Abstract: An electric arc welding apparatus comprising at least a first consumable electrode and a second consumable electrode movable in unison along a welding path between the edges of two adjacent, mutually grounded plates, a first power supply for passing a first welding current at a first low frequency between the first electrode and the two plates, a second power supply for passing a second welding current at a second low frequency between the second electrode and the two plates, where each of the power supplies includes a three phase voltage input operated at line frequency, a rectifier to convert the input voltage to a DC voltage link and a high frequency switching type inverter converting the DC voltage link to a high frequency AC current, an output rectifier circuit to provide a positive voltage terminal and a negative voltage terminal, and an output switching network operated at a given low frequency for directing a pulsating welding current at the given low frequency from the two terminals across one of the

Abstract: An electric arc welding apparatus comprising at least a first consumable electrode and a second consumable electrode movable in unison along a welding path between the edges of two adjacent, mutually grounded plates, a first power supply for passing a first welding current at a first low frequency between the first electrode and the two plates, a second power supply for passing a second welding current at a second low frequency between the second electrode and the two plates, where each of the power supplies includes a three phase voltage input operated at line frequency, a rectifier to convert the input voltage to a DC voltage link and a high frequency switching type inverter converting the DC voltage link to a high frequency AC current, an output rectifier circuit to provide a positive voltage terminal and a negative voltage terminal, and an output switching network operated at a given low frequency for directing a pulsating welding current at the given low frequency from the two terminals across one of the

Abstract: An electric arc welder for creating a welding cycle with a real time current waveform constituting several control parameters by a microprocessor that controls a power supply by a signal so the output of the power supply traces a desired waveform and dynamic reaction behavior to arc conditions defined by the control parameters. The welder has a controller for creating the signal and reading the parameters, a graphic user interface program controlled by input from a graphic user interface computer, a system with a first interface for an interactive display for displaying the desired waveform and dynamic behavior and at least one manipulative control parameter, a second interface for a manual data entry device to change the waveform and/or the parameters and a digital communication link from the graphic user interface to the welder microprocessor controller for causing the welder to perform the desired waveform by controlling the signal.

Abstract: An electric arc welding apparatus comprising at least a first consumable electrode and a second consumable electrode movable in unison along a welding path between the edges of two adjacent, mutually grounded plates, a first power supply for passing a first welding current at a first low frequency between the first electrode and the two plates, a second power supply for passing a second welding current at a second low frequency between the second electrode and the two plates, where each of the power supplies includes a three phase voltage input operated at line frequency, a rectifier to convert the input voltage to a DC voltage link and a high frequency switching type inverter converting the DC voltage link to a high frequency AC current, an output rectifier circuit to provide a positive voltage terminal and a negative voltage terminal, and an output switching network operated at a given low frequency for directing a pulsating welding current at the given low frequency from the two terminals across one of the

Abstract: An electric arc welding apparatus comprising at least a first consumable electrode and a second consumable electrode movable in unison along a welding path between the edges of two adjacent, mutually grounded plates, a first power supply for passing a first welding current at a first low frequency between the first electrode and the two plates, a second power supply for passing a second welding current at a second low frequency between the second electrode and the two plates, where each of the power supplies includes a three phase voltage input operated at line frequency, a rectifier to convert the input voltage to a DC voltage link and a high frequency switching type inverter converting the DC voltage link to a high frequency AC current, an output rectifier circuit to provide a positive voltage terminal and a negative voltage terminal, and an output switching network operated at a given low frequency for directing a pulsating welding current at the given low frequency from the two terminals across one of the

Abstract: An electric arc welder including a high speed switching power supply with a controller for creating high frequency current pulses through the gap between a workpiece and a welding wire advancing toward the workpiece, where the pulses and a background current defining a series of weld cycles. A wave shape generator defines the shape of the pulses and the background current including a controlled ramp up and/or ramp down in each of said cycles and a circuit to change the shapes of the pulses and/or background current in a repeating pattern in each of the weld cycles. The shape change in a cycle can be between first and second shapes or by a rhythmic AC modulation.

Abstract: A control system for an electric arc welder performing a welding process between an electrode and a workpiece, which system comprises: a high speed switching type power supply with a controller operated at a switching frequency of at least about 10 kHz with an input current control signal to adjust the output current of the power supply; a first sensor sensing the actual arc voltage; a second sensor sensing the actual arc current; a first circuit for creating a power signal representing the desired real time power level at progressive times during the welding process; a second circuit for creating a function of the sensed actual voltage and the sensed actual current; and a third circuit for adjusting the current control signal in accordance with the difference between the power signal and the function of the actual voltage and current, preferably arc power.

Abstract: An electric arc welding apparatus comprising at least a first consumable electrode and a second consumable electrode movable in unison along a welding path between the edges of two adjacent, mutually grounded plates, a first power supply for passing a first welding current at a first low frequency between the first electrode and the two plates, a second power supply for passing a second welding current at a second low frequency between the second electrode and the two plates, where each of the power supplies includes a three phase voltage input operated at line frequency, a rectifier to convert the input voltage to a DC voltage link and a high frequency switching type inverter converting the DC voltage link to a high frequency AC current, an output rectifier circuit to provide a positive voltage terminal and a negative voltage terminal, and an output switching network operated at a given low frequency for directing a pulsating welding current at the given low frequency from the two terminals across one of the

Abstract: An electric arc welding apparatus comprising at least a first consumable electrode and a second consumable electrode movable in unison along a welding path between the edges of two adjacent, mutually grounded plates, a first power supply for passing a first welding current at a first low frequency between the first electrode and the two plates, a second power supply for passing a second welding current at a second low frequency between the second electrode and the two plates, where each of the power supplies includes a three phase voltage input operated at line frequency, a rectifier to convert the input voltage to a DC voltage link and a high frequency switching type inverter converting the DC voltage link to a high frequency AC current, an output rectifier circuit to provide a positive voltage terminal and a negative voltage terminal, and an output switching network operated at a given low frequency for directing a pulsating welding current at the given low frequency from the two terminals across one of the

Abstract: An electric arc welding apparatus comprising at least a first consumable electrode and a second consumable electrode movable in unison along a welding path between the edges of two adjacent, mutually grounded plates, a first power supply for passing a first welding current at a first low frequency between the first electrode and the two plates, a second power supply for passing a second welding current at a second low frequency between the second electrode and the two plates, where each of the power supplies includes a three phase voltage input operated at line frequency, a rectifier to convert the input voltage to a DC voltage link and a high frequency switching type inverter converting the DC voltage link to a high frequency AC current, an output rectifier circuit to provide a positive voltage terminal and a negative voltage terminal, and an output switching network operated at a given low frequency for directing a pulsating welding current at the given low frequency from the two terminals across one of the

Abstract: An electric arc welding apparatus comprising at least a first consumable electrode and a second consumable electrode movable in unison along a welding path between the edges of two adjacent, mutually grounded plates, a first power supply for passing a first welding current at a first low frequency between the first electrode and the two plates, a second power supply for passing a second welding current at a second low frequency between the second electrode and the two plates, where each of the power supplies includes a three phase voltage input operated at line frequency, a rectifier to convert the input voltage to a DC voltage link and a high frequency switching type inverter converting the DC voltage link to a high frequency AC current, an output rectifier circuit to provide a positive voltage tenninal and a negative voltage terminal, and an output switching network operated at a given low frequency for directing a pulsating welding current at the given low frequency from the two terminals across one of the

Abstract: An aquatic trap, the aquatic trap including a chamber, the chamber being bounded by a netted periphery that is permeable by water, at least one inlet passing through the netted periphery, the inlet converging toward the interior of the chamber, a rotatable wall portion formed in the netted periphery, the rotatable wall portion being connected to the netted periphery by a pivotal connection, the rotatable wall portion being rotatable about the pivotal connection from a closed position in which the rotatable wall portion is substantially within the plane of the netted periphery to an open position in which the rotatable wall portion is substantially outside of the plane of the netted periphery, a biasing mechanism for biasing the rotatable wall portion toward the closed position, and a stop mechanism for abutting the rotatable wall portion in the closed position against the biasing action of the biasing mechanism.