Abstract:
An ON/OFF operating state and brightness adjustment control arrangement for a phase cutting control dimmer including a microcontroller that receives and interprets a pulse signal with a characterisation dependent on degree of rotary angular positioning, acceleration and/or time of rotation made by the user when rotating a rotary encoder, wherein the pulse signal assists in defining levels of light brightness for the lamp under the control of the phase cutting control dimmer or changing the ON/OFF operating state of the dimmer.
Abstract:
A method for reducing the influence of a DC component in a load current of an asynchronous three-phase motor, in which the voltages of two of the three phases are controlled by adjusting firing angles of semiconductor devices of the type turning-off at zero-crossing of the current therethrough comprises the steps carried out for each said controlled phase: detecting turn-off times of the semiconductor devices, calculating a value of a change of firing angle of the semiconductor devices needed for changing the length of the time period between two subsequent turn-off times for compensating for the influence of a DC component, and determining the firing angle of said semiconductor devices in dependence of the result of this calculation.
Abstract:
The ac voltage regulator apparatus of the present invention uses back-to-back silicon-controlled rectifier ('SCR') power output switches which are triggered into conduction after being delayed for a period of time from the previous ac supply voltage zero point. The SCR switches are switching the load voltage at a determinate phase angle in order to obtain a constant true RMS voltage. The delay time of the trigger signal is variable and is changed to obtain regulation of the RMS voltage applied to the ac load. This regulation feature compensates for temperature changes, ac supply voltage variations, and ac load current changes.
Abstract:
An apparatus and method for controlling the voltage applied to a load is taught. The method includes receiving an AC line voltage, generating an operating AC voltage from the AC line voltage and applying this operating AC voltage across the load. A measured signal which is a function of the magnitude of the operating AC voltage is generated, and then averaged to generate an average signal representative of the average value of the measured signal. The operating AC voltage is continually readjusted in response to changes in the average signal. The apparatus implementing this method includes terminal means for receiving an AC line voltage, means for generating an operating AC voltage from the AC line voltage, connector means for applying the operating AC voltage across the load, and voltage detection means for generating a measured signal which is a function of the magnitude of said operating AC voltage. Signal averaging means are provided for generating an average signal representative of the average value of the measured signal. Finally, the apparatus includes AC voltage modulation means for adjusting the operating AC voltage in response to the average signal. In the preferred embodiment of the apparatus of the present invention, the AC voltage modulation means comprises voltage reduction means for switching off the line voltage for a portion of each cycle, the length of the portion being determined by the average value of the measured signal. The voltage modulation means may comprise a phase control integrated circuit device for controlling a triac. The phase control integrated circuit device is responsive to the average signal to generate a control signal operative to control a triac to switch off transmission of the line voltage to the load for the portion of each cycle.
Abstract:
A method for determining a limit of a phase control power range includes applying a first gate pulse to a switch at a first firing angle near the limit of the power range, sensing the conductive state of the switch after the first gate pulse, and determining the limit of the power range in response to the conductive state of the switch. If the switch remains conductive after the first gate pulse, the first firing angle may be used as the limit of the power range. If the switch does not remain conductive after the first gate pulse, the limit may be determined by repeatedly incrementing the firing angle, applying a gate pulse to the switch at the incremented firing angle, and sensing the conductive state of the switch after each gate pulse until the switch is conductive after a gate pulse.
Abstract:
Disclosed is a universal dimmer which detects the type of load it is connected to each time the universal dimmer is activated. Information relating to the type of load connected to the universal dimmer is therefore not required to be stored for future use. In one form, the universal dimmer begins each operation in the trailing edge mode and upon detection of an inductive load, switches to leading edge mode.
Abstract:
Um eine Vorrichtung (8) zum Einstellen der Impedanz einer Wechselstrom führenden Hochspannungsleitung (9) mit wenigstens einer in Reihenschaltung in die Hochspannungsleitung (9) einfügbaren Regelspule (2) und mit wenigstens einer jeweils einer Regelspule (2) zugeordneten Schalteinrichtung (3,10) bereitzustellen, die kompakt und kostengünstig ist, wobei eine Steuerungseinheit (4) zum Steuern jeder Schalteinrichtung (3,10) auf einer Weise vorgesehen ist, dass durch das Schalten der Schalteinrichtung (3,10) die in der Vorrichtung wirkende Reaktanz der Regelspule (2) einstellbar ist, wird vorgeschlagen, dass jede Schalteinrichtung (3,10) parallel zu der ihr zugeordneten Regelspule (2) in einem Parallelzweig (5) angeordnet ist.
Abstract:
The present invention relates to a power control device and the method therefor that save unnecessary power consumption by controlling the input power of induction motor used in household appliances or industrial machines. The power control device of this invention is to achieve predetermined power efficiency by comparing the output variation responsive to input variation with the power value predetermined for each type of motor, and by controlling the phase angle of output drive part based upon the differences between the variation and the predetermined power value. The power control device includes: a period detection means for reading the frequency of power applied to input terminal by using zero-crossing method; a power energy sensing means for sensing the power energy applied to input terminal by sensing the quantity of light of the power flowing on the motor; a power efficiency setting means for selecting predetermined efficiency of the power energy applied to motor, the predetermined efficiency being predetermined in accordance with each motor type; a microcomputer unit which compares the value of the period detected by said period detection means, and the value of the power energy detected by said power energy sensing means, with the value of predetermined power efficiency set by said power efficiency setting means; and a gate trigger means for controlling the electric continuity angle of SCR drive parts after receiving output signal of the microcomputer unit.