Abstract: A backlight controller for driving multiple light emitting diode (LED) strings includes feedback circuitry, phase array circuitry, and encoder circuitry. The feedback circuitry generates multiple feedback signals indicative of currents flowing through the LED strings respectively. The encoder circuitry generates a code signal indicative of a total number of operative LED strings among the multiple LED strings based on the feedback signals. The phase array circuitry generates multiple saw tooth signals according to the code signal. A phase shift amount between two adjacent signals of the saw tooth signals is determined by the total number of the operative LED strings. The phase array circuitry compares each of the saw tooth signals with a dimming control signal to generate multiple phase shift signals so as to respectively control the operative LED strings.

Abstract: Disclosed herein are a system and a method for controlling lighting. In the lighting control system, one or more lighting devices are installed in a separate area within a building and a remote controller generates a scheduling data by setting lighting scenes at each time and controls the lighting of the corresponding lighting device via a short range wireless communication. In addition, the remote controller transmits the scheduling data to a remote server through a gateway and when the remote controller is not normally operated, the remote server controls the lighting device according to the scheduling data through the gateway.

Abstract: A system and method for detecting light fixture failure and for enhancing energy efficient operation of multiple light fixtures. The system includes multiple light control modules and a gateway. The light control modules alert the gateway of a bulb or ballast failure based on light fixture power consumption. The light control module can indicate a sudden failure, a slow failure, a striating failure, a stuck relay failure and a start-up failure. The light control modules can include a photo-sensor and an occupancy sensor for measuring brightness and occupancy, respectively, in the vicinity of one or more light fixtures. The gateway can distribute operating instructions to the light control modules based on changes in the ambient temperature and based on the power consumption of nearby light fixtures.

Abstract: The present invention introduces a new class of lightweight tile-based illumination systems for uses wherein thin directionally-illuminating light distributing engines are embedded into the body of otherwise standard building materials like conventional ceiling tiles along with associated means of electrical control and electrical power interconnection. As a new class of composite light emitting ceiling materials, the present invention enables a lighter weight more flexibly distributed overhead lighting system alternatives for commercial office buildings and residential housing without changing the existing materials. One or more spot lighting, task lighting, flood lighting and wall washing elements having cross-sectional thickness matched to that of the building material or tile into which they are embedded, are contained and interconnected within the material body's cross-section.

Abstract: Various embodiments relate to an light-emitting diode (LED) driver and related method that drives various LEDs in an LED string beyond their isolated nominal luminance. Individual LEDs in an LED string may be thermally dependent so that specific LEDs may operate at higher temperatures without degradation. This may include driving specific LEDs beyond isolated nominal luminance when associated LEDs dim below their isolated nominal luminance. Such operation allows the LED to receive higher amounts of current and therefore exhibit higher luminous intensity. A control circuit may monitor the forward voltage and temperature in a feedback loop to ensure that the LEDs in the string are operating below a defined maximum junction temperature. The control circuit may signal a processing unit to adjust adjacent circuits to compensate when the controlled LEDs cannot produce a requested luminance without operating beyond a maximum junction temperature.

Abstract: A light emitting diode (LED) illuminating system includes a LED illuminating circuitry, which includes a plurality of LEDs connected in parallel, and an actuator connected to the LED illuminating circuitry to actuate the plurality of LEDs. The actuator includes a sensor and a control circuitry, which includes a controller connected to the actuator. The sensor is configured to detect an output signal of the actuator and to output the detected data value to the controller. The controller is configured to compare the detected data value with a predetermined data value, and to output a scan signal to the actuator when a LED is found to be malfunctioning. The actuator is configured to scan each LED and to output a location parameter of the malfunctioning LED to the controller based on the scan signal. A method for controlling the LED lighting system is also provided.

Abstract: A lighting control system is coupled to one or more ballast/drivers operating one or more light sources. A low power control module receives analog, digital and/or DALI signals from one or more sources, processes the signals to provide an appropriate lighting response and outputs one or more commands related to light output of the one or more ballast/drivers operating one or more light sources. A gateway component receives wireless signals from the low power control module to relay to one or more control components. The control components provide instruction to modify the light output of the one or more ballast/drivers operating one or more light sources based at least in part upon the one or more commands received from the low power control module and/or the gateway component.

Abstract: Disclosed herein is a system for driving light emitting devices. The system for driving light emitting devices includes a main light emitting device and at least one sub-light emitting device. The main light emitting device includes a first communication unit for exchanging information with a central monitoring server and a close sub-light emitting device using a wireless communication module, a first light emitting unit having at least one light emitting element, and a first control unit for controlling the light emission of the first light emitting unit, and transmitting a command signal for controlling the sub-light emitting device to the sub-light emitting device. The sub-light emitting device includes a second communication unit for exchanging information with the main light emitting device, a second light emitting unit having at least one light emitting element, and a second control unit for controlling the light emission of the second light emitting unit.

Abstract: A light-emitting apparatus includes a plurality of light-emitting devices which are connected in series and formed by alternately disposing electrodes and organic layers including a light-emitting material, wherein the electrodes include one electrode and another electrode disposed at an anode end and a cathode end of the light-emitting devices, respectively, and an intermediate electrode disposed between two of the organic layers which serves as a cathode of the light-emitting device disposed on a side of the anode end and as an anode of the light-emitting device disposed on a side of the cathode end; the intermediate electrode is connected to a drive circuit having two current output terminals connected in common; the drive circuit receives data signals concerning two of the plurality of light-emitting devices for which the intermediate electrode serves as the anode and the cathode, respectively; and the drive circuit outputs currents which are different in direction from each other from the two current out

Abstract: A method of setting up a luminaire, said luminaire being part of a network of luminaires and each luminaire of said network of luminaires being a node of a wireless communication network, comprises, for said luminaire: receiving (S32) signals from neighbouring luminaires; generating (S34) indicators from the received signals, wherein indicators give respectively indications of distances between the neighbouring luminaires and said luminaire; ranking (S35) at least a part of the neighbouring luminaires according to their respective indicators; providing (S36) a lighting scenario for said ranked neighbouring luminaires depending on their respective ranks.

Abstract: A lighting unit includes a power supply, a light source, a controller, and an output intensity adjustment mechanism. The adjustment mechanism is configured to allow a user to set an output intensity of a plurality of non-zero intensities generatable by the light source. The controller is operable to control a supply of electrical power from the power supply to the light source such that the light source illuminates in accordance with the intensity set by the user. The lighting unit is also operable to optionally report usage information for the lighting unit (e.g., cumulative on time) using the light source to produce a visually undetectable information signal. The controller is further optionally operable to adjust (e.g., increase) the electrical power supplied to the light source when the cumulative on time for the light source corresponds to a point on a lumen depreciation curve indicating a reduction in light source intensity.

Abstract: There is provided a lighting device that can reduce the occurrence of both color irregularity and brightness irregularity of light to be irradiated onto an irradiation surface even if one of a plurality of light-emitting elements included in light sources fails to light properly, and a display device using this lighting device. The lighting device includes a plurality of light sources (8), each having a plurality of light-emitting elements (26) of different luminescent colors, arranged on a plane, and can control color and luminance of light to be irradiated from the light sources (8) by controlling brightness of each of the light-emitting elements (26) based on a light source driving signal.

Abstract: In embodiments of the present invention, a method and system is provided for designing improved intelligent, LED-based lighting systems. The LED based lighting systems may include fixtures with one or more of rotatable LED light bars, integrated sensors, onboard intelligence to receive signals from the LED light bars and control the LED light bars, and a mesh network connectivity to other fixtures.

Abstract: An apparatus for detecting failures in an illumination device includes at least two light emitting diodes connected in series. The apparatus includes a first, a second, and a third circuit node for interfacing the illumination device such that the voltage drop across at least two light emitting diodes is applied between the first and the second circuit node and a fraction of the voltage drop is applied between the second and the third circuit node. An evaluation unit is coupled to the first, the second, and the third circuit node and configured to assess whether the electric potential present at the third circuit node is within a pre-defined range of tolerance about a nominal value that is defined as a pre-defined fraction of the potential difference present between the first and the second circuit node.

Abstract: A light emitting diode drive device includes a drive circuit section that applies a direct-current voltage to a light source including a plurality of light emitting diodes connected in series to allow the light source to light up, a voltage detection circuit section that detects a voltage across the light source, and a malfunction determination circuit section that determines that the light emitting diode is short-circuited when the voltage detection circuit section detects a voltage drop and a potential between the voltage before being dropped and the voltage after being dropped is equal to or more than a predetermined threshold value. Thus, it is possible to detect a fact that a light emitting diode, which lights up, is short-circuited or is not short-circuited, with a simple circuit configuration.

Abstract: The invention relates to a method for operating a lighting system having at least one central control device and a plurality of lighting devices, wherein at least one point of light can be created with each lighting device, and wherein at least one illumination parameter can be modified with a local control device in each lighting device, and wherein the location of the lighting device can be determined with a positioning sensor system in each lighting device, and wherein data transmitted wirelessly can be received from the central control device by each lighting device via a data interface, with the following process steps: a) generation of an illuminated pattern in the central control device, wherein the illuminated pattern contains a plurality of location indicators and illumination parameters assigned to the location indicators; b) wireless transmission of the illuminated pattern from the central control device to various lighting devices; c) determination of the location of the each individual lightin

Abstract: A method for activation of an electrical device, for example, in case of power loss. The method may include sensing an effect associated with activity of the electrical device, detecting an electrical power interruption, and activating the electrical device if a change in the effect of the device is sensed in proximity to the power interruption. The invention also provides an activation circuit for activation of an electrical device. The activation circuit may include a device operation detector for sensing an effect associated with activity of the electrical device, a power supply detector for detecting an electrical power interruption, and a driver for activating the electrical device if a change in operation of the device if the change is sensed in proximity to the power interruption.

Abstract: A method for driving a plurality of LEDs comprises the steps of: driving the plurality of LEDs according to a series of display signals; synchronously detecting the plurality of LEDs in a display mode for obtaining fault information; and serially outputting the fault information.

Abstract: A system and method for producing a flash of a desired intensity and duration utilizing devices of a lower intensity, such as light emitting diodes (LED's). The on period of the LED is lengthened so that the product of the LED's intensity and the on period is approximately equal to the product of the desired intensity and duration of the flash. A parameter for determining intensity, such as operating current or voltage, can be measured and the on period can be adjusted accordingly. The device can be turned on responsive to an external trigger signal, and a timer can be utilized to turn the device on if the external trigger signal is not received within a predetermined time.

Abstract: A portable electronic device operable to indicate received media is disclosed. A first set of lighting units is used to indicate a received media based on an orientation of the portable electronic device. A second set of the lighting units may be activated based on a change in the orientation of the portable electronic device.

Abstract: A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source.

Abstract: A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source.

Abstract: A trouble detecting circuit includes (a) a loop circuit conducting a loop current to two discharge tube lamps in a normal state, in which the two discharge tube lamps are driven with two alternating driving voltages having phases reverse to each other by one or two secondary side windings of one or two transformers, and (b) a monitoring circuit monitoring a voltage between two points which are at a substantially same potential in a normal state in the loop circuit.

Abstract: A dielectric barrier discharge lamp lighting apparatus includes twenty-four dielectric barrier discharge lamps, and a ballast circuit for lighting the twenty-four dielectric barrier discharge lamps which includes a DC power supply, an inverter circuit, a step-up transformer, and a lighting lamp number detecting circuit. The lighting lamp number detecting circuit detects the number of normally lighting dielectric barrier discharge lamps based on a first peek appearing right after polarity change of an approximate rectangular wave provided from the step-up transformer. When the detected number is less than a predetermined value, the operation of the ballast circuit is controlled to be stopped.

Abstract: The inventive signal incorporates an intelligent diagnosis module inside a light emitting diode (LED) signal, such as an LED traffic signal. The inventive signal can self-extinguish or send a signal through its communication port at the end of its useful life when the LEDs are no longer providing the required light output. Additionally, the inventive signal sends a signal to increase the current as the LEDs degrade to ensure the light output is above a threshold minimum.

Abstract: A detector circuit monitors the phase relationship between the lamp voltage and the excitation voltage, and if one or more conditions are met, triggers the open lamp protection process in a discharge lamp system. The detection circuit can be incorporated into a lamp voltage feedback circuit and implemented on the integrated circuit level with less cost and circuit complexity.

Abstract: A coin shaped light-emitting device is disclosed and includes a light-emitting member formed by encapsulating and wiring a plurality of LEDs on a thin substrate, a constant current controller for operating the light-emitting member in constant current and causing the light-emitting member to emit bright light, and a shell for enclosing the light. A water-resistant arrangement is further incorporated into the light-emitting device. A coin shaped spotlight is further disclosed and is formed by connecting a plurality of light-emitting devices in series, in parallel, or in another configuration. The spotlight has advantages of increased reliability, energy saving, and prolonged useful life.

Abstract: A lighting device with night light and human body sensing capability includes a first illumination device, a second illumination device, a sensor and a main body. The first illumination device is designed to illuminate a local predetermined area, and the second illumination device is designed to illuminate an entire predetermined area. The sensor comprises a first sensing member and a second sensing member. The first sensing member is to detect the illumination status of the predetermined area and to activate the first illumination device. The second sensing member is to detect a human body approaching and to activate the second illumination device. The main body is provided with fixtures to dismantle a cover for replacing the second illumination device.

Abstract: There is disclosed a germicidal treatment system having a status indicator. The germicidal treatment system comprises at least one mounting assembly attachable to an outside of a wall of an air handling apparatus. Each of the mounting assemblies includes a germicidal lamp and a ballast. The germicidal lamp is coupled to the ballast. The germicidal treatment system includes a power cord to receive electrical power and to provide electrical power to the ballast. A status indicator to indicate the functioning status of the germicidal treatment system.

Abstract: An airport strobe lighting system includes a BCD source of pulses generating trigger voltages for a plurality of strobe lamps and a sensor circuit for comparing confirmation signals with the trigger pulses and generating corresponding return pulses indicative of the operation of the strobe lamps. A microcontroller is supplied with conditioned 5 bit address inputs from the BCD source of pulses and conditioned confirmation signal outputs from the sensor circuit and compares each confirmation signal with the 5 bit address of the corresponding strobe lamp. The microcontroller controls the illumination of dedicated LEDs to indicate the status of each of the strobe lamps.

Abstract: Remote monitor and control of an airfield lighting system. A processing system local to the airport is provided in communication with the airfield lighting system for monitor and control thereof, the airfield lighting system producing airfield information for processing by the local processing system. The local processing system connects to a global communication network such that the airfield information is accessed from a remote location disposed on the global communication network.

Abstract: A method and system for visually guiding an aircraft in its landing approach to a runway having an approach area equipped with approach lights operable in off, low, medium, and high intensity states. The lights are communicated with a secondary side of a transformer, which has a primary side with low, medium, and high taps that correspond to the light states. Off, low, medium, and high lighting intensity requests correspond to the low, medium, and high states of the plurality of lights. AC power is switched between the transformer taps in response to a request for an increase in lighting intensity. Power is sequentially applied to the taps by supplying the power to the low tap for a first predetermined time interval before supplying the power to the medium tap.

Abstract: Disclosed is a method and circuit for repetitively firing a flash lamp. The method utilizes a power supply having a periodic voltage signal. The method times the discharge of the flash lamp to occur when the power supply signal is below the flash lamp self extinguishing voltage such that the flash lamp de-ionizes while the power supply signal remains below the self extinguishing voltage, thus preventing afterglow. The circuit utilizes a means for detecting when the voltage of the power supply voltage signal falls below the self extinguishing voltage to trigger the flash lamp. An additional embodiment adds a means for interrupting current flow in the flash lamp before the voltage across a storage capacitor falls below said self extinguishing voltage. The method and circuit may be extrapolated for use with other electromechanical devices.

Abstract: A light signaling device related to the operating state of a system has at least one light and circuits of detection of a failure of this or these lights, in which each light comprises m branches in parallel each composed of n light emitting diodes in series, and a branch selector; where m and n are integers such that m?2 and n?1. This invention also relates to a process for management of such device.

Abstract: This invention relates to a process for management of a light signaling device related to the operating state of a system comprising several lights each comprising several branches of several light elements, that includes a step for dynamic management of redundancy if a branch of a light should fail. This invention also relates to a device making use of this process.

Abstract: LED lamp circuitry that emulates an incandescent lamp's behavior upon remote verification of the LED lamp. The LED lamp circuitry presents an input power switch circuit, a fuse blow-out circuit and a cold filament detection circuit permitting the use of LED lamps in applications, such as railway signal light applications, where there is a need for remote monitoring of the lamps, while keeping the advantageous features of lower power consumption and longer life.

Abstract: The present invention is a programmable electronic unit mounted into a case, allowing to light or making flash varied luminous element connected independently by means of ballast inside the case and letters, so as to give a desired visual effect according a predetermined sequence.

Abstract: A light monitoring system provides a sensing unit coupled to a luminaire. The sensing unit monitors both the input and the output of the luminaire for both current and voltage. In this manner, a variety of problems with the luminaire can be detected by the sensor and this information can be passed to monitoring equipment that is either hard-wired or remotely coupled to the sensing unit.

Abstract: A method of monitoring faults in a vehicle bulb circuit including bulb and a fuse. The method includes detecting acceleration of the vehicle and comparing the acceleration of the vehicle to a limit. Based on the relationship of the acceleration to the limit, it is determined whether a fault exists in the bulb circuit. An indicator is activated in response to detecting a fault in the bulb circuit. A system for implementing the method is also disclosed.

Abstract: Monitoring and control apparatus for fail-safe monitoring for normal operation of traffic signal lights provided at an intersection or the like where a plurality of roads intersect. The illumination conditions of respective signal lights are detected using as sensor device, and when the number of illuminated or non-illuminated signal lights is a predetermined number, a normal judgment output of logic value 1 corresponding to a high energy condition is generated while, when the number of illuminated or non-illuminated signal lights is not the predetermined number, an abnormal judgment output of logic value 0 corresponding to a low energy condition is generated. As a result, when a fault in the monitoring apparatus stops the output, the resultant output condition is the same as for a danger condition due to a signal light abnormality, resulting in an extremely safe signal light monitoring and control with excellent fail-safe characteristics.

Abstract: A solid state light apparatus ideally suited for use in traffic control signals having a Self Diagnostic/Predictive Failure Analysis (SD/PFA) function facilitating a real time status of the signal as well as prediction of failure years in advance of the actual failure. Unlike incandescent signals, all LED based signals degrade over time until they are no longer in DOT light output specifications. Current state of the art solid state signals must be periodically monitored to see if the light output is in specification. This is done by having DOT or contracted personnel ascend in a bucket truck and place a light meter on the signal typically on an annual basis. A signal system with SD/PFA coupled with a modem or RF link provides real time data, without the use of a bucket truck on the status of the signal. The system also provides data which allows the determination via an algorithm of when the signal will go below light output specifications in the future.

Abstract: A constant current regulator that receives an AC input current from a source provides a constant AC current to a load. The regulator includes first, second, third, and fourth electronically controllable switches, a transformer coupled to the switches, and a controller connected to the switches. An output of the first switch is electrically connected to an input of the second switch and one input of the transformer primary winding. An output of the third switch is electrically connected to an input of the fourth switch and another input of the transformer primary winding. The controller provides a trigger signal to each of the switches. The controller adjusts a duty cycle of the trigger signals based on a comparison between an actual current value and a reference current value to provide a constant AC current to the load.

Abstract: Monitoring and control apparatus for fail-safe monitoring for normal operation of traffic signal lights provided at an intersection or the like where a plurality of roads intersect. The illumination conditions of respective signal lights are detected using as sensor device, and when the number of illuminated or non-illuminated signal lights is a predetermined number, a normal judgment output of logic value 1 corresponding to a high energy condition is generated while, when the number of illuminated or non-illuminated signal lights is not the predetermined number, an abnormal judgment output of logic value 0 corresponding to a low energy condition is generated. As a result, when a fault in the monitoring apparatus stops the output, the resultant output condition is the same as for a danger condition due to a signal light abnormality, resulting in an extremely safe signal light monitoring and control with excellent fail-safe characteristics.

Abstract: A flood light lamp removal alarm for security lights mounted on or near a home, wherein the lights are designed to turn on automatically if a motion detector is triggered and the ambient light level is low, detects by a current if any of the flood light lamps are unscrewed or loosened, either prior to a burglary or during the attempt to disable the flood light assembly. A central contact of a lamp socket is modified so that it maintains contact with the lamp therein for a longer distance as the lamp is unscrewed out, so that the alarm is triggered before the light from the lamp is disabled. Alternatively, current detectors verify when a lamp is loosened from a socket by detecting changes in current draw across the socket.

Abstract: A microprocessor-controlled airfield lighting control and monitoring system having bi-directional communication between the controlling microprocessor and the airfield lights and/or sensors. The system also includes a metal container for the remote control microprocessor and an improved attachment arrangement for the power transistor associated therewith. A DC power supply is connected to the remote controller microprocessor and has an integrated circuit adapted to sense a threshold voltage, which causes the power transistor to short around the associated power source.

Abstract: An uninterruptible power source for emergency lighting in an AC powered electrical system utilizes X-10 protocol transmitters and receivers for transmitting and receiving data signals over existing wiring to emergency wall switches interposed in the wiring for maintaining emergency lighting in the on condition when AC commercial power is interrupted and a battery powered backup unit converting DC to AC is activated upon the interruption of the commercial AC source.

Abstract: A microprocessor-controlled airfield series lighting circuit communications system and method allows bi-directional communication between the controlling microprocessor and the airfield lamps. The bi-directional communications signals are formed by using a modulated radio-frequency signal that is transmitted through a circuit containing many transformers having their primary windings connected in series. Respective secondary windings of the transformers are connected to various devices, such as lamps or sensors. A high frequency signal is imposed on the series-connected primary windings to control the lamps. The frequency of this signal is selected to be able to be detected on the secondary side of the transformer. A remote controller is connected to the secondary of each transformer to receive the control signal and selectively switch power obtained from the transformer secondary to the respective connected device.

Abstract: A power semiconductor device (2) has a first main electrode (S) for coupling to a first supply line (3), a second main electrode (D) coupled to a first terminal (4) for connection via a load (L) to a second voltage supply line (5) and an insulated gate electrode (G) coupled to a control terminal (GT) for supplying a gate control signal to enable conduction of the power semiconductor device (2). An open-circuit detection arrangement is integrated with the power semiconductor device (2) for providing an indication that a load (L) coupled to the power semiconductor device (2) is open-circuited. The detection arrangement has a reference current (Ir) providing arrangement (7, R3, R4, R7, Q1, Q2) and a current deriving arrangement (Q3, Q4) for deriving a current (Id) dependent on the voltage at the second main electrode (D).

Abstract: An automatic control system for a series circuit, in particular for airport signaling lights, physically separated from the work circuit feeding the lights and galvanically separated from the latter, includes a computer; several Main Stations each containing several Main Modules, each controlling several Remote Modules which check and act on a single airport light, each of said Main and Remote Modules having firmware boards; a full duplex transmission network linking the computer with the Main Stations; each Remote Module has externally two pairs of electric terminals of which one pair is connected to the secondary of an insulating transformer making part of the work circuit and the other pair is connected to a light or a group of lights being controlled, the two pairs of electric terminals being connected to each other by electrical leads, wherein connected in series to one of the electrical leads is a coil which is magnetically coupled to a Hall sensor of the Remote Module; and further including an electron

Abstract: The present invention includes an airfield lighting and control system for energizing at least one airfield control device and containing a ground fault detection system, comprising: (1) at least one airfield control device; (2) an AC electrical circuit conducting an AC signal and connected to said at least one airfield control device; (3) an inductive device, in electrical contact with said AC electrical circuit, which comprises (a) an inductive coil having an input pole and an output pole, and being loaded by a capacitor; (b) a driver winding for the inductive coil, the driver winding adapted to sense AC current flow through the inductor coil; (c) a sampling resistor connected to the driver winding and adapted to detect AC current in the form of a voltage across the sampling resistor; (d) signal processing circuitry comprising: (1) an inverting amplifier adapted to amplify the voltage; and (2) a phase shifter adapted to shift the phase of the voltage; and (e) a power amplifier connected to the signal proces