Abstract: An electronic relay for single phase induction motor, the electronic relay including a triac located between a start winding and a start capacitor of the single phase induction motor to control current flow of the start winding and an induced voltage detection circuit to detect an induced voltage of the start winding proportional to an angular velocity of the motor. The electronic relay is adapted to detect a zero-point voltage of a motor line voltage before start of the motor and to calculate an acceleration torque during start of the motor. The electronic relay is programmed to turn on the triac when the zero-point voltage of the motor line is detected and to turn off the triac when the acceleration torque begins decreasing.

Abstract: A motor starter system includes a plurality of switches, and a controller operatively connected to each of the plurality switches. The controller is configured and disposed to selectively activate select ones of the plurality of switches upon detecting a particular phase angle of each of a plurality of phases of a multi-phase electrical source.

Abstract: In the motor drive apparatus, a Hall element outputs a first sinusoidal signal and a second sinusoidal signal, of mutually opposite phases, in accordance with rotor position. A hysteresis comparator compares the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a rectangular wave signal. A pulse width modulation signal generation circuit detects timing at which phase switches, based on the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a pulse width modulation signal in which duty ratio gradually changes, in a predetermined time-period in which the phase switches. A drive circuit combines the rectangular wave signal and the pulse width modulation signal by a logical operation, and drives the fan motor.

Abstract: The method for initially starting the motor improves the reliability to the start of the motor. In particular, even though the external load is at more than a predetermined level, a rotor located at an arbitrary angle can be aligned to an accurate initial position. Moreover, it can prevent the damage of the motor or the damage of the electronic device where the motor is installed. In order to initially align the rotor of the motor, a position on a stationary coordinate system, to which an alignment current of a rotation magnetic field is applied, is varied.

Abstract: An input circuit includes an interface structured to output a logic signal from an alternating current signal of a pair of elongated conductors. A load is switchable to the elongated conductors. A processor outputs a control signal to switch the load to the elongated conductors asynchronously with respect to the alternating current signal for a first predetermined time, inputs the logic signal, determines if the input logic signal is active a plurality of times during the first predetermined time and responsively sets a first state of the alternating current signal, and, otherwise, sets an opposite second state of the alternating current signal, and delays for a second predetermined time, which is longer than the first predetermined time, for the opposite second state before repeating the output, and, otherwise, delays for a third predetermined time, which is longer than the second predetermined time, for the first state before repeating the output.

Abstract: An object of the present invention is providing permissible values of start currents with sufficiently high start torque ensuring the possibility of the start of a loaded motor, the smoothness of the motor's start, without spikes and fluctuations of the currents, voltages and torques. The other objects of the proposed device are simplicity, reliability and economic efficiency. The proposed method of an induction motor start includes an acquisition of two components of the voltage, feeding the motor. The both components have the different controlled frequencies and root mean square values. The proposed device for an induction motor start comprises two channels forming signals, which create two corresponding components of the motor's feeding voltage.

Abstract: Permanent magnet alternating current (PMAC) motor systems and methods for starting or restarting PMAC motor system sensorless control algorithms are provided. One system includes a PMAC motor including a rotor, an inverter, and a controller. The controller includes control logic, start/restart logic, drive logic, current detect logic, and estimation logic configured to estimate a position of the rotor, a speed of the PMAC motor, or both based on current detected in each phase of the inverter. A start/restart method includes determining to start/restart the sensorless control algorithm and modifying the inverter voltage in response to the determined start/restart. The method also includes detecting current in each inverter phase after the inverter voltage is modified and estimating a rotor position, a PMAC motor speed, or both based on the current detected in each inverter phase after the inverter voltage is modified. Another controller includes means for performing the above start/restart method.

Abstract: A blower motor assembly having a variable speed motor that is suitable for direct, drop-in replacement in a residential HVAC (heating, ventilation, and air conditioning) system that employs a PSC motor. The blower motor assembly includes at least a neutral input and two hot AC line connections, one for connection to the heating power source and the other to the cooling power source. A sensing circuit senses which of the inputs is energized by sensing either voltage or current on the inputs. The sensing circuit delivers a corresponding signal to a motor controller to control the speed of the variable speed motor. The blower motor assembly may also be equipped with additional hot AC inputs, more than one neutral line, and several sensing circuits for sensing current or voltage in the hot inputs and/or the neutral lines for controlling various aspects of the variable speed motor.

Abstract: A soft-start circuit includes a power source, a switch, a capacitor and a regeneration brake circuit. The regeneration brake circuit absorbs a return current. The regeneration brake circuit includes a resistor, a diode and a transistor. The resistor is connected between two poles of the power source via the transistor. The diode is connected between the resistor and the positive pole of the power source via the switch. The capacitor is connected between the negative pole of the diode and the transistor. The switch is connected between the negative pole of the diode and resistor. When the switch turns off, the power charges the capacitor via the resistor and the diode of the regeneration brake circuit. When the switch turns on, the return current turns the transistor on, and the resistor absorbs the return current.

Abstract: A method and a circuit for controlling a triac intended to be series-connected with a resistive element of positive temperature coefficient or a capacitive element, and a winding for starting an asynchronous motor, for supply by an A.C. voltage, the present invention including the steps of: detecting a voltage representative of the voltage across the series connection of the element and of the triac; comparing this detected voltage with respect to a threshold; and blocking a turning back on of the triac when the threshold has been exceeded.

Abstract: An arrangement for the control of a soft starting or stopping of a three phase current motors (1), a so-called soft starter, is furnished for starting of heavy mechanical, electrical, or hydraulic drives. In order to obtain a space savings with individual or multiple installation and to obtain a better accessibility during servicing, at least one switch cell (3) is formed in a switching cabinet (2), wherein the switch cell (3) comprises at least a three phase power block (4), and the power electronic (5) as well as contactors (6, 18) and is as a unit towards the front easily demountable or inversely incorporatable and is arranged without attachment at the rear or side wall (8) of the switch cabinet (2). In addition, it is furnished that in contrast a separating switch (9) attached at the switch cabinet wall (2) with a collection rail connection (10) by way of a pluggable contact coupling (10a) is connectable upon shifting inside and disengageable upon pulling out.

Abstract: A starting circuit for a single-phase AC motor, comprising a main winding, a detecting circuit, a rectifying and filtering circuit, a triggering circuit, a switching circuit and a starting winding. The detecting circuit is connected in series to the main winding for transforming current parameters thereof into detecting signals. The switching circuit is connected in series to the starting winding. The rectifying and filtering circuit processes the detecting signals and the processed detecting signals to the triggering circuit. The triggering circuit enables or disables the switching circuit according to the detecting signals, so as to energize or deenergize the starting winding. The starting circuit features high reliability, long lifetime, simple circuit structure, low cost, and small size.

Abstract: An inexpensive, productivity-enhanced single-phase AC synchronous motor in which stabilized synchronous pull-in can be carried out by suppressing generation of counter torque during a starting operation. Starting operation is performed while the energizing range of motor current is suppressed such that the energizing direction of motor current waveform lagging in a phase behind the output waveform from a detection sensor (17) is switched at at least the zero cross point of the output waveform from the sensor when the number of revolutions of a permanent magnet rotor (1) reaches a predetermined number of revolutions in the vicinity of the synchronous number of revolutions.

Abstract: When manufacturing a starting device for a three-phase electric motor, especially a soft starter, in at least one embodiment an arc quenching system is at least partly removed from a commercially available contactor that so becomes to a modified contactor. In at least one embodiment, a modified contactor is used as a contactor in the starting device.

Abstract: A method and a device with a control apparatus (50) for starting an electric machine (10) with a rotor (20), particularly the spinning cup of an open-end spinning machine, magnetically mounted by a bearing having permanent magnets (31, 32, 33, 34). An actuator system controls the position in the axial direction (35, 36) and two limitation bearings (41, 42), determine the axial end positions of the rotor. The actuator system brings about a lifting from the first axial end position, and a system variable during such lifting is compared with a reference value, and the rotor (20) is moved into the second end position, and the actuator system brings about a lifting from the second axial end position, and a system variable on lifting from the second end position is compared with a reference value.

Abstract: In the motor drive apparatus, a Hall element outputs a first sinusoidal signal and a second sinusoidal signal, of mutually opposite phases, in accordance with rotor position. A hysteresis comparator compares the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a rectangular wave signal. A pulse width modulation signal generation circuit detects timing at which phase switches, based on the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a pulse width modulation signal in which duty ratio gradually changes, in a predetermined time-period in which the phase switches. A drive circuit combines the rectangular wave signal and the pulse width modulation signal by a logical operation, and drives the fan motor.

Abstract: An energy saver delay circuit for an induction motor is disclosed. The energy saver delay circuit includes a power factor control circuit including an integrator, the integrator having a negative summing junction and a current injection circuit electrically connected to the negative summing junction, the current injection circuit configured for injecting an offset current into the negative summing junction to cause about the maximum available voltage from a power source to be supplied to the motor for a predetermined amount of time. Current injection may be triggered by voltage being applied to the motor, wherein the voltage exceeds a predetermined value. Alternatively, current injection may be triggered by current flowing through the motor, responsive to the current exceeding a predetermined threshold current. Alternatively, current injection may be triggered by voltage across the power factor control circuit, responsive to the voltage exceeding a predetermined threshold voltage.

Abstract: A method and a system for controlling an asynchronous electric motor for detecting cabling errors between the electric motor and a motor starter. The electric motor including three windings distributed over three branches in a delta configuration and controlled by the motor starter, which includes power semiconductors directly connected in series within the three branches of the delta configuration of the three windings. In one embodiment, the method includes applying a voltage in a first branch of the delta, priming the semiconductor of the first branch after a priming delay, measuring an electrical current generated within the first branch during the priming, and determining the configuration of the cabling of the first branch according to the measured electrical current.

Abstract: A self-adapting soft-starter device includes an electric current limiter limiting electric current supplied to the motor to a preset maximum current limit, a ramp-up time determiner determining the actual ramp-up time of the electric motor, a storing device storing a preset minimum ramp-up time, a comparator comparing the determined actual ramp-up time with the preset reference ramp-up time, a replacing device replacing the preset maximum current limit with an auto-adapted current limit based upon the outcome of the comparison between the determined actual ramp-up time and the preset reference ramp-up time. The soft-starter automatically optimizes the maximum current limit driven by the motor to match its load requirements which is useful to cater for load variations with time during the lifetime of the product in the application by avoiding the need for human intervention to change the soft-starter settings. Wear and tear is also reduced, extending motor lifetime.

Abstract: An electrical switching apparatus includes a plurality of poles each having a Rogowski coil and a conductor passing through an opening thereof, and a processor circuit including a sensor circuit including a plurality of inputs each electrically interconnected with an output of the Rogowski coil of a corresponding pole. The sensor circuit further includes a number of outputs having values each corresponding to current flowing through the conductor, a memory including for each corresponding pole an offset value and a gain correction factor for the sensor circuit, and a gain correction factor for the Rogowski coil, a number of routines, and a processor cooperating with the sensor circuit and the routines to provide for each pole a corrected current value as a function of a corresponding one of the values, the sensor circuit offset value and gain correction factor, and the Rogowski coil gain correction factor.

Abstract: A method and circuit arrangement for determining position of the rotor of an electronically commutated motor, wherein the rotor has magnetic axes having different permeances. Voltage is applied to stator phases, and resultant phase currents are monitored for purpose of determining rotor position in the standstill state of the motor. First and second rise times of phase currents are determined until predetermined limit values are reached in unsaturated state. The assignment of a magnetic axis to a stator phase is determined from first rise times of the currents in unsaturated state of the rotor core, and the polarization of the rotor is determined from second rise times of currents upon energization with saturation effects. After run-up of the motor, initial energization of the stator can be determined comparing levels of the magnet wheel voltages and corrected by changing the commutation of stator energization.

Abstract: The present invention relates to a system and a method for energizing an auxiliary winding of a capacitor-start single-phase induction motor. Said system and method aim at reducing the voltage level in the bidirectional switches present in the topology during the blocking of said switches. The system and method proposed also aim at providing smooth switching of the electromechanical bidirectional switch existing in the topology.

Abstract: An alternating current motor control system constituted of: a control unit; a current monitor in communication with the control unit, the current monitor arranged to provide an indication of the amount of current flowing through at least two windings of a target alternating current motor; and a semiconductor switching unit arranged to connect the windings of the target alternating current motor to a three phase power input in one of a star and a delta configuration responsive to the control unit, wherein the control unit is arranged to alternately connect the winding of the target alternating current motor in one of a star and a delta configuration responsive to a predetermined condition of the amount of current flowing through the at least two windings of the target alternating current motor.

Abstract: A method for turning a three-phase alternating current motor on again, after it has been separated from a supply voltage, if a residual field voltage induced by a rotor residual field is present, and to an electrical circuit for implementing the method. The time progressions of the residual field voltage and the supply voltage are recorded, and the phase difference between the voltages is calculated in advance from the time progressions. A time point ts is determined, at which the phase difference goes below a predetermined maximum value ??max. A switching command for applying voltage is triggered at a time interval that corresponds to a predetermined switching time delay ?s, before the time point ts is reached, so that the motor is connected to the supply voltage approximately at the time point ts. The electrical circuit has a measurement value detection device, a microcontroller and a direct current setting device.

Abstract: An excitation current processor of a current controller processes the excitation current corresponding to the magnetic flux instruction from the magnetic flux instruction processor. It multiplies this excitation current with a boost coefficient to obtain an excitation current instruction. Here, the boost coefficient is determined based on the difference obtained by subtracting the magnetic flux estimation value processed by the magnetic flux processor based on the excitation current feedback from the voltage conversion device from the magnetic flux instruction input from the magnetic flux instruction processor. Further, the boost coefficient can be found from the function of time from the start of the rise of the magnetic flux.

Abstract: A control apparatus is for controlling an AC rotary machine which includes a first and second stator elements and a rotor, in which the first stator element can be turned, or offset, in a circumferential direction relative to the second stator element. The control apparatus includes an actuator for adjusting a voltage induced in a stator coil due to rotation of the rotor by driving the first stator element, a magnetic flux command calculator for calculating a desired magnetic flux amplitude command based on rotating speed of the AC rotary machine, a magnetic flux estimator for estimating magnetic flux amplitude of the AC rotary machine, a speed command calculator for calculating an actuator speed command to be given to the actuator so that the estimated magnetic flux amplitude follows the magnetic flux amplitude command, and an actuator controller for controlling the actuator according to the actuator speed command.

Abstract: A starting circuit for a single-phase AC motor, consisting at least of a rectifying and voltage-stabilizing circuit, a control circuit with a zero-cross detecting circuit and a counter, and a bidirectional thyristor. The bidirectional thyristor is serially connected to a starting winding and a starting capacitor, the bidirectional thyristor, the starting winding and the starting capacitor are connected a utility power AC input. The input end of the rectifying and voltage-stabilizing circuit is connected to the utility power AC input. The output end of the rectifying and voltage-stabilizing circuit supplies power to the control circuit. The input end of the zero-cross detecting circuit is connected to the utility power AC input. The output end of the zero-cross detecting circuit is connected to the input end of the counter. The zero-cross detecting circuit detects zero crossing points of the utility power AC input and inputs the zero crossing points to the counter.

Abstract: A submersible motor is provided for a submersible pump, the motor being configured as a single-phase asynchronous motor, which includes a main winding (6), an auxiliary winding (8), and a starting device (10, 14, 16, 18, 20, 22) for controlling the starting procedure of the submersible motor. The starting device (10, 14, 16, 20, 22) for the control of the current feed of the auxiliary winding (8) includes at least one electronic switch (20) in the circuit of the auxiliary winding (8).

Abstract: A method of starting and apparatus for starting a multiphase electrical machine is disclosed. The aim is to reduce oscillatory pulsation in torque generated by the motor and inrush current that occurs shortly after start-up. The starting method comprises the steps of first connecting at least one, but less than all, of a plurality of windings to a respective phase-shifted supply voltage at a controlled point in the supply phase. Then, after a controlled delay following the first connection, connecting the or each remaining winding of the machine a respective phase-shifted supply voltage. The invention has particular application to multiphase (most usually, 3-phase) motors. However, it can also be applied to other electrical machines, such as generators and transformers. The method can be performed at initial start-up or, in the case of application to a motor, at Y-delta switchover.

Abstract: A motor start circuit for an AC induction motor employs a DC relay whose NC contacts are placed in series with the start capacitor. A half full-wave rectifier arrangement has an AC input connected to the junction of the relay switch and the start capacitor, and DC outputs applied across the relay actuator coil. In the event of intermittent application of power to the motor, any residual charge on the start capacitor will feed current to the actuator coil to hold the relay switch open until the residual charge has decayed sufficiently, to avoid damage to the motor from capacitive discharge. A high magnetic retentivity core can be used to hold the relay off for sufficient time for stored energy to dissipate.

Abstract: A system, method, and device for monitoring an AC induction motor are disclosed. The exemplary system provides the architecture of an intelligent motor controller. On one hand, the controller has self-commission and adaptive tuning capability and can provide smooth start and stop for motor driven systems. On the other hand, the controller can provide fault detection, power metering, and history data logging, to ensure motor operates under optimal conditions. The exemplary system may have one or more sensors for monitoring characteristics of the AC induction motor and producing one or more inputs from the characteristics.

Abstract: Motor start circuit for an induction motor-with a main winding and an auxiliary winding having two end connections supplied with current via current supply connections, and with a start circuit device serving the purpose of stopping the current flow through the auxiliary winding after the start of the motor, and being connected via a conductor to a control device connected between the current supply connections, and with a preset timer device interacting with the start circuit device to stop the current flow through the auxiliary winding, as soon as a predetermined period after the start of the current flow has lapsed. With the purpose of optimizing the motor start circuit, a voltage presetting device, with which a predetermined voltage value can be set, the start circuit device being disconnected if this value is exceeded, and a period duration presetting device, are connected to or integrated in the control device.

Abstract: A sump pump control includes a microprocessor that sends a trigger pulse to an alternistor to turn the alternistor on and connect the sump pump to an NC power source. The microprocessor also monitors the power source to find a positive/negative crossover point. The microprocessor adjusts the trigger to apply full power to the pump motor during normal operation and delays the trigger to apply reduced power for a soft start and soft stop. The microprocessor also triggers an alarm in the event of failure of the device, including failure of the alternistor or the microprocessor.

Abstract: An accurate slip calculation for providing monitoring and protection to an electric motor. The slip calculation is made using a minimum value of stator resistance as the initial stator resistance, where the minimum value of stator resistance is the minimum value of stator resistance calculated during an initiation period of the motor. The initiation period may be a predetermined time period or a predetermined number of cycles during the motor startup. The initiation period may start after a predetermined settling time or after a predetermined condition is met.

Abstract: In a motor driving apparatus, a control unit detects a rotation frequency of a motor to be driven and generates a control voltage Vcnt in a manner such that the rotation frequency thereof is brought close to a desired rotation frequency. A clamping circuit sets an upper limit Vcu and a lower limit Vcl of the control voltage Vcnt. A drive unit drives the motor based on the control voltage Vcnt generated by the control unit. A start circuit fixes the control voltage Vcnt to a predetermined initial voltage Vinit at the start of driving the motor.

Abstract: A single-phase induction motor comprises a power consumption prevention device, which includes a current signal transfer element and a switching element. The switching element is turned on/off according to the current signal received from the current signal transfer element. The power consumption prevention device prevents current flow to a start device when the motor runs in normal mode, and thus avoids unnecessary power consumption by the start device when the motor runs in normal mode, thereby preventing a reduction in the efficiency of the single-phase induction motor due to the unnecessary power consumption.

Abstract: Power capacitors for AC motors are mounted diametrically on associated transmissions. The power capacitors are in one embodiment annular and in another embodiment, arcuate. By having power capacitors mounted on transmission housings diametrically, cooling of the power capacitors is facilitated for both air and liquid cooling.

Abstract: A drive and a method, including an electric motor, which is supplied by a rectifier, the rectifier including a time-discrete closed-loop control structure, which regulates the stator current of the electric motor by setting the voltage applied at the motor, the current of the motor being acquired in time-discrete fashion, the closed-loop control structure including a closed-loop controller whose actual value is a first current component of the current, the setpoint input of the closed-loop controller being coupled with at least one upstream setpoint limiter.

Abstract: A motor control unit includes a power converter unit that energize a motor based on a commutating signal, the motor having a rotor provided with a permanent magnet and a stator having a coil wound thereto; a start-up controller that outputs a commutating signal to the power converter unit during a start-up operation, the commutating signal having a predetermined conductive pattern corresponding to a command rotational speed; a voltage calculator that calculates a voltage of the motor during the start-up operation by applying a parameter for the motor, the command rotational speed, and a current flown in the coil of the motor to a voltage-current equation of the motor; and a determiner that, during the start-up operation, compares a voltage calculated by the voltage calculator and an actual voltage of the motor and that determines occurrence of rotational abnormalities when the actual voltage is lower than the calculated voltage.

Abstract: An apparatus for controlling the starting and stopping of an AC induction motor, the apparatus comprises a first and a second magnetic permeable portions having a plurality of legs wherein a magnetic control flux of the second magnetic has an opposite magnetic polarity to the magnetic control flux of the first magnetic permeable portion; anon-spacer separating the first and second magnetic permeable portions to prevent magnetic control flux cancellation between the first and second magnetic permeable portions; a first and second AC power phase windings; and a first and second group of DC excitation control windings.

Abstract: Methods and apparatus are provided for startup of a permanent magnet alternating current (AC) motor. The method comprises the steps of detecting startup of the permanent magnet AC motor; detecting a mechanical oscillation of the permanent magnet AC motor when startup of the permanent magnet AC motor is detected; and, in response to detection of the mechanical oscillation of the permanent magnet AC motor when startup is detected, suppressing the mechanical oscillation of the permanent magnet AC motor.

Abstract: To provide a motor control apparatus, including a rotational number detecting means for detecting the rotational number of a motor; a current detecting means for detecting a motor current; a voltage detecting means for detecting an impressed voltage to be supplied to a motor; a temperature estimating means for obtaining a motor temperature from the rotational number of a motor, the motor current, and the impressed voltage; and a protection signal generating means for generating an operational signal in order to protect the motor when the obtained motor temperature exceeds a predetermined value.

Abstract: A method is disclosed for operating a two-phase rotary current controller. In order to optimize the operation of a two-phase rotary current controller, magnitudes of a parameter that can be varied in both controllable phases of a two-phase rotary current controller is matched in these phases. In particular, the existing principle of phase-symmetric control with a uniform ignition delay in both controlled outer conductors is abandoned, and a separate ignition delay is stipulated for each of the two controlled outer conductors.

Abstract: A method for determining an initial position of a rotor of a polyphase motor is described. The method comprises determining current change values from a plurality of phases of the motor during saturation of the motor relating to the initial position of the rotor; identifying a set of modelled current change values according to a modelled behaviour of the motor, in which the modelled current change values represents modelled positions of the rotor under the modelled behaviour; and comparing the current change values to the set of modelled current change values to identify the initial rotor position from the modelled positions. A system implementing the method is also described.

Abstract: A system, method, and device for monitoring an AC induction motor are disclosed. The exemplary system provides the architecture of an intelligent motor controller. On one hand, the controller has self-commission and adaptive tuning capability and can provide smooth start and stop for motor driven systems. On the other hand, the controller can provide fault detection, power metering, and history data logging, to ensure motor operates under optimal conditions. The exemplary system may have one or more sensors for monitoring characteristics of the AC induction motor and producing one or more inputs from the characteristics.

Abstract: A control device of a fan system, which has at least one fan, receives a starting voltage. The control device includes a start controlling unit and a driving unit. The start controlling unit receives the starting voltage and outputs a start controlling signal according to the starting voltage. After a predetermined period, the start controlling unit stops sending the start controlling signal. The driving unit is electrically connected to the start controlling unit and the fan, respectively. The driving unit receives the start controlling signal for controlling the rotation speed of the fan.

Abstract: Indirect rotor resistance estimation for an AC induction motor is achieved by successively stepping the quadrature command to zero and the direct current command to a predetermined value causing the quadrature stator voltage to decay as a representation of rotor current decay; defining, in response to the decaying stator voltage reaching two spaced thresholds, a voltage/time difference, and retrieving from a storage device the rotor resistance associated with the voltage/time difference.

Abstract: When manufacturing a starting device for a three-phase electric motor, especially a soft starter, in at least one embodiment an arc quenching system is at least partly removed from a commercially available contactor that so becomes to a modified contactor. In at least one embodiment, a modified contactor is used as a contactor in the starting device.

Abstract: An inductive contactless starter for single-phase AC motor, comprising a current inductor and a triac; wherein, one terminal of secondary coil of said current inductor is connected to the gate electrode of said triac, the other terminal is both connected to the first electrode of said triac and the terminal of secondary winding of the motor, and the two terminals of primary coil of said current inductor are connected to the motor and the power supply. By sampling relevant current signals with said current inductor, the invention can control heat loss of the current sampling system effectively down to milliwatt level (i.e., the starter is a “zero power loss”starter for single-phase AC motors), and thereby improve energy efficiency greatly; in addition, the invention has a simple circuit and fewer components and is reliable, improving reliability of the electric starter system while delivering electric starting function.

Abstract: A driving controlling apparatus for a linear compressor, comprises a controlling unit for detecting a TDC by a phase difference inflection point between a stoke and a current with increasing the stroke by controlling the current applied to a linear motor, and for varying the current applied to the linear motor based on the detected TDC.