An electric working machine according to one aspect of the present disclosure comprises a motor, a rectifier circuit, a capacitor, a series switching element, a resistive element, a drive circuit, a peak voltage value acquirer, and a controller. The capacitor smooths power rectified by the rectifier circuit. The series switching element is coupled in series with the capacitor. The resistive element is coupled in parallel with the series switching element. The controller brings the series switching element into conduction in a case where AC power is inputted to the rectifier circuit and where a specified conducting condition based on a peak voltage value acquired by the peak voltage value acquirer is satisfied.

Device for operating an electric motor, comprising a detection unit for detecting zero-crossings and phase angles of applied phase-shifted sinusoidal voltage phases of a multi-phase power supply network; and a switching unit for connecting half-waves of the applied sinusoidal voltage phases through by means of semiconductor switches in accordance with switching patterns applied to the semiconductor switches, said patterns being synchronised with the detected phase angles and zero-crossings, to generate phase-shifted quasi-sinusoidal voltage phases which are applied directly to the electric motor.

Techniques involve controlling battery access on a utility vehicle. Such techniques involve monitoring status of input signals from a group comprising: a lithium battery system, a keyed switch, and a charging receptacle, comparing the status of the input signals to timeout settings stored in memory of the motion control system, initiating a timer based on comparison of the input signals to the timeout settings, and disconnecting at least one direct current (DC) path between a lithium battery interface and a power distribution interface of the utility vehicle in response to expiration of the timer. Such techniques further involve, after disconnecting, reconnecting the at least one DC current path between the lithium battery interface and the power distribution interface in response to a change in status of at least one of the input signals. Such techniques may be performed by a motion control system of the utility vehicle.

Controllers for controlling hybrid motor drive circuits configured to drive a motor are provided herein. A controller is configured to drive the motor using an inverter when a motor commanded frequency is not within a predetermined range of line input power frequencies, and couple line input power to an output of the inverter using a first switch device when the motor commanded frequency is within the predetermined range of line input power frequencies.

A vehicle control apparatus capable of protecting a pre-charge circuit is provided. When a voltage has entered an operating voltage range, a microcomputer determines whether a preset period has elapsed from then. Upon determining that the preset period has elapsed, the microcomputer starts initial check. To carry out the initial check, the microcomputer starts charging a capacitor for power supply stabilization of a drive circuit by turning on the pre-charge circuit and, when the charging of the capacitor is completed, turns on a power supply relay provided on a power supply line that connects between a battery and the drive circuit.

A theft deterring system includes a power tool with a motor connectable to a power source, a switch connected to the motor, a controller controlling to the switch for controlling an amount of power provided to the motor, and a state circuit having a memory for storing a state value. The controller activates the switch to provide power to the motor when the state value stored in the memory equals a desired value. The system may also include a tag programmer for changing the stored value.

Provided are an inverter device, which is capable of preventing a malfunction of the inverter device while reducing the number of interface wirings, and a method of controlling the inverter device. A communication terminal of a communication circuit having a function of communicating to/from a vehicle, an input terminal for a start signal for starting a control circuit, and a signal for holding the control circuit active even when the start signal is changed after the start of the control circuit are used. A drive prohibition signal issued from the vehicle is received through the same terminal as that for the start signal to unify terminals for the start signal and the drive prohibition signal, to thereby reduce the number of interface wirings.

A method of performing temperature-based diagnostics for motor starters within a physical grouping of motor starters is performed by determining a presently expected temperature operating range for each starter based on measuring operating temperatures of the starters; measuring their current draws, and evaluating the temperature and load draw data in light of compensation values assigned for the known power ratings of the starter and the starter's physical location within the grouping. With the presently expected temperature operating range of the starter determined, and the periodic monitoring of starter temperatures, when an individual starter's temperature exceeds its expected range, a diagnostic warning will be issued for that starter and/or for the control panel itself as a guide for preventative maintenance. Alternately, the warning may be issued for an unexpected temperature rise for a given rise in current draw, or for values exceeding an expected rate of temperature change.

Techniques control a utility vehicle. Such techniques involve storing electric power in a lithium battery of the utility vehicle. Such techniques further involve operating a motor controller of the utility vehicle in a normal mode in which the motor controller provides electric power from a lithium battery of the utility vehicle to an electric motor of the utility vehicle to turn one or more ground engaging members of the utility vehicle. Such techniques further involve, after operating the motor controller in the normal operating mode, operating the motor controller in a walkaway mode in which the motor controller configures the electric motor to provide braking torque.

A contactor includes: at least one moveable contact mounted on a contact carrier; at least one stationary contact mounted on a housing; an electromagnet arranged to cause the contact carrier to move relative to the housing between a first position and a second position, and thus to cause the at least one moveable contact to travel from a contacts open position to a contacts closed position with respect to the at least one stationary contact; a sensor coupled to one of the contact carrier and the housing and arranged to detect an intermediate position, in between the first position and the second position, at which the housing and the contact carrier are located at a given moment in time as the contact carrier moves relative to the housing between the first position and the second position; and a controller connected to receive the signals from the sensor.