An electric working machine in one aspect of the present disclosure includes: a motor; a driver to drive the motor; a first control circuit; and a second control circuit. The first control circuit controls the driver such that the motor rotates in a set rotation direction. The second control circuit is provided separately from the first control circuit. The second control circuit detects a rotation direction of the motor and performs an abnormality handling process to stop rotation of the motor in response to a situation where the detected rotation direction is reverse to the set rotation direction.

A control circuit is applied to a system provided with a rotary electric machine, a power converter electrically connected to a winding of the rotary electric machine, a power source, a cutoff switch provided on an electrical path that connects the power source and the power converter, and a storage unit. The control circuit is provided with a failure determination unit that determines whether a failure occurs in the system and a regeneration prevention unit that prevents a power regeneration, where a current flows from a rotary electric machine side towards a storage unit side, from occurring. In the case where the failure determination unit determines that a failure occurs in the system, the cutoff switch is turned OFF after the regeneration prevention unit prevents an occurrence of the power regeneration.

An apparatus for detecting a motor failure may include: a first motor failure detector configured to apply a reference voltage for failure detection to a motor, and then detect a changed voltage; a first motor power switch and a second motor power switch configured to switch both terminal voltages applied to drive the motor; a gate amplifier configured to apply a gate signal for controlling the turn on/off of the first and second motor power switches; and a controller configured to diagnose a failure of the motor controlled in one way, on the basis of voltages detected by the first and second motor power switches and the first motor failure detector, respectively.

Improved systems and methods for operating moveable architectural elements (e.g., furniture) are described. The system can include improved features implemented throughout various elements, including hardware elements, controller elements, and/or software elements. As one example, the system can feature the ability to map a characteristic load profile across a particular length of actuation and, if during operation a measured load exceeds the profile, adjust (e.g., stop) the system's motion. The system can also advantageously map its current draw to increase energy efficiency. In addition, the system can include a positioning system that enables it to automatically determine its position upon start up and during operation. In some implementations, the system includes multiple moveable elements (e.g., furniture items). In some cases, power is distributed to the moveable element(s) using a moveable power distribution module. Many other improvements and features are contemplated and described.

An electric working machine in one aspect of the present disclosure includes two or more circuits and a control circuit. The control circuit executes two or more diagnoses one by one in order. The diagnoses at least include a first diagnosis and a second diagnosis. The first diagnosis diagnoses a first circuit. The second diagnosis diagnoses a second circuit. The control circuit executes the first diagnosis or the second diagnosis at a first diagnosis timing. The control circuit executes the first diagnosis or the second diagnosis at a second diagnosis timing. The second diagnosis timing follows the first diagnosis timing.

Systems and methods for estimating electrical component degradation include a processor programmed to: compute a cumulative degradation value for an electrical system component of an electrical system based on an operating parameter of the electrical system component; and to compute a corrosion compensated cumulative degradation value for the electrical system component based on the cumulative degradation value and a corrosion rating of the electrical system.

A drive device of an elevator includes a frequency converter to be connected to a public AC supply network and an elevator motor. The frequency converter includes a network rectifier configured to be connected to the AC supply network, a motor bridge to be connected to the elevator motor and a DC intermediate circuit located between the network rectifier and the motor bridge. The motor bridge is controlled by a control circuit which feeds the motor bridge with control pulses to regulate the motor speed. The drive device further includes at least one drive prevention circuit connected between the control circuit and the motor bridge. The drive prevention circuit is configured to obtain a safety signal from an elevator safety circuit includes two separate safety input circuits each configured to be connected to the elevator safety circuit to receive a safety signal. Each of the safety input circuits is configured to interrupt the connection between the control circuit and the motor bridge in response to the safety signal status.

Provided is a semiconductor device comprising a high-side switching device, a low-side switching device, a high-side driver configured to turn on/off the high-side switching device, a low-side driver configured to turn on/off the low-side switching device, a high-side driving external terminal configured to supply a power supply voltage for driving the high-side driver, and a protection circuit section connected to the high-side driving external terminal. The high-side driver may include a reference potential terminal set to a reference potential of the high-side driver. The protection circuit section may be connected between the high-side driving external terminal and the reference potential terminal.

A chiller assembly is provided. The chiller assembly includes a compressor (102), a condenser (106), an expansion device and an evaporator (108) connected in a closed refrigerant circuit. The chiller assembly further includes a motor (104) connected to the compressor to power the compressor, and a variable speed drive (110) connected to the motor to power the motor. The variable speed drive is operable to provide a variable voltage to the motor and a variable frequency to power the motor. The variable speed drive includes multiple sensors and an input current estimator that determines an estimated RMS input current based on sensor data received from the sensors. The chiller assembly further includes a control panel to control operation of the variable speed drive.

A power tool includes a motor, a rectifier circuit, and a driver circuit. An input terminal of the rectifier circuit is connected to a power module, an output terminal is connected to a direct current bus, an input terminal of the driver circuit is connected to the direct current bus, an output terminal is connected to the motor, and a bus capacitor is connected between a high voltage terminal and a low voltage terminal of the direct current bus. A first protection circuit is connected to the input terminal of the rectifier circuit and a second protection circuit is connected in parallel to two terminals of the bus capacitor. The first protection circuit is configured to absorb an overvoltage signal on an input side of the rectifier circuit. The second protection circuit is configured to absorb an overvoltage signal of the direct current bus.