An impact protection controller for an electric height-adjustable desk. The controller comprises an MCU, a motor drive circuit, a motor current sampling circuit, a current amplifier circuit, a Hall pulse generator, and a Hall filter. The MCU controls the motor drive circuit. A signal transmitted by the Hall pulse generator is sent to the MCU via the Hall filter. A motor current is sampled by the motor current sampling circuit, and the result is sent to the MCU via the current amplifier circuit to detect a change of the current. The controller further comprises a shock switch provided outside of and connected to the MCU, or provided inside of the MCU. The present invention combines current detection and shock detection to improve sensitivity and reliability of impact protection.

An apparatus can include an inverter to provide an output N-phase alternating-current to an external component. When N equals two, a phase of the N phases can include an upper gate and a lower gate. The apparatus can also include a current detector configured to detect a phase current magnitude of the output alternating current. The apparatus can also include a controller coupled to the current detector and to the inverter. The controller can generate a gate command for controlling a gate of the inverter. The controller can also determine a value for a current threshold less than a shutoff current threshold for the external component. The controller can provide a protection command to turn off the upper gate of a corresponding phase of the inverter responsive to detecting that the phase current magnitude is greater than the current threshold.

A motor driving device includes an inverter to supply an alternating current, a switch unit that switches the number of at least one permanent magnet synchronous motor to which the alternating current is supplied from the inverter, a detector to detect a detection value corresponding to the alternating current supplied to the at least one permanent magnet synchronous motor, and a control device to control the inverter and the switch unit. The control device sets an overcurrent interruption threshold value at a value based on the number. When the detection value is greater than or equal to the overcurrent interruption threshold value, the control device makes the inverter stop the supplying of the alternating current to the at least one permanent magnet synchronous motor.

Systems and methods for extracting motor operational state parameters from an electric motor for improved motor control and motor fault or failure detection are discussed. An exemplary system includes an excitation circuit to apply a drive voltage to an electric motor, and a processor circuit to measure a resulting winding current, extract a current waveform by oversampling the winding current in an entire PWM frame at a sampling rate higher than the PWM frequency, and fit the current waveform in the PWM period to a parametric model. The processor circuit can determine a motor operational state parameter using one or more of the applied drive voltage or the parametric model of the winding current.

A high-lift shielded permanent magnet multistage water pump includes a pump shell, a motor assembly and an impeller. The motor assembly includes a motor barrel, a stator, a rotor and a rotor shaft. The pump shell is sleeved on an outside of motor barrel. An upper and a lower connection base for fixing the motor barrel is provided in the pump shell. A waterway cavity is formed between the pump shell and motor barrel. An upper and a lower impeller cavities are respectively formed at an upper and a lower ends of the pump shell. The lower impeller cavity, water passing cavity and upper impeller cavity are in sequential fluid communication. Both ends of the rotor shaft with an axel provided on pass through the upper and the lower connection bases respectively. The impeller is a multistage structure and mounted on the axle at both ends respectively.

A direct-current power supply device includes a reactor, a bridge circuit that converts alternating-current voltage output from an alternating-current power supply, which is connected to the reactor, into direct-current voltage, a capacitor that smoothes the output voltage of the bridge circuit, a current detector that detects a first current flowing as an alternating current between the alternating-current power supply and the bridge circuit, a current detector that detects a second current flowing as a direct current between the bridge circuit and the capacitor, an overcurrent determination unit that determines on the basis of a detected first current value whether or not the first current is an overcurrent, and an overcurrent determination unit that determines on the basis of a detected second current value whether or not the second current is an overcurrent. The bridge circuit stops operating when a determination result of either the overcurrent determination unit or the overcurrent determination unit indicates an overcurrent.

A motor drive device of an embodiment includes a first drive circuit, a second drive circuit, a first detection circuit, a second detection circuit, a third detection circuit, a fourth detection circuit, and an output circuit. The first drive circuit drives a first phase of a motor. The second drive circuit drives a second phase of the motor. The first detection circuit detects a first anomaly of the first phase. The second detection circuit detects the first anomaly of the second phase. The third detection circuit detects a second anomaly of the first phase. The fourth detection circuit detects the second anomaly of the second phase. The output circuit outputs an occurred anomaly as a flag signal based on results of detection by the first to fourth detection circuits.

A voltage comparator and a programmable counter coupled to a high-speed clock are used to provide a near constant delay time for use in a closed-loop system. The voltage comparator input-output time delay is characterized at a certain temperature and operating voltage then variances in the voltage comparator delay times over a range of operating temperatures and voltages are measured and/or extrapolated. A number of clock pulses used for a delay time count are programmed into the programmable counter to provide for a near constant delay time from a change at the input of the voltage comparator to a change at the output of the programmable counter.

A multi-phase electric motor includes a stator winding. The multi-phase electric motor is controlled by regulating a current flowing in the multi-phase electric motor in response to an applied voltage. An overload condition of the multi-phase electric motor is detected by monitoring a thermal increase of the value of a stator resistance of the stator winding of the multi-phase electric motor during a steady state condition of said multi-phase electric motor in which the current flowing in the motor has constant phase, and the motor is operating at constant load with constant speed.

A motor including: a stator including plural windings that form coils and are connected together at a neutral point; a switching circuit that generates a rotating magnetic field around the stator by switching of a power supply to the plurality of windings; a rotor that rotates in response to the rotating magnetic field generated around the stator; a resistor for current detection that detects a current in the switching circuit and that is disposed between the switching circuit and a grounding point; and a filter element that reduces a fluctuation in potential at the neutral point, the filter element being disposed between the neutral point and the resistor for current detection and being grounded at the grounding point via the resistor for current detection.