Daikin Industries, Ltd.

Sumio Kagimura

Hiroshi Doumae

Hirotaka Doi

Toshiaki Sato

Keito Kotera

Shinichi Ishizeki

Masafumi Hashimoto

Hiroshi Dohmae

Nobuyasu Hiraoka

Michiya Takezoe

Takuji Koyama

Masahiro Yamamoto

Kenichi Sakakibara

Reiji Kawashima

Satoshi Yagi

Motonobu Ikeda

Toshiaki Satou

Yoshitsugu Koyama

Shuuji Genda

Tooru Masuda

Isao Tanatsugu

Hidehiro Ishii

An inverter driver of an air conditioner drives an inverter of an actuator that actuates the air conditioner. The inverter driver includes a drive circuit outputting a drive signal to the inverter, a microcomputer controlling the drive circuit, a first mechanical relay connected to the drive circuit, and an inverter control power supply continually supplying power to the microcomputer. The first mechanical relay is capable of cutting off an inverter drive power supply of the drive circuit or cutting off the drive signal of the drive circuit. The first mechanical relay cuts off the inverter drive power supply of the drive circuit or the drive signal of the drive circuit when an abnormality in the air conditioner has been sensed and stopping the driving of the actuator has been requested.

Inverter driver of air conditioner

An inverter apparatus variably controls an operation frequency of an electric motor provided in a refrigerating device, and includes: a printed wiring board; a power device attached to one surface of the printed wiring board, the power device including a converter circuit and an inverter circuit; a reactor arranged on a side of the one surface of the printed wiring board, at least a part of the reactor being arranged within a plane projection area of the printed wiring board; and a cooler for cooling the power device and the reactor, the cooler being arranged such that the power device and the reactor are interposed between the cooler and the printed wiring board.

Inverter apparatus

An inverter device uses an inverter to convert DC voltage supplied from a rectifying component to AC voltage and applies the AC voltage to an inductive load. The inverter device includes a shunt resistor provided on a direct-current link interconnecting the rectifying component and the inverter, a first terminal passing current to the shunt resistor, a second terminal to which the current from the shunt resistor flows, and a printed board having a conductive pattern with first and second conductive pattern components joining the shunt resistor and the first and second terminals, respectively. The first conductive pattern component includes a first central region connecting right and left side ends of the shunt resistor to right and left side ends of the first terminal, and first right and left side protruding regions. A ratio of areas of the first left and right side protruding regions is 0.6 to 1.6.

Inverter device having shunt resistor and printed board with conductive pattern component joining shunt resistor and terminal

A converter receives input of an AC voltage, converts the AC voltage into a DC voltage, and applies the DC voltage between a first power line on a positive electrode side and a second power line on a negative electrode side. A snubber circuit has a capacitor provided between the first and the second power lines, and a diode connected in series with the capacitor between the first and the second power lines, and including an anode on a side close to the first power line on the positive electrode side in a series path with the capacitor. An inverter converts the DC voltage into an AC voltage, and applies the AC voltage to an inductive load. An inverter-side current detection unit detects a current that flows through the first power line on the positive electrode side or the second power line on the negative electrode side between the inverter and the snubber circuit.

Indirect matrix converter

A reverse recovery current prevention device includes a full wave rectifier having a plurality of diodes, first and second diodes, a switch part and a switch control unit. The full wave rectifier rectifies a power source voltage from an alternating current power source inputted into first and second input terminals. The first and second diodes have anode terminals connected to the first and second input terminals, respectively. The switch part opens or shorts an electrical circuit between a negative-side output terminal of the full wave rectifier and each cathode terminal of the first and second diodes. The switch control unit prohibits the switch part from shorting the electrical circuit between the negative-side output terminal and each of the cathode terminals when a voltage between the negative-side output terminal and each of the cathode terminals is at or above a threshold.

Reverse recovery current prevention device and motor driving apparatus

A connecting member such as a terminal base is used in connection with a printed circuit board unit in which circuit elements such as a power module are mounted on a printed circuit board. The connecting member connects the circuit element of an electrical circuit including the printed circuit board, to an electrical wire. The connecting member includes a terminal connecting section to be directly connected to terminal pins of the circuit element; a wire connecting section to be connected to the electrical wire; and attachment sections for attaching the connecting member to the printed circuit board.

Connecting member of electrical circuit

A voltage smoothing circuit is configured to smooth a voltage outputted from a power supply portion. The voltage smoothing circuit includes first and second smoothing capacitors, a first balancing resistor, and a second conduction regulating portion. The first smoothing capacitor and the second smoothing capacitor are connected in series to each other and are connected in parallel to the power supply portion. The first balancing resistor is connected in parallel to the first smoothing capacitor. The second conduction regulating portion is connected on a current path in parallel with the second smoothing capacitor and conducts current in one direction on the current path in a case where a voltage equal to or greater than a second predetermined voltage has been applied.

Voltage smoothing circuit for smoothing voltage from power supply

A circuit board unit includes a printed circuit board and a terminal block mounted on the printed circuit board and connecting a power module and an electrical wire together. The terminal block includes a terminal connection part to be directly connected to the power module, and a wire connection part to be connected to the electrical wire. In the printed circuit board, a hole having an orthographic projection area larger than that of the terminal connection part as viewed in plane is formed. The terminal connection part is positioned below or above the hole of the printed circuit board.

Circuit board unit

A fan control system includes a first fan, a second fan that is adjacent to the first fan, a first motor that is configured to rotate the first fan, a second motor that is configured to rotate the second fan, and a control unit. The control unit is configured to control the rotational speeds of the first motor and the second motor, and to decrease the rotational speeds of both the first motor and the second motor when the rotational speed of the first motor must be decreased.

Fan control system and air conditioner that includes the same

A fan control system includes a first fan, a second fan adjacent to the first fan, a first motor that rotates the first fan, a second motor that rotates the second fan, and a control unit. The control unit controls the rotational speeds of the first motor and the second motor. The control unit decreases the rotational speed of the first motor and increases/decreases the rotational speed of the second motor when the rotational speed of the first motor must be decreased. The control unit can decrease the rotational speed of the second motor when the rotational speed of the first motor whose rotational speed has been decreased is lower than a prescribed rotational speed, and increase the rotational speed of the second motor when the rotational speed of the first motor whose rotational speed has been decreased is higher than the prescribed rotational speed.

A fan control system includes first and second adjacent fans, first and second motors configured to rotate the first and second fans, and a control unit configured to control rotational speeds of the first and second motors in order to control rotational speeds of the first and second fans. The first and second motors are energized such that the rotational speeds of the first and second fans reach target rotational speeds prior to increasing the rotational speeds of the first and second fans to required rotational speeds. The target rotational speeds are lower than the required rotational speeds. The first and second motors are energized such that the rotational speeds of the first and second fans reach the required rotational speeds after the rotational speeds of the first and second fans reach the target rotational speeds.

Multiple fan speed control system for preventing overload at start-up

A zero-phase current is outputted by detecting a ground-fault current with a zero-phase-sequence current transformer. A circuit having an open collector output operates when the voltage of the zero-phase current exceeds a positive side threshold value or it falls below a negative side threshold value to discharge a capacitor. When the inter-plate voltage of the capacitor falls below a threshold value voltage, a controlling means detects electric leakage to transmit that to a control unit of an air conditioner.

Earth leakage detection circuit

A noise filter eliminates noise generated by a noise generating source in an outdoor unit in an air conditioner. Power is supplied from a power source to an indoor unit via the outdoor unit. A choke coil is formed by winding power source lines and indoor/outdoor lines inter unit lines around a common magnetic body. The number of turns of the power source lines and that of the indoor/outdoor lines are preferably set so as to be almost proportional to their impedances. Due to this arrangement, noises of the lines can be cancelled while maintaining balance of influences on the magnetic field of the choke coil.

Noise filter, outdoor unit and air conditioner

A capacitor-input type three-phase rectification circuit comprises a three-phase AC power supply (), a diode rectifier circuit (), and a low-frequency filter connected between the three-phase AC power supply () and the diode rectification circuitry (), the low frequency filter consisting of AC reactors ()()() and &#x394;-connection or Y-connection capacitors ()()(), so that higher harmonic currents are reduced to be equal to or less than standard values, and that lowering in input power factor and lowering in DC voltage are prevented from occurrence.

Growing community of inventors

Sakai, Japan

Sumio Kagimura