Abstract: A power source for wire-cut electric discharge machines which is designed to increase the cutting speed and improve the surface roughness of a workpiece. A capacitor for supplying a discharge energy across a wire electrode and the workpiece is always by a DC power supply and the charged voltage across the capacitor is applied across the machining gap via a switching element. The switching element is turned ON when the voltage across the capacitor reaches a predetermined level, and turned OFF when the voltage becomes substantially zero, permitting rapid charging of the capacitor and the generation of a uniform discharge energy.

Abstract: A motor drive control system for use in a machine tool having spindle and feed shaft motors. If the spindle motor, which is rotating at a constant speed during a machining operation, is subjected to an overload, and consequently experiences a drop in speed, this fact is detected by a detector for detecting the armature current of the spindle motor. The feed shaft motor is slowed down to a predetermined speed if the overloaded condition continues for a prescribed period of time. The feed shaft motor is stopped if an even greater armature current is detected to be flowing due to a continuing overload despite the fact that the feed shaft motor has been slowed to the predetermined speed.

Abstract: An automatic cutting condition changeover equipment for automatically changing over an electrical cutting condition of a wire-cut, electric discharge machine in accordance with the thickness of a work. The equipment is provided with a feed control circuit for controlling the cutting speed of the work so that a mean working voltage between a wire electrode and the work may be constant, an arithmetic logic unit for calculating a predetermined optimum cutting condition formula on an on-line basis, and electrical cutting condition changeover control circuit for changing a peak current of the power source of the wire-cut, electric discharge machine so that the output from the arithmetic logic unit may be reduced to substantially zero.

Abstract: A system for controlling the rotation of a spindle includes a motor, a speed detecting circuit for detecting the speed of the motor and for producing a signal indicative of the actual speed thereof, a speed control circuit for controlling the motor so as to narrow to zero a deviation between the actual speed thereof and a commanded speed, a spindle driven by the motor, and a position control circuit for producing a position deviation signal on the basis of a commanded stopping position and the rotational position of the spindle. The spindle is rotated at a commanded speed by the speed control circuit and is rotationally controlled by an orientation command signal so as to make the position deviation signal zero.

Abstract: A direct current motor having E-shaped interpoles, each of the E-shaped interpoles comprising interconnecting members which are made of a non-magnetic material having rigidity and which are tightly and irremovably inserted in gaps between a center pole and side poles of the E-shaped interpole. In the direct current motor according to the present invention, the side poles are mechanically interconnected to the center pole, so that noises generated by the vibration of the side poles are greatly reduced.

Abstract: A control system for an industrial robot having a robot controlled in accordance with a position command signal and a position feedback signal and a control circuit for controlling the movement of said robot, said control circuit comprising an error register, a digital-analog converter, and a position gain multiplier between said error register and said digital-analog converter, wherein when the motor which drives said robot stops the rotation or when said motor gets ready to stop the rotation and an error value held in said error register becomes higher than a predetermined value, the multiplication factor of said position gain multiplier is increased, thereby a high accuracy of the positioning is accomplished.

Abstract: A system employed in a machine tool of the type in which a gear mechanism disposed between the spindle and spindle motor transmits the rotational motion of the motor to the spindle. The system allows the spindle to be brought to a stop at a predetermined rotational position in a shorter period of time when the gear mechanism is set in low gear, that is, while the rotational speed of the motor is being reduced by the gear mechanism as it is being transferred to the spindle. This permits the spindle to be stopped at the predetermined position in the same amount of time which is required when no reduction in speed takes place between the motor and spindle. When the spindle arrives at a region where it is to be controlled in order to stop at the predetermined rotational position, a position deviation signal for guiding the spindle to the position is applied as an input signal to a speed control loop for controlling spindle rotation.

Abstract: A speed detector including a circular rotational member having a plurality of equally spaced-apart teeth on the outer circumference thereof, and first and second magnetic sensors. The first and second magnetic sensors each comprise a permanent magnet, a magnetic pole which permits the passage therethrough of a magnetic flux generated by the permanent magnet, and a detection coil wound on a portion of the magnetic pole. The magnetic poles of the first and second magnetic sensors are disposed in close proximity to, and arranged to face, the teeth on the rotational member, whereby each magnetic sensor produces an alternating output signal as the rotational member rotates, the frequency of each output signal being proportional to the speed of the rotational member.

Abstract: A feed speed control system for use in numerical control systems or the like, in which a set feed speed can be adjusted through a simple structure. The control system includes a memory circuit for storing a plurality of numerical values corresponding to feed speeds, a command circuit for issuing a command indicative of a prescribed numerical value from among the plurality of numerical values, an arithmetic circuit for incrementing or decrementing a numerical value read from the memory circuit in response to an output pulse from manual operation device, and a pulse generating circuit for generating pulses of a frequency which is proportional to an incremented or decremented numerical value from the arithmetic circuit.

Abstract: A numerically controlled machine tool is equipped with a programmable sequence controller having a first storage area capable of storing operation commands, and a second storage area capable of storing a duplicate of the data planted in the first storage area without erasing the planted data. An operation command, when sent from a numerical control device to the machine tool, is stored in the first storage area and then, when the machine tool has completed the instructed operation, is read out from the first storage area and stored in the second storage area, this operation being repeated as each new command is issued. When electric power is connected to the machine tool, the data stored in the first and second storage areas is compared, an alarm being generated when the two sets of data do not agree.

Abstract: Data for determining a limit value of the trace range of a model are stored in a memory and the stored data are read out therefrom by a processor to calculate the limit value of the trace range. The current position of a movable machine part is detected and compared with the limit value and when it is detected by the processor that the current position of the movable machine part has reached the limit value, a trace feed is switched to a pick feed. After the pick feed is performed a predetermined distance, it is switched again to the trace feed. A desired trace range is set to achieve tracer control without the provision of limit switches.

Abstract: A method of checking a memory in a computer system having memory for storing at least one logical block composed of a plurality of words, and a processor for retrieving data from the memory to perform a memory check wherein the method includes inserting an operational control word into the logical block in advance, sequentially subjecting each word in the logical block to a prescribed operation, such as an exclusive-OR operation applied to corresponding ones of the bits in each word, and then determining whether or not the result of the operation is the same as a predetermined value. The operational control word, before being inserted into the logical block, is determined in such a manner that the result of the operation will be equivalent to a predetermined value, such as all "0"s.

Abstract: Disclosed are a numerical controlling method and system for controlling a machine such as a machine tool, robot or the like, through an exchange of data between the machine and a numerical controlling apparatus.The system includes conversion circuits incorporated in both of the numerical control apparatus and the machine, the conversion circuits being adapted to convert serial data into parallel data and vice versa; a cable connected between the conversion circuits; an address signal generating circuit adapted to generate an address signal; and a decoder circuit incorporated in the machine and adapted to decode the address signal.

Abstract: An input signal is written in n memory elements one after another in accordance with clock pulses, the contents of the n memory elements are added together by an adder, and the added output from the adder is divided by n in a divider, thereby converting an input signal having an abrupt change to a signal having a gentle change.

Abstract: An output voltage-drop detecting apparatus added to a stabilized DC power source device which includes a power control circuit for controlling a DC input voltage to produce a DC output voltage of a specified value, a reference voltage source whose voltage is capable of being varied, and an error amplifier, with the DC output voltage and the reference voltage being compared by the error amplifier and the power control circuit being controlled by the output of the error amplifier to stabilize the output voltage.

Abstract: In order to attain a more suitable control of a robot unit which serves a machine tool in accordance with various conditions of the operations of the machine tool and the robot unit, the number of the kinds of signals produced in the machine tool is increased and a predetermined control of the robot unit is attained in response to each of the increased kinds of signals.

Abstract: An image display system suitable for use in displaying, at an enlarged scale, any desired portion of an image presented on a picture surface of a display apparatus, or in displaying, in a reduced scale, the whole portion of the image presented on the picture surface. The picture surface is divided into sub-regions arranged in m lines and n columns. Sub-region appointing numeral keys are arranged to correspond to these sub-regions, so that any desired sub-region is appointed by a depression of the corresponding appointing keys, thus designating that to make the image portion in the appointed sub-region be enlarged and displayed over the entire area of the picture surface or that the whole part of the image on the display surface be reduced and displayed in the appointed sub-region of the picture surface.

Abstract: A tachometer generator comprising a generator section for producing rectangular polyphase alternating voltages having a peak value which is proportional to the speed of the rotor, and a commutator section including contactless change-over switches for successively transferring the alternating voltages from the generator section, and sensors for producing switching signals which actuate the change-over switches in accordance with the rotational position of the rotor of the generator section. In the commutator section the sensors are equivalent in number to the change-over switches and comprise Hall devices arrayed about a rotary shaft which is coupled to the generator section. The alternating voltages which are obtained successively from the coils of the generator section as the rotary shaft rotates, are transferred in order by the change-over switches to produce a speed signal, in analog form; which is proportional to the rotating speed of the rotor.

Abstract: Disclosed is a DC motor drive circuit adapted to prevent thyristor commutation failure when a thyristor-controlled three-phase full-wave reversible bridge undergoes a transition in operating mode from a power inversion mode to a power rectification mode.

Abstract: An induction motor drive apparatus of the type having a speed detector for detecting the rotational speed of an induction motor, speed command device for producing a command speed, and an error amplifier for amplifying a difference between the rotational speed of the induction motor and the command speed, the induction motor being driven by so controlling the amplitude of the primary current as to vary the amplitude of the secondary current in accordance with the difference between the rotational and command speeds. Included are two-phase sinusoidal wave generating device for generating two sinusoidal signals displaced in phase from one another by .pi.