electrodes as the PWM drive signal. The high level signal and the low level signal have potentials higher and lower than that of the reference signal, respectively. The drive circuit outputs the high level signal to one of the pair of electrodes and the low level signal to the other of the pair of electrodes.

Abstract: A circuit for delivering power to a load from a wireless power supply comprises an inductor coil for placing in the electromagnetic field of an inductor coil of a supply and a switchable capacitor bank with capacitors switchable at least between a series and a parallel configuration. The voltage across the capacitor bank is used as a feedback control parameter for controlling the capacitor bank switching. A voltage regulator is used to supply the load with a constant voltage power supply derived from the capacitor bank output.

Abstract: An electromagnet has a core with a pair of magnetic poles, a primary coil wound around the core, and a series circuit of a first auxiliary coil wound around the first magnetic pole of the core, a second auxiliary coil wound around the second magnetic pole of the core, and capacitors, and is connected in parallel to the primary coil and the series circuit. The first and the second magnetic poles are each divided into a plurality of split magnetic poles. The first auxiliary coil is composed of a plurality of split auxiliary coils wound around the respective pole in the plurality of split magnetic poles of the first magnetic pole so that the mutual inductance with the primary coil becomes zero. The second auxiliary coil is composed of a plurality of split auxiliary coils wound around the respective pole in a plurality of split magnetic poles of the second magnetic pole so that the mutual inductance with the primary coil becomes zero.

Abstract: The invention provides a method for improving operation lifetime of a capacitor module in an electronic circuit employing the capacitor module, comprising the steps of providing two or more capacitor modules of same configuration; and controlling alternately a respective one of the capacitor modules to operate in the electronic circuit for a first predetermined period of time. The invention also relates to a capacitor control circuit structure for use in a location of an electronic circuit previously occupied by an original capacitor module, and the capacitor control circuit structure exhibits the extended operation lifetime with respect to the original capacitor module. The invention also relates to the use of the capacitor control circuit structure in the electronic applications.

Abstract: When a rotational angle of a pedal is in a range from an angle of zero degrees to a predetermined rotational angle, which is larger than a full-opening-time rotational angle, a first Hall IC outputs a first voltage, which is twice larger than a second voltage outputted from a second Hall IC. When the rotational angle of the pedal is larger than the predetermined angle, the first Hall IC outputs a predetermined constant voltage. When an output difference, which is computed based on the first voltage and the second voltage, is equal to or smaller than a second threshold value, an abnormality of the sensed rotational angle of the pedal is determined.

Abstract: To provide a magnetic bearing control device that identifies a movable range of an eddy current gap sensor configuring a magnetic bearing and a center of the movable range and easily controls a rotor shaft and other controlled shafts, which are lifted by the magnetic bearing, in a central position of a protective bearing.

Abstract: Electrical current and/or conductivity in an electrical current channel varies in response to spatiotemporal magnetic flux pattern and/or to variation in electromotive force (EMF). For example, a channel with time-varying electrical conductivity can have induced electrical current variation due to flux pattern resulting from electrical current in another channel or set of channels; the current variation can increase magnetic flux density. The electrical currents can be transient electrical currents, and can cascade to amplify a resulting electromagnetic waveform. A channel can include the channel of a zener or zener-like diode or of a transistor, as well as an extended conductive channel. Channels can be configured in electrical current loops and in various orientations and combinations to obtain current and/or conductivity variation. A transient electrical current can be triggered in a channel, e.g.

Abstract: A system and methods for redundant current-sum feedback control of an actuator system is presented. An actuator comprises actuation coils configured to actuate the actuator, and an actuation coil current sensor senses a measured total coil current comprising a sum of coil currents of each of the actuation coils. Actuator coil controllers control the actuation coils based on a commanded total coil current and the measured total coil current.

Abstract: A multi-actuator motion control system includes a control methodology that coordinates the motion of multiple actuators while limiting the force-fight between the actuators. Control logic is provided in a relative coordinate system that allows control of the mean actuator position. Force-fight between the actuators is decoupled from the actuator position by estimating load forces on the actuator using reduced-order observers.

Abstract: Provided is a radial direction controller capable of handling changes in negative bearing stiffness according to the mounting orientation.

Abstract: A driver circuit includes a first current source configured to sink part of the current from a power supply through a load and a second current source configured to sink part of the current from the power supply to a return path, bypassing the load, so that the current through the load is the difference between the current from the power supply and the current through the second current source.

Abstract: Methods may be provided to control an electro-permanent magnetic device powered from an AC mains power source provided through first and second power lines of a controller, wherein a first switch is provided on the first power line between the AC mains power source and the electro-permanent magnetic device and a second switch is provided on the second power line between the AC main power source and the electro-permanent magnetic device. In particular, a sequence of switching pulses may be transmitted through the first and second switches to change a magnetic state of the electro-permanent magnetic device. Related controllers are also discussed.

Abstract: A magnetic manipulation and navigation system for moving a magnetic element through a body comprising at least six electromagnets fixed in relation to said body and a control unit supplying the current for the electromagnets. The electromagnets have soft magnetic cores and the current supplied by the control unit to each of the electromagnets is adapted to operate the electromagnetic coils of each of the electromagnets in their core's linear regions being delimited by the value of the flux density of each electromagnet being in an interval between the negative and positive saturation value of each electromagnet, the lower representation showing the deviation due to the use of soft magnetic cores in all electromagnets.

Abstract: A method of queuing access to a power supply shared by a set of electrical access points. The access points turn on independently from one another and thus have independent power draws. Each access point has a specific power draw when on. The on state and associated power draw of each of access point is identified, and a load duration curve for each access point is normalized (i.e., combined with load duration curve(s)) from the other access points) into a probability distribution function. The probability distribution function is a normalized load duration curve that thus accounts for a varying set of “operating states” that may occur with respect to the set of access points (when viewed collectively). Each operating state has an associated probability of occurrence. As the operating state of the set (of access points) changes, access to the power supply is selectively queued, or de-queued (if previously queued).

Abstract: An electrical component having a primary winding, a first field-effect transistor, configured as a switch of the primary winding, for switching the primary winding, a quench winding for quenching the inductive load of the primary winding when switching off the primary winding, and a second field-effect transistor, configured as a switch of the quench winding, for switching the quench winding. In the process, the first field-effect transistor is operated in linear operation and the second field-effect transistor is operated in linear operation or in a clock-pulsed operation between the linear operation and a switched-off state during a switching-off process of the quench winding.

Abstract: A method determines a change in the activation state of an electromagnetic actuator.

Abstract: A method and apparatus provide an improved EM reverberation chamber which facilitates the dynamic three dimensional (3D) manipulation of EM field polarization within the chamber and produces a uniform field distribution inside the chamber. The chamber includes one or more walls with tunable lumped elements. A controller is provided to generate one or more control signals that are applied to the lumped elements and tunes their impedance in response to the one or more control signals. The result is to generate, within the chamber an electromagnetic field that appears to be random or pseudo-random in polarization, but which is sufficiently uniform in magnitude for EM testing.