Abstract: For the purpose of providing a two-phase asynchronous motor of the kind comprising a wound stator made up of two portions spacedly disposed parallel to each other and in which the flux flowing in all the field magnets of the stator is exclusively that of their own phase and in which sufficient space is available for a comparatively large number of field magnets, the stator windings of each phase are each accommodated in one said portion of the stator only and the poles of a member movable with respect to the stator are in the form of ferromagnetic bridges, surrounded and magnetically separated with respect to each other by a short-circuit element, the arrangement being such that the magnetic circuit of adjacent stator poles is completed directly via the pole shoes of the oppositely disposed portion of the stator. The invention is applicable to both linear and rotary motors. In the case of a rotary motor, the said member defines the rotor and the said element is in the form of a short-circuit cage.

Abstract: An electric motor comprises a rotor constructed by a disk-shaped multi-pole magnet secured to a rotary shaft and rotatably supported, and a stator constructed by a pair of star-shaped flat drive coils arranged adjacent and opposing to the disk-shaped multi-pole magnet. Sinusoidal wave currents, the phase angles of which differ by 90.degree. from each other, are supplied to the pair of drive coils to drive the magnet. A speed detection coil having a plurality of power generating strands is arranged in a field of the magnet and a field of the drive coils to produce a signal having a frequency corresponding to a rotational speed of the magnet.

Abstract: A control system for regulating the torque and speed of an alternating current induction motor used in the traverse drive of an overhead travelling crane comprises an SCR bank controlled by a firing circuit responsive to actuation of an operator-controlled induction master control. The control system further comprises means for deriving a torque signal indicative of instantaneous rotor torque, means for deriving a speed signal indicative of instantaneous rotor speed, and summing means for combining the torque signal, the speed signal, and a reference signal from the induction master control to provide an error signal which is used to operate the firing circuit to thereby control the power delivered by the SCR bank to the motor and ensure that motor torque is constant for the control position selected or speed is controlled up to the torque level selected.

Abstract: A mixing control system for elastomeric materials is described that includes a mixer housing forming a mixing chamber therein for receiving said elastomeric materials; at least one rotatable mixing means in the chamber; a dynamometer coupled to and driving said rotatable mixing means; torque sensing means for detecting torque exerted by the mixing means; said sensing means providing a torque signal level for controlling said mixing means; voltage-to-frequency conversion means for processing signal in which the pulse frequency varies in correspondence to the amplitude of the signal level; pulse counting means for continuously and cumulatively counting the pulses of said pulse signal; display means for displaying the count of said pulse counting means as the value of the integral of said signal level with respect to time; and control responsive means automatically responsive to a predetermined integrated value of said display means for controlling the total mixing energy input to the mixing control system.

Abstract: A combination starting and protecting device particularly useful with split phase motors such as those used with refrigeration compressors is disclosed in which an element of material having a positive temperature coefficient (PTC) of resistivity characteristic and a thermally responsive switch are disposed in the same housing. A thermal coupling of a preselected value between the PTC element and the thermally responsive switch is provided so that a desired reset or "off" time is obtained for the thermally responsive switch without affecting the "on" time.

Abstract: A driven load is advanced to a selected position by the rotor of a large angle step motor, the housing of which is driven by a small angle step motor having a stationary housing. Driving pulses are fed to the plural phase windings associated with the large angle step motor under control of digital logic, by means of a slip ring assembly. Driving pulses are also fed to the plural phase windings of the small angle step motor under control of the same digital logic.

Abstract: A method and apparatus for damping stepper motors are disclosed. A tachometer feedback is used to modulate the phase angle of the stepper motor command currents to achieve damping.

Abstract: In apparatus for controlling the speed and torque of a multiphase a.c. motor in accordance with digital control signals, a first regulation circuit regulates the frequency of the a.c. electrical signal applied to the motor and another regulation circuit regulates the voltage of the a.c. signal. Both regulation circuits are controlled by digital control signals in a series of discrete steps over a range of control values and the control signals are supplied periodically to the regulation circuits. The speed and torque are controlled in accordance with an algorithm relating speed and torque to the frequency and voltage of the source of electric power which is applied to the motor, calculated by computing apparatus on a periodic basis. In one embodiment the position of the magnetic flux of the stator is controlled directly.

Abstract: A power management system for controlling the power usage by a plurality of loads in a facility and including a system control unit for monitoring the power consumption of the loads and for generating a control signal when the consumption falls below a low level and when the consumption exceeds a high level, and a load control unit and a plurality of switching modules for receiving the control signal, and based upon eligibility and a preassigned priority ranking, selecting and shutting down one or more of the loads for a first predetermined time period followed by a second predetermined time period during which the load is allowed to run, any shutdown load being designated as ineligible for further shutdowns during the cycle including both of the first and second time periods.

Abstract: An automatic punch press and monitoring system. The monitoring system includes a piezoelectric accelerometer mounted within the stationary die shoe of the punch press, and electronic circuitry including a variable gain amplifier, a detector, an integrator, and a comparator. The monitoring system is manually placed in a "LEARN" mode whereupon the signal produced by the accelerometer during normal operation of the punch press is amplified, detected, and integrated over the time period of one stroke to produce a test function. The gain of the amplifier is automatically adjusted during successive normal strokes of the punch press until the test function is equal to an arbitrary set point, thereby establishing a reference function. The monitoring system is then automatically placed in an "AUTO CONTROL" mode whereupon on each succeeding stroke, with the gain of the amplifier fixed, the test function produced is compared with the reference function.

Abstract: An electrical circuit arrangement for filtering electrical brush noise transmitted from an open switching wire connected at one end to an intermittently used brush of a multi-speed electric motor driven by a power source and having an electrically grounded housing and stator, said circuit arrangement utilizing a switching transistor located in close proximity to said brush and motor.

Abstract: For use with an adjustable speed a-c electric motor having a stator adapted to be coupled to a source of variable frequency excitation and a rotor in which torque is developed when the motor is excited, the strength of said torque being dependent on interacting current and flux in the motor, a scheme is provided that comprises means for deriving an angle feedback signal representative of the actual phase angle between the aforesaid current and flux and means responsive to said angle feedback signal for controlling the source of variable frequency excitation so as to control the frequency of stator excitation as a function of the angle feedback signal.

Abstract: For use with an adjustable speed a-c electric motor comprising a stator having effective direct and quadrature axes and a rotor spaced from the stator by a gap, said stator including windings adapted to be connected to a source of excitation of variable frequency and amplitude, a scheme is provided that comprises means for deriving a "torque angle" feedback signal representative of the phase angle between current and flux that interact in the motor to develop electromagnetic torque tending to move the rotor relative to the stator, in combination with means responsive to the torque angle feedback signal for controlling the source of excitation so as to control the frequency of stator excitation as a function of the torque angle feedback signal. In one aspect of the invention, means is provided for controlling the source of excitation so as to control the amplitude of stator excitation as a function of a variable command signal that is prevented from deviating below a predetermined limit.

Abstract: A control system for a commutatorless motor, comprising a synchronous motor having a polyphase armature winding and a field winding; a frequency converter for supplying the armature winding with alternating current having a variable frequency; an angular position detector for detecting the angular position signal corresponding to the angular position of the rotor of the synchronous motor; a speed control circuit for delivering a current reference signal having an amplitude corresponding to the deviation of the actual speed of the synchronous speed from the reference speed; a current control circuit for controlling the amplitude of the output current of the frequency converter in accordance with the current reference signal and for maintaining the amplitude of the output current of the frequency converter constant in the range where the torque reference signal assumes a value smaller than the intermittent threshold of the armature current; and a phase control circuit for controlling the phase of the output cur

Abstract: A switching system comprises a switching mechanism including at least two stationary contact members, a movable contact and a rotatable switching member. The switching member rotates in one direction to urge the movable contact into contact with a first and then the second of the two stationary contacts and in the opposite direction to urge the movable contact into contact with the second and then the first stationary contact. A circuit has the two inputs thereof connected to the stationary contacts and has two outputs and is responsive to the order in which the first and second stationary contact members are contacted for generating an output signal at only a first of the two outputs when the rotatable switching member is rotated in one direction and for generating an output signal at only the second of the two outputs when the switching member is rotated in the other direction.

Abstract: A Hall effect shaft angle position encoder is constructed using a plurality of magnetic elements independent of any magnetic rotor of the electrical device which may be a brushless motor or brushless tachometer. The plurality of magnetic elements has serially alternating polarities of magnetic north and south with at least one Hall effect sensor mounted in spaced and confronting relation with the magnetic elements for sensing the alternating polarities and producing output signals representative of the magnetic polarities where the signals include a ramp voltage passing through zero value. The magnetic elements are secured to the rotor outside the normal rotor elements of the device.

Abstract: A drive circuit for energizing the winding of a stepper motor includes a first amplifier circuit which receives a unipolar input signal and depending upon the amplitude couples a positive or negative voltage potential to one terminal of the winding. A second amplifier circuit also receives the input signal and applies the same polarity voltage potential to a differentiating circuit. The differentiating circuit operates a transistor switch to couple for a predetermined period of time, a voltage potential of opposite polarity but equal in magnitude to that coupled to the first terminal of the winding, to the second terminal thereof. The application of the double voltage to the winding causes a rapid torque buildup and great acceleration to the stepper motor for a short period of time. The differentiating circuit includes a capacitor having a predetermined time constant which controls the period of time the opposite polarity voltage potential is applied to the second terminal of the winding.

Abstract: Accurate induction motor speed control is accomplished by controlling the duty cycle of operation of high voltage switches which in turn drive the motor windings. For two phase operation logic circuitry generates two bipolar variable duty cycle waveforms with the off-time of each waveform being adjustable to vary motor speed. For single phase operation a single control waveform is generated. An initialization circuit is also provided and forms a part of the circuitry for converting the input AC line voltage to a DC voltage level useable by the high voltage switches. This initialization circuit controls the charging of capacitors of the AC to DC converter and provides efficient power transfer.

Abstract: A variable-reluctance electric motor comprises a stator of ferromagnetic material, having poles provided with induction windings and distributed in four equal groups. The motor is provided with at least one ferromagnetic material rotor ring having equidistant teeth and bearing switching means actuated by the rotation for distributing direct current to the stator windings. The windings and switching means are so combined that, during each advance of the rotor by one tooth pitch, each pole is subjected to two opposite switching operations staggered by a time equal to that taken by the motor for a one-fourth of a tooth pitch rotation. The stator poles are equidistant, each bearing one winding, and are number (4kl), k being at least equal to 2 and l being any number. The rotor has (lm) teeth, m being an odd number greater than (4k). The switching means are so actuated as to switch over the d.c.

Abstract: An electric motor system comprising a rotor including permanent magnets providing a plurality of correspondingly directed magnetic poles angularly displaced around said rotor, a stator comprising first and second windings adapted to cooperate with the poles of said rotor, each of said windings having transversely disposed conductive portions for intercepting the magnetic fields of said poles during rotation of said rotor, and an amplifier having its input coupled to said first winding so as to be energized by alternating voltage induced in said first winding during rotation of said rotor, and having its output coupled to said second winding to supply alternating current therethrough in synchronism with the interception of the magnetic fields of said poles by the transverse portions of said second winding.