Abstract: Droop-control circuitry of a multiphase power converter determines when multiphase switching signals are concurrently at either a high or low state and temporarily clamps the output of the power converter to either a high or low voltage level in response thereto.

Abstract: A dimmer circuit arrangement is disclosed including a second control circuit (40) for controlling the operation of a triac (50) for delivering current to a load (60), and a first control circuit (10) for controlling the operation of an IGBT power semiconductor switch (20) for controlling the rate of rise of load voltage. The first control circuit also controls the operation of the second control circuit.

Abstract: A control circuit of rotational speed of a fan is provided, wherein by a switching of a switch unit, a PWM (Pulse Wide Modulation) unit can output a sampling pulse whose period is changing. A voltage is also changing following the period after taking a sample to an AC voltage by the control unit. The voltage after sampling serves as a working voltage of a load unit, so as to enable a fan device and a lamp device of the load unit to achieve effects of adjusting speed and brightness.

Abstract: An exemplary embodiment of the present invention described and shown in the specification and drawings is a transceiver with a receiver, a transmitter, a local oscillator (LO) generator, a controller, and a self-testing unit. All of these components can be packaged for integration into a single IC including components such as filters and inductors. The controller for adaptive programming and calibration of the receiver, transmitter and LO generator. The self-testing unit generates is used to determine the gain, frequency characteristics, selectivity, noise floor, and distortion behavior of the receiver, transmitter and LO generator. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: A fixed phase power controller that converts a line voltage to an RMS load voltage includes an analog control block with a capacitor that receives an input that is independent of a change in magnitude of the line voltage and that charges and discharges to provide a trigger signal at a first frequency, a reset circuit that periodically resets an initial condition of the analog control block, a synchronization connection that provides a sync signal that synchronizes the trigger signal with a waveform of the line voltage, and a control circuit that clips a load voltage based on the synchronized trigger signal to define the RMS load voltage. The controller finds application in a lamp where it reduces the line voltage to an RMS load voltage suitable for a light emitting element.

Abstract: It is an object of the present invention to provide a control circuit and a control method for a current mode control type DC—DC converter capable of preventing a subharmonic oscillation even if an on-duty is not less than 50% and capable of preventing a switching frequency from fluctuating depending on an input voltage. When a high-level output signal Vo1 is inputted to a reset input terminal R of a flip-flop FF, a transistor FET1 is turned off. A phase comparator FC outputs a comparison result signal CONT in accordance with a phase difference between a delay signal FP and a reference signal FR. A delay circuit DLY outputs a high-level delay signal FP after the passage of a delay time DT adjusted in accordance with the comparison result signal CONT from the turn-off of the transistor FET1. The transistor FET1 is turned on in accordance with an input of the high-level delay signal FP.

Abstract: A voltage regulator includes a load control unit having an output configured to be coupled to a load. The load control unit is configured to be responsive to a load control signal for controlling the delivery of power to the load. A voltage regulator further includes a feedback unit coupled to the output of the load control unit. The feedback unit is configured to produce a feedback signal indicative of a voltage level applied to the load at the load control unit output. A voltage regulator still further includes a controller responsive to the feedback signal that is configured to generate the load control signal such that the voltage applied to the load substantially corresponds to a predetermined reference voltage level.

Abstract: A voltage transformer for the conversion of an input d.c. voltage into a three-phase a.c. voltage (UR, US, UT) in the mains frequency range having at least one inductor (L1, L2) and having multiple switches (S1, . . . , S9) controlled by a drive circuit (AST) in which a first transformer element is provided (S1, D1, L1, S2) to produce positive output voltage portions and a second transformer element (S3, L2) is provided to produce negative output voltage portions and the output of the first transformer element is connected to the three phase outputs (R, S, T) via one each of first longitudinal phase circuit breakers (S4, S5, S6) and the output of the second transformer element via one each of second longitudinal phase circuit breakers (S7, S8, S9).

Abstract: An apparatus and process are provided for regulating the voltage across a resistive or inductive load by phase angle control of the applied load voltage. Instantaneous load voltage is compared with a preset reference value to control the phase angle of the applied load voltage by means of rms voltage approximation feedback control. A visual display can be provided to assist the user in establishing the preset reference value.

Abstract: The operating mode of a power modulation system is determined according to the nature of the load. The power modulation system can operate in either of two operating modes, namely a “reverse phase control” mode and a “forward phase control” mode. To this end, the load is supplied with power under predetermined low-load operating conditions by the power stage in the “reverse phase control” mode, overvoltages are detected and the power modulation system is caused to change to the “forward phase control” operating mode if an excessive number of overvoltages is detected.

Abstract: A phase controlled drive circuit includes a drive circuit operable to provide gate signals to an SCR bridge circuit and a phase control circuit. The phase control circuit includes a first phase generator operable to generate a first phase signal, and a second phase generator operable to generate a second phase signal. The second phase signal is periodically reset to an initial value. A drive circuit actuator in the phase control circuit is operable to place the drive circuit in a first activation state when a sum of the first and second phase signals exceeds a threshold value, and is further operable to place the drive circuit in a second activation state when the sum of the first and second phase signals is less than the threshold value.

Abstract: A method and apparatus for sharing current among a plurality of power modules is provided. The method includes sensing of a characteristic of an output power signal of at least one of the plurality of power modules and providing a first signal having a pulse width corresponding to the sensed characteristic. The first signal is imparted onto a current share bus coupled to each of the plurality of power modules if the first signal has a pulse width greater than corresponding first signals of other power modules coupled to the current share bus, whereupon one of the first signals from the plurality of power modules having greatest pulse width is imparted onto the current share bus as a second signal. A phase difference between the first signal and the second signal is detected and a feedback signal is provided to the at least one power module in response to the detected phase difference. The feedback signal thereby controls the at least one power module to regulate the output power signal.

Abstract: A plurality of single-phase synchronizing converter automatically synchronize on a peer-to-peer basis. Each synchronizing converter is configured as a DC-to-DC converter. The synchronizing converters operate in parallel as a multi-phase converter. A common bus between the synchronizing converters includes a sync line and a common phase control line. Proper phasing automatically occurs when power is applied, and the phasing changes automatically as converters are added or removed. When the system powers up, the converters arbitrate for phase position. The phasing positions are random, but the phasing is relatively symmetrical regardless of the number of phases. In one embodiment, a hot-swappable converter module can be plugged into any location of a parallel multiphase bus to produce a common output voltage. When an additional module is plugged in, the converters readjust their phases to maintain phase symmetry. In one embodiment, each module shares a substantially equal portion of the output load.

Abstract: A system and method to parasitically take electrical power from a source of ac load power to provide a voltage source to directly power an associated control device is described. The system utilizes a controllable transconductance device to both selectively provide power to a controlled load and to develop a predetermined voltage to directly power the control device in a system where the ac load power is applied at one terminal and is passed through the transconductance device to be returned through the load. The system includes a means for establishing the predetermined voltage level to power the control device and for continuously monitoring that voltage level to maintain it as required, whether power is applied to the load or not. Alternative voltage regulators to provide isolated or non-isolated power to the control device irrespective of whether or not power is applied to the load are also described.

Abstract: A method of providing a regulated AC output voltage at a predetermined level that makes use of an AC input voltage having a higher level, includes the steps of rectifying the input voltage to provide a DC input reference voltage, rectifying the output voltage to provide a DC output reference voltage, comparing the DC output reference voltage to the DC input reference voltage to provide a comparator signal, providing a triac circuit connected to the AC input voltage that supplies the AC output voltage and using the comparator signal to control the triac circuit.

Abstract: An on-die multiple phase power converter reduces output voltage ripple and reduces input current ripple while allowing for higher input voltage and reduced input current to a circuit board. The on-die multiple phase power converter also allows for more than one supply voltage on a die. The converter includes a plurality of single phase switching blocks and a clock signal phase generator. The single phase switching blocks receive phase-shifted clock signals from the clock signal phase generator and provide an output voltage. The output currents of the single phase switching blocks may combine to form a single output to provide current to one or more functional unit blocks on the semiconductor die. One or more or the single phase switching elements may be combined to provide current to one or more functional unit blocks on the semiconductor die.

Abstract: An electric heating blanket control circuit assembly is constructed to include an electric heater, a sensor adapted for detecting the temperature level of the electric heater, a controller, the controller having a monitoring circuit adapted for monitoring normal functioning of the sensor and the electric heater and a main control circuit adapted controlling the operation of the electric heater subject to the detection result of the sensor to keep the temperature of the electric heater to be maintained within a limited range, and a power adapter adapted for providing low voltage DC to the electric heater, the sensor, and the controller for working.

Abstract: A power supply system includes a photovoltaic generator, a load to which electric power is supplied from the photovoltaic generator, an electrical system for receiving a portion of the electric power generated by the photovoltaic generator and supplying electric power to the load, and a control unit for controlling the reception and the supply of the electrical power by the electrical system. To ensure that the photovoltaic generator generates electric power at an optimal operational point, the control unit is adapted to not operate when the maximum electric power Pmax generated by the photovoltaic generator and an electric power PL consumed in the load are equal to each other, and to be operated when Pmax>PL, thereby permitting the electrical system to receive a surplus electric power &Dgr;P1, and to be operated when Pmax<PL, thereby supplying a deficient electric power &Dgr;P2 from the electrical system to the load.

Abstract: In order to produce a phase control device which is free of the constraints of drifts due to the supply frequency or to the temperature of the components forming it, a method is recommended in which a command signal delivered by a control is modified by a converter in order that the activity of the actuator controlled by this device is a linear function, in all cases, of a control signal. As an improvement, account is taken of the variation in frequency of the supply signal by multiplying the convertible signal by a measurement of the duration of the period of the power signal.

Abstract: A method and apparatus for providing welding power includes controlling a phase controlled power circuit to provide a reduced OCV output. Preferably, the output is controlled in response to feedback, such as current being less than or greater than a threshold.

Abstract: A digital phase-locked loop (DPLL) (22) for use in one or more integrated circuits (20) that may be combined within an electronic system is disclosed. The DPLL (22) includes a phase detector (30) that generates a shift clock and a shift direction signal responsive to a phase difference between a system clock and a feedback clock. The shift direction signal is stored in a latch (32), applied to one input of an exclusive-NOR gate (34), and to shift direction inputs (R/{overscore (L)}) of first and second digital delay lines (38, 42). The first digital delay line (38) receives the system clock and generates a delayed clock that is distributed within the integrated circuit (20) by clock distribution circuitry, and that is applied to an input of the second digital delay line (42); the second digital delay line (42) generates the feedback clock that is received by the phase detector (30).

Abstract: A controllable electrical switch having a power system and switching device for connecting a source voltage to a load. The power system includes a switching regulator to extract energy directly off the non filtered full wave rectified input voltage to minimize the average magnitude of the current when the switching device is in the off-state. For on-state power the controllable electrical switch may include a transformer connected in series with the switching device. The controllable electrical switch and power system may be used to replace a standard two- wire or three-wire wall switch, and may be used over a wide voltage and load power range in a low cost, small package with low power dissipation.

Abstract: A circuit arrangement for simulating an alternating current load. The simulating circuit includes a current waveform generating circuit capable of generating a phase control signal with a phase angle coherent, lagged, or leading to that of the alternating current power source voltage. A voltage and current phase control circuit generates a first and second switching control signals according to the phase control signal generated by the current waveform generating circuit and a series of counting pulses generated by a voltage zero-crossing detecting circuit. The switching control signals are used to control a switch circuit so as to generate a power source current with a phase angle coherent, lagged, or leading to the phase angle of the power source voltage.

Abstract: Pulse width modulation of a high frequency series of AC current that is delivered to a lighting load(s) in “slices ” of current by a controller device that enables users to dim their loads while minimizing and/or virtually eliminating the externalities associated with current dimming systems.

Abstract: A switching power supply system is disclosed for powering electrical equipment while minimizing disturbance to an AC power line source. The system includes first and second AC switches which are operated at alternate intervals with respect to each other to permit current to flow between the AC power line source and the load over intervals of the AC voltage cycle. An energy storage element is included in an output filter and stores energy during intervals of the AC voltage cycle and releases the stored energy during the alternate intervals of the AC voltage cycle. By the disclosed switching power supply, the voltage applied to the load and the current flow between the source and the load are sinusoidal, have minimal energy in frequencies other than the fundamental AC power line frequency, have minimal harmonic distortion, result in a power factor close to unity, and are steady and non fluctuating.

Abstract: An AC voltage reduction system and method providing highly efficient reduction of utility voltage with minimal electromagnetic interference is provided. The systems and methods may also be used to improve overall facility power factor. The AC voltage provided to a load, such as a group of lighting ballasts connected on a single circuit, is reduced by a controllable switch coupled in parallel with a capacitor between the AC source and the load. The switch is controlled to turn-on when the voltage across the capacitor is very close to zero and turn-off prior to the next zero-crossing of the line current. The turn-off time is selected in an open loop configuration independently of a measured characteristic of load voltage or watts. In order to provide proper operation of gas discharge lighting, the switch is initially turned off just in advance of the AC source current zero-crossing.

Abstract: A method of controlling the load in an electric circuit by means of detecting the time state of same frequency of alternating current sine wave and alternating current square wave, which includes the step of picking up a half cycle wave signal, then attenuating the picked up half cycle wave signal and shaping the signal into a pulse wave signal, the step of chopping the picked up half cycle wave signal and shaping the signal into a square wave signal and then delayed the square wave signal, the step of comparing the rising edge of the square wave signal with the descending edge of the pulse signal so as to obtain a time difference, and the step of controlling the load of the electric circuit by means of a first control mode if the voltage level of the time difference thus obtained is at low potential, or by means of a second control mode if the voltage level of the time difference thus obtained is at high potential.

Abstract: A main power supply unit 10 of this power supply apparatus for laser comprises asingle-phase rectifying circuit 16 for receiving a single-phase AC voltage E.sub.A at a commercial frequency to convert (rectify) it into a direct current, a capacitor 18 for temporarily storing the DC power from the single-phase rectifying circuit 16, a charging circuit 20 connected between the single-phase rectifying circuit 16 and the capacitor 18, and a lamp current supply circuit 22 connected between the capacitor 18 and an excitation lamp 102. The charging circuit 20 includes a switching element 24 for charging connected in parallel with the capacitor between the single-phase rectifying circuit 16 and the capacitor 18, an inductance coil 26 connected in series between the single-phase rectifying circuit 16 and the switching element 24 for charging, and a diode 28 connected in series between the switching element 24 for charging and the capacitor 18.

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 method for controlling the power of a load (1) powered from a source of AC voltage U having a period T using a phase control system, wherein, for a predetermined set power, a sequence of an integer p of elements, where p is greater than 1, is periodically delivered to the load (1), each element, numbered i, of the sequence being characterized by an integer n.sub.i with a half-period T/2 during which the AC voltage U is switched according to a series of different phase angles .alpha..sub.i from .alpha..sub.1 to .alpha..sub.n corresponding to respective durations t.sub.i from t.sub.l to t.sub.n during which the load (1) is cut: off from the power supply. The phase angles .alpha..sub.i of element i and .alpha..sub.i+1 of element i+1 have similar repetitive values so that the mean current is zero over a complete cycle.

Abstract: A motor controlling device for controlling the rotational speed of an AC motor (3) connected with an AC power supply (1) through a speed control thyrister (2) includes a negative charging circuit (5) for charging a negative half cycle voltage of the AC power supply (1) in a negative direction for each cycle to trigger the thyrister (2) in a positive half cycle period of the AC power supply (1), and a positive charging circuit (6) for charging a positive half cycle voltage of the AC power supply (1) in a positive direction from the end of the negative half cycle by the negative charging circuit (5) for each cycle to trigger the thyrister (2) when the charged voltage reaches a trigger voltage of the thyrister (2).

Abstract: An apparatus for a controlled supply of current to an electric consumer, including a turn-on function. The apparatus including a circuit board having conductor paths, a subordinated phase control circuit mounted on the circuit board and having a triac switching in both directions of an AC supply voltage and a trigger circuit for triggering the triac, the triac being connected in series with the consumer, a contact point mounted to the board, and a springing metal tongue having a first end mounted to the board and a second end that extends above the contact point at a distance from the board. The metal tongue and the contact point form electric contacts with the conductor paths on the board so as to define a switch. The electric contacts lead to connection points in the trigger circuit of the triac.

Abstract: A lighting system made up of a plurality of light fixtures which each produce a light beam, in which each of a plurality of varying devices, each having an input and an output, and each capable of varying at least one parameter of the light beam from at least one of the light fixtures, is responsive to a first value received at the input, where the first value corresponds to the desired adjustment of a parameter of the light beam. Each of the varying devices is also capable of generating a second value which represents status information, and transmitting the second value via the output. A controller produces the first value and sends it to an output which is coupled to the input of the varying device. A monitoring device has an input and is separate from the controller, and its input is coupled to the output of the varying device.

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 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.

Abstract: Instabilities in the output voltage provided from an AC power supply system such as an uninterruptible power supply connected to a power factor correcting load are suppressed by a dynamic voltage regulation stabilizer system which is connected across the output lines from the power supply system to the load. The DVR stabilizer system includes a rectifier connected to the power supply system output lines. A capacitor is connected across the output nodes of the rectifier. Switching devices form a bridge that connects the capacitor to the output lines. Selected switching devices in the bridge are turned on for a selected duration encompassing the time of the peak of each half-cycle of the AC voltage waveform provided by the power supply system. During normal operation, where the peak AC voltage from the power supply system is substantially constant, the capacitor charges up through the rectifier to a voltage level near the peak value of the AC voltage waveform.

Abstract: A circuit for providing a periodic output having a regulated magnitude is derived from a periodic input source. A switch is serially connected to the input for periodically sampling the input at a sampling frequency which is much higher than the frequency of the periodic input, while the duty ratio of the sampling is modulated as an inverse function of the output magnitude. The pulse train of samples is filtered to remove the sampling frequency and its harmonics and the result is a regulated output which replicates the input waveform.

Abstract: A light dimmer is provided in which semiconductor power devices for each of the polarities of an alternating current supply are coupled between the alternating current supply and a lamp load. In the course of varying average power supplied to the lamp load, the semiconductor power devices transition between an initial one and a subsequent other of substantially conductive and non-conductive power conditions. The duration of the transition by the power device is increased beyond the minimum possible duration to reduce generated EMI. Methods of restoring each power device to its initial condition, including during a subsequent half-cycle, are described.

Abstract: A low voltage power control circuit supplies substantially equal voltages to a plurality of loads distributed along a pair of parallel wires. Moreover, the voltage delivered is automatically controlled by a feedback control circuit, so that the number of loads in the system may be varied without causing a substantial change in overall supply voltage supplied to the plurality of loads.

Abstract: An improved method and apparatus for handling the large load currents which occur with overloads, short circuits, and momentary overcurrents such as in starting motors or cold incandescent lamp filaments. The method involves turning the load current off when an overcurrent is detected, and then back on again before the end of the half-cycle in which the overcurrent occurred. This allows more current to flow during the half-cycle without the need to increase the peak current capability of the power-handling components. With an incandescent lamp load, this results in more rapid lamp brightening without the need for larger, more expensive components. Several embodiments are disclosed which respond to different features of the power line voltage cycle, including a very low-cost microprocessor circuit and power supply.

Abstract: A dimmer circuit uses a triac for controlling application of power to a hot terminal where a load will be connected. A DC power supply develops DC power for powering a control circuit which includes a zero crossing detector circuit connected to an integrated circuit chip which develops a timer pulse at the appropriate time to dim the light. The timer pulse is output to a pulse stretching circuit which actually drives the triac. The pulse stretching circuit stretches the pulse to a maximum of one-half of a cycle. This ensures that the triac will be turned on even if the inductive current delays the establishment of adequate latching current. This creates a more symmetrical waveform and results in a reduced DC offset.

Abstract: This invention relates to an improved laser printer power supply that maintains 24-, 12-, and 5 volt DC power to run exhaust fans for a brief period after the power switch is turned off. These fans remove undesirable ozone from the photo-conducting print drum so as to extend the life of the photo-conductor. The circuits utilize a timer circuit and an optically isolated photo-diac to turn a power triac on and off.

Abstract: A circuit can control the power to a load having a predetermined voltage rating. The circuit includes a first terminal adapted to connect to the load and a second terminal adapted to be connected through a power switch to an alternating voltage source. This voltage source has a magnitude rated substantially in excess of the predetermined voltage rating. A switching device is serially connected between the first and second terminal. Also, a capacitive filter circuit has dual terminals separately connected to the first and second terminals. This filter can shunt from the switch transient currents flowing through the load. A timing circuit is coupled to the switching device for periodically operating it at a frequency proportional to that of the alternating voltage source. The switching device is timed by the timing circuit to keep the magnitude of average voltage to the load less than that of the alternating voltage source, for each half cycle of the alternating voltage source.

Abstract: An apparatus and method for controlling the voltage applied to an induction motor is taught. Load sensing is incorporated by monitoring the current through the motor, and combining that signal with a signal derived from the AC line voltage and AC voltage across the motor. This composite signal is averaged, with the resulting averaged signal being utilized to control a device for modulating voltage applied to the motor such as a phase control integrated circuit device.

Abstract: To eliminate pulsating current of vaporized gas by controlling a heater by means of a phase control, instead of controlling the heater by means of an on-off control which causes the vaporized gas to become a pulsating current, in a vaporized gas cooling apparatus using heater heating used in a thermal analysis apparatus and the like. By performing a phase control of the sine wave of the alternating power source by means of a thyristor and supplying power to the heater the duration of control at a time is reduced to as short as 10 msec (in case of 50 Hz). Accordingly, a filter effect is obtained by the fact that a changing speed of the heater temperature and a vaporization speed of coolant are too slow to follow the control action which prevents vaporized gas to become pulsating current. Since vaporized gas coming out is not a pulsating current, using this for cooling makes less fluctuation of temperature and makes the temperature more stable.

Abstract: In the open-loop control of A.C. power controllers through the phase-angle control of semiconductor valves (4), the chronological sequence of the firing signals (Z) for the semiconductor valves (4) is determined by reference signals (X). When the reference signals (X) fail for one or more periods, this chronological sequence is disturbed and damage to the load (2) to be controlled can result. Therefore, according to the invention, a method is provided whereby a safety firing signal (ZS) is always derived from the preceding firing signals (Z) when the expected reference signal (X) fails. In addition, a device for implementing the method is specified.

Abstract: A method for regulating the power in a load connected to the mains through a controlled switch and a device for implementing the method. The method includes the following steps: detecting a mains synchronization pulse, which determines the start of a cycle, within a fixed time interval of the preceding cycle; as soon as the pulse has been detected, waiting for the end of the fixed interval, then counting down a first time interval that substantially corresponds to a selected time interval; at the end of the first time interval, triggering the switch on and counting down a second time interval that ends before the normal arrival of the next synchronization pulse; and at the end of the second time interval, counting down the fixed time interval within which the next synchronization pulse must be detected.

Abstract: An alternating current voltage regulator providing a stable RMS output voltage across a load. The voltage applied to the load being determined by controlling the firing angle of a triac, which is controlled by the pulse width of a timing signal generated in a timer circuit. The pulse width of the timing signal is controlled by an error signal. The error signal is based upon the actual triac output voltage as compared with a comparison signal. The voltage delivered to the load is compared with a RMS reference voltage to produce the comparison signal. The potential difference between the output voltage and the comparison signal is constantly monitored to produce the error signal. The error signal is thus constantly applied to vary the pulse width of the timing signal and thus vary the firing angle of the triac in accordance with the deviation of the actual output voltage from the stable RMS reference voltage.

Abstract: A circuit array, adapted to be coupled to a load and a source of a main AC voltage, for reverse phase angle control whereby a current flow in the load is limited to a defined phase angle (.alpha.) of the main AC voltage, comprising the following components for sequential control of the reverse phase angle control: a switching element, connected to the load and coupled to the source of the main AC voltage, for actuating the current flow in the load; a time determining component; and an integrated circuit.