The present invention relates micro resistance welding apparatus and to a method of welding. In particular, the present invention relates to small scale or micro welding apparatus and to a method of micro resistance welding using a controlled sequence of current, voltage and/or power signal profile for an electric arc. The invention provides a welding apparatus comprising: a controller supplying a controlled drive current to a weld head circuit in which the controller supplies said controlled drive current in dependence upon electrical feedback from the weld head circuit and in which the controlled drive current is defined by a sequence of segments and for each segment the welding apparatus operates in a mode defined by setting one of a predetermined current target, a predetermined voltage target or a predetermined power target; and at least two of the segments are operated in a different mode from one another. The invention also provide a method of operating such an apparatus.

A resistance welder controller controls a welding current flowing through an inverter transformer, detects the welding current flowing through the inverter transformer, measures an energizing time and a point time interval of the detected welding current, calculates a usage rate of the inverter transformer using the energizing time and the point time interval, stores an equivalent current curve indicating a relationship between a current value of the welding current and the usage rate of the inverter transformer when the inverter transformer is operated at a rated capacity, and determines whether a relationship between the current value and the calculated usage rate of the inverter transformer exceeds the rated capacity of the inverter transformer based on the equivalent current curve, continues an operation when the relationship does not exceed the rated capacity of the inverter transformer, and stops the operation when the relationship exceeds the rated capacity of the inverter transformer.

Provided is an inverter power supply including a measurement function of measuring deterioration of a rectifier element such as a diode.

The inverter power supply includes a step-down stabilization unit that applies a reverse voltage increasing gradually to diodes, an isolation amplifier that detects a current value of a current flowing to the diodes when the reverse voltage is applied, and an inverter control unit that decides that the diodes have deteriorated when the detected current value is larger than a determination current value for determining deterioration of the diodes, and decides that the diodes have not deteriorated when the detected current value is smaller than the determination current value.

A stored time variation curve and cumulative amount of heat generated of each step are each used as a target. In the case where a time variation of an instantaneous amount of heat generated per unit volume differs from the time variation curve in any of the steps, a current passage amount is controlled in order to compensate for the difference within a remaining welding time in the step so that a cumulative amount of heat generated per unit volume in actual welding matches the stored cumulative amount of heat generated in the test welding. Further, in the case where expulsion is detected in any of the steps, then in subsequent welding, the cumulative amount of heat generated per unit volume used as the target is reduced, and the current passage amount is adjusted in accordance with the reduced cumulative amount of heat generated per unit volume.

A system and method of welding or additive manufacturing is provided where at least two welding electrodes are provided to and passed through a two separate orifices on a single contact tip and a welding waveform is provided to the electrodes through the contact tip to weld simultaneously with both electrodes, where a bridge droplet is formed between the electrodes and then transferred to the puddle.

Provided is an evaluation system including: an analog-to-digital converting section comprised of a programmable circuit and configured to convert an analog signal, the analog signal being acquired by a physical quantity acquiring section and indicative of a time-series change of at least one of (i) welding current, welding voltage, or load applied to pieces to be welded and (ii) a displacement, during welding, of a welding head; and an evaluating section configured to determine, based on a digital signal, whether or not the time-series change satisfies a predetermined condition, wherein configuration data for configuring the programmable circuit is arranged to be changeable by a user.

An example apparatus to monitor a welding-type system includes: a test signal generator configured to output a test signal to a monitored circuit; and a lock-in amplifier configured to: receive a reference signal based on the test signal; measure a leakage current in the monitored circuit based on the reference signal; and generate an output signal representative of the leakage current.

A resistance welding machine includes a first electrode and a second electrode which are configured so that the first and second electrodes can hold a workpiece therebetween and apply a current to the workpiece. The first electrode includes a first inner electrode and a first outer electrode disposed outside the first inner electrode at a predetermined interval. The second electrode includes a second inner electrode and a second outer electrode disposed outside the second inner electrode at a predetermined interval. The resistance welding machine further includes a control unit that can control a pressing state of the workpiece with the first and second electrodes according to predetermined welding conditions and selects a pair of electrodes that apply a current to the workpiece from the first inner electrode, the first outer electrode, the second inner electrode, and the second outer electrode.

A resistance welding apparatus includes a welding controller configured to control a welding tool. The welding controller has an assignment device including a parametrization device. The assignment device is configured to read out a current point to be welded from a list of points to be welded, to read out a first setpoint curve from a record of a database assigned to the current point to be welded, and to assign the first setpoint curve to the first regulator and the parametrization device is configured to read out the first value from the record of the point to be currently welded and to parametrize a first parameter of the first regulator with the first value. The welding controller further includes the first regulator configured, using a first parameter, to regulate a temporal profile of an electric current at the current point to be welded in accordance with the first setpoint curve.

There is provided a power supply device that supplies an output current to an electric processing device which performs electric processing on workpieces. The device includes: a first power supply; a magnetic energy recovery switch that receives a current supplied from the first power supply, and converts the received current into the output current; and a control unit that controls the magnetic energy recovery switch such that an electric current frequency of the output current includes a first electric current frequency and a second electric current frequency which are different from each other within a one-time electric processing time using the electric processing device.