Fanuc Corporation

Fujitsu Fanuc Limited

Katsuo Kobari

Mitsuyuki Taniguchi

Hiroshi Ishida

Naoto Ota

Yoshitaka Takekoshi

Shigeki Kawada

Naoyuki Suzuki

Yoshiaki Hachisuka

Yuji Kanamori

Shunsuke Matsubara

Hirofumi Kikuchi

Shinji Seki

Toshio Kobayashi

Yoshinori Kozai

Keiji Sakamoto

Computerized overcurrent detector

Digital pulse circuit for processing successive pulses

Drive motor control unit

Signal processor of pulse encoder

Pulse encoder

Terminal for connecting electronic components

Method and apparatus for controlling torque of a servomotor

The drive system of an induction motor wherein the exciting current command value I.sub.o of the induction motor (14) is held constant and the rotational speed thereof is caused to quickly respond to a command speed by the vector control circuit the induction motor (104) has exceeded a predetermined speed, an exciting current amplitude-controlling circuit (51) increases the exciting current command value in accordance with the rotational speed. The level of the driving supply voltage of the induction motor is sensed by a supply voltage output circuit (52), whereupon the exciting current amplitude-controlling circuit (51) is controlled so that the predetermined speed serving as a threshold value for changing the exciting current command value may be increased in accordance with the sensed level.

Induction motor driving system

Discharging circuit for power source device with rectifier circuit

A control system for a synchronous motor which is employed as a servomotor, wherein a pulse coder is employed for detection of the absolute position of one of the field poles of the motor, the absolute position being a component of the input signals for generating a poly-phase alternating current voltage which generates a rotating field maintaining a fixed amount of phase difference with respect to the absolute position of one of the field poles of the motor, thereby the synchronous motor is controlled to run maintaining a fixed amount of internal phase angle of e.g. .pi./2 for the entire operation period, wherein the improvement is that the pulse coder has two pulse coder elements, one of which detects the absolute position of one of the field poles of the motor and the other of which generates incremental pulses during each interval of the signals representing the absolute position of one of the field poles, thereby a larger amount of resolving power is realized for the pulse coder, ultimately improving the performance of the control system.

Control system for synchronous motor employed as servomotor

A control circuit for driving an induction motor wherein an AC voltage is converted into a direct current by a rectifying circuit and the direct current is converted into a signal having a variable voltage and frequency by a transistor inverter connected in parallel with a smoothing capacitor, and a regenerative circuit is connected in parallel with the inverter, and a circuit is provided for comparing the terminal voltage V.sub.C of the smoothing capacitor and a reference voltage V.sub.r when braking is to take place is disclosed. When condition V.sub.C .gtoreq.V.sub.r exists, the transistor inverter is disabled but the regenerative circuit is allowed to operate; when the condition V.sub.C &lt;V.sub.r exists, the transistor inverter is operated in the regenerative braking mode.

Induction motor control system

A control circuit for driving an induction motor wherein an AC voltage is converted into a direct current by a rectifying circuit and the direct current is converted into a signal having a variable voltage and frequency by a transistor inverter connected in parallel with a smoothing capacitor, and a regenerative circuit is connected in parallel with the inverter, and a first monitoring circuit is provided for comparing the terminal voltage V.sub.C of the smoothing capacitor and a first reference voltage E.sub.1 when braking is to take place. When the condition V.sub.C .gtoreq.E.sub.1 exists, the transistor inverter is disabled but the regenerative circuit is allowed to operate. When the condition V.sub.C &lt;E.sub.1 exists, the transistor inverter is operated in the regenerative braking region. A second monitoring circuit is provided for comparing the smoothing capacitor terminal voltage V.sub.C and a second reference voltage E.sub.2 (E.sub.2 &gt;E.sub.1). When the condition V.sub.C .gtoreq.E.sub.2 exists, both the transistor inverter and regenerative circuit are disabled immediately.

An apparatus for preventing malfunctions in a phase control mechanism of the type in which the firing angle of thyristors in a thyristor bridge is controlled to regulate the rotational speed of a DC motor comprising the load of the thyristor bridge. Thyristor firing pulses are produced each time a rising analog speed command signal generated in response to the phases of a N-phase power supply intersects N-number of sawtooth signals. Immediately after the generation of each firing pulse, the thyristors are not supplied with firing pulses for a time interval at least equivalent to the thyristor commutation overlap time.

Apparatus for preventing phase control mechanism malfunction

A device for driving a DC motor with feedback control provides a circuit for judging whether the motor is in acceleration or in deceleration and a circuit for switching the gain modification signal, and said switch circuit is controlled by the output signals of said judgement circuit.

Device for driving a DC motor with feedback control

In a DC motor control apparatus for driving a DC motor in accordance with a signal of the difference between a revolving speed signal from a speed detector coupled with the DC motor and a command speed signal so as to drive the DC motor at a revolving speed indicated by the command speed signal, when a voltage to be applied to the DC motor and the revolving speed signal from the speed detector are both detected, the operation of the DC motor control apparatus is decided as normal, and when the voltage to the DC motor is detected but the revolving speed signal from the speed detector is not detected, the operation of the DC motor control apparatus is decided as abnormal and an alarm signal is produced.

Abnormality detecting system for DC motor control apparatus

Growing community of inventors

Tachikawa, Japan

Katsuo Kobari