Abstract: A detection device for detecting a diameter and/or composition of a welding wire and/or welding electrode for a welding device, includes an oscillating circuit, which has a coil through which the welding wire and/or welding electrode can be passed. The device further include an evaluation unit connected to the oscillating circuit for determining at least one first oscillating circuit parameter which is characteristic of an attenuation of an oscillation signal occurring in the oscillating circuit, and at least one second oscillating circuit parameter which is characteristic of a signal frequency f of the oscillation signal occurring in the oscillating circuit. The evaluation unit detects the diameter and/or composition of the welding wire passed through the coil of the oscillating circuit and/or of the welding electrode using the determined oscillating circuit parameters.

Abstract: Device (10) for manufacturing a component compound by resistance welding, comprises a welding electrode (12) for transmitting an electric current to a joining element (17) and for exerting a joining force onto the joining element (17) along a joining direction (22) in order to establish a connection of the joining element (17) with a structural element by resistance welding; as well as a positioning device (20) for positioning at least one joining element (17) on the axis of the joining direction (22) in order to contact and particularly apply a force to the joining element (17) by means of the welding electrode (12). The positioning device (20) comprises a retention device (30) for exerting a retention force onto the joining element (17), wherein the retention device (30) is movably arranged.

Abstract: A welding device of a robot arm includes a welding machine having a first pressing member which includes a cylindrical first pressing part and a second pressing member which includes a second pressing part inserted into a hollow of the first pressing part. A transformer supplies a positive (+) current to the first pressing member and a negative (?) current to the second pressing member. The first and second pressing parts have the same co-axis.

Abstract: A spot welding apparatus includes a stationary frame having a housing formed therein. An upper welding gun is mounted to a length direction of a pressing unit disposed in the housing of the stationary frame. A plurality of lower welding guns are mounted on an outside of the stationary frame and ends of the plurality of lower welding guns selectively face one end of the upper welding gun in a length direction of the lower welding guns by the plurality of lower welding guns. A plurality of actuators are mounted on the outside of the stationary frame. A plurality of link units are disposed between the actuators and the lower welding guns, connect the actuators and the lower welding guns, respectively, and rotate as the actuators are operated.

Abstract: A heat exchanger device for a heater a motor vehicle, having a housing with at least one fluid channel disposed therein, with a fluid inlet and a fluid outlet, an element generating an alternating magnetic field, and at least one, preferably metallic, flat heating element around which a fluid can flow on one or both sides, whereby at least one further flat heating element is provided, which is configured to divide the at least one fluid channel into subchannels. A heater with a heat exchanger device is also provided.

Abstract: The invention relates to a power source (10) for providing a direct current, comprising a heavy-current transformer (12) with at least one primary winding (13) and at least one secondary winding (14) with center tapping, a synchronous rectifier (16) connected with the at least one secondary winding (14) of the heavy-current transformer (12) and comprising circuit elements (24), and a circuit (17) for actuating the circuit elements (24) of the synchronous rectifier (16), and a supply circuit (48) for supplying the synchronous rectifier (16) and the actuation circuit (17), and to a method for cooling such a power source (10). For reduction of losses and improvement of efficiency, the synchronous rectifier (16) and the actuation circuit (17) and the supply circuit (48) thereof are integrated in the heavy-current transformer (12).

Abstract: A dummy weld apparatus including a dummy weld gun which allows a direct weld robot with a conventional weld gun to clamp down on the dummy weld gun to apply force and weld current for performing welding of workpieces of a first composition (e.g., aluminum). This arrangement allows the current provided by the conventional weld gun to flow through the dummy weld gun for welding the workpieces using weld tips dedicated to welding parts of the first composition, but also allows the dummy weld gun to be removed from the conventional weld gun to allow the conventional weld gun to performing welding operations on workpieces of a second composition (e.g., steel) using the original welding tips of the weld gun, avoiding material contamination of the tips.

Abstract: It is possible to control a welding in a high speed and a high precision large electric current, and consumption electric power is also reduced. In the welding transformer, a loop magnetic core 25, a wound primary coil 12, plural positive side coils 14 and plural negative side coils 16 that are alternately sandwiched between respective gaps 12a of the primary coil 12, are comprised. A coil is fixed on the other surface of a contact base member 62. On the other surface of the contact base member 62, a first connection polar board 44 is electrically connected to a positive side electric conductor 30 through the first connection polar board 44. A negative side coil 16 is electrically connected to a negative side electric conductor 32. The connecting part of the positive side coil 14 and the negative side coil 16 is electrically connected to the third connection polar board 48.

Abstract: A welding system includes a first field bus. The welding system further includes a first welding converter, wherein the first welding converter is operatively connected to the first field bus via a first interface. The welding system further includes at least one further component, wherein the at least one further component is operatively connected to the first field bus. The first welding converter is configured to transmit an actuation data to the at least one further component using the first field bus to actuate the at least one further component.

Abstract: A resistance welding high frequency transformer and a high frequency resistance welding machine using the same are disclosed. The transformer comprises a magnetic core (6), primary coils (1, 2, 3) and secondary coils (4, 5). The primary coils and the secondary coils are alternatively positioned layer by layer. Each secondary coil is arranged between two primary coils. The primary coils are provided at the internal side and the external side of the secondary coil. The secondary coil is composed of red copper pipes through which water flows. Each secondary coil is wound with one to two turns. The red copper pipes of the secondary coils and rectifier diodes constitute a full-wave rectifier circuit. The resistance welding high frequency transformer can be wound conveniently.

Abstract: The invention relates to a resistance welding device (1) comprising a power source (10) in order to provide a welding current for welding workpieces (2, 3), a welding gun (4) with two gun arms (5) comprising one electrode (7) each in order to impress the welding current into the workpieces (2, 3), wherein the power source (10) comprises a heavy-current transformer (12) with at least one primary winding (13) and at least one secondary winding (14) with center tapping, a synchronous rectifier (16) connected with the at least one secondary winding (14) of the heavy-current transformer (12) and comprising circuit elements (24), and a circuit (17) for actuating the circuit elements (24) of the synchronous rectifier (16).

Abstract: A programmable polarity module that permits rapid on-demand control of the polarities assigned to the welding electrodes retained on a welding gun is disclosed. The programmable polarity module is electrically connectable to the welding gun and a direct current power supply unit to provide direct current to the welding electrodes for exchange during spot welding. A first interchangeable polarity output lug and a second interchangeable polarity output lug of the programmable polarity module permit the polarities of the welding electrodes to be switched without having to electrically disconnect the module from the welding gun.

Abstract: A resistance spot welder includes: a motor, having a shaft; a cylindrical casing; a hollow guide rod, inserted into the casing, and adapted to be moved linearly for moving a first electrode tip facing a second electrode tip provided at a gun arm; a ball nut, fixed in an inner circumference of the guide rod; a ball screw, fitted through the ball nut; a coupling, including a first fastening portion into which the shaft of the motor is inserted and a second fastening portion into which the ball screw is inserted and which is opposite to the first fastening portion; and a bearing, fitted between an outer circumference of the first fastening portion and an inner circumference of the casing. The guide rod is moved between a first point which is a motor side and a second point which is an electrode tip side. When the guide rod is positioned at the first point, the guide rod accommodates at least a part of the second fastening portion.

Abstract: A resistance welding high frequency transformer and a high frequency resistance welding machine using the same are disclosed. The transformer comprises a magnetic core (6), primary coils (1, 2, 3) and secondary coils (4, 5). The primary coils and the secondary coils are alternatively positioned layer by layer. Each secondary coil is arranged between two primary coils. The primary coils are provided at the internal side and the external side of the secondary coil. The secondary coil is composed of red copper pipes through which water flows. Each secondary coil is wound with one to two turns. The red copper pipes of the secondary coils and rectifier diodes constitute a full-wave rectifier circuit. The resistance welding high frequency transformer can be wound conveniently.

Abstract: The invention relates to a winding element (200) for conducting current, forming a component of a coil winding (132, 133; 408, 409), especially of a (welding) transformer winding, comprising fixing means (205) for fixing the winding element (200) to a carrier component (402, 403, 404). The invention also relates to a transformer arrangement (100; 600), especially a welding transformer arrangement, comprising a primary winding (132; 408) and a secondary winding (133; 409), the primary winding (132; 408) and/or secondary winding (133; 409) comprising at least one winding element (200) according to the invention.

Abstract: A semiconductor module (500) for connecting to a transformer winding (132, 133; 408; 409) includes a semiconductor component (501) that is disk-shaped and disposed between two contact plates (502). One of the contact plates (502) is acted upon using a cooling fluid on its side facing away from the semiconductor component (501).

Abstract: A weld gun including a frame structure, a weld arm mounted on the frame structure, an electrode mounted on the weld arm and including an electrode cap at one end of the electrode, a transformer, and a shunt fixedly secured at one end thereof to another end of the electrode and fixedly secured at another end thereof to the transformer.

Abstract: A resistance welding apparatus characterized by very low output impedance, and providing a substantially constant voltage source to low impedance (e.g., resistances on the order of 1-100 micro-ohms) materials-to-be-joined. The welding apparatus includes one or more primary and secondary winding pairs disposed about a high permeability core with the secondary coil(s) positioned between the primary coil(s) and the core. In a preferred form, the secondary coil(s) are capable of delivering more than 75,000 amperes of welding current. The welding apparatus is lighter, more cost efficient, and more energy efficient than conventional systems.

Abstract: A pinch type weld gun wherein a shunt is fixedly secured at one end thereof to a gun electrode and fixedly secured at another end thereof to the gun transformer. The shunt is formed of a plurality of elongated strips of flexible copper material which are arranged in stacked configuration whereafter the end portions of the stack are electrically welded to fuse the end portions together to form solid unified end portions. The strips are unsecured intermediate the unified end portions to form a flexible intermediate portion extending between the transformer and the electrode. The solid end portion of the shunt for securement to the transformer is thereafter machined to form intersecting longitudinal and transverse bores to define a passage for delivery of a coolant fluid to the transformer coolant passage system through the solid end of the shunt.

Abstract: A pinch type weld gun wherein a shunt is fixedly secured at one end thereof to a gun electrode and fixedly secured at another end thereof to the gun transformer. The shunt is formed of a plurality of elongated strips of flexible copper material which are arranged in stacked configuration whereafter the end portions of the stack are electrically welded to fuse the end portions together to form rigid unified end portions. The strips are unsecured intermediate the unified end portions to form a flexible intermediate portion and the unified end portion connected to the transformer is bent into a curvilinear configuration to provide a compact and relaxed routing for the shunt between the transformer and the electrode.

Abstract: A resistance welding apparatus characterized by very low output impedance, and providing a substantially constant voltage source to low impedance (e.g., resistances on the order of 1-100 micro-ohms) materials-to-be-joined. The welding apparatus includes one or more primary and secondary winding pairs disposed about a high permeability core with the secondary coil(s) positioned between the primary coil(s) and the core. In a preferred form, the secondary coil(s) are capable of delivering more than 75,000 amperes of welding current. The welding apparatus is lighter, more cost efficient, and more energy efficient than conventional systems.

Abstract: An apparatus for welding that includes a fixture for locating product including a weldable material having a relatively sharp melting point. The apparatus also includes a robot positioned adjacent the fixture and that has a moveable arm and a controller programmable to control movement of the arm, and a welder assembly that includes a mid-frequency DC transformers and a weld mechanism attached to the arm and operably connected to the mid-frequency DC transformer. The weld mechanism includes a pair of opposing weld tips adapted and configured to weld a pair of plates that include the weldable material.

Abstract: A resistance welding system with a self-contained close-loop cooling arrangement which includes a chiller, a welding transformer, a cable and a welding gun. The chiller has a feed-port and return-port for the cooling fluid. The welding transformer has an inlet and outlet for a defined cooling path and the inlet is coupled with the feed port of the chiller while the outlet is coupled with the return port of the chiller. One end of the cable is connected to one side of the transformer, for carrying the welding current. The cable is capable of being coupled to the chiller in a manner to internally transfer the cooling fluid in either direction. The welding gun is connected to the other end of the cable and has a pair of electrodes for applying the current through a pair of workpieces. The welding gun also has a built-in cooling system which is capable of receiving, circulating and returning the cooling fluid to the chiller without external fittings and hoses.

Abstract: A multiple spot resistance welding machine for the welding of wire grids by direct current comprises several contact electrodes (4.1.1, 4.2.1, 4.1.2, 4.2.2, . . . ) contacting a respectively associated grid point from both sides. The switching arrangement for the simultaneous application of welding current to all contacted grid points exhibits, for each contact electrode pair (4.1.1/4.2.1, . . . , 4.1.5/4.2.5), a welding transformer. Juxtaposed welding electrode pairs are floating with respect to potential in accordance with this invention so that the sole transverse connection is constituted by the transverse wire (1). A separate contact electrode pair is provided for each grid point.

Abstract: A direct current resistance welding machine and a method of controlling the direct current resistance welding machine wherein primary current of a welding transformer is detected when a plurality of switching devices of an inverter are controlled based on corresponding pulses having a predetermined frequency and each having a time width corresponding to the value of a required secondary current. Rise and fall times of the detected primary current are detected. An upper limit frequency Of the primary current is computed based on the time width of each pulse and on the rise and fall times. Thus, the primary current of the welding transformer is controlled by controlling the switching devices based on pulses having a frequency falling within the computed upper limit frequency.

Abstract: A multi-unit welding apparatus has a row of electric welding units all of which are connected in parallel with a single welding transformer through an electric conductor assembly. The electric conduction assembly includes a single strip of electric conductor and a double-folded strip of electrode conductor which are connected at one end to positive and negative terminals of a secondary winding of the welding transformer and are arranged along and connected to the welding units of the welding unit row so that the combined length of conductor between secondary winding and each welding unit is the same for all welding units.

Abstract: In a DC type C-shaped welding gun apparatus having a transformer mounted thereon, a center tap of the transformer is communicated to a movable gun arm via an ounce metal plate. A rear end portion of a stationary gun arm is pressingly held between a pair of terminal plates via rectifiers. Both terminal plates are disposed such that their center line is offset to one widthwise side of the transformer. The stationary gun arm is thus disposed to one widthwise side of a projected area of the transformer. The ounce metal plate for supplying electric power to the movable gun arm is disposed to the other side of the projected area. In an X-shaped welding gun apparatus, a first gun arm is rotatably supported by a supporting shaft provided on a gun bracket. A second gun arm is directly connected to one of feeder terminals of a transformer to constitute the second gun arm and the transformer into a unit.

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 welding transformer for use in a resistance welding machine has primary and secondary coils. The primary coil includes a plurality of spaced juxtaposed coil units mounted on a base board. Each of the coil units includes a plurality of juxtaposed coil unit elements with insulating members interposed therebetween. Each of the coil unit elements includes a plurality of turns of a conductive member, and a plurality of conductors mounted on the base board and electrically interconnecting the coil unit elements. A pair of cores is combined with the coil units.

Abstract: A welding transformer in a welding gun for robot capable of lightening the weight thereof as a whole and of reducing the assembling and disassembling process of the constituents thereof. The welding transformer is disposed within a cradle composed of a hollow frame and has a core fixed to the cradle by fastening members so as to be integrated with the cradle.

Abstract: A welding apparatus is disclosed to include an electrically insulating casing, first and second welding electrodes, and one or more welding transformer cores having toroidal cores, multi-turn primary windings and a single-turn secondary winding. The cores include a grain-oriented silicon steel material coiled with an insulator. The primary windings have turns axially wound about the cores. The secondary windings include at least two conductive arm sections which are connected to the electrodes and a wound section including conductive wire cable which electrically connects the two arm sections. One of the arm sections can provide the frame member to support the transformer. The apparatus is suitable for spot or linear welding.

Abstract: There is disclosed a welding transformer control apparatus capable of controlling the voltage supplied to the primary winding of the welding transformer. The welding transformer control apparatus comprises a voltage detecting circuit connected to the thyristor for detecting a power voltage and a digital operation unit connected to the voltage detecting circuit via an A/D converter for receiving the digital converted power voltage. The digital operation unit is also connected to a voltage setting unit for receiving a predetermined voltage to be supplied to the primary winding of the welding transformer. The digital operation unit compares the predetermined voltage supplied from the voltage setting unit with the power voltage supplied from the A/D converter and provides a signal to suppress the power voltage under the predetermined voltage.

Abstract: The present invention provides a welding gun for robot provided with a cradle formed of a hollow frame. The cradle has side plates serving also as stopper receivers for receiving stoppers of the welding gun arms, thereby eliminating an extra member for receiving the stoppers and laborious working for attachment of such extra member. A space to be occupied by the extra member is omitted and can be effectively utilized for holding a welding transformer.

Abstract: A connection member in a welding gun for a robot having a cradle of the welding gun generates less stress by directly connecting the cradle with a robot wrist, whereby the welding gun is positioned as close as possible to the robot wrist. The welding gun for robot can be shortened by accommodating a welding transformer inside a hollow frame defined in the cradle.

Abstract: A variable pitch spot welding gun assembly for a welding robot has a fixed base (16) directly attached to the robot wrist (12) of an industrial welding robot, welding transformers (24, 26) fixed to the fixed base (16), a fixed spot welding gun (22) provided apart from the welding transformers (24, 26), a movable spot welding gun (20) provided apart from the welding transfomers (24, 26) and capable of being moved relative to the fixed spot welding gun (22), to adjust a pitch between the fixed spot welding gun (22) and the movable spot welding gun (20), and secondary conductors (44a to 44e) connecting the fixed and movable spot welding guns (22, 90) respectively to the welding transformers (24, 26).

Abstract: A resistance welding apparatus mounted on a robot arm includes a transformer having primary and secondary windings. Two gun arms supporting respective welding electrodes in confronting relation to each other are relatively movable toward and away from each other. Conductors extending from the secondary winding are electrically connected to one of the welding electrodes through one of the gun arms, and the transformer is supported on said one gun arm. Rectifiers are used which have terminals engaging said one gun arm and opposite terminals engaging the conductors. The rectifiers and the conductors are securely joined to the one gun arm.

Abstract: A welding gun assembly includes a welding gun with a pair of electrodes for welding workpieces together therebetween. The welding gun assembly includes an array of transformers extending in one direction and having respective secondary coils. The welding gun assembly also has a plurality of terminal plates connected to the secondary coils, and a plurality of center tap terminal plates connected to intermediate portions of the secondary coils. A first conductor plate extends along the transformer array and interconnects the terminal plates, the first conductor plate being connected to one of the electrodes of the welding gun. A second conductor plate extends along the transformer array and interconnects the center tap terminal plates, the second conductor plate being connected to the other electrodes of the welding gun.

Abstract: A welding apparatus is disclosed to include an electrically insulating casing, first and second welding electrodes, and a welding transformer having a toroidal core, a multi-turn primary winding and a single-turn secondary winding. The core includes a grain-oriented silicon steel material coiled with an insulator. The primary winding has turns axially wound about the core. The secondary winding includes two conductive arm sections which are connected to the electrodes and a wound section including conductive wire cable which electrically connects the two arm sections. One of the arm sections can provide the frame member to support the transformer. The apparatus is suitable for spot or linear welding.

Abstract: A transformer apparatus for use with a welding gun includes four transformer/rectifier assemblies each including a transformer having a secondary winding and a rectifier, a terminal plate connected to the secondary winding through the rectifier, and a center tap terminal plate connected to an intermediate portion of the secondary winding. The terminal plate and the center tap terminal plate are disposed on one side of the transformer, and the transformers of the transformer/rectifier assemblies are disposed side by side. The terminal plates of the transformer/rectifier assemblies are disposed closely to each other in confronting relation. First and second conductive bodies interconnect the terminal plates and the center tap terminal plates of the transformer/rectifier assemblies. The transformer/rectifier assemblies are symmetrically disposed.

Abstract: The present invention relates to an apparatus for continuous-direct-resistance heating of long-length articles wherein the travelling long-length article is made to contact with roll electrodes disposed in a specified spacing, then made to pass through an annular transformer disposed between the roll electrodes.Conductive members with sufficiently less electrical resistance than that of the long-length article located between the both electrodes are disposed on the periphery of the transformer with the both ends thereof connected to the roll electrode through a slider, thereby a current being induced in the long-length article with the conductive member as the retrace, which heats the long-length article having a higher resistance very efficiently, but does not result in an external voltage nor any electrical hazards along the production line in which the apparatus is installed.

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: The specification discloses a physically compact, low-inductance, high power-factor D.C. power unit assembly for producing rectified, multi-phase or single-phase, full-wave voltage. The assembly includes a plurality of single-phase, full-wave D.C. power units each having a planar rectified pad oriented perpendicular to the plane of the coil turns. The D.C. power units are aligned so that the rectified pads are coplanar. A common bus overlies and is electrically insulated from the rectified pads and is connected to the common terminal of each D.C. power unit. A pair of rectified buses are positioned on opposite sides of, and parallel to, the common bus. Each rectified pad is electrically connected at opposite ends to each of the rectified buses. The common bus is coaxial with the two rectified buses to permit an optimal power factor.

Abstract: An assembly is provided for mounting on an end of a robot arm actuator as an integral spot resistance welding gun and transformer unit. A gun slide support bracket is connected to the transformer and serves to provide a mount for a sliding gun cylinder having a piston connected to one of the jaw electrodes. The lower jaw is removably connected to the cylinder. Roller shunts are used to provide electrical connection between secondary terminals on the transformer and the two electrodes. A proximity switch assembly is advantageously utilized to provide signals to the robot controller indicating a fully retracted position of the jaws.

Abstract: High frequency resistance spot welding structure and method. In one embodiment, the structure includes dual, mirror image welding transformers, each including a transformer secondary circuit, an endless transformer core, and a transformer primary winding wound around the transformer core. The transformer secondary circuits may be single member, U-shaped transformer secondaries with integral electrode portions. In another embodiment, one of the transformers is replaced by a pair of spaced apart welding electrodes which are connected by a conductor. Means are provided for supplying welding pressure to the transformers to move them with their associated welding electrodes during a weld sequence. A high frequency, electrical welding signal is applied to the transformer primary circuits which are synchronized when two transformers are used so that the welding currents passing through the transformer secondary circuits reinforce each other.

Abstract: The present invention relates to an apparatus for continuous-direct-resistance heating of long-length articles wherein the travelling long-length article is made to contact with roll electrodes disposed in a specified spacing, then made to pass through an annular transformer disposed between the roll electrodes.Conductive members with sufficiently less electrical resistance than that of the long-length article located between the both electrodes are disposed on the periphery of the transformer with the both ends thereof connected to the roll electrode through a slider, thereby a current being induced in the long-length article with the conductive member as the retrace, which heats the long-length article having a higher resistance very efficiently, neither resulting in an external voltage, nor causing electrically any obstacle to the production line in which the apparatus is installed.

Abstract: A resistance seam welding machine is described, particularly for the longitudinal seam welding of can bodies, wherein, in the secondary loop (16), feed and return lines are constructed partially as a double line (18, 28) and in all the remaining portion (18a, 18b, 18c, 20, 24, 26) in the form of a substantially coaxial line. The voltage loss occurring in the secondary loop (16) between welding transformer (14) and welding position (8, 10) and the heat due to energy losses in the machine parts adjacent to the secondary loop are considerably reduced as a result of this construction of the feed return lines.

Abstract: A variable-ratio transformer for arc and plasma setups, comprising a magnetic core made up of a main part composed of two yokes and legs in accordance with the number of phases and an additional part disposed on the side of the yoke of the main part of the magnetic core. The additional part of the magnetic core is made up of a yoke and legs whose number is equal to the number of the legs of the main part, at least one leg being placed with a gap in relation to the first yoke of the main part. The primary winding of each phase comprises two series-connected parts, the first part being located on the main part of the magnetic core, while the second part is located on the additional part thereof. A controlled electronic switch which regulates the load current flowing through the secondary winding of each phase, disposed on the main part of the magnetic core, is connected in parallel to one of the parts of the primary winding of each phase.

Abstract: A method of and structure for high speed seam welding. The method comprises placing an auxiliary transformer between a three phase source of electrical welding energy and seam welder structure, which auxiliary transformer includes three separate primary windings connected to the separate phases of the source of welding energy, phase controlling the energizing of each separate primary winding and energizing the seam welder from the auxiliary transformer. In one embodiment, the phases of the auxiliary transformer are energized in the order of the phase of the welding energy and a delay of approximately 120.degree. of the welding energy is provided between the energizing of each auxiliary transformer winding. In another embodiment of the invention, the auxiliary transformer primary windings are energized in a first, third, second, welding energy phase order with a delay of 240.degree.

Abstract: A control device having a single static converter incorporating a rectifier and stabilizer block and a transistorized inversion block, the output signal of which is controlled by an amplitude and frequency regulator in response to a feedback signal taken off the primary or the secondary winding of the welding transformer. The device features an additional rectifier block located between the output from the secondary winding and the input to the welding rollers.

Abstract: A measuring winding (208) which is connected to a signal frequency generator is additionally disposed on the core (206) of a welding transformer (TR2). A voltage depending on the state of saturation of the core (206) is tapped off at the measuring winding (208) by a detector circuit (204). An amplitude demodulator (204b) delivers a direct voltage signal which is inversely proportional to the saturation. By comparison with a reference value, a discriminator circuit determines whether a threshold value related to saturation has already been reached or not. If it is reached, the firing of the power semiconductors is interrupted by a blocking signal. With this saturation monitoring arrangement, the welding device can be operated more easily and the welding transformer can be utilized in the optimum manner. The method of control becomes considerably simpler because the welding time no longer needs to be split up into individual impuses by the operator.