Abstract: The present disclosure provides a high-precision dimming circuit. A dimming circuit (107) includes an input stage (IN) and an output stage (OUT). The input stage (IN) includes a plurality of amplifiers (AMP1 to AMP3) which have non-inverted input terminals (+) thereof inputted with different dimming input voltages (DCDIM1, DCDIM2 and VH), respectively, and inverted input terminals (?) thereof inputted with a common dimming output voltage (V3). The output stage (OUT) is connected between respective output terminals of the plurality of amplifiers (AMP 1 to AMP3) and an output node of the diming output voltage (V3), and outputs, among the plurality of dimming input voltages (DCDIM1, DCDIM2 and VH) respectively inputted to the plurality of amplifiers (AMP1 to AMP3), a lowest voltage as the dimming output voltage (V3).

Abstract: The present invention relates to a system for performing phase detection and synchronization in an AMI communication network using a relay communication, and a method thereof. According to an embodiment of the present invention, a system for performing phase detection and synchronization in an AMI communication network using a relay communication includes an AMI server for collecting a ‘reference zero-crossing detection (ZCD) time difference by phase’ of input/output terminals of a main transformer installed in a substation; and a data concentration unit (DCU) comparing the ‘reference ZCD time difference by phase’ transmitted from the AMI server with a ‘ZCD time difference by phase’ collected by itself, and matching the same to have a time difference close to an error range.

Abstract: A packaged food product includes a container and a food product. The container has a rim and at least one wall extending away from the rim. The at least one wall defines a storage area, and the food product is retained within the storage area such that the food product is in contact with the at least one wall. The at least one wall is readily deformable by a hand of a user to reduce a volume of the storage area. Reducing the volume of the storage area causes the food product to exit the storage area. The container includes an integral tool portion for breaking up the food product after removal from the storage area. The food product can be a wet cat or dog food.

Abstract: Rotation speed control systems for an Electronically Commutated (EC) motor and method for controlling rotation speed of an EC motor are described. An rotation speed control system includes a phase detector for detecting a period, an ON time interval, an OFF time interval, and zero crossing time points of the phase cut AC signal; a voltage regulator for converting the phase cut an AC signal into a DC signal; a controller for generating a compatible waveform to drive the EC motor with a rotation speed instructed by the controller, in accordance with an ON/OFF time ratio determined based on the ON time interval and OFF time interval of the phase cut AC signal; and an EC motor interface, powered by the DC signal, for driving each of a plurality of windings of the EC motor with the compatible waveform.

Abstract: An electronic system and method include a controller to operate in a start-up mode to accelerate driving a load to an operating voltage and then operates in a post-start-up mode. A start-up condition occurs when the controller detects that a load voltage is below a predetermined voltage threshold level. The predetermined voltage threshold level is set so that the controller will boost the voltage to an operating value of a load voltage at a faster rate than during normal, steady-state operation. The controller causes a switching power converter to provide charge to the load at a rate in accordance with a start-up mode until reaching an energy-indicating threshold. When the energy-indicating threshold has been reached, the controller causes the switching power converter to (i) decrease the amount of charge provided to the load relative to the charge provided during the start-up mode and (ii) operate in a distinct post-start-up-mode.

Abstract: A method of transmitting signals applied for a loading control system, which includes a phase angle control module and a driving module, wherein the phase angle control module is electrically connected to an input interface. The method includes the following steps: A. switch the input interface from a first status to a second status; B. modify a voltage waveform of an AC power to make the voltage waveform have a delayed conduction angle in half of its wave period; C. check the delayed conduction angle of the voltage waveform; D. transmitting an electric signal to a loading according to the delayed conduction angle.

Abstract: Simple and efficient techniques for closed loop control of a boost converter. In an aspect, a current feed-forward (CFF) mode of operation includes providing current information to a control logic block controlling transistor switches of the boost converter to advantageously smooth the signals present in the closed loop control of the system. In another aspect, a modified peak current (MPC) mode of operation includes providing a simplified control mechanism based on a peak current mode of operation. Both CFF mode and MPC mode may share similar circuit elements, allowing a single implementation to selectively implement either of these modes of control. Further techniques are provided for determining average current information for the logic block.

Abstract: A power supply for a load control device generates a DC voltage and provides an asymmetrical output current, while drawing a substantially symmetrical input current. The power supply comprises a controllably conductive switching circuit for controllably charging an energy storage capacitor across which the DC voltage is produced. The energy storage capacitor begins charging at the beginning of a half-cycle and stops charging after a charging time in response to the magnitude of the DC voltage and the amount of time that the energy storage capacitor has been charging during the present half-cycle. The charging time is maintained substantially constant from one half-cycle to the next. The power supply is particularly beneficial for preventing asymmetrical current from flowing in a multiple location load control system having a master load control device supplying power to a plurality of remote load control devices all located on either the line-side or the load-side of the system.

Abstract: An integrated circuit includes an operational circuit module receiving a supply voltage from a voltage regulator external to the integrated circuit, and an adaptive voltage scaling module to adjust the supply voltage based on performance characteristics of the operational circuit module. The adaptive voltage scaling module can include a performance monitoring module disposed on the integrated circuit and configured to generate at least an indicator corresponding to at least one performance characteristic of the operational circuit module. The adaptive scaling module can include a voltage requirement determination and voltage feedback generator module disposed on the integrated circuit and coupled to the performance monitoring module. The voltage requirement determination and voltage feedback generator module is configured to output a feedback voltage signal having a voltage level as a function of at least the indicator.

Abstract: A lamp heater and a drying apparatus including the same, the lamp heater including a plurality of three-phase power source lamps, a dummy load, the dummy load being configured to maintain a phase balance of the three-phase power source lamps, and a controller, the controller controlling the three-phase power source lamps and the dummy load depending on a lighting condition of the three-phase power source lamps.

Abstract: An electronic control system for operating lighting is rated and operable from normal AC mains supply voltages. A street light controller is adapted to activate a luminaire when ambient light levels are considered too dark and, conversely, when ambient light levels are sufficient, the luminaire is turned off.

Abstract: A phase current sharing network that adjusts operation of a current mode multiphase switching regulator in which the phase current sharing network includes multiple synthetic ripple networks and a current share network. The regulator develops phase currents including ripple currents through corresponding phase inductors as controlled by corresponding pulse control signals. Each synthetic ripple networks develops a corresponding ripple voltage that simulates a corresponding phase ripple current and uses the ripple voltages to develop the pulse control signals. The current share network adjusts each ripple voltage by a combined adjustment value. The combined adjustment value is a combination of phase adjustment values in which each phase adjustment value is based on a difference between a corresponding one of ripple voltage and a reference voltage. Transconductance amplifiers may be used to convert the voltage differences to current adjust values applied to the ripple capacitors developing the ripple voltages.

Abstract: The present invention provides a synchronous regulation circuit for turn-on and turn-off phase angle of the AC voltage, wherein a solid switch unit is installed between an AC power source and a load, and a phase angle regulation circuit is utilized to synchronously regulate both of the turn-on phase angle and turn-off phase angle of the solid switch unit, so that the sine waveform voltage of the AC power source can be kept to output in symmetrical waveforms within the range in which the turn-on and turn-off phase angles being synchronously regulated.

Abstract: In various embodiments, a power supply device for light sources may include a feed line from mains via a phase-cut dimmer, selectively switchable between a conductive state and a non-conductive state, to permit or interrupt feeding of the device from mains. The device may include a power stage to feed at least one light source from said feed line from mains; a drive stage for said power stage; and a supply stage for said drive stage, said supply stage connected to said feed line from mains. The device may further include a sensor to detect when said dimmer is non-conductive and when said dimmer is conductive. The drive stage may be coupled to the sensor to disable driving of said power stage when the sensor indicates that the dimmer is non-conductive, and enable driving of the power stage when the sensor indicates that the dimmer is conductive.

Abstract: Timer-based switching circuit synchronization in an electrical dimmer is provided. The energizing of a switching circuit in a dimmer is synchronized with an AC wave to facilitate providing by the dimmer electrical power to a load. The synchronizing includes starting a timer having a predetermined timeout, responsive to receipt of a zero-crossing signal. Responsive to receipt of a subsequent zero-crossing signal prior to reaching the timeout, the timer is restarted, and responsive to expiration of the timeout, a switching circuit is energized at a predetermined firing angle with respect to the zero-crossing signal to supply electrical power to the load.

Abstract: Systems and methods for providing variable-frequency soft start of an AC load are disclosed. In one exemplary embodiment, a method for starting an alternating current (AC) load with a variable-frequency AC power output includes receiving an indication of a duty cycle for chopping the AC power output during starting of the AC load, and determining a frequency of the AC power output. The method further includes chopping the AC power output at the duty cycle, based on the determined frequency of the AC power output, and providing the chopped AC power output to start the AC load.

Abstract: A controller and methodology for a power supply are disclosed. The controller includes output channels for providing a pulse width modulation (PWM) voltage signal for driving a load, for example, a microprocessor. Each channel provides a portion of the PWM signal. The controller receives user input information and uses that information to automatically determine window sizes. A window size defines the maximum output current level for a given window. The controller uses feedback signals to determine the current being drawn by the load, and selects the number of windows and channels that are needed to adequately provide that current. The controller selectively activates and deactivates the output channels accordingly. In response a change in the user input information the controller automatically adjusts the window sizes.

Abstract: A load control device adapted to be coupled between an AC power source and an electrical load for controlling the power delivered to the load includes a power supply having an energy storage capacitor and a charge pump circuit adapted to conduct an input charging current through the load and to conduct an output charging current through the energy storage capacitor to thus generate a DC supply voltage across the energy storage capacitor, where the output charging current has a magnitude greater than the input charging current. The charge pump circuit includes a switched capacitor operable to charge through the load during a first half-cycle, and to discharge into the energy storage capacitor in a second, subsequent half-cycle. The charge pump circuit operates at line frequency and the magnitude of the input charging current is substantially small so as to avoid generating noise in a noise-sensitive circuit of the load control device.

Abstract: A load control device for controlling an amount of power delivered to an electrical load from an AC power source, the load control device comprising a semiconductor switch operable to be coupled in series electrical connection between the source and the load, the semiconductor switch having a control input for controlling the semiconductor switch between a non-conductive state and a conductive state; a controller operatively coupled to the control input of the semiconductor switch for controlling the semiconductor switch between the non-conductive state and the conductive state; a touch sensitive front surface; a touch sensitive device responsive to a point actuation on the touch sensitive front surface, the point actuation characterized by a position and a force, the touch sensitive device comprising a resistive divider and an output operatively coupled to the controller for providing a control signal to the controller; and a capacitor coupled to the output of the touch sensitive device for stabilizing the c

Abstract: An apparatus for shaping a varying input voltage signal received at an input locus to effect a desired varying output voltage signal at an output locus includes: (a) at least one energy transferring unit coupled with the input locus and with the output locus; and (b) at least one energy storing unit coupled with the at least one energy transferring unit. The at least one energy transferring unit presents at least one predetermined range of the input voltage signal at the output locus. The at least one energy transferring unit cooperates with the at least one energy storing unit to store energy in the at least one energy storing unit and to present energy from the at least one energy storing unit at the output locus when the input voltage signal is not presented at the output locus.

Abstract: A two-wire load control device, such as, a dimmer switch, for controlling the amount of power delivered from an AC power source to an electrical load comprise a bidirectional semiconductor switch having first and second anti-series connected switching transistors (such as, for example, field-effect transistors) that are adapted to be coupled between the source and the load, and are controlled to be conductive and non-conductive in a complementary basis. The bidirectional semiconductor switch is operable to be rendered conductive and to remain conductive independent of the magnitude of a load current conducted through semiconductor switch. The dimmer switch also comprises a drive circuit for rendering the first and second switching transistors conductive and non-conductive each half-cycle on the complementary basis, so as to control the amount of power delivered to the electrical load to a desired amount of power.

Abstract: In order to prevent a short circuit of top and bottom arms of a motor driving IC when noise is added to six control signals for controlling six switching elements, there is provided a semiconductor device for driving a motor, being sealed with resin as one package and comprising: six switching elements for driving a three-phase motor; three output terminals for outputting voltages to the three-phase motor; at least one driving circuit for driving the six switching elements; three control signal input terminals; and a function) of generating six control signals for control of the six switching elements based on three control signals inputted through the three control signal input terminals.

Abstract: A load control device, such as a dimmer switch, has a touch sensitive actuator, such as a three-wire touch sensitive screen, that produces an output voltage representing the position of a manual pressure touch along a longitudinal axis of the actuator. A stabilizing circuit receives the output voltage of the actuator and comprises, for example, a capacitor. The stabilizing circuit operates to prevent the detection of transient touches and touches having less than a certain actuation force, such that the output voltage is responsive only to the position of the touch. In addition, a usage detection circuit may also be coupled to the output voltage of the actuator for determining whether the touch is presently occurring. Alternatively, the actuator may comprise a four-wire touch sensitive screen that produces a first output voltage received by the stabilizing circuit and a second output voltage received by the usage detection circuit.

Abstract: A transformation circuit includes a bidirectional switch, a capacitor, and a triac. A first electrode of the triac is for receiving an input alternating current (AC) voltage. A second electrode of the triac is for outputting a transformed AC voltage. A control electrode of the triac is electrically connected to one terminal of the bidirectional switch, and the other terminal of the bidirectional switch is electrically connected to one terminal of the capacitor, and the other terminal of the capacitor is electrically connected to the first electrode of the triac. When the capacitor is charged or discharged, the bidirectional switch is switched on or off, and the triac is triggered on or off accordingly, such that a duty cycle of the input AC voltage is changed to form the transformed AC voltage.

Abstract: An AC line powered RF transmitter light switch is described. The RF transmitter light switch is installed within a 3-way wall switch circuit thereby allowing direct and constant electrical connection of the RF transmitter light switch and the RF receiving light switch. The RF transmitter light switch is in RF communication with the receiving light switch to control the circuit load or light fixture. The RF receiving light switch is in direct electrical connection to the load and acts as a master controller regarding of the position of the RF transmitter light switch even though the RF transmitter light switch is installed within the 3-way wall switch circuit.

Abstract: Methods, systems, and devices are described for sensing a phase-cut dimming signal and outputting a control signal compatible with a switching power circuit. Embodiments of the invention generate at least one of a low-frequency pulse-wave-modulated control signal, an analog output control signal, or a digital (e.g., higher-frequency pulse-wave-modulated) output control signal. Some embodiments further provide preloading and/or startup control functionality to allow proper functioning of the circuitry under small-conduction-angle (i.e., highly dimmed) conditions.

Abstract: An AC power source controller includes an input side, which is electrically connected to an output side via a power source controlling interface; and a phase modulator, which is electrically connected to the power source controlling interface. The phase modulator includes a microcontroller unit, an encoding DIP switch, a control signal receiving module, and a signal detecting interface, which may accurately detect the phase variation of an input power source so that, according to chosen conducting phase Pn, the microcontroller unit may automatically adjust the time delay Dn between conducting and cutting off orders sent to the power source control interface to control the power source output accurately, whereby the inaccuracy and instability of AC power source output control and phase difference between current and voltage generated by reactance load may be improved.

Abstract: A multi-channel current regulator includes two or more channels, each channel acting as a current source or sink for a respective load. Each channel regulates its load current so that the load current is proportional to an input voltage supplied to the channel. An operational amplifier is shared between the channels. Each channel is selected in a rotating sequence for connection to the amplifier. As each channel is selected, a two-phase refresh cycle is initiated. During the first phase, the output of the amplifier is charged until it substantially matches the drive voltage of the selected channel. This is followed by the second phase where the output of the amplifier is adjusted until the load current of the selected channel is proportional to a set voltage Vset.

Abstract: A load control device is adapted to be installed in an electrical wallbox having a barrier. The load control device comprises a split enclosure having first and second enclosure portions spaced apart so as to define a gap, such that the gap is adapted to receive the barrier of the electrical wallbox when the load control device is installed in the wallbox. First and second connectors are provided in first and second openings of the first and second enclosure portions, respectively. The load control device is operable to receive a first control signal at the first connector and to generate a second control signal, which is provided at the second connector, in response to the first control signal.

Abstract: An image forming apparatus includes a main power supply section, an auxiliary power supply section, a plurality of sensors, and a power control section. The sensors are disposed at a plurality of positions. The sensors change output levels thereof upon detection of a user's operation for initiating an image forming process. The power control section switches the apparatus from a normal operation mode to the power-saving operation mode after a predetermined time period during which no image forming process is performed. The power control section detects the respective output levels of the sensors through sequential power supply from the auxiliary power supply section to the sensors. The power control section switches the apparatus to the normal operation mode upon detection of a change in output level of either one of the sensors.

Abstract: A heater lamp control apparatus and method of detecting an input AC voltage and providing a pulse signal corresponding thereto, includes an AC voltage phase detection unit to detect a phase of the inputted AC voltage when a magnitude of the inputted AC voltage is over a predetermined level. The heater lamp control apparatus also includes a pulse signal generation unit to generate a pulse reference signal based on a result of the detection, a pulse delay signal that is phase-delayed, and a heater lamp control pulse signal based on a result of the comparison of the magnitudes of the pulse reference signal and the pulse delay signal. The heater lamp control pulse signal includes a control unit to control a drive-timing of the heater lamp based on the heater lamp control pulse signal. Thus, the heater lamp control apparatus minimizes a flickering phenomenon as well as an amount of electric power consumed in a heater lamp.

Abstract: A method of operating a power controller that converts a line voltage to an RMS load voltage includes a soft start in which a duty cycle of a pulse width modulation circuit is gradually increased to a steady state value that defines the RMS load voltage. The controller has a circuit with a time-based signal source that triggers conduction independently of line voltage magnitude and a transistor switch whose gate receives signals from the time-based signal source to trigger the circuit. When starting the power controller, a microcontroller increases the duty cycle of the pulse width modulation circuit in plural steps to provide the soft start.

Abstract: A lamp includes a lamp voltage conversion circuit which converts a line voltage to an RMS load voltage by clipping or modulating a load voltage. The voltage conversion circuit includes a time-based signal source that triggers conduction in the voltage conversion circuit independently of line voltage magnitude. A transistor switch whose gate receives signals from the time-based signal source triggers the voltage conversion circuit. A microcontroller increases one of a rate and a duration of the signals from the time-based signal source sent to the gate of the transistor switch when starting the lamp.

Abstract: A method of operating a power controller that converts a line voltage to an RMS load voltage includes a soft start in which a conduction angle or duty cycle is gradually increased to a steady state value that defines the RMS load voltage. The controller has a circuit with a time-based signal source that triggers conduction independently of line voltage magnitude and a transistor switch whose gate receives signals from the time-based signal source to trigger the circuit. When starting the power controller, a microcontroller increases a rate and/or duration of the signals from the time-based signal source in successive cycles of the load voltage to provide the soft start. The power controller may be in a voltage conversion circuit that converts a line voltage at a lamp terminal to the RMS load voltage usable by a light emitting element of the lamp.

Abstract: A phase-control power controller that converts a line voltage to an RMS load voltage includes an analog load voltage sensor that includes a light emitter that provides an optical output related to an RMS load voltage, and a phase-control circuit that has a comparison circuit that varies a resistance in the phase-control circuit responsive to the optical output. The comparison circuit includes an optically coupled transistor that senses the optical output from the light emitter, a load sensitive resistor that emits an amount of thermal energy corresponding to an amount of optical energy sensed by the optically coupled transistor, and two thermally dependent resistors connected in series, where one of the two resistors has a resistance that corresponds to the amount of thermal energy emitted by the load sensitive resistor and that varies the resistance in the phase-controlled dimming circuit.

Abstract: A phase-control power controller that converts a line voltage to an RMS load voltage includes a phase-control circuit with a potentiometer and a capacitor whose resistance and capacitance determine clipping of a load voltage, a load sensing circuit that senses the load voltage and provides a DC signal that is different from but related to the RMS load voltage, and a comparator circuit that compares the DC signal to a reference and adjusts the resistance of the potentiometer to control the RMS load voltage.

Abstract: This power converter comprises a plurality of switching elements, an inductor, and a smoothing capacitor. An input current of low frequency from the AC source is intermitted by the switching element turned on and off at high frequency, and an output current to a load is restricted by the inductor. These switching elements are controlled in different patterns. While these patterns are repeated, a current is always supplied to the load and inductor. Therefore, the power converter can provide a desired output power, making the inductance required for the inductor into the minimum. That is, the power converter can combine miniaturization and high-efficiency.

Abstract: A method for performing power conversion provides a converter output AC waveform from a converter input AC waveform, the convertor input waveform having an input power level, an input frequency, an input waveform shape, and an input voltage/current characteristic. The converter input AC waveform is applied to a converter switch with a switch frequency and the switch is operated at the switch frequency to provide a switched waveform having a plurality of switched waveform notches with a notch repetition rate substantially equal to the switch frequency. A filter performs filtering of the switched waveform to provide the converter output AC waveform with an output power level substantially equal to the input power level, an output frequency substantially equal to the input frequency, an output waveform shape substantially similar to the input wave form shape, and an output voltage/current characteristic substantially different from the input voltage/current characteristic.

Abstract: A phase control switch with an RFI suppression inductor includes a first winding on the inductor in series with a triac. A first capacitor is in parallel across the series combination of the first winding and triac. The switch further includes a second winding on the inductor with a second capacitor connected in parallel across the second winding. When the second capacitor and second winding resonate, a Q rise in flux occurs in the inductor core, intercepting the flux in the first winding to produce a greater voltage drop across the first winding and a corresponding decrease in the rate of current rise in the triac. Fewer turns are needed in the first winding for proper RFI suppression, resulting in a smaller device.

Abstract: An apparatus for and method of inhibiting and overriding the normal operating mode of one or more input devices connected to a communications network. The present invention functions within an electrical network made up of a plurality of input devices wherein a group of input devices is capable of commanding an electrical control device to apply and remove electrical power from an electrical load connected thereto. The input devices or nodes communicate with the electrical control device over a communications network. When one of the input devices is turned off, the normal operating mode of all the other input sensors is inhibited. The electrical control device remains inhibited until all the input devices are no longer in the off position. Thus, electrical power to the load controlled by the electrical control device remains disconnected until all input devices are in the on position. Local and remote signaling, control and indication diagnostic and monitoring functions are also provided.

Abstract: A communications processor is disclosed for a power generation system that permits data and control signals to be communicated to and from the power generation system and a host computer. The control signals include a power level command and power factor that are sent from a remote host to the power generation system which responds by delivering the requested power level having the desired power factor to a grid. The remote host receives performance data that permits an operator to accurately gauge the performance of the power generation system including the performance and any fault conditions of a line power unit, generator, and engine driving the generator. The communications processor unburdens the line power unit controller that is responsible for controlling power generation from the task of processing input data and driving local displays. The host may also be provided at a location remote from the power generation system.

Abstract: When the phase control is effected on a supply voltage to a load having positive resistance characteristics with respect to temperatures before a current is allowed to pass, a voltage is supplied for a current passing time T1, and the voltage is supplied for a current passing time T2 longer than the current passing time T1, and the voltage is supplied for a current passing time T3 shorter than the current passing time T2. Also, a second control pattern is effected at least once, in which the current is passed while the current passing time is kept substantially constant, then the current passing time is extended before the attenuation rate of the peak value of the resulting load current saturates, and then the current is passed while the extended current passing time is kept substantially constant. Consequently, a voltage drop can be reduced effectively without causing large distortion of the current waveform or large conduction noise by omitting an expensive noise filter or special hardware.

Abstract: An alternating current power control device for controlling the amount of power energy supplied to an electric load by controlling the cycle numbers of an alternating current power source in a predetermined cycle period is disclosed. The control device includes a voltage zero-crossing detecting circuit, a current detector, a power adjusting circuit, a control unit, an output driving circuit, and a switching circuit. The switching circuit is connected in series between the alternating current power source and the load. The control unit generates a control signal to control the switching circuit according to a voltage counting pulses generated by the voltage zero-crossing detecting circuit, a current counting pulse generated by the current detector, and a power adjusting signal generated by the power adjusting circuit to determine the cycle numbers of the alternating current power source supplied to the load.

Abstract: A power factor correction circuit for a boost converter includes a current feedforward loop that senses the input voltage by detecting variations in the rate of change of current in an inductor, thereby eliminating the need for a voltage feedforward loop. A current sense circuit generates a current signal responsive to the input current flowing through the inductor when a switching transistor is turned on. A comparator compares the current signal to a sawtooth signal, thereby generating a control signal for turning the transistor off. The output of the converter is controlled by a voltage feedback loop which includes an error amplifier that generates an error signal responsive to the output voltage. The error signal is then multiplied by the current signal before the current signal is compared to the sawtooth signal.

Abstract: An energy control system (10) comprises at least one controllable load (110), a master controller (200), a traveler wire (300) and at least one remote switch (400). The master controller (200) transmits control commands that effect corresponding control actions in the controllable load (110). The remote switch (400) transmits remote commands to the master controller (200) over the traveler wire (300). The energy control system (10) is well suited for installation in standard three-way switch or four-way switch electrical systems and requires neither additional wiring nor complicated installation procedures.

Abstract: A motor drive method and apparatus for reducing noise of a motor. The motor drive apparatus includes first, second and third half bridge circuits. Each of the first, second and third half bridge circuits includes a first transistor which is adapted to form a current path between a first operational potential and an output terminal thereof and a second transistor which is adapted to form a current path between a second operational potential and the output terminal thereof. Each of the output terminals are connected to the corresponding drive coil of a motor. Each of the first and second transistors includes a control terminal to which a control signal is supplied.

Abstract: A method for controlling the power supplied to a load (1) which is powered by an AC voltage source U with a period T via a generalised phase adjustment system, includes the steps of periodically delivering a sequence of p elements to the load (1), in accordance with a predetermined set power, wherein p is an integer and each element comprises n.sub.i periods T, where n.sub.i is an integer, during which the voltage U is divided symmetrically at an angle .alpha..sub.i, the consecutive phase angles .alpha..sub.i and .alpha..sub.i+1 being different, and the combination of angles .alpha..sub.1 . . . .alpha..sub.i , . . . .alpha..sub.p being selected in such a way that they limit current harmonics, and limit a flicker effect. The method is particularly suitable for power control in electric motors.

Abstract: A method and system for controlling the output current of large, low-voltage, DC power supply which includes at least one transformer primary by controllably switching an AC power line voltage to the primary as a function of actual and desired output currents. SCRs are used to switch, using phase control, the AC primary voltage to the transformer(s) of the power supply in order to control the output current. Given the incoming power line voltage, the current value from the previous power line cycle and the desired current for the present cycle, the function is used to find the SCR firing angle to attain the desired output current in the present power line cycle. Actual measurements of output current and power line voltage are used to modify the function to reflect changes in power line voltage and/or circuit impedance to obtain a modified function.

Abstract: A semiconductor switching circuit using semiconductor devices includes steep front wave thyristors which are connected in parallel and inverse with each other in their forward directions. An inductor is connected in series between a power source and the semiconductor switching circuit. The semiconductor switching circuit has an instant disconnection time of 100 to 1000 microseconds.

Abstract: Apparatus and methods for AC power regulation for a wide range of complex capacitive and inductive loads which provide substantial reduction in power consumption while also providing a leading power factor. The system is self-adjusting for a wide range of loads and can reduce power consumption by 25 percent in lighting loads while producing minimal reduction in light output. The system utilizes a main switch consisting of back-to-back MOS Controlled Thyristor devices (MCTs) and a parallel capacitor bank in series with the load. The main switch is initially turned off slightly in advance of the load current zero crossing, and this in combination with the capacitor bank allows power to be reduced in a low noise fashion. The turn-off time is advanced gradually to regulate power at a target reduced level. At the target power level, load phase angle is measured and maintained to control the power savings ratio.