An active filter for reducing the common mode current in a pulse width modulated drive circuit driving a load, said drive circuit comprising an a-c source, a rectifier connected to said a-c source and producing a rectified output voltage connected to a positive d-c bus and a negative d-c bus, a PWM inverter having input terminals coupled to said positive d-c bus and negative d-c bus and having a controlled a-c output, a load driven by said a-c output of said PWM inverter, a ground wire extending from said load, and a current sensor for measuring the common mode current in said drive circuit, said current sensor producing an output current related to said common mode current; said active filter comprising a first and second transistor, each having first and second main electrodes and a control electrode, and an amplifier circuit driving said transistors; said first electrode of said first and second transistor coupled to a common node, said second electrodes of said first and second transistors being coupled to said positive d-c bus and said negative d-c respectively; said amplifier circuit having an input coupled to said output of said current sensor and having an output connected to said control electrodes; and a d-c isolating capacitor connecting said common node of said first electrode of said first and second transistors to said ground wire; and wherein said current sensor is a current transformer having a primary winding connected in series with said ground wire and a secondary winding connected as the signal input to the amplifier circuit.

Active filter for reduction of common mode current

Apparatus and methods are provided for setting a clock in an appliance. The method includes the steps of initiating a telephone connection with a remote site, downloading over the telephone connection a first sequence of commands for setting the clock in the appliance, and storing the first sequence of commands in a memory in the remote controller. The method further includes the steps of entering a single command into the remote controller to set the clock in the appliance to be equal to a second clock in the remote controller, processing the single command in the remote controller to insert a time read from the second clock in the remote controller into the first sequence of commands for setting the clock in the appliance to form a sequence of time commands, and transmitting the sequence of time commands from the remote controller to set the first clock in the appliance. Another method is provided for initializing settings in an appliance. The method includes the steps of initiating a telephone connection with a remote site, downloading over the telephone connection a first sequence of commands for initializing settings in the appliance, and storing the first sequence of commands in a memory in the remote controller. The method further comprises the steps of entering a single command into the remote controller to initialize settings in the appliance, processing the single command in the remote controller to transmit the first sequence of commands from the remote controller to initialize settings in the appliance.

Apparatus and methods for providing initializing settings to an appliance

A motor drive and a choke therefor are disclosed, wherein the choke comprises a magnetic core with an inner leg and two outer legs, and four coils, which may be connected in DC current paths in the motor drive. First and second differential coils are wound around first and second outer legs, respectively; and first and second common-mode coils are wound around the inner leg of the choke. The first and second differential coils smooth the DC current on a DC bus in the motor drive, and the first and second common-mode coils suppress common-mode voltages in the motor drive. Also disclosed is a method for suppressing common-mode voltages in a motor drive.

Integrated DC link choke and method for suppressing common-mode voltage in a motor drive

The present invention is an inverter for a portable refrigerator. The inverter includes a square wave generator operable by a DC voltage source. A timer is also included which, in conjunction with the square wave generator, provides a multiple phase waveform for operating a compressor motor. For conventional three winding compressor motors, the inverter provides a six-step waveform for operation of the portable refrigerator. The inverter can also drive the motor using either a first or second DC voltage level, by minor changes in the inverter and using either a wye or delta winding configuration. The inverter also includes a protection circuit which protects against locked rotor and overload current conditions, as well as a shut-off circuit to guard against operating at low speeds and completely draining the battery.

Protection circuit in inverter for refrigerators

An internal AC adapter which incorporates a space efficient EMI filter is positioned within a main chassis portion of a portable personal computer having at least one energy-demanding component also positioned within the main chassis portion. The internal AC adapter, which converts alternating current received from an alternating current main to direct current for transmission to the energy-demanding components, includes a first connector for electrically connecting the internal AC adapter to the alternating current main, a bridge rectifier circuit having an AC input side electrically connected to the first connector and a DC output side and a space efficient electromagnetic interference filter having an input side electrically connected to the DC output side of the bridge rectifier circuit and an output side. The bridge rectifier circuit converts alternating current received from the first connector to direct current for transmission to the electromagnetic interference filter. In turn, the electromagnetic interference filter includes at least one capacitative element for filtering noise from the direct current transmitted thereto by the bridge rectifier circuit. The filtered direct current is then transmitted to the energy-demanding components electrically connected to the output side of the electromagnetic interference filter. By placing the electromagnetic interference filter on the DC output side of the bridge rectifier circuit, reduced size capacitors such as a multilayer ceramic capacitor may be used as the capacitative element.

Portable computer having built-in AC adapter incorporating a space efficient electromagnetic interference filter

A device for reducing the leakage noise of a power converter having a rectifier circuit connected to an alternating current power source and an inverter circuit connected to the rectifier circuit has a first noise filter, with a plurality of inductors and capacitors, and which is coupled between the alternating current power source and the rectifier circuit; and a second noise filter, with a plurality of inductors and capacitors, and which is coupled between the rectifier circuit and the inverter circuit.

Device for reducing the leakage noise of a power converter

A wireless remote control system has a hold-type wireless remote controller and a fixedly mounted main controller. When the wireless remote controller sets an operation time of a controlled object, it sends to the main controller a first code representative of a setting time corresponding to a difference between the operation time and a current time. Upon reception of the first code, the main controller sets the setting time at its timer. When a current time becomes the operation time, the wireless remote controller transmits a second code for operating the controlled object. If the main controller can receive the second code, the controlled object can be operated in response to the received second code. If on the other hand the main controller cannot receive the second code, the controlled object is operated by a time-up signal of the time in the main controller.

Wireless remote control system

PROBLEM TO BE SOLVED: To providing a refrigerating unit for a refrigerated vehicle for improving operation efficiency by reducing a heat loss from a refrigerant pipe, reducing cost by reducing a refrigerant encapsulated quantity, and largely reducing a work burden in manufacture, by shortening the length of the refrigerant pipe. SOLUTION: This unit is constituted so as to convert output of a converter part 60 into an alternating current by an inverter part 40, by arranging the converter part 60 in a lower part of the refrigerated vehicle 1 and in the vicinity of a generator 51. A compressor 31 operated by the output of this inverter part 40 is arranged above a cab 2, and a condenser 32 is arranged above the cab 2. COPYRIGHT: (C)2005,JPO&NCIPI

Refrigerating unit for refrigerated vehicle

PROBLEM TO BE SOLVED: To provide a vehicle storage battery unit, an automobile or a chill car with an excellent safety capable of previously preventing an electric shock by a connector while realizing an enhancement of a workability by adopting the connector. SOLUTION: A plurality of storage batteries 63 are stored in a first box 61 and a connector B for carrying out a connection/disconnection of the respective storage battery 63 to an external circuit for charging/discharging is provided on an outer periphery surface of the box 61. A second box 62 is provided on a side part of the box 61 and a relay 45 is provided in the box 62. The relay 45 is energized by an energization voltage inputted through connectors A, B accompanying with a connection of the connector A (external circuit) to the connector B to form an energization passage between the connector B and the respective storage battery 63.

Yuichi Ide

Papers

Device for reducing the leakage noise of a power converter

Wireless remote control system

Refrigerating unit for refrigerated vehicle

Vehicle storage battery unit, automobile and chill car