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

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.

A switching power source device can enhance the power factor by increasing the conduction angle of an input current in a wide input voltage range, while obviating the increase of size and the increase of cost thereof, and lower the switching loss by removing higher harmonic waves from the input current. The device includes at least first, second, and third series circuits constituted of a rectifying circuit, at least first and second primary windings, a plurality of diodes, a smoothing capacitor, and first and second switching elements. The device further includes an error amplifier, which outputs an error amplified signal, and a control circuit that performs a PWM control of the switching element in response to a first modulated wave that is generated based on an inverted and amplified waveform, which is the product of the error amplified signal and a full-wave rectified waveform of an AC input voltage, and performs a PWM control of the switching element in response to a second modulated wave that is generated based on the error amplified signal and the full-wave rectified waveform of the AC input voltage to alternately turn ON and OFF the both switching elements.

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 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.

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 present invention relates to the technical field of rectification circuits and capacitor filter circuits in AC-DC conversion, in particular to a circuit for improving the conduction angle of a rectifier bridge stack, including a first rectification circuit and a second rectification circuit, characterized in that the first rectification circuit An adjustment circuit is arranged between the circuit and the second sorting circuit, and the adjustment circuit is electrically connected to the first rectification circuit and the second rectification circuit respectively. The circuit in this scheme adds an adjustment circuit between the original independent two-way rectification circuit to increase the conduction time of the diode in the original rectification circuit, thereby increasing the conduction angle to reduce the inrush current, thereby prolonging the diode's life. service life. The circuit for improving the conduction angle of the rectifier bridge pile increases the conduction time of the rectifier diode in the capacitor filter circuit, increases the conduction angle, and thus prolongs the service life of the diode.

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.