Abstract: A programmable electronic speed control for controlling the speed of a motor responsive to an ac signal source. A triac switch is interposed between the ac signal source and the motor. A programmable digital counter is connected between the ac signal source and the triac switch. The programmable counter counts zero voltage crossings of the ac signal generated by the ac signal source and repetitively causes the triac switch to alternately pass and block selectable numbers of cycles of the ac signal to the motor. The speed of the motor is determined by the relationship between the selectable numbers of cycles of the ac signal which are alternately passed and blocked by the triac switch. The speed control is particularly suited for use in controlling the pump motor and/or the program timer motor in a beverage dispensing machine.

Abstract: A device for controlling the phase of an output pulse sequence relative to an input pulse train of the same frequency comprises a multiplier receiving the pulse train from a frequency generator and emitting to a divider a rectangular waveform having a frequency m times that of the pulse train. The divider is controlled by a comparator to divide the frequency of the rectangular waveform by a factor of m.div.1, m-1, or m, depending on whether the actual phase difference between the pulse train and the sequence is less than, greater than, or equal to a predetermined phase angle, the actual phase difference being communicated to the comparator by a counter registering during each cycle of the pulse train a number of pulses proportional to the phase difference.

Abstract: An AC motor having AC windings with an internal electromotive force is driven by an electric valve feeding apparatus having electric valves commutated by the internal electromotive force of the AC windings. The commutation of the electric valve is carried out under the condition of U>.pi./m where m designates the number of commutation times per AC cycle of the electric valve feeding apparatus and U designates a commutation overlapping angle of the electric angle to feed the current to the AC windings whereby the motor is driven by the electric valve feeding apparatus.

Abstract: A phase lock loop commutation position control and method for a drive system for a DC field motor having a rotor and a plurality of stator windings is disclosed. Electric power is supplied to the stator windings in accordance with gating signals. The gating signals are generated in accordance with timing signals, which are provided in response to a clocking signal. A position signal is furnished as a function of the position of the rotor with respect to a preselected stator position. An error signal is generated proportionally to the phase difference between a preselected timing signal and the position signal. The clocking signal is produced as a function of the error signal. The invention also can include a shift signal produced as a function of the rotation of the rotor. The shift signal is added to the error signal effectively to cause the preselected timing signal to be advanced with respect to the position signal.

Abstract: A tachometer is coupled to the rotor of an A.C. motor and generates an output voltage proportional to the rotor's speed. A VELOCITY COMMAND voltage is generated having an amplitude which specifies a desired rotor speed. The tachometer voltage is subtracted from the VELOCITY COMMAND voltage to produce a VELOCITY ERROR voltage. The output of a D.C. power source is chopped at a fixed frequency and variable pulse width, the pulse width being proportional at any time to the amplitude of the VELOCITY ERROR voltage. The chopped D.C. voltage is filtered to provide a variable D.C. voltage having an amplitude which is proportional to the amplitude of the VELOCITY ERROR voltage. The variable D.C. voltage is applied to an inverter which changes it into an A.C. voltage. The A.C. voltage is applied to the stator windings of the motor to drive the rotor thereof. The frequency of the A.C. voltage is variable and is proportional, at rotor speeds above 150 RPM, to the amplitude of the velocity command voltage.

Abstract: In an inverter-synchronous machine drive system wherein a synchronous machine is excited by an inverter from a source of direct current, a pair of controlled bidirectional conduction means are serially coupled across the source of direct current potential, and are coupled at their junction through a commutating capacitor to the machine neutral terminal. Each controlled bidirectional conduction means, together with corresponding phase connected thyristor within the inverter, is correspondingly gated in a predetermined sequence so as to cause alternating voltage to be applied across each corresponding machine phase for initial machine excitation.

Abstract: A control device for a thyristor motor is disclosed by which the advance angle is switched at a predetermined slow rate of change in order to avoid an abrupt change in the motor torque. The thyristor motor comprises a thyristor frequency converter for a frequency conversion and a synchronous motor driven by the frequency converter, and in the thyristor motor the advance angle is switched at low and high speeds of the motor.

Abstract: A load-commutated inverter synchronous machine drive system control apparatus comprises at least one microcomputer for determining optimum or desired values for inverter turn-off time, inverter link current and machine air gap flux from machine drive system voltage and currents. Inverter frequency is regulated in accordance with the difference in magnitude between optimum and actual inverter turn-off time to minimize the inverter turn-off angle irrespective of machine frequency, thereby reducing synchronous machine reactive power. Inverter link current and synchronous machine field current are regulated responsive to the difference in magnitude between optimum and actual inverter link current and the difference in magnitude between optimum and actual machine air gap flux, respectively, thereby assuring machine operation at maximum efficiency.

Abstract: A motor drive apparatus includes a two-phase synchronous motor having two power windings. The motor is supplied with power from an alternating voltage network through a direct convertor. The converter has two controllable converter bridges that are supplied with power by the network. Each power winding of the motor is connected between a DC terminal of one bridge and a DC terminal of the other bridge. The power windings have center taps that are connected.

Abstract: In a commutatorless motor device including a synchronous motor driven through a frequency converter including gate-controlled electric valves, and a device for detecting the phase voltages of the synchronous motor, there is a device for multiplying a signal corresponding to a stator current of the synchronous motor with the detected phase voltages. The output signal of the multiplying device is added to the output signal of the phase voltage detecting device, and the sums are passed through a logic circuit and a gate-pulse generating circuit for generating gate pulses for controlling the electric valves of the frequency converter.

Abstract: To achieve synchronization of an inverter-synchronous machine drive system, feedback of a phase angle signal, derived in part from stator current drawn by, and voltage supplied to, the synchronous machine, is provided to control the frequency of inverter thyristor conduction. At light or zero synchronous machine load conditions, machine stator current may be of insufficient magnitude to permit derivation of the phase angle feedback signal; therefore, substitute simulated stator current signals, proportional to a preselected combination of inverter thyristor gating pulses, are utilized to derive the phase angle feedback signal, thereby allowing inverter-synchronous machine drive synchronism to be maintained.

Abstract: In an inverter-synchronous machine drive system subject to operator control, feedback control is employed to synchronize machine-inverter operation. A phase angle command signal, responsive to a fixed value phase angle signal during initial machine excitation and alternately responsive to machine load variation as controlled by an operator command, is generated and compared against the actual machine phase angle difference between machine phase current and air gap flux. A frequency command signal, responsive to the angle difference therebetween, is impressed on the inverter to vary machine excitation responsive to the magnitude of the phase angle difference.

Abstract: Control systems for starting and synchronously driving gyroscope rotors establish magnetic polarization of the rotor ring prior to start-up and then accelerating the magnetic field vector as the rotor accelerates to its normal operating speed.

Abstract: In a control system of an AC motor fed from a frequency converter including a thyristor rectifier and a thyristor inverter, the speed of the motor is controlled by a current control system comprising a speed control circuit responsive to a reference speed signal and an actual speed signal, and a current control circuit which produces a pulse signal supplied to the rectifier. The inverter is controlled by another pulse signal corresponding to the angular position of the rotor of the motor. An additional current instruction circuit is provided which in response to the two pulse signals described above controls the current control circuit.

Abstract: A controlled current inverter system forms the basis of an a.c. motor drive system for furnishing the motor load with a variable frequency, variable magnitude a.c. current from an inverter which is supplied from a variable d.c. current source by way of a d.c. link including an inductor. Torque is the control parameter employed in the system and the motor speed and torque are controlled through the control of motor flux and motor current, by maintaining a controlled ratio between the direct and quadrature motor currents, through separate control paths to the d.c. source and the inverter. A third control path functioning on the difference between the desired and actual motor flux serves as a modifier to the main control paths to improve overall operation and control. Means associated with the basic control paths provide for dynamic braking of the motor.

Abstract: A control system for a multi-phase synchronous machine having a shaft driven at variable speed or for developing a variable torque angle includes shaft angular position detectors that derive first and second output pulses respectively representing a shaft angular displacement corresponding with each pole of the machine and a predetermined shaft angular displacement within each pole. In response to a plurality of the second output pulses, a frequency locked loop derives a variable frequency pulse output. Individual pulses are selectively inserted and deleted from the variable frequency output to derive a variable phase pulse output representing machine torque angle. A triangle up/down counter responds to the variable phase output to derive a pulse output signal having a frequency that is a submultiple of the variable frequency output and a phase determined by the phase of the variable phase output.

Abstract: A motor speed control system for reducing instantaneous speed variations as a result of hunting in hysteresis synchronous motors utilized to drive optical scanners by controlling the frequency of the drive signal applied to the motor. A laser beam is reflected from the facets of the optical scanner and scans a surface along a scan line, a signal being generated at the start and end of each scan line. A counter is driven by an accurate clock which is started and stopped in accordance with the start and end of scan signals. The resulting count of the counter is thus inversely proportional to the speed of the motor and is converted to an analog input signal and coupled to a voltage controlled oscillator whose frequency is controlled for driving the motor such that undesirable oscillations of the motor are damped out. Additional embodiments for controlling the motor speed are disclosed which utilize only the start of scan signal to both start and stop the counter.