Abstract: Provided is a surge protection circuit, which includes a bidirectional voltage suppressor; and a thyristor surge suppression unit connected in parallel with the bidirectional voltage suppressor. The first end of the bidirectional voltage suppressor is connected to the first end of the thyristor surge suppression unit, and the second end of the bidirectional voltage suppressor is connected to the second end of the thyristor surge suppression unit. The breakover voltage or the breakdown voltage in the direction from the first end to the second end of the thyristor surge suppression unit is greater than the clamping voltage in the direction from the first end to the second end of the bidirectional voltage suppressor. The breakover voltage in the direction from the second end to the first end of the thyristor surge suppression unit is less than the clamping voltage in the direction from the second end to the first end of the bidirectional voltage suppressor.

Abstract: Various embodiments include a circuit arrangement for controlling a power semiconductor switch including a gate terminal, a source terminal, a drain terminal, and a conduction channel between the source and drain terminals, comprising: a controller for generating a control signal to alternate the semiconductor switch between a turned-on state and a turned-off state; a current source for injecting a current into the gate terminal; and an evaluation unit. The evaluation unit measures a voltage between the gate terminal and one of the source terminal and drain terminal while the semiconductor switch is in the turned-on state; and determines from the measured voltage and the current an absolute temperature of the semiconductor switch.

Abstract: A semiconductor device is disclosed that includes, among other things, a computing device including a plurality of transistors, an activity monitor to determine an activity metric associated with the plurality of transistors, and a power controller to, responsive to the activity metric indicating a first activity level, set a power supply voltage for the plurality of transistors to a first value, and responsive to the activity metric indicating a second activity level less than the first activity level, set the power supply voltage to a second value greater than the first value and apply a first reverse back bias voltage to the plurality of transistors to increase a threshold voltage of the plurality of transistors.

Abstract: A method of controlling the connection of a multiple phase power source to a plurality of capacitors. The method including, for each phase of the power source, determining a first voltage using a first voltage divider, the first voltage divider having a first high voltage resistor and a first low voltage resistor, wherein the first voltage is equal to a voltage across the first low voltage resistor. The method further including, for each phase of the power source, determining a second voltage across using a second voltage divider, the second voltage divider having a second high voltage resistor and a second low voltage resistor, wherein the second voltage is equal to a voltage across the second low voltage resistor. The method further including, for each phase of the power source, generating a close signal when the difference between the first voltage and the second voltage is approximately zero.

Abstract: The embodiments discussed herein relate to systems, methods, and apparatus for controlling power consumption of a computing device in a standby or sleep mode. During the standby or sleep mode an external device can be plugged into the computing device. The external device can be provided power from a standby power supply until a determination is made as to whether a main power supply is operating. The determination can be based on comparing the output of the main power supply to an output of the standby power supply. If the main power supply is operating, a switch in the computing device can close to allow the main power supply to provide power to the external device. Moreover, in some embodiments, the switch can close based exclusively on a current demand of the external device from the standby power supply.

Abstract: One or more variable configuration controller (VCC) systems may produce various combinations of series or parallel couplings of coils, winding or inductive elements of an electric machine such as a generator and/or electric motor. The VCC systems include a plurality of bridge rectifiers, and a first number of switches operated to selectively couple respective pairs of coils in series from parallel on an AC side of the bridge rectifiers. The bridge rectifiers provide for automatic electrical isolation of coils on occurrence of open circuit, low voltage or short circuit conditions. A second number of switches with different performance characteristics (e.g., speed, loss) than the first number of switches may be coupled in parallel with respective ones of the first number of switches. Power factor correction may be used.

Abstract: A circuit to be utilized for an LED driver bleeder activation. The circuit comprises a circuit block for timing a duration of any removed portion of a rectified line signal. The input of the circuit to be coupled to receive the phase controlled rectified line signal through a voltage divider. Comparing the divided rectified line signal with a threshold voltage and output a comparison result. A timer coupled to the comparator and responsive to the comparison result to time the duration of the removed portion of the rectified line signal and activate the bleeder activation circuitry to turn on the switching element of the bleeder to sink a controlled current from the input line.

Abstract: Systems and methods for a digital-to-charge converter (“DQC”) are disclosed. A DQC may include a converting circuit configured to receive a first digital signal indicative of a voltage across a capacitor coupled to an output pin of the digital-to-charge converter and to determine a present charge of the capacitor based at least in part on the first digital signal. The DQC may also include an error determining circuit coupled to the converting circuit, wherein the error determining circuit is configured to receive a second digital signal indicative of a target charge via an input pin of the digital-to-charge converter and to determine a difference between the target charge and the present charge. The DQC may further include a correction circuit coupled to the error determining circuit and configured to control a programmable current source to produce an analog signal at the output pin in response to the determined difference.

Abstract: Circuits and methods to limit an in-rush current of a load circuit such as a processor are disclosed. A charge pump is used as driver for switches with pulse modulation width (PWM) control on the duty cycle of a clock. A clock generator generates a ramp signal with variable slope and a reference voltage. The slope of the ramp signal is dependent on the in-rush current of the switch. No dedicated slew rate driver or an external capacitor is required. The main building blocks are: a charge pump used as driver connected to single supply domain, one external (or internal) switch device, a single capacitive feedback between the switch device and the PWM control, and a PWM control comprising a fix frequency voltage triangular pulse generator with variable slope proportional to the in-rush current measurement.

Abstract: Rather than operating in asynchronous mode during turn-on ramps, a switching power regulator system may be configured to synthesize a digital waveform, which may protect against a pre-bias condition and maintain the desired ramp-up time and rate. The desired turn-on ramp may be generated digitally by counter logic, beginning with an initial value and incrementing at a programmed rate until a digital value equivalent to the desired output voltage is reached. When a pre-bias condition is not present, the output of the digital ramp generator may control a digital-to-analog converter (DAC), which may be configured to generate the reference voltage for the power regulator. To correct for a pre-bias condition, the pre-bias output of the power regulator may be measured prior to turn-on, using an analog-to-digital converter. The digital pre-bias value may be used to control the DAC until the value of the digital waveform generated by the ramp generator reaches the pre-bias value.

Abstract: In an induction motor group control system, magnetic energy recovery switches (3) are connected in series to an induction motor (2) directly driven by a commercial power supply, and a plurality of induction motor control devices (10) enabling voltage control and reactive power control of the induction motor 2 are employed to control generation of reactive power so as to maximize a power factor of the entire plurality of AC loads including the induction motor or compensate variations in voltage of an AC power supply (1).

Abstract: A stepwise voltage ramp generator includes a tank capacitor, a terminal of which is coupled to a reference potential to be charged with a voltage ramp. A transistor couples the tank capacitor to a supply line. A diode-connected transistor, biased with a bias current is coupled to the transistor to form a current mirror. A by-pass switch is electrically coupled in parallel to the diode-connected transistor, and is controlled by a PWM timing signal, the duty-cycle of which determines a mean slope of the generated voltage ramp.

Abstract: A measuring apparatus including a self test function, the circuit comprising a capacitor; first to fourth switches; a test signal injector; at least one comparator having a signal input and a reference input the first switch being interposed between a first plate of the capacitor and a first input node, the second switch being interposed between a second plate of the capacitor and a second input node, the third switch being interposed between the first plate of the capacitor and the signal input of the comparator and the fourth switch being interposed between the second plate of the capacitor and a voltage reference, wherein the self test function comprises the steps of i) operating the signal injector to produce a first signal representative of an out of range voltage for an expected voltage difference between the first and second input nodes, and using the signal to cause the at least one comparator to place its output in an error state, and to charge the capacitor to the out of range voltage, ii) isolating

Abstract: A device, such as a pump capacitor or an energy storing inductor, is charged by coupling it to a voltage source. Thereafter, the device is connected in parallel to one of the capacitors or capacitance cells to be charged, and the charging of the device and successive connections of it in parallel to a selected capacitor of the series of capacitors for charging it are replicated for all the capacitors of the series. The sequence of different connections of the device to the charge voltage source and to the selected one of the capacitors of the series is actuated through a plurality of coordinately controlled switches that establish distinct current circulation paths, according to a switched-capacitor or switched inductor techniques driven by respective periodic control signals that may be generated from a master clock signal.

Abstract: Rather than operating in asynchronous mode during turn-on ramps, a switching power regulator system may be configured to synthesize a digital waveform, which may protect against a pre-bias condition and maintain the desired ramp-up time and rate. The desired turn-on ramp may be generated digitally by counter logic, beginning with an initial value and incrementing at a programmed rate until a digital value equivalent to the desired output voltage is reached. When a pre-bias condition is not present, the output of the digital ramp generator may control a digital-to-analog converter (DAC), which may be configured to generate the reference voltage for the power regulator. To correct for a pre-bias condition, the pre-bias output of the power regulator may be measured prior to turn-on, using an analog-to-digital converter. The digital pre-bias value may be used to control the DAC until the value of the digital waveform generated by the ramp generator reaches the pre-bias value.

Abstract: A control loop system is provided that employs an active DC output control circuit that more accurately calibrates the desired voltage at a load, e.g. 3.3 volts, by adjusting a trim pin on a DC/DC converter.

Abstract: To present a DC-DC converter efficient in conversion and not requiring an external diode. The DC-DC converter includes a main NMOS transistor FET1 as a main switching device, a driver DVH1 for driving a gate terminal of the main NMOS transistor FET1, a capacitor C2 connected between a source terminal of the main NMOS transistor FET1 and a power source terminal of the driver DVH1, and an NMOS transistor FET3 connected between a route leading to an input power source and the power source terminal of the driver DVH1. The NMOS transistor FET3 does not conduct when the main NMOS transistor FET1 conducts, and conducts when the main NMOS transistor FET1 does not conduct.

Abstract: In one embodiment, a multi-channel power supply controller adjusts the value of an error signal to minimize overshoot and undershoot during load transients.

Abstract: A pulse-width-modulation (PWM) control system with nonlinear ramp is disclosed. A nonlinear ramp generator generates a nonlinear ramp varied with the duty (Vout/Vin) in a waveform signal, which could be a logarithm ramp, an exponent ramp, a multi-piecewise-linear ramp, a power ramp or a combination of above. The slope of the ramp is not a constant due to the non-linear characteristic. The voltage Vramp will vary with the input voltage Vin, output voltage Vout, and duty (Vout/Vin), therefore it will reduce the influence of the input voltage Vin or output voltage Vout on the modulation gain and loop gain, even to keep the modulation gain and loop gain in constant value. As mentioned-above, the present invention improves the transient response of system, the sensitivity for variation of Vin and Vout, thus it is capable of correcting the output voltage quickly, for supplying a more steady power output.

Abstract: A first constant-current source supplies a charging current to a second terminal of a first capacitor in which a first terminal is grounded. A first terminal of a second capacitor is grounded, and a first switch is provided between the second terminal of the first capacitor and a second terminal of the second capacitor. A second constant-current source supplies current to the second capacitor, and a second switch is provided on a current path of the second constant-current source. A third constant-current source draws out current from the first capacitor and the second capacitor. A switch controller turns on the first switch and turns off the second switch when an output voltage appearing in the second terminal of the first capacitor reaches a predetermined upper-limit voltage. The switch controller turns off the first switch and turns on the second switch when the output voltage drops to a predetermined lower-limit voltage.

Abstract: A voltage regulator has a reference voltage generator that outputs a reference voltage based on first and second electrical source voltages, an output circuit which generates a predetermined direct-current voltage based on the reference voltage and generates a comparison voltage lower than the predetermined direct-current voltage, and a differential amplifier coupled between the reference voltage generator and the output circuit. The differential amplifier provides a control voltage to the output circuit responsive to a difference between the reference and comparison voltages. The voltage regulator has a voltage adjustment circuit that adjusts the reference voltage responsive to a variation in the first electrical source voltage. The differential amplifier may include a constant-current circuit and an operation current generating circuit.

Abstract: A method and a device determine an operating temperature of a semiconductor component during operation, wherein the semiconductor component has a PROM memory area which can be read from the outside. The device further has a programming device for programming the PROM memory area of the semiconductor component in which the operating temperature is obtained by interpolation in between a first calibration temperature value and a second calibration temperature value in dependence from an actual measurement. The device has a multivibrator for generating a measurement signal which has a measuring circuit and a driver circuit. The frequency of the measurement signal depends on the temperature of the measuring circuit in the semiconductor component. A frequency counter for senses the frequency of the measurement signal in a predefined measuring interval.

Abstract: A regulator is provided with circtuiry for restraining a variation in a frequency band and to provide a transient response characteristic which does not depend upon load current. A load current detecting transistor is connected in parallel with an output driver transistor of the regulator to detect load current. The ON resistance of a transistor of a phase compensation RC network is varied in accordance with current variations detected by the load current detecting transistor. As a result, a frequency of a zero point for phase compenstation of the RC network is varied so that the frequency band of the regulator does not vary with load current and the transient response characteristic of the regulator is improved.

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 control system for an electric lift truck that controls a traction motor and a hydraulic pump motor is disclosed. The speed of rotation of both motors is controlled by a pulse width modulated current supplied from a battery source by the controller in direct response to a demand communicated to the controller through an interface manipulated by an operator. A pump driven by the pump motor supplies pressurized hydraulic fluid to a lift mechanism and a power assisted steering unit. A joystick with function switches mounted thereto is provided so that the operator steers with one hand while controlling truck propulsion and all functions of the lift mechanism with the other hand. The direct control of the pump motor speed enables a fully proportional control of the hydraulic system. The control system is a compact structure that requires minimal cabling and ensures that the hydraulic system operates with energy efficiency and minimal wear.

Abstract: A lamp protection device includes a circuit to prevent a lamp from being switched on at full line voltage and which provides for the gradual heating of the filament to reduce the expansion rate of the filament. The circuit is connected to a switched alternating current power source and to an incandescent bulb. The circuit includes two silicon controlled rectifiers which are connected in reverse parallel configuration. One of the silicon controlled rectifiers being connected to a capacitor to prevent the full sinusoidal AC current from reaching the lamp until a time delay has expired after the lamp is turned on. A reference switch is connected to the other silicon controlled rectifier to permit the bulb to be turned on only when the AC voltage crosses zero.

Abstract: A pulse width modulation type power supply modulator capable of operating at high switching frequencies (>10 MHz) is achieved by eliminating resonant circuits which limit the maximal switching frequency. The modulator includes a power circuit including a power transistor, a first control circuit connected to the gate of the power transistor and a second control circuit connected to the output of the power circuit. In a preferred embodiment the active components are isolated from each other by areas of metalization on a printed circuit to minimize unwanted coupling and the electrical lengths are minimized.

Abstract: An apparatus and method for supplying a regulated direct electric current comprises a switch mode regulator having an input for receiving a varying source of electrical power. A linear regulator provides a source of low noise direct current and has an input connected so as to receive a voltage that is dependent upon an output of the switch mode regulator. A first servo-loop provides a first control signal to the switch mode regulator. The first control signal is varied according to a variation in the voltage across the linear regulator. A second servo-loop provides a second control signal to the linear regulator. The second control signal is varied according to the difference between a voltage that is related to an output of the linear regulator and a reference voltage. The second servo-loop has a higher gain than the first servo-loop when both of the servo-loops are operating at frequencies that are within their operating frequency ranges.

Abstract: The present invention provides a electronic switch suitable for fading on/off control of electrical equipment like lamps and motors. The main circuit comprises a rectifier bridge circuit and a thyristor. A control circuit includes a fast discharging synchronic integrator and a trigger pulse integrator, the former acts as a pulse phase shifter to provide a self-adapting magnitude variable sawtooth waveform, while the latter acts as a dynamic phase variation memory so as to provide a variable reference for comparison. Trigger pulses which are feed back via the main circuit causes the synchronic integrator to fast discharge. If a control switch is closed, the voltage on the integral capacitor and the trigger angle decreases gradually to produce the fade on. In the fade off process, the conditions are just the opposite. Fading on/off time can be independently set.

Abstract: A low voltage dimmer is shown with the dimming function being on a primary side of a low voltage transformer. Live voltage feeds through a triac to the primary side of the transformer with the gate for the triac being controlled by a microprocessor. To prevent burnout of the transformer if the secondary load side is open, zero crossing of the incoming signal is determined by the microprocessor. If the time constant between the zero crossing of the live voltage and the charging of a capacitor with resistance being provided by the primary side of the transformer exceeds w predetermined time period, the microprocessor will be inhibited from generating a pulse to fire the triac. When the primary side of the transformer has been opened, the load on the secondary side can be re-established, i.e. light bulb replaced. Power for the microprocessor is from the charging of a capacitor used to provide the triggering signal to the microprocessor. Also the microprocessor may be triggered from remote locations.

Abstract: An ozonator power supply including a step-up transformer having one end of its primary winding connected to one side of an AC supply, its other end connected to the other side of the AC supply via a pair of switches connected in antiparallel, and a controller for providing switching pulses to said switches for making them conductive during variable portions of alternate half cycles of the AC voltage provided by said supply. An inductor is included in the circuit with the primary or secondary winding of the transformer that resonates with the capacitive impedance of an ozonator, for presenting a substantially non-reactive load to said AC supply.

Abstract: An improved phase-controlled power control apparatus includes a semiconductor switching element for varying the effective power delivered to a load from the power lines. The conduction angle of the semiconductor power switch element is varied from a nominal angle to compensate for changes in power line voltage and for changes in load current. The amount of load current flow is continuously compared to the power line voltage to detect any overcurrent condition, even very close to the zero-crossing of the power line voltage. The shape of the transition from load current on to load current off (or vice versa) in controlled to minimize audible noise from the load. The load current can be shared between a plurality of compatible power control sections.

Abstract: A dimmer with reduced filtering losses is connected into a conductor supplying power to a load from a mains power supply. It conventionally comprises a triac in series with a filter inductor between an input terminal and an output terminal and a circuit generating triggering signals for the triac. To reduce the losses in the inductor, which conventionally is in series with the load at all times but is active only during moments following triggering of the triac, to reduce the amplitude of the transient currents, a second triac triggered by a circuit with a time-delay greater than the time constant defined by the filter capacitor and inductor diverts the load current. An auxiliary low-value inductor attenuates transients due to triggering of the second triac.

Abstract: An apparatus and method is disclosed for controlling a load capable of functioning for a predetermined purpose in response to a predetermined amount of electrical power. The load can be operated from either an AC or DC source using a two-wire connection. The predetermined amount of electrical power is applied to the load if a sensor senses a triggering event. During the time period when a triggering event is sensed, power is cycled on and off to the load in order to enable continuous monitoring of the trigger event. During most of the time period, the sensor receives power to maintain its operations from a storage circuit. If the charge in a capacitor decreases to a predetermined value, the predetermined amount of electrical power is removed from the load momentarily to allow replenishment of the capacitor charge.

Abstract: Reverse phase-controlled dimming of an a.c.-powered load is accomplished by switching power to the load on and off during each half cycle. In one embodiment of the present invention, power is switched on when line voltage is substantially equal to load voltage and off at a selected time later in the half cycle or at any time that the voltage across the switch exceeds a predetermined value. Preferably, switching is accomplished with a pair of field effect transistors. The load preferably includes a capacitor from load hot to neutral. The present circuit permits quiet dimming of incandescent lamp loads without the need for complex circuitry. It is particularly well adapted for dimming low voltage lamps using a solid state transformer.

Abstract: A switching regulator including a direct voltage source for producing an input voltage, an electronic switch connected between the voltage source and an output for switching the input voltage to the output, a pulse width modulator connected for controlling the electronic switch, a sawtooth signal generator connected for feeding the pulse width modulator a sawtooth signal of constant maximum amplitude, and a proportional signal circuit connected for feeding the pulse width modulator a signal proportional to current through the electronic switch.

Abstract: A device for regulating delivery of power from an AC voltage source to a load such as a lamp, a motor, a heating element or the like is described. Electronic circuitry responsive to the AC voltage generates a periodic signal whose magnitude indicates the instantaneous phase angle of the AC voltage relative to the most recent zero crossover of the AC voltage throughout the entirety of each half cycle of operation. A comparator generates a triggering signal when the phase angle signal corresponds to a threshold signal which may be manually set by adjustment of a voltage divider or which may be generated by a sensor in response to a predetermined condition, such as ambient light level or temperature, which is to be regulated by appropriate delivery of power to the load. The triggering signal is applied to a triac series connected with the load to initiate conduction of load current.

Abstract: A low voltage two wire dimming circuit comprises a voltage compensating circuit for regulating the RMS value of an AC voltage applied to a load and a correcting circuit for eliminating damaging DC current that may flow through the load. The voltage compensating circuit adjusts the firing angle of an electronic switch disposed in the dimming circuit to compensate for fluctuations in the AC supply voltage. The correcting circuit advances or retards the firing angle during selected half cycles to correct for asymmetries in the AC load voltage waveform caused by excessive DC current. According to the invention, there is also provided a two wire low voltage dimming circuit without voltage compensation but having improved dimming ability at low load currents and improved resistance to the flow of damaging DC currents.

Abstract: A switch mode electrical power controller arranged to provide a width modulated output pulse signal in response to a control input signal representing a parameter controlled by the power controller, in which a signal processing network for generating the width modulated waveform is arranged to execute all its operations in parallel. The performance, in parallel, of the operations required for the generation of the output signal minimizes the delay along a critical signal path and facilitates high frequency operation.

Abstract: A control device for switching a thyristor in a circuit including an a.c. voltage source, which comprises firing signal circuit having an input for receiving control signals, an output for providing firing signals for a thyristor and a detector for detecting zero-crossings of an a.c. voltage provided by the a.c. voltage source. The firing signal circuit further comprises an accumulating circuit for accumulating the control signals and for providing a firing signal when both the detector detects a zero-crossing of the a.c. voltage and the value of the accumulated signals is equal to or exceeds a first predetermined value, and subtracting circuit for subtracting a second predetermined value from the value of the accumulated signals when the firing signal is provided.

Abstract: A low voltage two wire dimming circuit comprises voltage compensating means for regulating the RMS value of an AC voltage applied to a load and correcting means for eliminating damaging DC current that may flow through the load. The voltage compensating means adjusts the firing angle of electronic switch means disposed in the dimming circuit to compensate for fluctuations in the AC supply voltage. The correcting means advances or retards the firing angle during selected half cycles to correct for asymmetries in the AC load voltage waveform caused by excessive DC current. According to the invention, there is also provided a two wire low voltage dimming circuit without voltage compensating means but having improved dimming ability at low load currents and improved resistance to the flow of damaging DC currents.

Abstract: A control circuit for generating gating signals to drive the SCRs of an AC switch coupled between a three phase AC source and a three phase load. A reference voltage signal is derived from the source and, after filtering, is applied to a squaring amplifier. The amplifier output is applied to a phase-locked loop (PLL). The output signal of the voltage controlled oscillator (VCO) of the PLL is fed back to the phase comparator thereof via two dividing counters. The output of one counter is applied to a logic block for generating a ramp reset signal in phase with a selected source phase-to-neutral voltage. The ramp reset signal is applied to a ramp forming circuit the output of which is applied to a first input of a comparator. The comparator receives a DC control voltage on its second input and provides on its output a gating signal corresponding to the source selected phase.

Abstract: A method and apparatus for controlling power delivered to a fastening machine solenoid comprises a half wave rectifier, a filter network, an adjustable frequency generator and a pulse conditioning circuit. The frequency of the frequency generator is varied in accordance with fluctuations in peak AC line voltage and is input to driving circuitry which engages a solenoid at a predetermined time and for a specific amount of time. By increasing or decreasing the solenoids on time in accordance with power line voltage fluctuations, a pulse of constant power will be received by the solenoid, regardless of fluctuations in power line voltage.

Abstract: A device for regulating delivery of power from an AC voltage source to a load such as a lamp, a motor, a heating element or the like is described. Electronic circuitry responsive to the AC voltage generates a periodic signal whose magnitude indicates the instantaneous phase angle of the AC voltage relative to the most recent zero crossover of the AC voltage throughout the entirety of each half cycle of operation. A comparator generates a triggering signal when the phase angle signal corresponds to a threshold signal which may be manually set by adjustment of a voltage divider or which may be generated by a sensor in response to a predetermined condition, such as ambient light level or temperature, which is to be regulated by appropriate delivery of power to the load. The triggering signal is applied to a triac series connected with the load to initiate conduction of load current.

Abstract: A supply circuit for an apparatus which is provided with a supply voltage which is low relative to the amplitude of a main voltage supplied from a main power supply network. The switching apparatus has a switching line arranged in the main power supply line, which is connected in series with a load, and in which the supply circuit is connected in parallel with a power-dissipating or resistance element connected in series with the load.

Abstract: The invention relates to a two-wire switch for connecting a load to an ac ltage source, and, in particular, to a two-wire switch with an auxiliary voltage source. A capacitor acting as charge storage device can be charged by the auxiliary voltage source which operates on the principle of phase angle control. In accordance with the invention, a series connection comprising a threshold element which can be brought into the conducting state when there is a prescribed minimum voltage across the capacitor, and a diode is inserted into a control current circuit for a controllable semiconductor device on the input side of the bridge.

Abstract: A circuit for controlling the initiation and operation of a phase control circuit employed in voltage regulation to a load such as dimming lights. The circuit uses a power semi-conductor which is triggered by a "walk-in" circuit. The "walk-in" circuit includes a regulator diode across a diode bridge which stabilizes the output of the load, such as a level of lighting.

Abstract: What is proposed is an electronic circuit for controlling the amount of AC power delivered to an inductive or resistive load which continuously measures the actual phase lag between the load current and applied voltage and automatically adjusts the firing angle to provide the desired amount of AC power. The circuit includes an auxiliary on/off input with soft start and independently adjustable time delays for the on and off functions and also incorporates an input for remote power level control and features a half-wave rectified mode which delivers pulsating DC power to the load.

Abstract: The frequency of an alternating current can be divided with a novel frequency divider, comprising a thyristor connected in series to main current circuit; a counting circuit (e.g. decimal counter or RC-time constant circuit); a trigger circuit for the thyristor, associated with the counting circuit; and a reset circuit. With use of the apparatus, half- or whole-cycle(s) of an alternating current can be supplied to ac appliance at desirable wave intervals.

Abstract: What is proposed is an electronic circuit for controlling the amount of AC power delivered to an inductive or resistive load which continuously measures the actual phase lag between the load current and applied voltage and automatically adjusts the firing angle to provide the desired amount of AC power. The circuit includes an auxiliary on/off input with soft start and independently adjustable time delays for the on and off functions and also incorporates an input for remote power level control and features a half-wave rectified mode which delivers pulsating DC power to the load.