Daikin Industries, Ltd.

Keiichi Yoshisaka

Keisuke Shimatani

Masafumi Hashimoto

Masakazu Katou

Ryou Nakamoto

Kiyoshi Shima

Masaharu Sogabe

Hisashi Sumida

Hirotaka Saruwatari

Mitsuhiko Yamamoto

Takeshi Kokura

Kouji Uchida

Toshinori Ushio

Masaaki Yokoi

Naoya Shibata

An increase in a ripple voltage of a capacitor in a smoothing circuit is prevented to achieve a compact capacitor and cost reduction for capacitors in an electric power supply circuit which performs PAM control using a switching element. An electric power supply circuit includes a bridge circuit for rectifying alternating current power, a smoothing circuit which has two capacitors serially connected to each other, and a PAM control section for turning a switching element on and off at a predetermined timing. The PAM control section includes a phase difference detection section which detects a phase shift of a PAM waveform based on a change in a voltage difference between the two capacitors, and a phase correction section which corrects the phase of the PAM waveform so that an input current has a sine waveform.

Electric power supply circuit and PAM control method for the same

The invention relates to a power conversion apparatus including a converter circuit and an inverter circuit. The invention allows more precise output control of the inverter circuit than a power conversion apparatus in which the output control is performed based on a current value only, thereby improving operation efficiency. A current sensor detects input current of the inverter circuit, and a voltage sensor detects input voltage of the inverter circuit. A power value calculator section in an inverter microcomputer obtains a power value based on the input current and the input voltage. The inverter microcomputer and the control microcomputer perform droop control of reducing the output of the inverter circuit to make the power value smaller than a predetermined power value.

Power conversion apparatus controlling output of inverter based on power value

An electric power supply circuit includes a switching element (S) for causing a short-circuit for output power of a diode bridge circuit (), a zero-cross detector section () for detecting a point at which an input voltage reaches a level equal to or lower than a reference level, a timer section () for starting a count upon the detection by the zero-cross detector section (), and a PAM waveform output section () for causing the switching element (S) to perform switching with a predetermined output timing so that a waveform of the input current is caused to approximate to a sine wave. The circuit further includes a correction section () for correcting, when a difference between a detection interval from detection to detection by the zero-cross detector section (), and an average value for detection intervals up to current detection occurs, an initial value of the count of the timer section () according to the difference.

Electric power supply circuit with PAM waveform correction

The power supply device according to the present invention converts alternating-current power into direct-current power, and supplies the direct-current power to a load. Further, the power supply device includes a buffer, a control section, a rectifier circuit, a smoothing circuit, and a switch. After a predetermined zero cross point is detected, the control section uses in common, over a predetermined period of the alternating-current power, predetermined parameters retained in the buffer in calculating a timing at which a PAM interrupt pulse is generated.

Power supply device

An electric power supply circuit includes a diode bridge circuit () for rectifying an alternating current, a switching element (S) for causing a short-circuit for output power of the diode bridge circuit (), and a PAM control section () for causing the switching element (S) to perform switching with a predetermined timing so that a waveform of an input current approximates to a sine wave. The PAM control section () outputs ON/OFF pulses so that five pulses are output for each zero-cross point and one of the five pulses located in center extends over the zero-cross point at any time.

Rectifier with PAM controller to force an input current to approximate a sine wave

An object of the present invention is to provide a technique capable of assembling a device in both of a first device performing a first function with a predetermined part and a second device performing a second function without a second part, and instructing each of the first and second functions. Determining means () determines the presence or absence of an electronic expansion valve () and gives the result to a central processing unit (). The central processing unit () allows a gate array () operate and instruct a first function including a function of performing communication between a communication network () and an indoor unit (). When there is no electronic expansion valve (EV), the determining means () sends a result of the determination result indicative of the absence to the central processing unit (). The central processing unit () instructs a second function of making the gate array () inoperative.

Function switching method, function switching apparatus, data storage method, data storage apparatus, device, and air conditioner

A transmission device is disclosed wherein a plurality of control units each having a transmitting/receiving block connected to one another through a positive signal line and a negative signal line, and bidirectional signal transmission is carried out with a predetermined polarity among the control units. The signal lines of the transmission device are connected to a power superposing source for applying a predetermined DC voltage to the signal lines and each of the control units include a signal switch connected to the transmitting/receiving block for inverting and switching a transmission signal sent or received by the transmitting/receiving block, and a polarity judging device adapted to supply a homopolar signal when the potential of the positive signal line is higher than the potential of the negative signal line, and adapted to supply a heteropolar signal when the potential of the positive signal line is lower than the potential of the negative signal line. The control unit further includes a changeover control adapted to supply a switching signal to the signal switch such that the signal switch inverts and switches the transmission signal, when the polarity judging device supplies a heteropolar signal.

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Osaka, Japan

Keiichi Yoshisaka