Abstract: A system to reconfigure a motor from induction mode to synchronous mode at a zero crossing of the field voltage during startup using only stator current signals is described herein. The zero crossing may be detected by asymmetry induced in the stator currents by a current asymmetry inducing module of the motor. The current asymmetry inducing module may include a resistor and diode in series and in parallel with a discharge resistor of the field windings. Asymmetry is induced in the current obtained from the stator, and used to determine a zero crossing of the field voltage. Upon the rotor reaching a startup frequency and the detected zero-crossing of the field voltage, the motor may be reconfigured from induction mode to synchronous mode.

Abstract: A system and a method for automatically correcting a rotational speed of a motor of a fan are provided. After the fan is moved from an open space to a closed space, a sample and hold circuit samples and holds working periods of a driving signal by which the motor is driven to rotate at a first rotational speed as a first sampled working period, and a working period of a driving signal by which the motor is driven to rotate at a second rotational speed. An arithmetic circuit calculates a difference between the first sampled working period and a first reference working period, and a difference between the second sampled working period and a second reference working period. The arithmetic circuit calculates other working periods of driving signals by which the motor is driven to rotate at other rotational speeds based on the differences.

Abstract: A control system for a single-phase induction motor including at least: one electronic control, a main switch, an auxiliary switch, one voltage conditioner block, the main switch being electrically associated to the main winding and the auxiliary switch to the auxiliary winding, the control circuit being electrically associated to the voltage conditioner block and to the switches, the switches being turned on or off by the control circuit, the control system and the motor being electrically associable to an alternating voltage source, the conditioner block is associated in parallel to the auxiliary switch, the conditioner block being capable of accumulating energy when the auxiliary switch is turned off, the conditioner block being arranged to supply electrical power greater than a minimum value to the control circuit, for at least a start-up time, by way of the energy accumulated in the conditioner block, when the switches are turned on.

Abstract: A device for improving efficiency of an induction motor soft-starts the motor by applying a power to the motor that is substantially less than the rated power of the motor then gradually increasing the power while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the phase angle between the voltage and the current to the motor is measured and power to the motor is increasing when the phase angle is less than a minimum phase angle (determined during soft-start) and power to the motor is decreased when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start.

Abstract: A system and a method for energizing an auxiliary winding of a capacitor-start single-phase induction motor for reducing the voltage level in the bidirectional switches during the blocking of said switches and for providing smooth switching of the electromechanical bidirectional switch. This is achieved by a system for energizing an auxiliary winding of an electric motor, the auxiliary winding being connectable in series with a voltage network, the system including a start capacitor and an electromechanical switch connected in series with the auxiliary winding, the system including an electronic switch connected in parallel with the series association of the electromechanical switch and the start capacitor, the electronic switch and the electromechanical switch being used to turn on the auxiliary winding, the system configured so that the electronic switch can be turned on simultaneously with the electromechanical switch and kept on simultaneously with the electromechanical switch for a stabilization time.

Abstract: The invention relates to a method for operating an electric motor (2) having a phase angle control with the following steps: Applying an AC voltage to a series connection of the electric motor (2) and a switching element (4), particularly a triac, wherein the switching element (4) connects through by applying an ignition signal and suppresses the flow of a current if the amount of current falls below a holding current; determining the time of a zero crossing of a virtual motor current that would flow if the switching element (4) were connected through; and turning on the switching element (4) at an activation time that is dependant on the time of the zero crossing of the virtual motor current.

Abstract: A device for improving efficiency of an induction motor that soft-starts the motor by applying a voltage to the motor that is substantially less than the rated voltage then gradually increasing the voltage while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the voltage to the motor is increased/decreased by measuring the phase angle between the voltage and the current to the motor and increasing the voltage when the phase angle is less than a minimum phase angle (determined during soft-start) and decreasing the voltage when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start.

Abstract: The present invention relates to a single phase induction motor, and more particularly, to a single phase induction motor, wherein a variable resistance element which can change a winding number of a main winding or an auxiliary winding capable of producing a magnetic field at the time of starting is connected in parallel to some portion of the main winding or the auxiliary winding. A single phase induction motor including a stator composed of a core, a main winding and an auxiliary winding, and a rotor rotated by a mutual electromagnetic force by the stator comprises a resistance variable element connected in parallel to some portion of the main winding.

Abstract: A starting circuit for a single-phase AC motor, the single-phase AC motor comprising a main winding and a starting winding, and the starting circuit comprising a detecting circuit, a rectifying circuit, a triggering circuit, and a switch, wherein the detecting circuit is connected in series with the main winding, the switch is connected in series with the starting winding, the detecting circuit transfers current parameters of the main winding into detecting signals, the rectifying circuit processes the detecting signals and transmits the detecting signals to the triggering circuit, the triggering circuit controls the switch according to the detecting signals whereby controlling power-on and power-off of the starting winding, and the triggering circuit is a hysteresis comparing circuit.

Abstract: A polyphase electric motor has a rotor, a stator with a plurality of slots, a plurality of main windings and a plurality of auxiliary windings installed in slots of the stator, and a main winding and an auxiliary winding that correspond to a selected phase of an alternating current power source. The auxiliary windings are connected to the motor terminals through a plurality of capacitors, and the auxiliary windings and corresponding capacitors are connected in parallel to the main windings. The main winding and the auxiliary winding of the selected phase are offset by about 80 to about 100 electrical degrees. A power of the plurality of main windings is at least 75% of a power of the polyphase electric motor at full load rating and the power of the plurality of main windings is motoring at 25% of the full load rating.

Abstract: A six lead, two speed, consequent wound, single phase induction motor with a tapped auxiliary winding having a 2-pole high speed mode and 4-pole low speed mode. A portion of the auxiliary winding is connected in series with the four pole main winding. The 4-pole low speed mode has an efficiency of over 80%.

Abstract: The invention relates to a two-phase permanent magnet motor which is controlled by a frequency converter. The frequency converter is advantageously provided with a three-phase inverter having six switches that are controlled in such a manner as to minimize switching losses.

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: 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 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: 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 method and a circuit for controlling a triac intended to be series-connected with a resistive element of positive temperature coefficient or which is at least capacitive, 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: A single-phase induction motor includes a main winding, an auxiliary winding, a run capacitor, and a subsidiary start device. The auxiliary winding is configured such that the number of turns of the auxiliary winding, through which a current flows, varies according to the operating mode of the motor. When the motor starts, the number of turns of the auxiliary winding, through which a current flows, is reduced, thereby increasing the start efficiency of the motor. When the motor runs in normal mode, the number of turns of the auxiliary winding, through which a current flows, is increased, thereby increasing the operational efficiency of the motor.

Abstract: An electronic circuit for starting a single phase induction motor, of the type containing a rotor and a stator with at least one running coil (B1) and one starting coil (B2), for operating jointly with an alternating current source (F), comprising: a trigger electronic switch; a trigger circuit (TR) of said trigger electronic switch; and a blocking circuit (BL) for controlling the trigger pulses of the trigger electronic switch, said blocking circuit (BL) sustaining its blocking state while there is voltage being induced to the coils of the motor (M) by rotation of the rotor, maintaining said blocking state for a certain time after said induced voltage has been substantially reduced.

Abstract: An electric machine assembly having an electric machine. The electric machine can include a first speed circuit and a second speed circuit. In some constructions, both speed circuits can be of a permanent split capacitor design. At least one of the speed circuits can include a switch that is controlled by the controller to limit current through an auxiliary circuit of the unused speed circuit when certain conditions exist.

Abstract: A speed controller for a single phase motor such as a permanent split capacitor motor allows the motor to be operated at a first speed, n1, and a lower speed, n2. High speed motor operation is produced by passing a single phase AC current through both the main and auxiliary windings of the motor. For low speed operation, the controller passes first and second reduced frequency AC waveforms through the motor's auxiliary and main windings, respectively. The first waveform bypasses the motor's auxiliary winding capacitor and is phase shifted 90 degrees from the second AC waveform. A split source capable of generating an AC signal and its inverted signal can be used by the controller to generate the reduced frequency waveforms. Specifically, the controller uses selected half cycles from each split source signal to produce the reduced frequency waveforms.

Abstract: A system includes a motor mounted within a housing and a compressor pump unit. A single-phase PSC motor includes a switch assembly which selectively connects primary or alternate windings. During normal load operation, when maximum efficiency is desired, the switch is placed in one position, then during high load operation, when maximum torque output is needed at maximum a load point, the switch is placed in the closed position. In effect, the number of main winding turns is decreased and the motor is strengthened. As the auxiliary capacitors are also now connected in parallel, the net effect is an increase in the total auxiliary capacitance, which also serves to strengthen the motor. Another embodiment provides a switch for a three-phase WYE connected motor. In yet another embodiment, a three phase delta connected motor switch is provided.

Abstract: An electric motor and its controller are specially adapted for variable speed applications. The stator of the motor has its main windings controlled by triacs. The triacs are placed to allow the main windings to operate in series at low speed and in parallel at high speeds. The firing delay of the operating triacs is controlled in both series and parallel winding operations to aid in smooth operation of the motor. The auxiliary winding is preferably left uncontrolled to contribute a regular sinusoidal component to the windings power at all times. The controller receives the speed command and figures firing delay and outputs triac control pulses at one of a plurality of settings to bring the motor to the selected speed. In this manner a simple, inexpensive, and continuously variable speed motor may be realized with good performance characteristics.

Abstract: A single phase, three-speed Pole-changing electric motor has a stator and a rotor rotatably mounted within the stator. The stator includes a core having a plurality of slots, and a plurality of windings in the slots for operating at least three speeds. The windings are configured and arranged so that a substantial portion of the windings used in operating at one speed are used in operating at another speed. The reconnection of windings for different speeds is simple and easy to implement, for example with an external timer, switch, or relay.

Abstract: Electrical power apparatus is disclosed for selectively powering either a three-phase ac motor or a single-phase ac motor. A dc/ac inverter is configured to provide appropriately phased input signals to the three input terminals of whichever motor is being driven, with no substantial hardware reconfiguration being required. In addition, a special clamp circuit prevents an excessively high voltage from being applied to the inverter by a variable-voltage power source such as a photovoltaic array, whereby the inverter need not be sized to accommodate voltage levels substantially greater than its design voltage.

Abstract: A permanent split capacitor motor operable in a full mode and in a modulated mode for improving efficiency. The motor includes a stator and a rotor in rotational relationship with the stator. The motor also includes a single set of windings wound on the stator. The windings are in a magnetically coupled relationship with each other such that one of the windings is a main motor winding while the other is an auxiliary motor winding. The windings define a plurality of A-ratios as a function of turns in the main motor winding compared to turns in the auxiliary motor winding. A switching circuit selectively energizes the first and second windings in a full mode configuration and in a modulated mode configuration based on motor load conditions. In the full mode configuration, the A-ratio of the windings is greater than in the modulated mode configuration.

Abstract: A secondary thermal overload device is connected to one winding of a motor having a bi-directional rotatable output shaft and is preset at a lower trip temperature than a trip temperature of a primary thermal overload device connected to the motor to deactivate only the one motor winding effecting closing movement of a garage door at a lower motor operating temperature and before the primary thermal overload device trips while enabling the motor winding associated with an opening movement of the garage door to be activated to open the garage door.

Abstract: A control circuit for an electric motor having start, low speed and high speed windings reactivates the start winding at different reduced motor speeds depending upon whether the motor is running on the low speed winding or the high speed winding. Reactivation of the start winding while the motor is running on the low speed winding automatically deactivates the low speed winding and activates the high speed winding.

Abstract: A winding circuit for use with different input signals includes a first main winding, a second main winding, and an auxiliary branch having an auxiliary winding permanently and serially connected to a capacitor. The windings and auxiliary branch are alternatively configurable in one of a first configuration or a second configuration for use with respective first and second input voltages. When in the first configuration, the first main winding, the second main winding, and the auxiliary branch are connected in parallel. The input voltage signal then may be applied across the first main winding. When in the second configuration, the first and second main windings are serially connected, and the auxiliary branch is connected in parallel with one of the first and second main windings. The input voltage signal then may be applied across the first main winding and the second main winding.

Abstract: The invention relates to a control device for stopping the operation of a single-phase asynchronous motor with a capacitor in the event an overload of this motor with respect to a threshold value is detected. This device is characterized in that it includes, on the one hand, device for measuring the phase shift between any one parameter, voltage or current (U1, U2, I2, I3) of the main phase (.phi.1) or the secondary phase (.phi.2) and another one of these parameters and, on the other hand, device for controlling the stoppage capable of interrupting the current supply to the motor in the event there is measured a time delay lower than a memorized threshold value.

Abstract: A variable speed control system for a single phase AC induction motor wherein a controllable switch is in series with the main winding of the motor, while the auxiliary winding of the motor, which is in series with a capacitor, is continuously energized. The switch is opened whenever the current through the main winding passes through zero. While the switch is open, the back e.m.f. in the main winding is sensed to provide a measure of the speed of the motor. This is compared with a desired speed signal and the comparison is utilized to control closure of the switch. The speed of the motor then remains constant at the desired speed, even with a varying load.

Abstract: The present invention discloses AC electrodynamic machines, such as electric motors, which are able to be operated in either a high speed mode or a low speed mode by not energizing one of the windings of the machine or by energizing the one winding so as to induce a magnetic pole of reverse polarity to that conventionally induced, respectively. Methods of operating AC electrodynamic machines are also disclosed.

Abstract: An AC induction motor has a two-pole run winding connected directly to power, a four-pole run winding connected to power by a "Triac" switch, and a separate start winding connected to power by a "Triac" switch and a centrifugal start switch. The centrifugal switch is connected between a common node to the start "Triac" and either one or the other of the power terminals. The motor always starts as a two-pole start and two-pole run winding motor. Depending upon the power terminal connection, the motor continues to run with power supplied to the two-pole run winding, or actuate the "Triac" switch of the four-pole winding to operate as a four-pole motor. In different embodiments, the centrifugal switch is connected between the start circuit terminal and either the power terminal of the four-pole winding or of the two-pole winding.

Abstract: An improved control circuit for a single-phase two-speed motor as used in a hermetic refrigerant compressor which includes start assist means is disclosed. In the preferred aspect of the invention, a start assist means is disposed between the start capacitor means and the run capacitor means for providing a discharge path for the run capacitor means into the start capacitor means after the motor is deenergized.

Abstract: An AC split-phase induction motor has a two-pole run winding, a four-pole run winding and a separate start or phase winding. The two-pole winding is connected directly to a corresponding first power terminal. The second run winding is connected to a second power terminal by a solid state gated run switch having a turn-on gate. The start winding is connected in circuit in series with a solid state gated start switch connected to the first power terminal and having a gate connected to a second power terminal. A centrifugal switch connects the first and second power terminals. The gate of the run switch is connected to the start winding circuit and includes connecting Diac and resistance elements to actuate the run switch only in response to a power connection to the second power terminal and the opening of the centrifugal switch. In operation, the motor always starts with the two-pole run winding and the start winding in the circuit. At switching speed, the start switch disconnects the start winding.

Abstract: A two-speed single phase motor of the capacitor-start type is disclosed wherein the motor is switched from the start condition to the run condition by means of a single contact centrifugally actuated switch. The motor comprises high speed and low speed main windings and a start winding employed in both the high speed and low speed configurations. A single pole single throw centrifugally actuated switch connected to the rotor has a single contact pair which opens when the motor exceeds a predetermined speed, and the same contact pair is used in both the high speed and low speed configurations. A relay comprising a coil in series with the centrifugal switch contacts has a pair of normally open contacts in series with the start capacitor so that when the centrifugal switch contacts open and interrupt the flow of current through the relay coil, the relay contacts will open thereby disconnecting the start capacitor from the circuit.

Abstract: A two speed, single phase electric motor having a stator assembly including a main winding and a supplemental winding. Each of these windings includes a pair of coil sets. The main winding coil sets and the supplemental winding coil sets are so connected to a source of electrical power such that during high speed operation of the motor the number of effective turns is the sum of the turns in one main winding coil set and its supplemental winding coil set, and during low speed operation, only the turns in the main winding coil set are energized so that there are fewer effective turns. Thus, by varying the number of turns included in the supplemental winding coil sets while keeping the total number of effective turns in the main winding and supplemental winding constant, the low speed breakdown torque of the motor may be preselected during the design of the motor to be less than, equal to, or greater than a desired high speed breakdown torque.