3032 results about "Half wave" patented technology

An apparatus for testing the life of a leakage current protection device having a leakage current detection circuit. In one embodiment, the apparatus a trip mechanism state generator, a fault alarm generator, a ground fault simulation unit. In operation, the ground fault simulation unit generates a simulated ground fault signal during every positive half-wave of an AC power, the simulated ground fault signal is detected by the leakage current detection circuit, the leakage current detection circuit responsively generates a signal to turn a switching device into its conductive state so as to allow a current to pass therethrough, the passed current is converted into a DC voltage in accordance with a trip mechanism state generated by the trip mechanism state generator, the fault alarm circuit receives and analyzes the DC voltage and indicates whether a fault exists in the leakage current protection device.

An antenna arrangement for dual mode radio devices such as WCDMA/GSM or Bluetooth radio devices. The arrangement contains two antennas close to each other, where a shorting switch is used at an open end of one antenna to increase isolation by effectively converting the one antenna from a quarter wave length antenna to a half wave length antenna when not needed in order to improve the efficiency of the other antenna. The shorting switch is typically a MEMS switch and the antennas are typically PIFA antennas. A radio device containing the arrangement has also been disclosed.

A driver circuit 3 feeds a pulse signal to an SSR 2 every half wave of alternating-current power from a commercial power source 4, and thereby separately controls the amounts of emitted light of LED groups 1x and 1y forming an LED unit 1, the LED groups 1x and 1y being connected in parallel in such a way as to point in different directions. That is, a first pulse signal for controlling the duration of light emission of the LED group 1x and a second pulse signal for controlling the duration of light emission of the LED group 1y are fed to the SSR 2 from the driver circuit 3.

A flow cytometer includes an optical flow cell through which particles to be characterized on the basis of at least their respective side-scatter characteristics are caused to flow seriatim. A plane-polarized laser beam produced by a laser diode is used to irradiate the particles as they pass through a focused elliptical spot having its minor axis oriented parallel to the particle flow path. Initially, the plane of polarization of the laser beam extends perpendicular to the path of particles through the flow cell. A half-wave plate or the like is positioned in the laser beam path to rotate the plane of polarization of the laser beam so that it is aligned with the path of particles before it irradiated particles moving along such path.

A rechargeable battery system and method are disclosed, in which an implantable medical device (IMD) regulates its transfer of energy from a separate charger unit. For recharging, a charger unit is brought into proximity to the implanted device. An oscillating current is generated in a primary coil, located in the charger. By inductive coupling through an oscillating magnetic field, an alternating current is generated in a secondary coil, which is implanted in or near the implanted device. The alternating current then passes through a half-wave or full-wave rectifier to form a one-sided current, then passes through a regulator to form an essentially direct current, which is in turn directed to the rechargeable battery in the implanted device. The secondary coil has a controllable damped resonant frequency, which can be dynamically tuned away from the driving frequency of the primary coil by a variable resistor and/or by varying a duty cycle of a rapidly switched electrical element. If a control loop in the implant senses that more power is being received at the second coil than is actually being used to recharge the battery, the control loop temporarily changes the variable resistance. When this happens, the resonant frequency of the secondary coil is detuned slightly away from the driving frequency, so that less of the incoming power is absorbed by the secondary coil. Alternatively, the secondary coil may be temporarily short-circuited. With less or no excess power entering the circuitry of the implant, the problem of overheating is mitigated.

A half-wave printed “patch” antenna includes, symmetrically with respect to a plane of symmetry of the antenna perpendicular to faces of the antenna, a dielectric substrate and two conductive layers on respective faces of the substrate. One face of the substrate includes a raised portion extending lengthwise of the plane of symmetry and one of the conductive layers extends over and along said raised portion. Consequently, the antenna has a small size, combined with a more open radiation diagram. The antenna includes only one raised portion for linear polarization, or two raised portions or a raised portion with axial symmetry for crossed polarizations.

A two-dimensional/three-dimensional (2D/3D) switchable autostereoscopic display apparatus is provided, including a display panel and a lenticular unit with a two-dimensional mode and a three-dimensional mode. In the two-dimensional mode, the lenticular unit transmits a single image, and in the three-dimensional mode, the lenticular unit separates an image from the display panel into a right-eye image and a left-eye image. The lenticular unit includes first and second lenticular lens sheets, a half-wave plate interposed between the first and second lenticular lens sheets, which rotates a polarization of incident light by 90 degrees, and first and second electro-optical mediums disposed between the first lenticular lens sheet and the half-wave plate and between the second lenticular lens sheet and the half-wave plate, respectively. First and second electro-optical media have refractive indices with respect to extraordinary rays that vary based on electric fields applied to the first and second electro-optical media.

A structure of light-emitting diode (LED) dies having an AC loop (a structure of AC LED dies), which is formed with at least one unit of AC LED micro-dies disposed on a chip. The unit of AC LED micro-dies comprises two LED micro-dies arranged in mutually reverse orientations and connected with each other in parallel, to which an AC power supply may be applied so that the LED unit may continuously emit light in response to a positive-half wave voltage and a negative-half wave voltage in the AC power supply. Since each AC LED micro-die is operated forwardly, the structure of AC LED dies also provides protection from electrical static charge (ESD) and may operate under a high voltage.

An apparatus (10) for supplying regulated voltage d.c. electrical power to an LED array (12) includes a rectifier (32) responsive to a.c. power for generating rectified d.c. power and a power factor correcting and voltage regulating buck/boost switchmode converter (38) responsive to the rectified d.c. power for generating regulated voltage d.c. power to illuminate the LED array (12). A battery backup system (62) receives the a.c. power applied to the rectifier (32) for charging a rechargeable battery (66) and sensing an a.c. power failure. A switch-over relay (82) is connected between the battery backup system (62) and the rectifier. Upon sensing a failure of the a.c. power, the battery backup system (62) controls the switch-over relay (82) to connect the battery backup system (62) to the rectifier (32) to provide d.c. power to the switchmode converter (38) to illuminate the LED array (12). A half wave power detector (88) causes the apparatus (10) to reduce regulated d.c. power to dim the LED array (12).

A light-adjusting device of an LED illuminating lamp comprises an LED illuminating lamp brightness control single firewire setting unit, an LED illuminating lamp brightness control adjusting unit, and an LED illuminating lamp brightness control drive unit. According to a light-adjusting method of the LED illuminating lamp, a method that positive and negative half-waves of a bidirectional thyristor are controlled to be triggered in a phase shifting mode is adopted, an LED illuminating lamp brightness increasing control signal or an LED illuminating lamp brightness reducing control signal is sent out in a single firewire mode, the brightness control signal is recognized through a micro controller, and the micro controller outputs a PWM signal with an adjustable duty ratio to control the brightness of the LED illuminating lamp to change between 0% and 100% in a 1% step value. The light-adjusting device is free of a remote controller and a control wire, a power supply wire does not need to be paved again, and replacement and upgrading of a common illuminating lamp are achieved.

The invention relates to a control method which can be applied to an active-clamp flyback miniature photovoltaic grid-connected inverter device. The active-clamp flyback miniature photovoltaic grid-connected inverter device comprises a flyback converter and a power frequency polarity conversion circuit. In the device, a current reference is used for controlling a flyback primary-side current peak value so that the device can output a half-wave sinusoidal current, and the output voltage is clamped by a grid voltage. When the instantaneous power is lower, a constant frequency current discontinuous mode in combined with a variable frequency current critical continuous mode is adopted in the flyback control method. When the flyback converter works in a variable frequency current critical discontinuous mode, an auxiliary switching tube can be conducted for a period of time when the secondary-side current of the flyback converter reaches zero, the conduction time can be accurately controlled by a digital chip, thus realizing the leakage inductance energy feedback and the soft switch of a master switching tube under the condition of wide-range output voltages and different instantaneous powers and greatly improving the efficiency under the condition of full loads.

The present invention discloses a stereoscopic display, which is suitable for watching by an observer wearing a spectacle. The spectacle is provided with two cycle partial lenses with different polarization characteristics. The stereoscopic display comprises a flat display panel, a quarter wave plate and a nano-pattern half-wave plate. The flat display panel is provided with a plurality of pixels which are arranged in array and is suitable for displaying a partial line pattern. The quarter wave plate is arranged between the flat display panel and the spectacle. The nano-pattern half-wave plate is arranged between the flat display panel and the spectacle. The nano-pattern half-wave plate is corresponded to the part of the pixel. The present invention also provides a manufacturing method for the stereoscopic display. The nano-pattern half-wave plate of the present invention is provided with different phase delays in different areas. The quarter wave plate is used for transforming the line partial pattern to the cycle partial pattern. So the observer can see the stereoscopic display effect with low visual angle dependency. The present invention uses a single distribution direction for integrating the quarter wave plate and the nano-pattern half-wave plate, which can reduce the working complexity.

A method and apparatus for reducing speckle in a laser illumination system uses a despeckle device including an optical retarder providing an odd integer multiple of substantially half-wave retardation for light emitted from a coherent laser in the laser illumination system. The near half-wave optical retarder has a substantially constant retardance and a spatially varied slow axis. The spatially varied slow axis imposes a phase mask on the beam of light, which provides sub-resolution optical phase modulation to a resolution spot on the detector. The near half-wave optical retarder is actuated mechanically or electrically to vary the sub-resolution optical phase modulation within an integration time of the detector.

A method and system for intrinsic timescale decomposition, filtering, and automated analysis of signals of arbitrary origin or timescale including receiving an input signal, determining a baseline segment and a monotonic residual segment with strictly negative minimum and strictly positive maximum between two successive extrema of the input signal, and producing a baseline output signal and a residual output signal. The method and system also includes determining at least one instantaneous frequency estimate from a proper rotation signal, determining a zero-crossing and a local extremum of the proper rotation signal, and applying interpolation thereto to determine an instantaneous frequency estimate thereof. The method and system further includes determining at least one instantaneous frequency estimate from a proper rotation signal, extracting an amplitude-normalized half wave therefrom and applying an arc sine function to the amplitude-normalized half wave to determine an instantaneous frequency estimate of the proper rotation signal.

Process for monitoring an alternating-voltage discharge between the electrodes of a double electrode and an apparatus. The process includes measuring values of at least one of a discharge current and a discharge voltage for each half-wave within an alternating-voltage discharge period, determining a difference between the measured values of a second half-wave and the measured values of the first half-wave, and comparing the determined differences to specific tolerance values. When the specific tolerance values are exceeded by the determined differences, a power supply is reduced, whereby the discharge is at least briefly suppressed. The apparatus includes a double magnetron including first and second targets arranged to form a double electrode, and a power supply coupled to supply power to the first and second targets. The power supply includes a measurement unit for measuring values of at least one of discharge current and discharge voltage, such that at least one of a discharge current and a discharge voltage for each half-wave within an alternating-voltage discharge period is measured. A device for determining a difference between the measured values of a second half-wave and the measured values of the first half-wave is provided, as well as a device for comparing the determined differences to specific tolerance values, and a device for at least briefly suppressing the discharge when the specific tolerance values are exceeded by the determined differences.

Three-level inverter and rectifier power conversion systems and space vector modulation (SVM) controls having even-order harmonic elimination for neutral voltage balancing with a predefined vector switching sequences for half-wave symmetry in open loop system operation. The vector sequence listings for each SVM diagram segment includes switching state entries individually indicating one of three possible switching state levels positive (P), zero (0), or negative (N) for each of three or more switching groups of the power conversion system, with listings for each pair of first and second diametrically opposite diagram segments include symmetrically opposite switching states, with positive levels in the entries of the listing for the first segment corresponding to negative levels in the entries of the listing for the second segment and vice versa.

The invention discloses a controlled-silicon adapting LED (light-emitting diode) driving circuit, method and switch power supply. The input voltage signal of the representing sine half-wave voltage signal is compared with a threshold voltage to obtain a first comparison pulse signal, and then the effective width of the first comparison pulse signal is extended for a period of time to obtain a first control signal, wherein the first control signal controls a power switch tube switches off before the input current is reduced to be equal to the maintenance current of a controlled silicon, and the power switch tube switching-off state is made to last for a period of time to the next cycle, so that the load current of the controlled silicon is made to be larger than the maintenance current all the way in the conducting time interval of the controlled silicon, the controlled silicon does not need to be re-conducted irregularly for many times, the input power of the system in each half cycle is same, and LED lamp is prevented from flicking under load and generating noise.

In a rotary electric system, a switch member includes at least one of a first switch and a second switch. The first switch is connected between a neutral point of multiphase stator windings and a high-side electrode of a direct current power source. The second switch is connected between the neutral point and a low-side electrode of the direct current power source. A controller works to turn the switch member off and on thereby switching control of the multiphase inverter between full-wave driving mode and half-wave driving mode. The full-wave driving mode allows the controller to drive all of the high-side and low-side switching elements per phase of the multiphase stator windings. The half-wave driving mode allows the controller to drive any one of the high-side switching element and the low-side switching element per phase of the multiphase stator windings.

The present invention belongs to the field of optical angle measuring technology, and includes setting half-reflecting mirror in the output light axis of Zeeman laser, setting half wave plate perpendicularly in the transmission light path of the half-reflecting mirror, and setting half wave plate, analyzer, one first photoelectronic detector successively and perpendicular second photoelectronic detector in the reflection light path; and one phase meter with input connected to the output of the first and the second photoelectronic detectors and output to the computer. The present invention hasstrengthened non-linearity and 4 times raised sensitivity, and the close measuring detectors and light source results in compact structure and ever high practicability.

In addition to having color, light waves have the attribute of polarization. An apparatus and method to convert circular polarized light into linearly polarized light over a wide range of wavelengths is provided by utilizing a first surface-relief grating functioning as a quarter-wave waveplate and a second surface-relief grating functioning as a half-wave waveplate. A plurality of such devices are arranged in a two-dimensional array and combined with an array of linear polarizers and an array of photodetectors to form a polarization imaging sensor. Such a sensor could have applications in automobiles to alert drivers of the presence of other vehicles, especially at night, in fog, or in rain. Military applications include the detection of vehicles placed among trees and shrubs. Another advantage of using circular polarization images is that the sign and magnitude of the circular polarization can potentially be used to reveal the spatial orientation, material, and surface roughness of the object's surface.

An LED light string employs a plurality of LEDs wired in block series-parallel, where the one or more series blocks, each driven at the same input voltage or rectified AC input voltage as the source voltage (110 VAC or 220 VAC), are coupled in parallel. This voltage matching requirement for direct AC drive places fundamental restrictions on the number of diodes on each diode series block, depending on the types of diodes used. The same method that apply to matching the sum of the LED lamps (VAC values) to the AC input, or applied voltage in an AC circuit apply to matching the sum of the LED lamps (VP values) to the full-wave or half-wave rectified AC (VP) voltage applied. Filtering capacitors may also be employed.

A power transmission device of a non-contact power transmission system includes a waveform monitoring circuit that generates and outputs a waveform-monitoring induced voltage signal based on a coil end signal of a primary coil, and a power transmission control device that controls a power transmission driver that drives the primary coil, the power transmission control device receiving the waveform-monitoring induced voltage signal and detecting a change in waveform of the induced voltage signal to detect a power-reception-side load state. The waveform monitoring circuit includes a first rectifier circuit having a limiter function, the first rectifier circuit including a current-limiting resistor provided between a coil end node where the coil end signal of the primary coil is generated and a monitoring node where the waveform-monitoring induced voltage signal is generated, performing a limiter operation that clamps the induced voltage signal at a high-potential-side power supply voltage, and subjecting the induced voltage signal to half-wave rectification.

A charging system is disclosed. In one embodiment, the system includes a charging unit having a primary coil, and an implantable medical device comprising a secondary coil to receive charge from the primary coil. The implantable medical device further includes a half-wave voltage-doubling rectifier coupled to the secondary coil, a full-wave rectifier coupled to the secondary coil, and a rechargeable power source. Control logic is provided to periodically configure the rechargeable power source to receive charge from a selected one of the voltage-doubling circuit and the full-wave rectifier in a manner that increases rate at which charge is transferred from the secondary coil to the rechargeable power source. The control logic may configure the rechargeable power source to receive charge based on one or more monitored conditions which may include, for example, an indication of a current, a voltage, a coupling coefficient, back-scatter, and temperature.