Abstract: According to one embodiment, an apparatus is described. The apparatus includes a vacuum chamber and an electrical transformer to induce an electromagnetic field within the vacuum chamber. The transformer includes a primary winding, a secondary winding formed by the plasma loop, and a separate secondary winding implemented to measure the voltage along the plasma loop. The apparatus also includes a current transformer to measure the current flow through the plasma loop.

Abstract: A method and apparatus for providing welding type power is disclosed. The power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the ac input into a dc signal. A dc voltage stage converts the dc signal to a desired dc voltage and an inverter inverts the dc signal into a second ac signal. An output transformer receives the second ac signal and provides a third ac signal that has a current magnitude suitable for welding, cutting or induction heating. The welding type current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and a controller power supply can also receive a range of input voltages and provide a control power signal to the controller, and a voltage independent of the input voltage.

Abstract: In accordance with one embodiment of the present invention, there is provided a switch-mode power supply to generate the heating current for a hot-filament electron-emitting cathode. The power supply directly couples, without an output transformer, the output from a full-bridge converter that operates at an output frequency in the range from ten Hz to ten kHz. A connection to a reference potential that minimizes the potential fluctuation of the cathode is provided by one of the direct-current inputs to the converter.

Abstract: According to one embodiment, an apparatus is described. The apparatus includes a vacuum chamber, an electrical transformer coupled to the vacuum chamber, and an ignition circuit. The electrical transformer induces an electromagnetic field within the vacuum chamber. The transformer includes a primary winding and a magnetic core. In addition, the transformer includes a secondary winding, to which the circuit used to ignite the vacuum chamber is coupled. The ignition circuit is used to establish a controlled capacitive discharge that is used to ignite the vacuum chamber.

Abstract: The invention relates to a method for providing a direct estimation of the power delivered to the plasma in a TCP source. According to one embodiment, an apparatus is described. The apparatus includes a vacuum chamber and an electrical transformer to induce an electromagnetic field within the vacuum chamber. The transformer includes a primary winding, a secondary winding formed by the plasma loop, and a separate secondary winding implemented to measure the voltage along the plasma loop. The apparatus also includes a current transformer to measure the current flow through the plasma loop.

Abstract: A method and apparatus for providing welding type power is disclosed. The power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the ac input into a dc signal. A dc voltage stage converts the dc signal to a desired dc voltage and an inverter inverts the dc signal into a second ac signal. An output transformer receives the second ac signal and provides a third ac signal that has a current magnitude suitable for welding, cutting or induction heating. The welding type current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and a controller power supply can also receive a range of input voltages and provide a control power signal to the controller, and a voltage independent of the input voltage.

Abstract: A power circuit for a welding power supply includes a control circuit, a power conversion circuit, a filter circuit, and a supplemental power circuit. The control circuit is configured to provide control signals to the power conversion circuit. The power conversion circuit is configured to generate a welding power based on the control signals. The filter circuit is configured to filter the welding power and to provide the filtered welding power at a welding output. The supplemental power circuit is configured to provide a supplemental power, wherein the supplemental power circuit is coupled across the filter circuit such that the filter circuit filters the supplemental power.

Abstract: A method and apparatus for providing welding type power is disclosed. The power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the ac input into a dc signal. A dc voltage stage converts the dc signal to a desired dc voltage and an inverter inverts the dc signal into a second ac signal. An output transformer receives the second ac signal and provides a third ac signal that has a current magnitude suitable for welding, cutting or induction heating. The welding type current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and a controller power supply can also receive a range of input voltages and provide a control power signal to the controller, and a voltage independent of the input voltage.

Abstract: A method and apparatus for providing welding type power is disclosed. The power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the ac input into a dc signal. A dc voltage stage converts the dc signal to a desired dc voltage and an inverter inverts the dc signal into a second ac signal. An output transformer receives the second ac signal and provides a third ac signal that has a current magnitude suitable for welding, cutting or induction heating. The welding type current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and a controller power supply can also receive a range of input voltages and provide a control power signal to the controller, and a voltage independent of the input voltage.

Abstract: A welding power supply that includes a series resonant converter, including at least one switch and at least one capacitor is disclosed. The converter includes a switching circuit including an enable input. A voltage sensing circuit that determines the earliest safe switching time of the switch is provided. The safe switching time is the time that will prevent a peak voltage on the capacitor from exceeding a predetermined threshold for a next cycle of the converter. The voltage sensing circuit provides an enable signal to the enable input when the earliest switching time has passed, to enable the switching circuit. A pair of welding output terminals connected to the series resonant converter receives the output. A controller including a curve shaper, for providing a constant current output in the welding range is also disclosed. The controller also provides an adaptive hot start that provides varying amounts of energy in response to the welders skill.

Abstract: A system and method for inductively heating a workpiece includes a controller and a plurality of power supplies that receive and send signals to the controller. Induction heads receive power from the power supplies. The induction heads may be aligned with adjacent segments of the workpiece, and can span the perimeter of the workpiece. The gap between adjacent induction heads is less than one half the size of the adjacent induction heads, and preferably the induction heads abut or substantially abut. Each of the power supplies include feedback for controlling the power delivered to the segments of the workpiece. In alternative embodiments the feedback may be based on the current or power provided to the induction heads, or the power provided to the workpiece.

Abstract: An inverter power supply for use with various voltage inputs is provided. The inverter power supply generally receives 208 VAC single-phase, 208 VAC three-phase, 230 VAC three-phase, 230 VAC single-phase, 460 VAC single-phase, or 460 VAC three-phase power and provides a DC output current for welding, heating or cutting applications. The power inverter circuit includes a first tank circuit and a second tank circuit which are configured in serial or parallel according to a particular voltage input. Dual contactor switches respond to control signals from an AC sense circuit in order to configure the inverter power supply for the appropriate voltage input. The dual contactors may be mechanically interlocked and driven off the DC power for the control board.

Abstract: A welding power supply that includes a series resonant converter, including at least one switch and at least one capacitor is disclosed. The converter includes a switching circuit including an enable input. A voltage sensing circuit that determines the earliest safe switching time of the switch is provided. The safe switching time is the time that will prevent a peak voltage on the capacitor from exceeding a predetermined threshold for a next cycle of the converter. The voltage sensing circuit provides an enable signal to the enable input when the earliest switching time has passed, to enable the switching circuit. A pair of welding output terminals connected to the series resonant converter receives the output. A controller including a curve shaper, for providing a constant current output in the welding range is also disclosed. The controller also provides an adaptive hot start that provides varying amounts of energy in response to the welders skill.

Abstract: A method and apparatus for arc welding, particularly starting an arc is disclosed. A welding power source that provides a welding current to an electrode and a workpiece includes a source of welding current having an inductor. The inductor and current source are connected to a pair of outputs, such as the output studs, and form a welding current path including the source of current, the output inductor, the outputs and the electrode and workpiece. A source of a high frequency voltage, such as a high frequency coupling coil is included in the welding current path. An arc starting circuit provides a controllable current path for current flow in the inductor prior to the application of high frequency voltage. The arc starting current path is not the welding current path.

Abstract: An induction heater comprises a coupled pair of inverters and an induction head for generating heat, coupled to the second inverter. The output signal of the first inverter which operates at a fixed frequency, is controlled by feedback indicative of the heat output of the induction head. A control circuit processes the feedback information to compensate for power losses in the induction head. The output of the first inverter is electrically coupled to the input of the second inverter, which operates at an adjustable frequency which is selected by the user to optimize heating. The power delivered to the induction head is dependent on the output voltage of the second inverter, which is dependent on the output signal of the first inverter.

Abstract: An induction heater comprises a coupled pair of inverters and an induction head for generating heat, coupled to the second inverter. The first inverter operates at a constant frequency, but the total output current is controlled through pulse width modulation. The output current is rectified and provided as a DC input voltage, proportional to the total output current of the first inverter, to the second inverter. The second inverter operates at an adjustable frequency which is selected by the user to optimize heating. The power delivered to the induction heater is dependent on the output voltage of the second inverter, which is dependent on the input voltage to the second inverter, and the output current of the first inverter.