Daikin Industries, Ltd.

Tamura Corporation

Motonobu Ikeda

Satoshi Yagi

Masahide Fujiwara

Shinichi Ishizeki

Hiroshi Doumae

Hirohito Maeda

Keisuke Shimatani

Masafumi Hashimoto

Kentarou Taoka

Junichi Teraki

Masanobu Kita

Akihiko Oguri

Hideaki Tanaka

Shin Higashiyama

Sumio Kagimura

Hirotaka Doi

Ryousuke Yamamoto

Hiroshi Dohmae

Mario Hayashi

Michiya Takezoe

Shunichi Uenaka

Kentaroh Taoka

Masaki Okauchi

Shinya Ohtsuki

Shingo Ohnishi

Shinichirou Nomura

Hiroki Imai

Yoshitaka Shimaya

Iwao Toyama

Hiroyuki Kondou

Yuusuke Kishiwaki

A preheater for a compressor that is capable of heating a lubricant oil efficiently with smaller power is provided. A preheater for a compressor includes: a capacitive oil surface sensor that is provided at a compressor used in a refrigerating cycle, and detects an oil surface of a lubricant oil A in the compressor; and a power supply unit that applies high-frequency voltage to the oil surface sensor.

Preheater for compressor

A reactor is provided. The reactor includes a coil and a terminal block that is fixed to conductor wires that led out from both ends in a winding core direction of the coil. The terminal block includes an input-side terminal block that is fixed to an input-side conductor wire that leads out from one end of the coil, and an output-side terminal block that is fixed to an output-side conductor wire that leads out from another end portion of the coil. The input-side terminal block and the output-side terminal block are disposed on different levels in the winding core direction based on lead-out positions in the winding core direction of the input-side conductor wire and the output-side conductor wire.

Reactor

A failure in the activation, of a motor, caused by external noise superimposed on an induced voltage is reduced. A detection circuit is connected to a connection node provided between an upper-arm switching element and a lower-arm switching element, and detects the induced voltage of a fan motor before activation. The switching controller activates the fan motor in accordance with a result of detection by the detection circuit. While the detection circuit detects the induced voltage, the switching controller performs switching control which involves alternately turning ON and OFF of the lower-arm switching element.

Power conversion device

A refrigeration device includes a high-voltage electrical parts group having reactors and cooled elements, a low-voltage electrical parts group, a printed wiring board with the electrical parts groups mounted, and a refrigerant jacket that uses refrigerant flowing through the refrigerant circuit to cool the cooled elements. The high-voltage electrical parts group form an interleaved power supply circuit. The cooled elements are placed in an order conforming to a power supply path of the power supply circuit. The power supply circuit has a rectifier circuit, a power factor improvement circuit, smoothing capacitors, and an inverter circuit. The power factor improvement circuit has the reactors connected to each other in parallel and diodes and switching elements serving as the cooled elements connected to each of the reactors. The reactors are placed on an opposite side of the smoothing capacitors, with the diodes and the switching elements sandwiched in between.

Refrigeration device

Malfunctions of a switching device included in a power factor corrector are reduced when an instantaneous voltage drop or an instantaneous power failure occurs. If the instantaneous voltage drop or the instantaneous power failure occurs in an AC power source while the power factor corrector is performing a power factor correction operation by boosting an input voltage, an instantaneous power failure controller turns off the switching device included in the power factor corrector so that the power factor correction operation stops. When the commercial power source recovers, too, the power factor corrector suspends the power factor correction operation.

Power converter and air conditioner

In a refrigeration apparatus, a main surface of a printed wiring board has a heavy electric region, which is a region in the lower part of the printed wiring board where a heavy electric component group is disposed, and a light electric region, which is a region positioned above the heavy electric region, where a light electric component group is disposed. A refrigerant jacket contacts a power device which is disposed in the heavy electric region. A liquid pipe of the refrigerant pipe includes a portion that extends upwards towards the refrigerant jacket, and a cooling portion contacts the refrigerant jacket.

Refrigeration apparatus

A refrigerant jacket includes a refrigerant cooling member, a cover member and a strength member. The cooling member is constructed of aluminum or aluminum alloy that thermally contacts a heat emitting electrical part, and has a groove portion. A refrigerant tube of a refrigerant circuit fits into the groove portion. The cover member covers the refrigerant cooling member in a state where the refrigerant tube has been fitted into the groove portion. The strength member is higher in strength than the cooling member, and is fixed to the cooling member. The cover member has a cover-side through hole opposing the strength member. The strength member has a cover member fixing screw hole opposing the cover-side through hole. The cover member is fixed to the strength member by a cover member fixing screw that passes through the cover-side through hole and screws into threads of the cover member fixing screw hole.

Refrigerant jacket and air conditioning apparatus equipped therewith

A facing surface of a refrigerant jacket includes a contact portion which contacts a device main body, a first recessed portion which faces a first lead section and secures an insulation distance to the first lead section due to being positioned further away from a power device than the contact portion, and a second recessed portion which faces the second lead section and secures an insulation distance to the second lead section due to being positioned further away from the power device than the contact portion.

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 motor current detecting device includes a first wire, an instantaneous current detecting unit, an average electric current detecting unit, and a calculation unit. The first wire is configured and arranged to carry flow of a motor current that has been passed through a motor and a drive current that has been passed through a motor drive unit to drive the motor. The instantaneous current detecting unit is configured and arranged to detect an instantaneous value for a sum of the motor current and the drive current flowing on the first wire. The average electric current detecting unit is configured and arranged to detect an average value of the sum of the motor current and the drive current flowing on the first wire. The calculation unit is configured to calculate the motor current on the basis of the instantaneous value and the average value.

Motor current detecting device and air conditioning apparatus

In an air conditioner, an auxiliary circuit configured to prevent a current flow in a power supply wiring in an operation stop period and to determine whether to adapt an outdoor unit to a unit that is able to transition to a standby mode, is provided on the power supply wiring.

Air conditioner

The current-sensing circuit () includes a shunt resistor (R) connected in series with a path of current from an inverter (), an operational amplifier () amplifying voltage across both ends of this shunt resistor (R) with a predetermined gain, a low-pass filter () averaging output voltage of this operational amplifier (), and an arithmetic unit () calculating the current flowing through the path based on output voltage of the low-pass filter (). The supply voltage of the operational amplifier () is set higher than the supply voltage of the arithmetic unit (). The output voltage of the operational amplifier () is averaged at the low-pass filter () to a lower value than the supply voltage of the arithmetic unit ().

Current-sensing circuit and air-conditioning device provided therewith

Triggered by a position detection sensor detecting that a rotor is positioned at any one of K predetermined electrical angles, for example, 60&#xb0;, 180&#xb0;, and 300&#xb0;, a voltage vector to be given to a motor is updated. When, for example, the rotation frequency is equal to or higher than a specified value, the predetermined electrical angles is changed into M, for example, into one angle of 60&#xb0;.

Motor control method, motor control device, fan device, compressor, and pump device

A current detecting device includes a current leveling unit, a first wire and a current detecting unit. The current leveling unit is configured to level a drive current that is passed through a motor drive unit to drive a motor. The first wire is configured and arranged to carry flow of a motor current that has been passed through the motor and the drive current that has been leveled by the current leveling unit. The current detecting unit is configured to detect a sum of the motor current flowing on the first wire and the drive current that has been leveled flowing on the first wire.

Current detecting device, air conditioning apparatus, correction constant calculating system and correction constant calculating method

Two current threshold values are adopted, which are larger than the upper limit of current of an operating region. When a rotating speed is smaller than a speed threshold value, the current threshold value is adopted as a criterion to judge whether an input current to an inverter is abnormal, and when the rotating speed Rot is larger than that, the other current threshold value is adopted as the criterion.

Growing community of inventors

Sakai, Japan

Motonobu Ikeda