Abstract: The invention discloses a controller for controlling an electric motor having a stator and an armature, the stator includes stator magnetic poles, the armature includes multiple two-node, open circuit armature windings. The armature windings are inductively linked the armature and insulated from the armature and from each other. The motor has at least one repeatable section, each repeatable section includes a group of poles and windings. The stator has two stator magnetic poles per repeatable section.

Abstract: A speed control device for a DC motor includes a voltage maintaining circuit connected between the DC motor and a comparator circuit for maintaining the voltage corresponding to an electromotive force when a pulse wave outputted from a pulse-width extension circuit is at a level for off-operation of a switch element. Additionally, an average voltage maintaining circuit is connected between the DC motor and the comparator circuit and maintains in average the voltage corresponding to the back electromotive force produced in the DC motor during the time when the control pulse signal outputted from the control pulse signal output circuit is not at a level for on-operation of the switch element.

Abstract: A transformerless control circuit turns the motor of a vacuum system ON/OFF using contact points at remote vacuum inlets, the contact points being electrically isolated from the 124/240 A.C. volt power line that supplies power to the vacuum system motor and the control circuit.

Abstract: A speed control circuit in combination with an electrical motor for use in a hand-held food mixer operated on AC household electrical current. The motor is a universal type having a series connected armature winding and field winding wherein the field winding includes a plurality of taps each selectably connectable to the current source by a multipoint switch. A Quadrac.TM. semiconductor switch containing a triac and triggering diac in one package conducts electrical current from the current source through the armature winding and the selected portion of said field winding over a portion of each cycle of the current source. A trigger signal causes switching of the semiconductor switch at a predetermined phase angle relative to the voltage waveform of the current source. An error signal of a magnitude proportional to motor speed and based on counter EMF of the motor is generated by the entirety of the field winding.

Abstract: A circuit for phase control of an AC-DC motor for a machine operated in defined (preferably two) load conditions with a controllable current flow control valve located in series with the motor and associated triggering pulse stage. The circuit includes a measuring circuit designed as a rectifier circuit with filter link for detection of the load current flowing through the load path of the current flow controller or through the motor as well as a threshold value circuit which determines a first basic desired value of the triggering voltage level at the triggering pulse stage at low load current values (idling). If a triggering threshold, adjustable at the triggering value circuit, is exceeded, then the triggering voltage level is switched over onto a second firmly or permanently adjusted value, so that the motor now operates at nominal load with nominal rpm through the current flow control valve, now controlled to be fully advanced.

Abstract: Disclosed is a DC parameter motor tester based on current time response, which tester does not require coupling of the motor (14) to some mechanical device or measuring other noise sensitive parameters taken from only a few discrete data points. As is disclosed, the steady state speed of the motor is determined from the frequency composition of the commutation noise and ripple in the steady state current by performing a fast fourier transform on the steady state current to determine its power-spectral-density which shows the frequency composition of the steady state current waveform by giving the power in the waveform at each frequency. The frequency at which the most power exists is divided by the number or twice the number, depending upon the construction of the motor, of commutation segments in the motor to determine the motor's frequency of rotation or velocity at measured power input.

Abstract: A system for driving a motor, comprising a DC power supply source, a chopper apparatus switching voltage of the DC source to convert it into predetermined voltage and a shunt DC motor, wherein an armature and a field winding are connected in series and both ends of the series circuit are connected to the positive and negative terminals of the DC source and at the same time voltage at the junction point between the armature and the field is controlled by the chopper apparatus, is provided.

Abstract: A device for independently regulating rotary speed and torque of an alternating current electric motor whose armature winding is connected as a branch of a bridge circuit balanced for a fixed rotary speed and a fixed operational voltage of the motor. The motor is controlled by a current phase adjuster having an input electrode. A polarity dependent resistive circuit including two anti-parallel diodes each connected in series with an adjustable resistor, forms a branch of the bridge circuit. A comparator in the form of an operational amplifier has its inputs connected to a diagonal of the bridge circuit and its output connected to the control input of the current adjuster. The rotary speed and torque are controlled independently by adjusting the resistors in the polarity dependent resistive means.

Abstract: Thermal overload of the power tool is sensed by comparing a continually updated thermal model of the tool with a predetermined limit. The thermal model is updated in accordance with operating parameters such as motor speed and power delivered (conduction angle) and implemented using numerical integration based on a look-up table matrix. When overload is detected, power to the tool is gradually reduced, with attendant reduction in speed, followed by a cyclic or warbling increase and decrease in power to provide fluctuating low speed behavior, which may be readily recognized by the tool operator as an overload warning.

Abstract: An indirect speed sensor for an electric motor, such as an electric motor of the universal type, provides for a resistive element in series with the motor windings so that current pertubations that occur as a consequence of armature rotation are manifested as speed-dependent voltage signals across the resistive element. The voltage signals are amplified and filtered to remove frequency components above and below the expected signal spectrum and then provided to an analog-to-digital converter that converts the filtered analog signal to digital values that are stored in a memory. A stored-program controlled microprocessor analyzes the stored digital information by performing a fast Fourier transform to provide an equivalent amplitude spectrum. The maximum amplitude spectral component is then identified to determine the speed of the motor.

Abstract: A brushless motor comprising seven or more armature windings mounted on a stator, a field magnet mounted on a rotating shaft to rotate therewith with respect to the armature windings, a plurality of semiconductor commutating devices, each being connected to one of the armature windings, and Hall sensors for detecting the polarity of magnetic fields immediately opposite the windings. Each commutating device controls the direction of the electric current to be fed to its respective armature winding, according to the magnetic polarity detected by the Hall sensors. The armature windings are connected together at one end thereof and are connected to respective commutating devices at the other ends thereof.

Abstract: An automatic speed controller for a universal, series-wound, electrical motor, is part of a system whereby the motor is energized by a A.C. supply from control means including a triac, in turn, controlled by the speed controller. Within the controller signals are derived comprising solutions of the equation: ##EQU1## or a derivative thereof, or an approximation thereof, where N is the armature speed, R.sub.a is the resistance of the armature, K is a constant dependent upon the motor design, (V.sub.a -I.sub.a R.sub.a) is the true average of the alternating quantity (v.sub.a -i.sub.a R.sub.a), where v.sub.a and i.sub.a are, respectively, the instantaneous armature voltage and current, and .0..sub.AV is the true average flux in the magnetic circuit of the motor, both true averages being obtainable when the motor is operating under steady state conditions.

Abstract: In a sewing machine with a universal motor, a speed control for the motor, a lamp, and a plug connection on the sewing machine housing for connecting the power supply and speed control lines to the motor and to the lamp, for equivalent replacement of the normal impedance starter by one with integrated phase angle control, a phase angle control is provided as a speed controller which comprises a rectifier bridge consisting of diodes for current supply to the phase angle control and to the lamp, as well as a rectifier bridge with semiconductor devices controlled by the phase angle control, for the control of the motor.

Abstract: An electronic control and regulating system for AC-operated appliances, especially universal motors and with symmetrical phase control. The control circuit includes among other things an inductive current-voltage converter 9, the primary side 8 of which is connected to the load current circuit and in which, in addition to the converter function, the inductivity of the secondary winding 10 is used and becomes a component of a resonant circuit 20 which is tuned approximately to the frequency of the AC voltage source. The feedback variable of the control system is formed by the resonant circuit voltage, i.e. the resonant circuit impedance, which depends not only on the magnitude of the load current but also on the phase angle of the load current. This quasi-resonance effect makes possible a direct influence of the trigger circuit which consists customarily of a trigger capacitor 13, a load resistor 11 and a trigger diode 15 and is possible without excessive use of additional circuit elements.

Abstract: A commutator motor can be set to different speeds by changing the external circuit connections between the single phase AC supply line and the stator field winding. The field winding is distributed in slots over at least part of the circumference of the stator bore and the field winding connection is switched, when going from a lower to a higher speed, in such a way that the axis of the stator field is rotated in the direction of rotation of the motor. For improved performance, the number of excitation turns may also be changed, simultaneously with the rotation of the field axis. The motor is particularly useful for automatic washing machine drives having a universal motor.

Abstract: A microcomputer controlled power tool including a semiconductor control device connected to the motor, one or more sensors, and a microcomputer interfaced to a keyboard and digital display for monitoring and controlling various operating conditions and parameters of the power tool.

Abstract: An induction and universal (commutator) motor combination which share a common lamination core and are supplied by a single-phase line. The stator and rotor are provided with multiple poles and phase windings. A winding system for at least one rotor phase winding is common to commutator motor as well as induction motor operation. A lap winding is connected to a commutator, said lap winding having a coil span corresponding approximately to a single pole pitch of the commutator motor stator winding and corresponding as well to an uneven integral multiple of the coil span of the multi-pole induction motor stator winding. The invention finds particular application in regard to drives for automatic washing machines.

Abstract: A universal series motor having its brushes shifted at an angle against the direction of rotation is provided with a braking arrangement which removes power from the field windings and applies power directly to the armature winding.

Abstract: A speed control circuit arrangement for controlling a rotational speed of an AC commutator motor by an AC controlled rectifier element. The speed control circuit arrangement comprises a pulse transformer which is connected at the secondary winding to the control electrode of the AC controlled rectifier element and one of two main electrodes of the controlled rectifier element and supplies a trigger pulse to the control electrode, a variable resistor for adjusting the rotational speed of the motor, a first capacitor connected at one end through the variable resistor to the other main electrode and at the other end to one end of an AC power source, a pulse generating element connected across said first capacitor with the primary winding of the pulse transformer intervening therebetween, and a first resistor connected at one end to the one main electrode and at the other end to the other end of the AC power source through the first capacitor.

Abstract: A hammer drill having a bypass switch which is activated by the selector ring to prevent the drill from operating in the hammer mode by shunting the reversing switch. This is a precaution to prevent damage to the clutch teeth which are designed for ratchet action when the tool is operated in the forward direction, but will lock down in reverse to stall tool or damage the mechanism. In the drill mode, the bypass switch connects the reversing switch in circuit with the on-off switch.

Abstract: A transformer having a secondary winding that delivers a regulating magnitude to a speed regulator circuit that approaches zero as the speed approaches the speed setting, is provided with two primary windings wound and connected so that they oppose each other in operation. The first is the conventional primary winding in series with the universal motor of which the speed is being controlled (as by a conduction phase angle control of the input voltage) while the second primary winding is in series with a resistance and, in some cases, also with a capacitor, with this series combination being connected in parallel with the armature winding of the motor for the best regulation, or in parallel with the motor as a whole if it is important to avoid additional internal connections to the motor. The capacitor is used to compensate for the inductive reactance of the second primary winding in cases in which that reactance is not negligible. A second capacitor across the secondary filters out commution "hash.

Abstract: A control circuit controls AC energization of a universal, series wound AC motor in a circuit breaker motor operator to power a breaker charging cycle. At the end of a charging cycle, the motor field winding remains energized from the AC source, however a braking resistor is switched across the de-energized motor armature to achieve dynamic braking. A timing circuit operates in the dual capacity of controlling dynamic motor braking and preventing continued running of the motor operator should the breaker operating mechanism fail to reset during a charging cycle.

Abstract: Variable-speed electric motor drive includes a universal motor having a power supply line wherein a thyristor is connected and operated in a phase gating circuit, a firing circuit for the thyristor, a variable first resistance connected to the firing circuit of the thyristor for varying the rotary speed of the motor, and a temperature-dependent second resistance associated with the firing circuit and thermally coupled to the thyristor.

Abstract: A universal motor is energized by a speed setting circuit during one half wave and a speed control circuit during the next half wave of each cycle of an AC supply. The speed setting and speed control circuits each have a separate timing circuit including a capacitor. There is thus no residual charge on the capacitor of the speed setting circuit remaining from the operation of the speed control circuit during the preceding half wave. The residual charge prevented the setting of low motor speeds in the known systems. The speed control circuit includes a storage capacitor transformer coupled to the motor so that its initial charge corresponds to the current through the motor during the preceding half wave. The charge is transferred to a second capacitor. When the voltage across the second capacitor reaches a predetermined threshold valve, a switch in the speed control circuit becomes conductive and current flows through the motor.

Abstract: The motor is serially connected with a diode and a sensing resistor so that half waves of one polarity, for example negative, can flow through the motor and provide, across the resistor, a voltage drop corresponding to loading placed on the motor. A thyristor is connected in parallel to the diode and reversely poled to conduct the other half wave, then the positive, if triggered. Triggering of the thyristor is controlled by the voltage drop across the sensing resistor so that, under no-load conditions, only the negative half waves will be applied to the motor, thus limiting its no-load speed but, as loading is placed thereon, increasing portions of the positive half waves are likewise passed through the motor.

Abstract: A first thyristor, under control of a speed setting provided in an RC circuit varies the phase duration of current supply to the motor during positive halfwaves of the a c supply, and a second thyristor controlled in accordance with the motor current provided through the first thyristor determines the phase angle during which current flows through the motor in the negative halfwave of the voltage supply, so as to maintain the speed at the set value under varying conditions of load. During positive halfwaves, a capacitor is charged to a voltage corresponding to the amount of current flow through the motor and during the following negative halfwave, the charge is increased at a rate set by an RC circuit, resulting in turning on the second thyristor early under heavy load conditions, and late under light load conditions, and indeed not at all under idling conditions.

Abstract: The variator comprises a triggerable silicon-controlled rectifier component for connection in series with the a.c. motor to the a.c. source, and a phase-shifting circuit connected to the terminals of the rectifier component and comprising a capacitive branch and a resistive branch which has a regulating potentiometer. The junction between these two branches is connected to the control electrode of the rectifier component. A unidirectional semiconductor component responsive to voltage is connected in parallel with the capacitive branch and a part of the resistive branch in which the potentiometer is inserted. The resistive branch comprises connected in parallel a first branch comprising a first resistor and the potentiometer and a second branch comprising a second resistor and a third resistor. The junction between the second and third resistors is connected to the slide of the potentiometer and the unidirectional component is connected to the junction between the potentiometer and the first resistor.

Abstract: A device for limiting the current in an a.c.motor having a commutator adapted to be supplied with current by a single-phase current source. The device comprising a triggerable silicon-controlled rectifier component connected in series with the motor and in parallel with an RC phase-shifting circuit furnishing the control voltage of the rectifier component. The capacitive branch of the RC circuit is connected in parallel with a shunt circuit which shunts a certain quantity of the charging current of the branch for modifying the trigger instants of the rectifier component. The shunt circuit comprises two transistors of opposed conductivity types which are connected with a common emitter configuration, the collector-emitter circuits of the transistors being connected in parallel with the capacitive branch. The limiting device further comprises a control circuit furnishing two d.c.

Abstract: In an SCR circuit controlled universal motor, means is provided for smooth speed control at all speed settings especially low settings which comprises a series wound stator field as part of the motor and at least one closed conductor loop of wire encircling the stator magnetic flux path.

Abstract: A motor speed control system which comprises: (a) a power modulator circuit having gating means adapted to control the power supplied to the motor; (b) means adapted to provide a voltage which is directly proportional to the instantaneous motor terminal current; (c) means adapted to provide a sensing current which is directly proportional to the voltage across means (b), and thus to the instantaneous motor terminal current; (d) means adapted to provide a sensing current which is directly proportional to the instantaneous motor terminal voltage; (e) summing means adapted to algebraically sum the instantaneous values of the two sensing currents; (f) integrator means adapted to average the sum of instantaneous values provided by means (e); and, (g) feedback means adapted to generate a signal for operating the gating means, said signal having a phase determined by the output of the integrator means, whereby the output of the integrator means controls the phase of the gating means and thereby controls the power su

Abstract: To reduce noise and idling speed of electric motors, particularly series motors, the speed-torque characteristic of the motor is dropped with respect to the loaded speed-torque characteristic, by sensing no-load operation of the motor and deriving a sensed signal, the sensed signal being applied to controlled switches to abruptly change the effective voltage applied to the motor between values corresponding to the no-load speed-torque characteristic, or the load speed-torque characteristic and resulting in the desired speed, in dependence on the value of the sensed signal. Preferably, the operating condition of the motor is sensed by an inductive transducer, and a speed change is obtained by phase control, or half-wave rectification.