Abstract: A facility for the production of containers from blanks, which facility includes: a forming unit equipped with a rotating carrousel driven by a motor; a unit for heating blanks, equipped with infrared emitters and a power feed for each emitter; a control unit having in the memory a nominal speed setpoint ?N of the rotation of the carrousel and a nominal electrical power setpoint PN. The control unit is programmed for: controlling the rotation of the carrousel according to the nominal speed setpoint ?N.

Abstract: A method and an apparatus for adjusting an operating frequency of an inverter compressor are provided. The method includes following steps: detecting whether an inverter air conditioner is in a heating mode; obtaining a target operating current of the inverter compressor if the inverter air conditioner is in the heating mode; adjusting the operating frequency of the inverter compressor according to the target operating current; obtaining an operating parameter of the inverter compressor and obtaining a maximum operating frequency of the inverter compressor according to the operating parameter; obtaining a current correction according to the maximum operating frequency and correcting the target operating current according to the current correction to update the target operating current.

Abstract: A regulating circuit that regulates rotary speed of a pulse-width modulated fan includes a measuring device that determines a period duration (TIst) of a tacho signal (TACH) of the fan, a digital regulating register that acquires a regulation value to drive the fan on the basis of a determined period duration (TIst) and a desired value (Tsoll), a digital control register that adjusts a duty ratio to drive the fan, the digital control register has a smaller register width than the digital regulating register, and a controller that updates the digital control register by evaluating a predetermined number of more significant bits of the digital regulating register.

Abstract: A control system (128) for controlling a switched reluctance (SR) machine (110) having a rotor (116) and a stator (118) is provided. The control system (128) may include a converter circuit (122) operatively coupled to the stator (118) and including a plurality of switches (132) in selective communication with each phase of the stator (118) and a controller (130) in communication with each of the stator (118) and the converter circuit (122). The controller (130) may be configured to determine a position of the rotor (116) relative to the stator (118), and generate a modulated switching frequency (152) based on the rotor position.

Abstract: A driving circuit for a single-phase-brushless motor includes a driving-signal-generating circuit to generate a driving signal for supplying, to a driving coil of the single-phase-brushless motor, first- and second-driving currents alternately with a de-energized period therebetween, an output circuit, and a zero-cross-detecting circuit.

Abstract: A drive system for an electrical machine is provided. The system includes a control unit and a monitoring unit, which is independent of the control unit. The control unit includes a device that converts one or more incoming operating parameters of the electrical machine to an output value. The monitoring unit includes a device that converts the operating parameters to a comparison value, with the conversion being carried out more quickly in the control unit than in the monitoring unit. A comparator compares the output value or an intermediate value of the output value with the comparison value of the output value or of the intermediate value.

Abstract: A fan motor control device comprises a clock signal generator and a drive unit. The clock signal generator generates a low-frequency clock signal. A frequency of low-frequency clock signal is less than 23 KHz. The drive unit converts the low-frequency clock signal to a high-frequency drive signal and outputs the high-frequency drive signal to drive the fan motor. A frequency of the high-frequency drive signal is higher than 23 KHz.

Abstract: One embodiment of the invention relates to a control system. A control system includes a controller configured to generate a drive signal as a function of a comparison between a first control signal and a second control signal, wherein the first control signal differs from the second control signal. A switching device is configured to generate an output control signal having a duty cycle that is a function of the drive signal. Other systems and methods are also disclosed.

Abstract: A digital motor control system utilizes time duration electric pulses generated by digital logic to control the motor speed and direction of rotation of a D.C. or A.C. motor. The digital logic produces width modulated pulses that can be connected to large or small electric motors by mechanical or electrical relays or switches to provide efficient motor control with little control circuit power loss. The mechanical or electrical switches are responsive to the digital logic to change motor direction or remove power from the motor windings. A variable control element such as a computer joystick can be utilized to control both direction and speed of the motor. The system can be configured as an open loop system or as a closed loop servo with a feed back element to control the rotational position of the motor.

Abstract: A compressor is powered by a motor which is, in turn, powered by a variable speed drive (VSD). The switching frequency and voltage/frequency relationship of the VSD may be adjusted dynamically to maximize efficiency.

Abstract: A fan motor control device comprises a clock signal generator and a drive unit. The clock signal generator generates a low-frequency clock signal. A frequency of low-frequency clock signal is less than 23 KHz. The drive unit converts the low-frequency clock signal to a high-frequency drive signal and outputs the high-frequency drive signal to drive the fan motor. A frequency of the high-frequency drive signal is higher than 23 KHz.

Abstract: A control and motor arrangement in accordance with the present invention includes a motor configured to generate a locomotive force for propelling the model train. The control and motor arragement further includes a command control interface configured to receive commands from a command control unit wherein the commands correspond to a desired speed. The control and motor arrangement still further includes a plurality of detectors configured to detect speed information of the motor, and a process control arrangement configured to receive the speed information from the sensors. The process control arrangement is further configured and arranged to generate a plurality of motor control signals based on the speed information for controlling the speed of said motor. The control and motor arrangement yet still further includes a motor control arrangement configured to cause power to be applied to the motor at different times in response to the motor control signals.

Abstract: A method of interfacing an electromagnetic sensor with a controller in a motor control system, the method including: applying an excitation signal to the electromagnetic sensor; receiving a first electromagnetic sensor output signal based on the excitation signal, the first electromagnetic sensor signal comprising an amplitude modulated signal corresponding to a position of a rotor of the electromagnetic sensor; and receiving a second electromagnetic sensor output signal based on the excitation signal, the second electromagnetic sensor signal comprising another amplitude modulated signal corresponding to the position of the rotor of the electromagnetic sensor.

Abstract: In a control apparatus for a motor, which rotates a fan, a semiconductor device is connected to the motor in series to drive the motor. An analog driver circuit drives the semiconductor device with an analog voltage. A PWM control circuit drives the semiconductor device with a PWM signal of a frequency of less than several tens. A switching control circuit selects the analog driver circuit and the PWM control circuit when the motor is to be rotated at speeds lower and higher than a predetermined speed, respectively.

Abstract: In the invention, a PWM signal is formed at a frequency of a reference pulse signal, the PWM signal which has a pulse width being changed according to a frequency difference between an FG pulse signal for detecting a speed of a brushless motor and the reference pulse signal of a target speed, an output signal for PWM control is formed by an N-fold frequency of the PWM signal, the output signal for PWM control in which a pulse having the divided pulse width is arranged in each N-divided period, the N-divided period in which each one period of the PWM signal is divided by N, and electric power supply to a coil of each phase of the brushless motor is turned on and off at intervals shorter than that of the output signal control without increasing the frequency of the reference pulse signal.

Abstract: A fan speed control includes a power adapter, a CPU programmed with a phase splitting program, a current-limit resistor, a capacitor, a TRIAC, and a switch module, the CPU having a signal input terminal connected in series to the power input terminals of the power adapter through the current-limit resistor to obtain synchronous signal frequency as input signal, a signal output terminal connected in series to the capacitor and then the gate of the TRIAC for enabling the CPU to control triggering of the TRIAC, the TRIAC having the gate connected in series to the capacitor, and the anode and cathode respectively connected to the fan motor and the power output terminal of the power adapter, so that the fan motor, the TRIAC and the power adapter form a loop in which the TRIAC controls the operation speed of the fan motor; the switch module having one end connected to the control input terminal of the CPU for controlling the output state of the signal output terminal of the CPU and the other end connected to the po

Abstract: A control system for an electric machine having a rotor position sensor that generates a rotor position signal, a velocity module that generates an electric angular velocity value based on the rotor position signal, a random pulse width modulation module that generates a switching period and a delay for a current cycle, and a phase angle compensation module that sums a sample rate, one half of the switching period, and the delay of a previous cycle and that outputs a delay time. The phase angle compensation module further multiplies the delay time and the electric angular velocity value and generates a compensating angle.

Abstract: A control system in the form of an all-digital phase-locked loop controls movement of a DC motor. The control system includes a movement detector in the form of an optical encoder to detect movement of a DC motor. A digital phase detector compares output of a feedback signal from the movement detector and a reference signal. The digital phase detector is phase frequency detector that follows a describing function to model non-linear components of the reference signal. A digital loop filter then filters noise from the comparison signal and the filtered signal is amplified to control the DC motor. The phase frequency detector includes a state machine to track a time varying reference signal and selectively output a response to provide for system damping.

Abstract: A frequency regulator protection circuit for controlling acceleration of electric vehicle comprises a power unit, a display unit, a protection unit, a control unit, a sensor unit, a data processor unit, a trigger unit, a regulator unit, and an output unit. The control unit receives a rotation speed signal from a motor. The sensor unit detects whether there is a current overload and delivers a corresponding overload signal to the data processor unit that consequently outputs a frequency change signal to the trigger unit which, in turn, delivers a first regulation signal to the regulator unit. The output unit further delivers a second regulation signal to the regulator unit, corresponding to different situations of insufficiency of pedal control, brake control, over-speed control, or motor overload. The regulator unit consequently effectuates an adequate cutoff of power supply.

Abstract: A frequency regulator protection circuit for controlling acceleration of electric vehicle comprises a power unit, a display unit, a protection unit, a control unit, a sensor unit, a data processor unit, a trigger unit, a regulator unit, and an output unit. The control unit receives a rotation speed signal from a motor. The sensor unit detects whether there is a current overload and delivers a corresponding overload signal to the data processor unit that consequently outputs a frequency change signal to the trigger unit which, in turn, delivers a first regulation signal to the regulator unit. The output unit further delivers a second regulation signal to the regulator unit, corresponding to different situations of insufficiency of pedal control, brake control, over-speed control, or motor overload. The regulator unit consequently effectuates an adequate cutoff of power supply.

Abstract: A motor rotational pulse generating circuit for a motor is provided which generates a correct pulse signal even at an initial turning-on stage of the motor, by adjusting a filter cutoff frequency in response to motor rotational condition. The motor rotational pulse generating circuit includes a rotational pulse generation circuit 20 which generates ripple pulses based on a signal being inputted from the DC motor 1, in which a ripple is superposed whose frequency is in proportion to a rotation number of the DC motor 1. A filter 3 makes a cutoff frequency variable on the basis of a clock signal issued from a PLL circuit 6. An oscillation frequency at an oscillator VCO10 is determined by the ripple pulses and a motor rotation condition signal inputted by way of circuits 12 to 16 inclusive. A microcomputer 20 operates, when the motor is turned on, to cause the oscillator VCO10 to issue a preliminary clock signal.

Abstract: A pulse generating circuit for motor rotation of a direct current motor which is capable of pulse generation following the variation of the motor rotation condition and of stable ripple pulse generation. The pulse generating circuit for motor rotation includes a filter for varying a cut-off frequency fc by the signal from outside and for removing the noise based on the input signal from the direct current motor, a pulse forming circuit for forming the ripple pulse in accordance with the motor rotation of the direct current motor based on the output from the filter, a clock generating circuit for varying the cut-off frequency fc of the filter by providing the clock signal fCLK which is generated based on the rotational condition signal of the ripple pulse and the direct current motor to the filter, and a pulse correction circuit for generating the corrected ripple pulse when the frequency ratio between the ripple pulse and the clock signal fCLK is deviated.

Abstract: A method and system for optimizing performance of vehicle control systems based on the dynamics of the specific vehicle include a sensor for sensing a predetermined parameter associated with any one of the vehicle control systems during a predetermined trigger event. A control logic determines a critical vibration mode characteristic for the vehicle control system based on the sensed parameter and operates the vehicle control system based on the determined critical vibration mode characteristic.

Abstract: An active attenuation system for a DC motor which yields global vibration reduction of slot or other motor induced tonals at the plate on which the motor is mounted without modifying the construction of the motor. The system comprises one or more vibration sensors, a signal synchronized to the slot rate or other motor induced tonal rate, an electronic adaptive controller and the means to supply the control signal into the motor field and/or armature current.

Abstract: In a closed loop control system that governs the movement of an actuator a filter is provided that attenuates the oscillations generated by the actuator when the actuator is at a resonant frequency. The filter is preferably coded into the control system and includes the following steps. Sensing the position of the actuator with an LVDT and sensing the motor position where motor drives the actuator through a gear train. When the actuator is at a resonant frequency, a lag is applied to the LVDT signal and then combined with the motor position signal to form a combined signal in which the oscillation generated by the actuator are attenuated. The control system then controls ion this combined signal. This arrangement prevents the amplified resonance present on the LVDT signal, from causing control instability, while retaining the steady state accuracy associated with the LVDT signal.

Abstract: The motor speed control device of the present invention is provided with an FG sensor and a waveform shaping circuit for obtaining N pulse signals (N.gtoreq.1 where N is an integer) in one rotation of a motor so as to control the rotation speed of the motor in accordance with period information of the FG pulse signal outputted from the waveform shaping circuit. The motor speed control device is further provided with an FG nonuniformity correcting circuit for correcting, by using respective period information of a rising edge-falling edge period and a falling edge-rising edge period, periodic nonuniformity of each period. The motor speed control device controls the motor in response to an actual speed error signal whose nonuniformity such as a duty error and a phase error has been corrected by the FG nonuniformity correcting circuit.

Abstract: A vehicular motor driving apparatus includes a control unit 15 for drive-controlling a motor by PWM-drive-controlling a motor driving circuit based on a motor starting signal. The control unit has a drive controller for setting a drive frequency of a PWM-drive control signal to be an integral multiple of or (integer+0.5) times a channel frequency interval of channel frequencies allotted for AM radio broadcasts. As a result, radiation noise associated with harmonics of the PWM-drive control signal, when coincided with the channel frequencies used by AM radio broadcast stations, is removed along with the channel frequencies through radio receiver detection. When the radiation noise does not coincide with the in-use channel frequencies, it is offset by the channel frequency interval therefrom, thereby preventing its reception.

Abstract: A motor rotational speed control apparatus is constructed by a control unit for performing an instruction to accelerate a rotational speed of a motor, an instruction to decelerate, or an instruction to maintain a rotational speed, a driving unit for driving the motor in accordance with an instruction outputted from the control unit, and first and second wires for transferring the instruction of the control unit to the driving unit. The control unit shows the instruction by a combination of signal levels of a first signal and a second signal and transmits the first and second signals to the driving unit through the first and second wires, and the driving unit drives the motor in accordance with the combination of the signal levels of the first and second signals.

Abstract: The invention provides an apparatus and a method for controlling the rotation frequency of an infinite variable-speed drive in which, when an error is caused in an output rotation frequency of the infinite variable-speed drive during a processing time period, a target rotation frequency is calculated in view of the error, so as to control the rotation frequency in the remaining processing time period in accordance with the calculated target rotation frequency. The target rotation frequency is calculated on the basis of the remaining processing time period and a pulse number to be counted in the remaining processing time period.

Abstract: The invention relates to an X-ray apparatus, comprising a rotary-anode X-ray tube, a device for monitoring the rotational speed of a rotary-anode drive motor of the X-ray tube, a sensor circuit for determining an angle signal which is dependent on the phase angle between a reference voltage and a current associated with the motor, a comparator circuit for detecting the angle signal variation which serves as a criterion for the rotational speed of the motor, and also comprising a frequency changer. Thanks to the fact that there is provided a device for forming a brief keying signal so as to trigger a reduction of the frequency of the rotary-anode drive motor, the device is also suitable for induction motors in which only a small phase angle variation is measured between standstill and the operating rotational speed.

Abstract: A DC motor control circuit which contains a DC motor as a part of bridge resistance constituting a bridge circuit includes a first terminal connected to one end of the DC motor in the bridge circuit. A switching transistor is connected to the first terminal. A second terminal is connected to the other end of the DC motor. A switching control circuit detects an unbalanced condition of the bridge circuit via the second terminal and controls the switching period of the switching transistor so as to restore the bridge circuit to a predetermined unbalanced condition or balanced condition. A part of the bridge circuit, the switching transistor and the switching control circuit are integrated into an IC, thereby the number of terminals for the IC is reduced and a coil and an externally added capacitor both for smoothing are unnecessary.

Abstract: A device for detecting the speed of a plural-phase motor in which a speed deviation occurring every m periods is eliminated, to provide a speed detection signal high in accuracy at low cost. The motor speed detecting device in which, among drive signals driving a plural-phase motor, m-phase drive signals (where m is a natural number which is not less than two (2) and equal to or smaller than the number of phases of said motor) are detected, and combined to form a signal, comprises a frequency divider adapted to subject the signal thus formed to 1/(m.times.n) frequency division (where n is a natural number).

Abstract: In two embodiments of the present invention, the speed of a DC motor is determined by examining the signal at the negative terminal of the motor. The signal is high-pass-filtered to extract the AC component of the signal. The frequency of this signal is, in almost all cases, proportional to the speed of the motor. This signal is then fed into a comparator, which converts the signal into a square wave, which is then input into a microprocessor. The microprocessor determines the frequency of the square wave. If the frequency of the square wave is below a threshold of acceptable motor speed, the microprocessor can turn off the motor and provide a malfunction indication. If the frequency of the square wave is above a second threshold of acceptable motor speed, the microprocessor can likewise turn off the motor and provide a malfunction indication.

Abstract: A system for controlling motion in machine tools and industrial robots. From the specification of a part to be cut or a path to be followed by a machine tool or a robot, the system calculates, for each axis, for each incremental step along the path, a position command, a time delay between successive position commands, and, optionally, a force command based on a prediction of predicted resistive forces. Calculations are specified for precisely controlling velocity, acceleration, and jerk. The generated data is stored in a memory device and subsequently directed to the machine tool or robot.

Abstract: A motor control system includes a microcomputer for executing a so-called software servo-control, and the microcomputer receives a speed signal and a phase signal from the motor. In the microcomputer, speed error data is evaluated on the basis of the speed signal, and speed integration data is evaluated on the basis of the speed error data and a first reference signal, and phase integration data is evaluated on the basis of the phase signal and a second reference signal. The speed error data, the speed integration data and the phase integration data is synthesized, so as to obtain motor control data.

Abstract: A speed controller for a DC motor minimizes speed droop and load droop through pulse width or frequency modulation. The controller provides an extra power increase upon engine starting or whenever a heavier load is temporarily encountered. The control circuit also has a current limiter, overload indicators, and a battery recharger. The controller is very inexpensive, primarily because all of the timing components are contained on a single integrated circuit timer chip such as a 556 timer. The controller contains other features, including a circuit for limiting the pulse width of the control signal from the pulse width modulator.

Abstract: In the spindle control system of the present invention the compensator is divided into two portions. The first portion is driven by a first clock signal at a first frequency and a second portion is driven by a second clock signal at a second frequency derived from the first clock signal. In particular, the integrator utilizes a clock which increases the time measurement to be a longer interval than the measurement utilized for the remainder of the compensator circuit. This allows the absolute speed to be adjusted with a high resolution independent of the gain. Therefore, the gain can be maintained and the loop dynamics are preserved, maintaining dynamic range and stabilization while increasing the resolution of control of the spin speed.

Abstract: A system and method for controlling the speed of an electric motor compares the actual speed of the motor with the desired speed of the motor. A digital comparison of the desired speed of the electric motor with the actual speed of the electric motor provides an error signal indicative of the error between the desired speed and the actual speed. A large timing current from a programmed timing control will cause an increase in the speed of the motor, while a smaller timing current from the programmed timing control will cause a decrease in the speed of the motor. In this manner, the programmed timing control affects the actual speed of the motor 12 to approach the desired speed. The programmed timing control can also provide a ramping acceleration or deceleration as the motor speed changes to approach the desired speed. The speed control system can also include a programmed stall detector which can cause the operation of the electric motor to be ceased when a stalled motor condition is detected.

Abstract: A procedure is disclosed for filtering the speed feedback signal in an elevator motor drive which is provided with a speed controller and in which the speed of rotation of the motor is measured. The procedure of the invention involves sampling the speed feedback signal, producing a prediction of the next sample by a predicting procedure that filters the noise in the speed feedback signal, and forming an estimate of the latest sample by delaying the prediction by a time corresponding to one sample.

Abstract: The flow of power through a field effect transistor to a DC motor is controlled by the output of a frequency modulator having a low frequency pulsed signal applied to one input thereof and a high frequency pulsed signal applied to a second input thereof. The pulse width of each "on" pulse of the low frequency pulsed signal is varied in response to a signal representing a desired motor speed. Optionally, the pulse width of each "on" pulse of the high frequency pulsed signal can also be varied in response to the signal representing the desired motor speed. A filter circuit can be employed to prevent rapid changes in the pulse width of the low frequency pulsed signal. Similarly, a filter circuit can be used to avoid rapid changes in the pulse width of the high frequency pulsed signal. A freewheeling diode can be used to minimize inverse voltage spikes across the motor.

Abstract: A method for measuring the rotary speed of a direct-current motor having a rotor and at least a shunt-wound field winding, wherein the field current includes an ac-component caused by mass-inhomogeneities in the rotor, including the steps of: frequency analyzing with a frequency analyzer the ac-component to form a frequency spectrum; selecting with a computing device a part of the frequency spectrum related only to the rotary speed; and determining from the selected part of the frequency spectrum the rotary speed of the motor.

Abstract: The stator current has a variable frequency which is changed by using a predetermined frequency change rate. The resulting effective value of the stator current is compared with the current control variable. If it is greater the frequency is now kept constant. If this corresponds to the setpoint speed the process terminates, if not, the frequency change will start again as soon as the effective value gets smaller than the current control variable. An a.c. voltage mains may operate, accelerate or brake the motor via a rectifier and an inverter, in cases of voltage failure the stator current is switched through to a load resistor. The variation of the speed may follow a steady or a garland-shaped course, from the from and dimension of a festoon element a measure for the "torsional rigidity" may be obtained. By means of shifting between star connection and delta connection the frequency range may be expanded in order to keep the torque essentially the same.

Abstract: A compressor drive system that includes a thermostat producing a signal indicating the measured air temperature, a modulation control circuit connected to the thermostat to produce a motor drive signal from the temperature signal and which is output to a motor drive switching bridge circuit. The motor drive switching bridge circuit is connected to a rectifier that converts single phase alternating current to direct current. The switching bridge uses the motor drive signal from the modulation control circuit and the rectifier output to produce multiphase power including a speed control signal imposed on the power for regulating speed. A motor connected to drive a compressor is included. The motor is powered by the motor drive switching bridge circuit multiphase power output. The speed of the motor is controlled as a function of the temperature signal.

Abstract: A motor stop control device for stopping a motor rapidly. The motor control includes a pulse generator for generating a pulse signal having a pulse width which is in relation to the speed of the motor, a CPU, and a drive for driving the motor. When a motor stop command signal is produced when the motor being rotated forward, CPU operates the drive to produce a counter drive torque, and, at the same time, CPU starts to compare the pulse width of the present pulse signal with that of the previous pulse signal, and produces a signal when the pulse width of the present pulse signal becomes shorter than that of the previous cycle. When the signal is produced, the drive stops to produces the counter drive torque.

Abstract: An error signal detection circuit in a servo control device comprises a reference signal generation circuit for selectively generating reference signals of different periods, each having a slope which changes from a reference value at a substantially constant gradient, an error detection timing generation circuit for generating timing of detection of an error signal of an object of control, an error signal detection circuit for generating an error signal by detecting the value of a reference signal generated by the reference signal generation circuit at a timing provided by the error detection timing generation circuit, and a slope varying circuit for varying the slope of the reference signal in accordance with the period of the reference signal.

Abstract: Method of measuring the rotary speed of an electromagnetically actuated rotating device having at least one winding carrying a current, which comprises analyzing the frequency of a voltage corresponding to an alternating component of the current, and a device for performing the method.

Abstract: An adjustable frequency motor drive system for a hoist is disclosed in which the frequency of the power supply to the motor can be selectively varied and the speed of the motor will follow the varying frequency at a slip speed relative to the frequency. The slip speed of the motor may not exceed a value beyond which the motor can control the hoist load. Accordingly, a frequency value based on the frequency of the power supply to the motor is selected as the frequency which is not to be exceeded by the motor speed expressed as a frequency. Signals representative of the actual motor speed and the selected frequency value are compared and, if the signal representative of the motor speed exceeds the signal representative of the frequency value which is not to be exceeded, an output signal is produced which may be used to apply a brake which stops and holds the motor and hoist and thereby maintains the load suspended.

Abstract: A locomotive propulsion system includes wheelslip control with the following interrelated features: comparing the rotational speeds of the locomotive's separately driven wheels and detecting the highest and lowest; providing a reference speed value indicative of the rotational speed of a wheel that is not slipping; determining a desired maximum difference between the reference speed and a selected one of the detected speeds; deriving a speed error value by summing the reference speed, selected speed, and maximum difference; obtaining a wheelslip correction value which is a function of the speed error value; reducing the magnitude of voltage applied to the locomotive's traction motors in accordance with the correction value.

Abstract: An apparatus for controlling a motor comprises an oscillator for providing a source of periodic signals, and a divider for converting the oscillator output into desired motor rotation frequency signals. A tachometer generates actual motor rotation frequency signals and a comparator compares the actual and desired motor rotation frequency signals and generates a rotation frequency error signal. The tachometer and the divider are coupled to the comparator. An SCR bridge controls motor rotation frequency. The comparator is coupled to the SCR bridge. An AND gate coupled to the source of periodic signals provides a counting gate during which periodic signals from any suitable source are to be counted and a counter coupled to the AND gate counts the periodic signals. A display displays the number of such periodic signals counted during the counting gate.

Abstract: In a speed control system for a carriage movable along a predetermined path, light beams originating at the ends of the path are deflected by light conductors aboard the carriage so that they are interrupted, as the carriage moves, by a slotted plate extending along the path. The light beams are then deflected by light conductors so that they are directed along the carriage path to light receivers situated at the ends of the path. Electrical pulses from the light receivers are ORed together and converted by a transducer to a signal representative of the actual carriage speed, and by a counter to a signal representative of the carriage position. The carriage position signal is converted, in accordance with a predetermined functional relationship, to a speed set signal which is compared with the actual carriage speed. A signal, representative of the difference between the actual speed and the set speed is used to control the driving motor for the carriage.