Abstract: An HVAC/R system is configured with a variable frequency drive power supply which provides power to each of a compressor, a condenser fan, and a blower. In some embodiments, the compressor has a three-phase motor and the condenser fan has a single-phase motor.

Abstract: An output buffer is provided, to which first and second input signals are applied and that delivers an output signal. The output buffer includes a second offset switching stage installed in cascade downstream from a first switching stage. The second offset switching stage generates control points shifted in time with respect to memory points.

Abstract: A method is provided for using a temporary power source to transfer a power bus from a first power source to a second power source. The first power source operates at a first electrical frequency, and the second power source operates at a second electrical frequency that is different from the first electrical frequency. The method includes adjusting the output frequency of the temporary power source to match the first electrical frequency and supplying power to the power bus from the temporary power source. The method also includes disconnecting the first power source from the power bus. The method further includes adjusting the output frequency of the temporary power source to match the second electrical frequency. The method further includes coupling the second power source to the power bus.

Abstract: A control part for causing transmission of a remote control signal from a transmission part according to a resistance of a pressure-sensitive conductive contact part causes periodic transmission of a repetition signal, when the resistance of the pressure-sensitive conductive contact part is kept constant. Thus, when an operating body is continuously held down with a constant force and the resistance of the pressure-sensitive conductive contact part is kept constant, the control part causes periodic transmission of the repetition signal having a smaller number of pulses, at predetermined intervals. With such an operation, a remote control transmitter capable of reducing power consumption is provided.

Abstract: Apparatus, systems, and methods for reducing resonance in a multiple inverter system are provided. One apparatus includes an inverter coupled to a decoupling element, wherein the inverter and the decoupling elements are couplable to a power source. A system includes a motor vehicle power source including first positive and negative terminals, and a plurality of inverters coupled to the power source. Each inverter includes a second positive terminal coupled to the first positive terminal and a second negative terminal coupled to the first negative terminal. A first inverter of the plurality of inverters includes a decoupling element coupled between the first positive terminal and the positive terminal of the first inverter. One method includes operating first and second inverters at different frequencies, and controlling the impedance of a decoupling element coupled between a power source and the first inverter based on the second inverter frequency.

Abstract: A railway power supply system and method for electrically powering an electrical device are provided. The electrical device is situated along a railway and is powered through an electrically conductive line generally used for carrying an electrical signal to a railway signaling device. The power supply system includes a power injector coupled to the line. The line is used for carrying a signal to the signaling device at a first frequency value for performing a signaling operation. The power injector is configured to introduce at the line a power signal for powering the electrical device. The injected power is at a second frequency value that is sufficiently spread apart from the first frequency value to avoid interference with the signaling operation of the railway signaling device. The power supply system further includes a power collector coupled to the line and to the electrical device for passing the signal for powering the electrical device.

Abstract: A circuit and method for detecting an operating transition of a mechanical apparatus driven by a hydraulic prime mover comprising a hydraulic pump driven by an electric motor, the operating transition causing a change in the force applied by the mechanical apparatus on the prime mover. A motor current sensing circuit is connected in a motor power supply circuit to provide a motor current signal representing motor current. A bandpass filter receives the motor current signal and provides a filtered motor current signal consisting essentially of motor current signal components in the frequency range from a lower frequency boundary greater than zero Hz to an upper frequency boundary below substantially all the motor noise frequencies. A comparison circuit compares the filtered motor current signal to a first selected threshold level and outputs a signal representing the occurrence of the operating transition when the filtered motor current signal exceeds the selected threshold level.

Abstract: A method and apparatus for distributing power in an electronic system including receiving a source power at a system power supply, converting the source power to a plurality of alternating current (AC) signals at multiple frequencies, and transmitting the plurality of AC signals at multiple frequencies to multiple voltage regulator modules (VRMs) in the electronic system.

Abstract: A fault tolerant isolation system providing fault tolerant electrical isolation between different components receiving power from separate power sources regardless of which of the power sources fails. One power source provides operating voltage to an isolation device, which is a transceiver, buffer, quick switch, etc. The other power source activates a transistor switch coupled to the output enable input of the isolation device, and a current limit device is provided between the output enable and power inputs of the isolation device. In this manner, failure of either power source disables the isolation device and therefore provides fault tolerant isolation between the devices on either side. In the preferred embodiment, the isolation device acts as a high impedance open switch if its power is removed thereby isolating the devices on either side.

Abstract: A three phase ripple control system for feeding a control signal onto each phase line employs an injection transformer having a primary winding and three secondary windings. A control signal generator is connected in circuit with the primary winding and serves to provide a signal thereto. A respective inductor is connected in series in each phase line and is connected in parallel with a respective one of the secondary windings. The inductors have a value of inductance arranged such that their impedance at line frequency is substantially smaller than the magnetizing impedance of the transformer. The secondary winding thereby introduce a common control signal onto each of the three phase lines.

Abstract: To prevent high-intensity-discharge (HID) lamps from extinguishing for prolonged periods due to a power interruption or an appreciable drop in line voltage, a rectifier-battery combination provides standby power for operating a high-frequency inverter. The output of the inverter connects to the HID lamps through impedance means which passes a greatly reduced high-frequency current as compared to the normal lamp operating current, in order to sustain the operation of the lamps at a very reduced power level. Upon restoration of the normal line voltage, the lamps again operate with normal power consumption. The same wiring can be used for both the normal lamp operating current and the high-frequency sustaining current or separate wiring systems can be used if desired. The high-frequency current can be supplied simultaneously with the normal operating current or the high-frequency current can be supplied only during periods of power interruption.