Abstract: This invention is a diode defect detecting device including a current detector for detecting the primary current of a transformer, a comparator for comparing the detection current detected by the current detector with a current reference and outputting a reset signal if the detection current is larger than the current reference, an oscillator for generating a clock signal, a flip-flop circuit for receiving a set signal on the basis of a front and an end edge of the clock signal generated by the oscillator and receiving the output reset signal from the comparator, a polarity changing circuit for outputting a polarity changing signal for changing the polarities of the plurality of diodes on the basis of the output clock signal from the flip-flop circuit, and a determination circuit for calculating, in order to detect malfunctions of the plurality of diodes, any impedance change on the secondary side viewed from the primary side of the transformer on the basis of the pulse width of each polarity of the output cl

Abstract: A method and an apparatus for carrying a workpiece for improving efficiency in a workpiece carrying operation. In the apparatus, a moving member having a workpiece holding member is driven with a linear motion in a horizontal plane along a carrier passage, and the workpiece holding member is driven with a revolutional motion in a vertical plane around a revolution axis displaced from a center of the workpiece holding member, while the workpiece holding member maintains an orientation in which a holder holding the workpiece points downwards. The holder of the workplece holding member is controlled to sequentially carry out holding of the workpiece and releasing of the workpiece at lowest positions of the workpiece holding member in the revolutional motion, so as to realize a continuous workpiece carrying operation.

Abstract: A work mounting apparatus according to the present invention comprises a rotating drum divided into upper and lower drums, a head unit arranged on the outer periphery of the rotating drum or the lower drum, a circular work head attached to the head unit, and a suction nozzle protruding from the outer peripheral surface of the work head toward a workbench. While the lower drum is rotating, the suction nozzle of the work head repeats cycloid motion along the workbench with its posture or orientation kept fixed with respect to the workbench. While repeating the cycloid motion, the nozzle receives a work from a work feeder of the workbench by suction, and mounts the work on a printed board on the workbench. The work mounting apparatus further includes a balance weight for the work head, and a friction brake for applying a frictional force to the turning shaft of the work head, to thereby stabilize the turning motion of the work head.

Abstract: In a parts mounting apparatus, suction nozzles are mounted on a rotating carrier driven by a motor. With rotation of the rotating carrier, parts are sucked by the nozzles at a feed station and carried to a mounting station where the parts such as electronic parts are mounted on substrates, for example. A counter counts output pulses from an encoder mounted in the motor driving the rotating carrier. A microcomputer determines the rotational speed and rotational position of the rotating carrier from the count value of the counter. Based on the result of the determination, the microcomputer calculates a timing for delivering a signal for switching the nozzles between two different pneumatic states.

Abstract: A work mounting apparatus or component mounting apparatus according to the present invention comprises a lower drum of a rotating drum, a head unit arranged on the outer periphery of the lower drum, a circular work head or component head attached to the head unit, and a suction nozzle protruding from the outer peripheral surface of the work head toward a workbench. While the lower drum is rotating, the suction nozzle of the work head repeats cycloid motion along the workbench with its posture kept fixed with respect to the workbench. While repeating the cycloid motion, the nozzle receives a work or component, such as an electronic component from a work feeder of the workbench by suction, and mounts the work on a printed board on the workbench.

Abstract: In a parts mounting apparatus, a suction nozzle is caused to perform a cycloid movement. A part such as an electronic part is sucked into the nozzle at one of bottom dead points of the cycloid movement and mounted onto another component such as a circuit substrate at the other or another bottom dead point. In compensation of the position of the nozzle at the bottom dead point, the nozzle is also caused to perform the cycloid movement. The position of the nozzle at the bottom dead point is monitored by a monitoring camera so that an amount of deviation of the position of the nozzle from the bottom dead point is obtained. The phase of the cycloid movement is compensated so that the amount of deviation of the nozzle is rendered zero. Alternatively, the part sucked in the nozzle positioned at the bottom dead point is monitored by the monitoring camera.

Abstract: In a control device for controlling a servo motor driving a robot arm, a target position command signal is input to a first operation section, which generates a speed command value for the speed feedforward. The target position command signal is also input to a delay section. A target position command signal delayed by a time period is obtained by the delay section and supplied to a second operation section. A positional deviation between the target position command signal and a position feedback signal is calculated by the second operation section. The obtained positional deviation is input to a third operation section and generated as a speed compensation command signal. A speed command signal obtained by addition of the speed feedforward signal and the speed compensation command signal is supplied to a servo driver for driving the servo motor.

Abstract: A method and an apparatus for workpiece installation capable of carrying out workpiece installation operation without a stopping of a rotational motion of a rotatable table member. In the apparatus, rotatable drum is continuously rotated while workpiece carrier member, provided along a circumference of the rotatable drum, for carrying a workpiece from a workpiece supply station to a workpiece installation station, which is capable of spinning on the circumference while carrying the workpiece, is controlled such that the workpiece carrier member spins while the rotatable drum rotates so as to move along a prescribed trajectory which is preferably a cycloidal or quasi-cycloidal trajectory, and that the workpiece is picked up by the workpiece carrier member at a prescribed pick-up position on the workpiece supply station and released at a prescribed installation position on the workpiece installation station.

Abstract: A welder apparatus has many welder assemblies. Each of welder assemblies is formed of a weld control transformer (WCT) to which a welding gun is attached, and a weld control unit (WCU) integrally but detachably connected to the WCT. The feature of the detachable connection between the WCT and the WCU provides a compact size for each of WCT and WCU. This feature also permits a standardized connection dimension and standardized connection interface between the WCT and the WCU for all welder assemblies. These standardized connection dimension and interface allow an optional combination of any of WCT's and any of WCU's, and plural assemblies of this combination can be managed by a single host computer (or machine control interface MCI). Further, no connection cables are required between the WCT and the WCU for all welder assemblies.

Abstract: In a vibratory parts feeder, an output power of an inverter supplying AC voltage to each vibration generator (electric power supplied to the vibration generator) or input power to the inverter is controlled so as to reach the maximum during the feeding operation so that the operational frequency is automatically adjusted to the resonant frequency. That is, upon increase or decrease of the operational frequency at predetermined intervals, the value of power supplied to each vibration generator or the inverter input power is obtained. The obtained value is compared with the last obtained value whose data is stored in a storage.

Abstract: A welder apparatus has many welder assemblies. Each of welder assemblies is formed of a weld control transformer (WCT) to which a welding gun is attached, and a weld control unit (WCU) integrally but detachably connected to the WCT. The feature of the detachable connection between the WCT and the WCU provides a compact size for each of WCT and WCU. This feature also permits a standardized connection dimension and standardized connection interface between the WCT and the WCU for all welder assemblies. These standardized connection dimension and interface allow an optional combination of any of WCT's and any of WCU's, and plural assemblies of this combination can be managed by a single host computer (or machine control interface MCI). Further, no connection cables are required between the WCT and the WCU for all welder assemblies.

Abstract: A contol apparatus for a single-phase full-wave resistance welder in which anti-parallel connected thyristors are connected in series with a primary winding of a welding transformer and which controls a firing phase .theta.n of the thyristors to adjust a welding current, includes storage means for calculating and storing a square sum SK in such a manner that a sinusoidal value VK=K0sin.theta.K having a given peak value is divided at predetermined phase intervals (1.degree.) within a predetermined phase range (180.degree.), and the square sum SK=V1.sup.2 +V2.sup.2 +V3.sup.2 +. . . VK.sup.2 of the sinusoidal value VK with respect to each phase .theta.K is calculated in units of divided phases .theta.K (.theta.K=1.degree., 2.degree., 3.degree., . . . , 180.degree.) in advance, and Vx calculating means for reading out square sums Sn and Sm of the firing phase .theta.n and energization end phase .theta.

Abstract: The present invention is directed to an inverter-type resistance welding machine. A PWM inverter supplies high frequency primary voltage to a transformer. A microprocessor controls the PWM inverter by proportional-integral-deviation (PID) control through a PWM control unit. The microprocessor determines a feedforward operation amount which corresponds to a desired welding current value before current is supplied to the welding electrodes. The time period for the calculation of an integral operation amount is effectively reduced to approximately zero by employing a calculated integral operation amount from a previous sampling.

Abstract: A DC power source apparatus is provided including a current regulator having an electronic contactor, a transformer having a primary winding and a secondary winding. A series circuit of the primary winding and the current regulator is adapted for connection to an AC power source. The AC power source apparatus also includes a rectifier connected to the secondary winding of the transformer, output terminals of the rectifier being adapted to supply DC current to a DC load having an inductance. The AC power source apparatus further includes a simulator connected to detect an AC current flowing through the series circuit for simulating the DC current flowing through the DC load based on the detected AC current and a simulated time constant of the DC load to produce a simulated signal, and a controller connected to receive the simulated signal for comparing the simulated signal with a predetermined current reference to produce a phase control signal based on a comparison result.

Abstract: A resistance welder is provided having an electronic contactor, a welding transformer coupled in series with the electronic contactor, and a secondary circuit with a welding load connected to the welding transformer. The series circuit of the electronic contactor and the welding transformer is adapted for receiving power from an AC power source. The resistance welder also includes a control device having a voltage detector coupled to detect a voltage across the electronic contactor for producing a first signal according to the detected voltage, a delay circuit coupled to receive a primary voltage across the welding transformer for delaying the primary voltage by a value determined by a first time constant thereof to produce a voltage signal, a switch coupled to receive the first signal for resetting the delay circuit according to the first signal, and a gain control circuit coupled to receive the voltage signal for controlling a transmission gain of the voltage signal to produce a gain controlled signal.