Sanken Electric Co., Ltd.

Other

Osamu Ohtake

Ryuichi Furukoshi

Takeki Sugahara

Mitsutomo Yoshinaga

Toshihiro Nakano

Junichi Takada

Koki Imai

Shinji Aso

Youichi Terasawa

An integrated circuit for digitally controlling a critical mode power factor correction (PFC) circuit according to one or more embodiments may include: an output voltage detector and a switching current detector; an A/D converter and a sample and hold circuit that perform analog-to-digital conversion of an output signal of the output voltage detector and the switching current detector; an arithmetic unit that performs calculation based on the output signal of the A/D converter and generates a pulse signal to turn on/off a switching device of the PFC circuit; a correction value calculator that calculates, based on a switching frequency of the PFC circuit, a correction value for linearly correcting the output signal of the A/D converter; and an adder that adds the correction value to the output signal of the A/D converter to correct the output signal of the A/D converter and inputs the corrected output signal to the arithmetic unit.

Integrated circuit and method of digitally controling critical mode power factor correction circuit

A method may include detecting an output voltage of the output smoothing capacitor in the bridgeless interleaved power factor correction circuit of a critical mode, comparing the detected output voltage with a reference voltage, controlling the first and the second half-bridge circuits included in the bridgeless interleaved power factor correction circuit of the critical mode to be on and off based on an error signal between the output voltage and the predetermined reference voltage, measuring ON time of a synchronous rectification switch operation of the first half-bridge circuit by measuring a time period between OFF timing of an active switch of the first half-bridge circuit and output of a differentiation signal generated by a differentiation circuit included in the bridgeless interleaved power factor correction circuit of the critical mode; and assigning the measured time to next ON time of the synchronous rectification switch operation of the second half-bridge circuit.

Integrated circuit and method of synchronous rectification control of bridgeless power factor correction circuit

Embodiments of this disclosure provide a control apparatus and method for a current resonance circuit and a current resonance power supply. The control method includes: performing integration on a resonance current of the current resonance circuit or a switching current of one or more switching elements to generate an integration signal; generating a feedback signal of the current resonance circuit; comparing the integration signal with the feedback signal, and generating a measurement signal according to a comparison result; performing digital filtering on the measurement signal; and according to the measurement signal after filtering, generating a pulse width modulation signal controlling the switching elements.

Control apparatus and method for current resonance circuit and current resonance power supply

A power conversion device according to one or more embodiments may include: a microcomputer; and an output circuit controlled by the microcomputer, including an output unit that converts an input power into a predetermined power and outputs the predetermined power, an internal power source that supplies a power source to the microcomputer, a driver that drives the output unit by a signal from the microcomputer, and a microcomputer stop transition unit that, when an operation of the power conversion device is stopped, outputs a microcomputer stop signal to the microcomputer and causes an operation of the microcomputer to transition to a stop state. In one or more embodiments, after the microcomputer stop transition unit causes the operation of the microcomputer to transition to a stop state, the microcomputer or the output circuit may stop an output of the internal power source.

Power conversion device and control circuit

An alternating-current voltage detection circuit for detecting an alternating-current voltage from an alternating-current power source according to one or more embodiments may include: a rectification circuit that performs full-wave rectification on an alternating-current voltage from the alternating-current power source and supplies a rectified output to a load; a series circuit comprising a first capacitor and a second capacitor electrically connected in series between one end of the alternating-current power source and the ground terminal of the rectification element; a discharge circuit that causes the second capacitor to discharge such that an absolute value of dv/dt voltage does not reach a predetermined voltage, wherein the second capacitor is electrically connected to the ground terminal side of the rectification element; and a predetermined period generator that outputs a signal after an elapse of a predetermined period of time from stoppage of a discharge operation of the discharge circuit.

Alternating-current voltage detection circuit

A device and method for calculating switching time. The device includes: a digital calculator configured to calculate a next on time according to an output voltage signal and an inductor current signal detected during an on period of a switching element and calculate a next off time according to the next on time, an input voltage signal and the output voltage signal; and a signal generator configured to generate a pulse width modulation signal for controlling the switching element, according to the next on time and the next off time. Therefore, a digital controlling manner is provided, not only the number of components and the cost are decreased, but also detection accuracy is improved with a simple structure.

Device and method for calculating switching time

A power conversion device may include: a microcomputer; and an output circuit controlled by the microcomputer, including an output unit that converts an input power into a predetermined power and outputs the predetermined power, an internal power source that supplies a power source to the microcomputer, a driver that drives the output unit by a signal from the microcomputer, and a microcomputer stop transition unit that, when an operation of the power conversion device is stopped, outputs a microcomputer stop signal to the microcomputer and causes an operation of the microcomputer to transition to a stop state. In one or more embodiments, after the microcomputer stop transition unit causes the operation of the microcomputer to transition to a stop state, the microcomputer or the output circuit may stop an output of the internal power source.

Power conversion device and control circuit including stop transitioning to stop state

A capacitor discharge circuit according to one or more embodiments includes a capacitor connected in parallel to an alternating-current power source; a rectification element; a first discharge circuit that includes a first diode and a second diode, and causes the capacitor to discharge; a first series circuit including a first capacitor and a second capacitor connected in series between one end of the alternating-current power source and a ground terminal of the rectification element; a second discharge circuit that causes the second capacitor to discharge such that an absolute value of voltage across opposite ends of the second capacitor does not reach a predetermined voltage; and a predetermined period generator that actuates the first discharge circuit after an elapse of a predetermined period of time from stoppage of a discharge operation of the second discharge circuit.

Capacitor discharge circuit

A first switch and a second switch connected in series to both terminals of a DC power source. A signal generation circuit generates a feedback signal based on the DC voltage detected by the voltage detection circuit, and outputs the feedback signal, the feedback signal for turning the first and second switches on and off. A burst oscillation circuit that generates a burst oscillation signal based on a feedback signal and turns the first switch element and the second switch element on and off based on the burst oscillation signal when the standby state is detected. The burst oscillation circuit comprises a capacitor and a rapid charge circuit. When this device returns from standby state to normal state, the rapid charging circuit charges the capacitor after the feedback signal exceeds the cancellation threshold voltage.

Current resonant power supply device

A burst oscillation circuit operates switches in a burst oscillation mode based on a feedback signal. A first burst operation cancellation threshold voltage comparator compares a first burst operation cancellation threshold voltage set higher than a voltage of the feedback signal that a load current reaches the standby threshold and a voltage of the feedback signal, and outputs a first output signal. A second burst operation cancellation threshold voltage comparator compares a second burst operation cancellation threshold voltage set lower than the voltage of the feedback signal that the load current reaches the standby threshold and higher than a voltage of the feedback signal during a non-oscillation period of the burst oscillation operation and the voltage of the feedback signal and outputs a second output signal. A standby cancellation circuit generates a standby cancel signal to cancel the standby state based on the first and second output signal.

The present invention includes: a series circuit formed of a reactor Lr, a primary winding P of a transformer T, and a capacitor C; a full-wave rectifier/smoothing circuit D, D, Cconfigured to perform full-wave rectification and smoothing on a voltage generated in a secondary winding S of the transformer thereby to extract a DC voltage; a control circuit FFconfigured to set a first ON time of the first switch element Qand a second ON time of the second switch element Qto the same predetermined time thereby to alternately turn on and off the first switch element and the second switch element; and a first ON time controller I, Cconfigured to set one of the first ON time and the second ON time, shorter than the predetermined time, under light-load conditions, based on the DC voltage detected by a detector

Current resonance type power supply device

The present invention includes: a series circuit formed of a reactor Lr, a primary winding P of a transformer T, and a capacitor C; a full-wave rectifier/smoothing circuit D, D, Cconfigured to perform full-wave rectification and smoothing on a voltage generated in a secondary winding S of the transformer thereby to extract a DC voltage; a control circuit FFconfigured to set a first ON time of the first switch element Qand a second ON time of the second switch element Qto the same predetermined time thereby to alternately turn on and off the first switch element and the second switch element; and a first ON time controller I, I, Cconfigured to set one of the first ON time and the second ON time, shorter than the predetermined time, under light-load conditions, based on the DC voltage detected by a detector

Disclosed is a switching control circuit for performing an ON-OFF control of a switching element. The switching control circuit includes a first external terminal; a second external terminal; a passive element connected between the first external terminal and the second external terminal; and a function setting circuit, which performs a function setting based on a constant of the passive element. An electric potential at the first external terminal and an electric potential at the second external terminal are controlled.

Switching control circuit and switching power-supply device

A power factor correction circuit includes: an ON time setting unit, which sets an ON time period of the switching element based on the output voltage; a bottom detection unit, which detects a bottom when a voltage between both ends of the switching element is damped-oscillated while the switching element is being turned off; and a bottom skip controller, which causes the switching element to perform quasi-resonant if a ratio of the ON time period set by the ON time setting unit to a regeneration period of a current flowing through the reactor while the switching element is being turned off is less than or equal to a predetermined value, and turns on the switching element at a timing when a next bottom is reached after one bottom skipped from an initial bottom if the ratio is greater than the predetermined value.

Growing community of inventors

Niiza, Japan

Osamu Ohtake