Abstract: A motor includes a motor housing, a rotating shaft assembly including a rotating shaft, a rotor, and a bearing in which the rotor and the bearing are mounted to the rotating shaft. The motor further includes a stator installed in the motor housing, the stator surrounding the rotor, a bracket mounted to the motor housing, and an elastic mesh that defines a plurality of pores, that is disposed between the bracket and the bearing, and that contacts at least one of the bracket or the bearing.

Abstract: An integrated circuit including a low drop out (LDO) regulator configured to implement transient response and loop stability in a capacitor-less configuration, including an error amplifier configured to receive a bandgap reference input; first and second pass elements configured to receive outputs from the error amplifier; first and second resistor feedback networks, the first resistor network configured to provide a feedback output as an input to the error amplifier; an overshoot protection circuit; and an output connected to the pass transistors; wherein the capacitor-less low dropout (LDO) regulator is operable without an output capacitor.

Abstract: Disclosed examples include inverting buck-boost DC-DC converter circuits with a switching circuit to alternate between first and second buck mode phases for buck operation in a first mode, including connecting an inductor and a capacitor in series between an input node and a reference node to charge the inductor and the capacitor in the first buck mode phase, and connecting the inductor and the capacitor in parallel between an output node and the reference node to discharge the inductor and the capacitor to the output node.

Abstract: A resonant converter, including: a primary side circuit including at least one set of primary side switches, where the primary side circuit is configured to receive an input voltage; a resonant network coupled to the primary side circuit; a transformer having a primary side winding and a secondary side winding, where the primary side winding is coupled to the resonant network; a secondary side circuit including at least one set of secondary side switches, where the secondary side circuit is coupled to the secondary side winding of the transformer; and a control block that controls the secondary side switches according to the input voltage, the output voltage and the current detection signal, so that the secondary side winding of the transformer is short-circuited during a preset time interval before operating state of the primary side switches changes.

Abstract: A band-gap reference circuit including a charge pump circuit and a reference circuit is disclosed. The charge pump circuit is powered by a supply voltage and thereby outputs a regulating voltage which is higher than the supply voltage and powers the reference circuit such that the reference circuit outputs a band-gap reference voltage. Powering the reference circuit with the regulating voltage that is made higher than the supply voltage by the charge pump circuit enables 1) normal operation of the band-gap reference circuit at the supply voltage that is lower than a lowest voltage required by the band-gap reference circuit; and 2) minimization (almost elimination) of fluctuations in the regulating voltage output from the charge pump circuit and hence a stable and more accurate band-gap reference voltage output from the band-gap reference circuit.

Abstract: A power converter including a load transient enhancing module and associated method for improving load transient response of the power converter. The load transient enhancing module detects whether load transient is occurring in a load of the power converter, and turns the secondary switch off and locks the secondary switch at “OFF” state to turn on a body diode of the secondary switch once load transient is occurring in the load.

Abstract: The system and method creates a substantially constant output voltage ripple in a buck converter in discontinuous conduction mode by varying the on-time of a pulse width modulator (PWM) signal driving the buck converter when the buck converter is operating in discontinuous conduction mode. A first signal is generated that is a function of the switching frequency of the buck converter. This signal is low-pass filtered and compared with a second signal that is a function of the switching frequency of the buck converter when operating in continuous conduction mode and with constant PWM on-time. The output signal generated by the comparator is a signal that is equal to the ratio of the first signal and the second signal. The on-time of a voltage controlled oscillator is controlled by the output signal, the oscillator signal causing the on-time of the PWM signal to vary in a controlled fashion.

Abstract: A power semiconductor circuit comprising a field effect transistor having a drain, a source and a gate as terminals, and further comprising a control device having a drive device and an undervoltage detection circuit. The drive device drives the field effect transistor and is electrically connected to the gate of the field effect transistor. The undervoltage detection circuit generates an undervoltage detection signal if a power semiconductor voltage present between the drain and the source of the field effect transistor falls below a specific voltage value. The drive device switches on the field effect transistor when a switch-on command for switching on the field effect transistor and the undervoltage detection signal are present. The invention provides a power semiconductor circuit with low energy loss.

Abstract: A hybrid permanent magnet includes a first magnet (M1) having a first magnetic material and a second magnet (M2) having a second magnetic material different from the first magnetic material. The M2 magnet is deposited or assembled on a north pole surface and/or a south pole surface of the M1 magnet and the volume of the M2 magnet is less than or equal to the volume of the M1 magnet.

Abstract: An electricity generating device including a magnet array; and an inductive body having one or more metal wires. The inductive body and the magnet array are movable relative to each other and a magnet mounting structure, on which the magnet array is mounted. The inductive body is fixed to the magnet mounting structure. The electricity generating device has a simple structure, is easy to manufacture, achieves high efficiency of electricity generation, and is easy to carry.

Abstract: A motor includes a stator including windings and a rotor. The windings include a first winding and a second winding connected in series. The rotor includes a plurality of rotor parts arranged in an axial direction. Each of the rotor parts includes a first magnet pole unit including a permanent magnet and a second magnet pole unit opposing the second winding at a rotational position of the rotor where the first magnet unit opposes the first winding. The second magnet pole unit applies a weaker magnetic force to the stator than the first magnet pole unit. The rotor parts each include an equal number of magnet poles. The first magnet pole units of the rotor parts are located at positions deviated from one another in a circumferential direction. The second magnet pole units of the rotor parts are located at positions deviated from one another in the circumferential direction.

Abstract: To provide a power tool configured to stably rotate an end tool. The provided power tool includes a brushless motor including a rotor configured to rotate; a rectifier circuit configured to rectify an AC voltage; a smoothing capacitor configured to smooth the AC voltage rectified by the rectifier circuit to a pulsating voltage; an inverter circuit configured to perform switching operations to output the pulsating voltage to the brushless motor; a deceleration mechanism including: a driving portion at a rotor side, a driven portion configured to transmit a rotating force to an end tool side, and an elastic member configured to transmit a rotational force of the driving portion to the driven portion, the deceleration mechanism configured to decelerate a speed of a rotation of the rotor and configured to transmit the rotation to an end tool.

Abstract: Systems, methods, techniques and apparatuses of power converters are disclosed. One exemplary embodiment is a method of controlling and modulating a converter with a controller including forming a mathematical representation of the electrical system including the converter, providing reference values for controlled variables, calculating gradients of controlled variables based on the mathematical representation of the electrical system, determining possible switching sequences in the modulation period, the switching sequence defining the order in which the switches are switched, for each possible switching sequence, minimizing the error between the provided references and the corresponding controlled variables based on the calculated gradients by optimizing the switching time instants of the switching sequence, selecting the switching sequence with the smallest error, and applying the switching sequence with the corresponding switching times in the modulation period to modulate the controllable switches.

Abstract: A flyback converter includes a primary-side circuit to receive an input voltage, a secondary-side circuit to generate an output voltage, a transformer coupling the primary-side circuit to the secondary-side circuit, a main switch coupled to a primary winding of the transformer, and a converter controller having a primary-side controller in signal communication with the main switch to control an on time and an off time of the main switch and to detect one or more valleys of a resonant waveform developed at the main switch during the off time of the main switch. The primary-side controller is configured to operate in a valley reduction mode of operation upon determining that the output voltage is less than a reference voltage minus a predetermined threshold value. The valley reduction mode of operation includes decrementing, for each switching cycle of the main switch, a number of valleys occurring during that switching cycle.

Abstract: An electrical machine includes a stator assembly having an annular core and a conductive winding. The annular core includes a central bore. The conductive winding includes one or more stator winding bars disposed circumferentially around the central bore. The one or more stator winding bars include a core conductor and an insulation layer surrounding the core conductor. An end segment of the one or more stator winding bars at a connection interface includes a stress control structure surrounding the insulation layer. The stress control structure includes a printed scaffold and a dielectric backfill material. The dielectric backfill material fills pores of the printed scaffold. The porous scaffold is composed of a stress control material that is different from the dielectric backfill material.

Abstract: A method for operating an inverter and an inverter configured to convert DC power supplied from a DC power source into AC power supplied to an AC network by applying operational parameter limits which define limits for allowed operating points of the inverter, collect, during the converting, data of operational conditions related to the inverter, determine on the basis of the collected data whether the set operational parameter limits can be optimized with regard to one or more optimization criteria, and in response to determining that the set operational parameter limits can be optimized, adapt one or more of the set operational parameter limits applied in the converting on the basis of the collected data.

Abstract: In inverter control for supplying power to a motor, a power conversion device includes a temperature sensor for detecting a temperature of the inverter, a voltage sensor for detecting a voltage between terminals of a capacitor that smooths the voltage between terminals between the power source and the inverter, an inverter controller for controlling the inverter, a rotation speed sensor for detecting a rotation speed of the motor, an electric current sensor for detecting electric current supplied to the motor and a discharge determination instruction controller for giving an instruction for discharging electric charges accumulated in the capacitor, in which, control of reducing the rotation speed of the motor and discharge control of the capacitor are performed in accordance with the temperature of the inverter, the rotation speed of the motor and the electric current supplied to the motor.

Abstract: A hybrid power converter includes a switching circuit, an LC circuit, and a detection circuit. The switching circuit includes three or more switching transistors in series that may turn on or off according to a switching cycle to generate a series of voltage pulses at an output port across one of the switching transistors. The LC circuit may be coupled to the output port of the switching circuit to receive the series of pulses and to generate an inductor current in the LC circuit. The inductor current may charge a capacitor of the LC circuit to generate an output voltage of the hybrid power converter. The detection circuit may be coupled to the switching circuit and may generate a low frequency portion of the inductor current based on one or more currents of the switching transistors to adjust the switching cycle based at least on the low frequency portion.

Abstract: A power management circuit generates a reference voltage and distributes it to a plurality of independently-enabled regulator voltage reference circuits, each of which generates a predetermined voltage for a voltage regulator. Separate enable signals and enable pre-charge signals are distributed to each regulator voltage reference circuit. As a regulator voltage reference circuit is enabled via its associated enable signal, an enable pre-charge signal is also asserted for an initial duration. Each regulator voltage reference circuit includes a voltage setting circuit and a first current limiting transistor in series and operative to interrupt current to the voltage setting circuit when the regulator voltage reference circuit is disabled. A second current limiting transistor is configurably configured as a current mirror with the first current limiting transistor, and a pre-charge bias current from a current source passes through the second transistor.

Abstract: A control device includes a first switch, a second switch, a switching circuit, a first circuit and a second circuit. The control device is selectively switched to a first mode or a second mode corresponding to an operating current and an operating state of a predetermined circuit. During the first mode, an output signal of the first circuit is transmitted to a control end of the first switch through the switching circuit, and the first circuit and the first switch form a low drop-out regulator. During the second mode, a plurality of driving signals of the second circuit are transmitted to the control end of the first switch and a control end of the second switch through the switching circuit, and the first switch, the second switch and an impedance circuit form a switching voltage converter.