41results about How to "Increase conduction angle" patented technology

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.

A switching power supply circuit ready for worldwide use is disclosed which suppresses a variation of a pulse voltage to be fed back when the alternating-current input varies. The switching power supply circuit includes a composite resonance type converter of a switching frequency control scheme wherein a voltage resonance pulse voltage generated in a primary side voltage resonance converter is fed back to a rectification diode through a high speed diode and an inductance or a transformer. An active clamp circuit is provided on the primary side to clamp the voltage resonance pulse voltage.

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.

The invention discloses a circuit for improving the linearity and power added efficiency of a power amplifier. The power amplifier is in a Cascode structure formed by overlapping a grounded-emitter transistor and a grounded-base transistor in series; a first secondary harmonic resonance network for suppressing secondary harmonic signals is connected between the collector of the grounded-emitter transistor and the ground; a second secondary harmonic resonance network for suppressing secondary harmonic signal output is connected between the collector of the grounded-base transistor and the ground; and a third harmonic resonance network for reflecting third harmonic signals to the collector is connected between the collector of the grounded-base transistor and the output port. The invention adopts the resonance networks for respectively processing the fundamental harmonic, the secondary harmonic and the third harmonic, thereby achieving the purposes of smoothly passing the fundamental harmonic, short circuiting the secondary harmonic to the ground and obstructing the third harmonic to be overlaid with the fundamental harmonic, and improving the linearity and the power added efficiency of the power amplifier.

The invention discloses an LED drive device with a valley fill circuit. The device includes a bridge rectification module connected to commercial power, a valley fill circuit, a filter capacitor C3, a constant current module connected to the bridge rectification module, and an LED load connected to both the bridge rectification module and the constant current module. One end of the filter capacitor C3 is connected to the output end of the bridge rectification module, and the other end of the capacitor C3 is connected to the ground. The valley fill circuit is connected to the output end of the bridge rectification module. The valley fill circuit is additionally adopted to greatly increase a conduction angle of a rectifier diode, input currents are made to change from spike pulses into waveforms similar to sine waves through valley point filling, the total harmonic distortion is substantially reduced, and a power factor can be increased to be around 0.9. The LED drive device has the advantages of simple structure and low cost.

The embodiment of the invention provides a draught fan PG motor control method, a draught fan and an air conditioner and relates to the field of air conditioners. The rotating speed of an air conditioner draught fan motor can be controlled accurately. The method comprises the steps of acquiring the actual rotating speed of the PG motor within a first preset time duration; matching the acquired actual rotating speed with a preset target rotating speed and reducing the conduction angle of the PG motor when the actual rotating speed is greater than the preset target rotating speed; increasing the conduction angle of the PG motor when the actual rotating speed is less than the preset target rotating speed; and keeping the conduction angle of the PG motor unchanged when the actual rotating speed is equal to the preset target rotating speed. The draught fan PG motor control method is used for conducting control over the air conditioner draught fan.

The invention relates to a lighting device. The lightning device comprises a rectification unit connected with a power supply, at least a lightning unit connected with the rectification unit through a buck circuit unit, and a buck circuit unit connected with the rectification unit and the lighting unit. The lighting device also comprises a main control unit connected with the buck circuit unit and the lighting unit. The main control unit is arranged to control the input current from the rectification unit to flow past a light emitting part of the lighting unit according to change of the input voltage of the rectification unit, and thus a total forward voltage of the light emitting part is adjusted. When the input voltage is more than the total forward voltage, the buck circuit unit lowers the voltage flowing past the lighting unit and thus the lighting device enters a voltage reduction state.

There is disclosed a passive power-factor correcting circuit for the electronic ballast, which includes BOOST circuit consisting of an inductor, a capacitor and a diode, and a current-follower circuit consisting of two electrolytic capacitors and four diodes. The BOOST circuit is series connected between the mains output circuit of the electronic ballast and the lead-in end of the filament. The current-follower circuit is parallel connected at the front end of DC / AC translation circuit of the electronic ballast.

A power supply device used for an elevator brake coil disclosed by the present invention comprises a time delay control circuit, an AC buck circuit and a bridge rectifier circuit B1, the time delay control circuit outputs a first control signal and a second control signal respectively when an elevator is started and the time delay time is ended, and the AC buck circuit comprises a relay K1, a capacitor C1, a resistor R0, a resistor R3, a bidirectional diode D1 and a bidirectional silicon controlled rectifier Q1. A live wire of the commercial power is connected with the first terminal of the bidirectional silicon controlled rectifier Q1, and the control end of the bidirectional silicon controlled rectifier Q1 is in series connection with the bidirectional diode D1 and then is connected with a normally-closed contact 4 of the relay K1. The capacitor C1 and the resistor R3 are connected in series and then are in parallel connection between the first terminal of the bidirectional silicon controlled rectifier Q1 and the normally-closed contact 4, and the second terminal of the bidirectional silicon controlled rectifier Q1 is connected with a common contact 6 of the relay K1. The resistor R0 is in parallel connection between the second terminal of the bidirectional silicon controlled rectifier Q1 and the normally-closed contact 4, and the normally-closed contact 4 of the relay K1 is closed and disconnected respectively according to the first and second control signals. Compared with the prior art, the power supply device used for the elevator brake coil of the present invention is simple and reliable in realization mode and low in cost, and realizes the high and low voltage isolation.

The invention discloses a capacitor type rectifying and step-down voltage regulator circuit. In the process of alternating current rectification, by utilizing the controllability of a self-turnoff device and the unilateral conductivity of diodes, a first capacitor composes serial charging via a charging diode and a second capacitor. When alternating-current voltage is lower than the voltage of the second capacitor, both ends of a blocking diode generate driving voltage for the self-turnoff device to drive the self-turnoff device to turn on, and the first capacitor carries out parallel charging on the second capacitor; and when output voltage reaches a required value, a voltage regulating control circuit controls the self-turnoff device to turn off in order to obtain stable direct-current voltage output used by an electricity-consuming load. Thus, the process of alternating current-to-direct current voltage-regulated transformation is simplified, and the purpose of utilizing the capacitors for rectification and step-down voltage regulation is achieved. The capacitor type rectifying and step-down voltage regulator circuit has the advantages of simple structure, low cost, high efficiency, high power factor and the like, and breaks through the bottleneck that the service life of the inductor type switching power supply is short due to high switching frequency.

The invention relates to a power factor compensating device. A BOOST circuit is adopted. The power factor compensating device is characterized in that the BOOST circuit comprises a soft switching circulation module, a parallel interleaving module, a magnetic integration module, a current feedback detecting module and a voltage feedback detecting module. The power factor compensating device is simple in structure and improves the conduction angle of switch power supply input currents, thereby improving the power factor, reducing current harmonic waves, reducing pollution to a power grid, and improving the use ratio of electricity generator power.

The invention provides a thyristor rectification soft start control method, a thyristor rectification soft start control device and a storage medium. The thyristor rectification soft start control method comprises the following steps of acquiring a phase voltage of a thyristor rectification module; determining the phase of the phase voltage; and when the phase of the phase voltage is in a preset conduction angle range, controlling a corresponding thyristor in the thyristor rectification module to be conducted, and increasing a conduction angle of the thyristor till the bus voltage of the thyristor rectification module is established. The thyristor rectification soft start control method is advantaged in that a technical problem that the cost is increased due to the fact that the bus voltage of the thyristor rectification module is established through a soft start circuit is solved.

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 of a phase-control clipping 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 conduction angle of the phase-control clipping circuit in plural steps to provide the soft start.

The invention relates to an automatic smoke exhaust fan, and belongs to the technical field of smoke exhaust fans. The automatic smoke exhaust fan can automatically start and stop, and the rotating speed of a fan motor can be adjusted. According to the technical scheme, the automatic smoke exhaust fan comprises a fan body, a fan controller inside the fan body and a smoke sensor G1 arranged at the air inlet of the fan body. The fan controller comprises a time base integrated circuit chip IC1, a silicon controlled rectifier D1, a bidirectional thyristor D4 and the fan motor M1. The automatic smoke exhaust fan is applicable to the field of smoke exhaust and air exhaust fans.

The invention refers to a power converter and to a method for power conversion. The power converter includes a primary winding adapted to receive a primary alternating voltage. The converter further includes a first secondary circuit magnetically coupled to the primary winding, the first secondary circuit generating a first secondary output signal, the power converter further includes a second secondary circuit magnetically coupled to the primary winding. The power converter includes a post regulator adapted to be coupled to the second secondary circuit, the post regulator having a switch which is opened at every zero-crossing of the first output signal.

The invention belongs to the field of wearable equipment energy supply, and particularly discloses an energy acquisition circuit for wearable equipment and a power management circuit thereof. An auxiliary charge pump is introduced into each stage of charge pump in the energy acquisition circuit; the auxiliary charge pump adopts a charge transmission switch structure and is used for generating threshold compensation voltage based on electromagnetic waves and controlling grids provided for main rectification switches in the main rectification charge pump through a clamping tube so as to reduce the threshold voltage of the main rectification charge pump; the power supply management circuit comprises a sub-threshold bias generation circuit which is used for starting and generating reference voltage VREF irrelevant to VCC and environment temperature based on VCC. The LDO circuit based on the sub-threshold amplifier performs filtering of ripple waves for VCC based on VREF in a sub-thresholdstate, and secondary power supply voltage VDD is obtained. The circuit is high in energy conversion efficiency, low in manufacturing cost, suitable for various electromagnetic wave energy environmentsand high in practicability.

The disclosed intelligent remote control lamp holder comprises: a receive lamp holder with a control circuit board of MCU2 connected with a wireless receive demodulation unit with antenna, a power reduce-voltage commutation stabilize-voltage unit to supply power, a control output drive unit with a power output control unit connected to control output electrode on holder connector, and a power detection unit; and a wireless remote controller. Wherein, the input electrode of firing line connects with said power reduce-voltage commutation stabilize-voltage unit and power output control unit, while zero line electrode connects with power reduce-voltage commutation stabilize-voltage unit and power detect unit and zero line electrode of holder connector.

The invention relates to the technical field of rectifying circuits and capacitor filtering circuits in alternating current and direct current conversion, in particular to a circuit capable of increasing the conduction angle of a bridge rectifier. The circuit comprises a first rectifying circuit body and a second rectifying circuit body and is characterized in that a regulator circuit body is arranged between the first rectifying circuit body and the second rectifying circuit body, and the regulator circuit body is electrically connected with the first rectifying circuit body and the second rectifying circuit body respectively. According to the circuit, the regulator circuit body is additionally arranged between the two rectifying circuit bodies which are originally independent so as to prolong the conduction time of diodes in the corresponding original rectifying circuit bodies to increase the conduction angle and reduce impact currents, and therefore the service life of the diodes is prolonged. The circuit capable of increasing the conduction angle of the bridge rectifier prolongs the conduction time of diodes in the capacitor filtering circuits, and increases the conduction angle, thereby prolonging the service life of the diodes.

The invention relates to the field of switching power supplies, and discloses a switching power supply and a valley fill circuit wherein the switching power supply comprises a first energy storage unit, a second energy storage unit, a first diode, a second diode, a third diode, a first switch, a second switch, a first winding and a second winding. The switching power supply can be applied to the field of switching power supplies with wide voltage input, when the input voltage is low-voltage input, the first switch and the second switch are controlled to be switched on, and when the input voltage is high-voltage input, the first switch and the second switch are controlled to be switched off. When the energy storage unit is a capacitor, the switching power supply can provide appropriate filtering capacity for input voltages in different ranges, can improve the PF value during high-voltage input, solves the problems of large output voltage fluctuation and impact current of a large capacitor during low-voltage input, and reduces the size of a system and the cost at the same time.

The invention discloses a main circuit for increasing the power factor of a controllable silicon power supply, which relates to the technical field of high-power controllable silicon power supplies and transformers thereof. The main circuit is characterized in that: a transformer is provided with at least two groups of secondary windings, wherein each group of secondary windings constitutes a basic low-voltage power supply together with a three-phase full-wave rectifier bridge, an inductor, a capacitor, an electronic switch and a diversion diode; and the diversion diode in the basic low-voltage power supply is reversely connected to an output positive terminal and an output negative terminal of the basic low-voltage power supply. When the power supply is continuously adjustable, primary controllable silicon of the transformer can keep a larger conduction angle, which is generally about 120 degrees, so that a higher power factor of a power grid can be always kept, a lower peak value of resonant current is kept, and small pollution to the power grid is kept.

The invention discloses an adaptive LED driving circuit, which comprises: a fluctuating DC power supply, used to generate a DC voltage signal with periodic voltage changes; a current control circuit, used to change the series and parallel relationship between LED strings, so as to Adaptive to the periodic change of the DC signal; a current limiting or constant current circuit, used to limit or constant current the DC voltage signal, and drive the current control circuit to run; the fluctuating DC power supply, the current control circuit and the current limiting Or the constant current circuit is connected in series to form a closed loop; the current control circuit includes at least two current control subunits, and each current control subunit includes a first normally closed switch, a second normally closed switch, a fourth normally closed switch, a a diode and a second diode. The LED strings of the present invention can be connected in parallel or in series through a normally closed switch according to the input voltage level and the magnitude of the circuit current, thereby changing the total voltage of the LED strings and automatically adapting to changes in the input voltage.

The invention relates to a three-phase switched reluctance motor system based on a quasi-Z-source modular converter. A quasi-Z-source modular converter of the system is composed of a front-end quasi-Z-source circuit and four groups of power conversion units connected in parallel, and a phase stator winding of a three-phase switched reluctance motor is connected among the four groups of power conversion units; the converter can realize four operation modes, namely a direct-through mode, a non-direct-through excitation mode, a non-direct-through zero-voltage follow current mode and a non-direct-through demagnetization mode. The bus voltage can be adjusted by changing the direct-through duty ratio of the quasi-Z-source modular converter, the change range of the DC bus voltage is greatly expanded, and thus the wide-range speed regulation of the motor can be realized. And meanwhile, the bus voltage is increased, so that the excitation and demagnetization processes can be accelerated, and the torque pulsation is reduced. The three-phase switched reluctance motor system is high in integration level, high in power density, high in reliability and adjustable in DC bus voltage.

There is disclosed a passive power-factor correcting circuit for the electronic ballast, which includes BOOST circuit consisting of an inductor, a capacitor and a diode, and a current-follower circuit consisting of two electrolytic capacitors and four diodes. The BOOST circuit is series connected between the mains output circuit of the electronic ballast and the lead-in end of the filament. The current-follower circuit is parallel connected at the front end of DC / AC translation circuit of the electronic ballast.

The invention discloses a multipath LED driving circuit model of a high power factor. The model comprises a rectifier bridge, n LED strings in serial connection, n power switch tubes, a switch tube driving circuit module, a first resistor, a second resistor and a sampling resistor; the anode of the first LED string is connected with one output end of the rectifier bridge and one end of the second resistor; the cathode of the nth LED string is connected with a sampling voltage port of the switch tube driving circuit module and one end of the sampling resistor; the other end of the sampling resistor is grounded; a reference voltage port of the switch tube driving circuit module is connected with one end of the first resistor and the other end of the second resistor; the other end of the first resistor is grounded; and grid electrodes of the n power switch tubes are connected with n output ports of the power tube driving circuit module respectively, drain electrodes of the n power switch tubes are connected with cathodes of n LED strings, and each of source electrodes of the n power switch tubes is connected with the sampling voltage port of the switch tube driving circuit module and one end of the sampling resistor. Thus, the total harmonic distortion is low, the power factor is high, and the amount of circuit components is reduced.

The invention discloses an LED drive circuit, an LED constant current driver and lighting equipment. The LED drive circuit comprises a rectifier module, an energy storage filter capacitor, a sampling module, a control module and a ripple elimination module. The rectifier module is used for rectifying input voltage; the sampling module is used for sampling the voltage output by the rectification module so as to output a feedback signal to the control module; the energy storage filter capacitor and the control module are connected in series between the rectifier module and the ground, and are used for charging and storing energy within the input current conduction time and providing driving current for the LED lamp group within the input current disconnection time; the control module is electrically connected with the sampling module, and is used for controlling the current of the LED lamp group according to the feedback signal and a current signal on a first sampling resistor in the control module, and controlling the conduction time and the charging current of the energy storage filter capacitor; the ripple elimination module is connected in series with the LED lamp group and then connected in parallel with the energy storage filter capacitor, and is used for controlling the current of the LED lamp group and eliminating the ripple current.

The invention provides a silicon controlled rectifier light modulation-supported AC / DC power supply circuit and a control method and a power supply method thereof. A light modulation signal generation circuit detects the DC voltage output from a rectifier circuit to generate a light modulation signal to provide a current reference signal. A current detection circuit detects a controlled current and provides a current feedback signal. A controller generates a control signal for a switch device in a current limiting-constant current circuit according to the difference between the current reference signal and the current feedback signal, so that the controlled current is enabled to change correspondingly with change in the DC voltage output from the rectifier circuit, thereby achieving silicon controlled rectifier light modulation. The power device loss is extremely low, the conversion efficiency is extremely high, and the power application range of the drive power supply can be easily expanded. The conduction angle of the rectifier bridge is increased, so that the power factor of the power supply circuit is enabled to be higher than the traditional rectifier circuit. The output voltage and the current ripple are small. The better anti-lightning stroke surge capability is achieved. The better silicon controlled rectifier light modulation compatibility is achieved. The integration is easy to implement.