Abstract: A portable stud welder apparatus is provided for welding a stud onto a work piece. The portable stud welder apparatus includes a housing and an energy storage device. A weld stud gun that is configured to hold a weld stud is electrically connected to the energy storage device for receiving energy from the energy storage device to pass a current through the stud and the work piece to form a weldment. At least one battery of the lithium ion type is removeably coupled to the housing to establish an electrical connection with said energy storage device and provide energy to the energy storage device.

Abstract: A portable stud welder apparatus is provided for welding a stud onto a work piece. The portable stud welder apparatus includes a housing and an energy storage device. A weld stud gun that is configured to hold a weld stud is electrically connected to the energy storage device for receiving energy from the energy storage device to pass a current through the stud and the work piece to form a weldment. At least one battery of the lithium ion type that is removeably coupled to the housing to establish an electrical connection with said energy storage device and provide energy to the energy storage device.

Abstract: A portable stud welder apparatus is provided for welding a stud onto a work piece. The portable stud welder apparatus includes a housing and an energy storage device. A weld stud gun that is configured to hold a weld stud is electrically connected to the energy storage device for receiving energy from the energy storage device to pass a current through the stud and the work piece to form a weldment. At least one battery of the lithium ion type that is removeably coupled to the housing to establish an electrical connection with said energy storage device and provide energy to the energy storage device.

Abstract: A portable stud welder apparatus is provided for welding a stud onto a work piece. The portable stud welder apparatus includes a housing and an energy storage device. A weld stud gun that is configured to hold a weld stud is electrically connected to the energy storage device for receiving energy from the energy storage device to pass a current through the stud and the work piece to form a weldment. At least one battery of the lithium ion type that is removeably coupled to the housing to establish an electrical connection with said energy storage device and provide energy to the energy storage device.

Abstract: A portable stud welder apparatus is provided for welding a stud onto a work piece. The portable stud welder apparatus includes a housing and an energy storage device. A weld stud gun that is configured to hold a weld stud is electrically connected to the energy storage device for receiving energy from the energy storage device to pass a current through the stud and the work piece to form a weldment. At least one battery of the lithium ion type that is removeably coupled to the housing to establish an electrical connection with said energy storage device and provide energy to the energy storage device.

Abstract: A drawn arc welding device includes a welding tool, and an energy storage device coupled to a power source. A charging circuit is connected to the energy storage device replenishing the storage device. A discharge circuit is connected to the welding tool and energy storage device. The discharge circuit regulates and adjusts a welding current of the welding tool to a specified amount. Also disclosed is a process that includes charging the energy storage device, actuating the welding tool, energizing a pilot arc current, lifting the weld stud off a workpiece to draw the pilot arc, energizing a welding arc wherein the discharge circuit regulates a welding current of the welding tool to a specified amount, and plunging the weld stud into the workpiece and turning off the discharge circuit.

Abstract: Systems and methods are disclosed for determining an impedance between a grounding device such as a welding wire feeder ground clamp and a power supply common, and selectively allowing current flow through an electrical device associated with a welding operation according to the impedance.

Abstract: An electric arc welder with a variable AC voltage input of up to 600 VAC and a rectifier to provide a DC link, a driven high frequency boost stage with first and second leads connected to the DC link. The boost stage comprises an inductor, a first series output branch with a first primary winding connected to the first lead and a first capacitor connected to the second lead, a second series output branch with a second primary winding connected to the second lead and a second capacitor connected to the first lead and a high frequency operated switch between the leads and having an opened condition charging said capacitors by current through the primary windings in a first direction and discharging the inductor and a closed condition charging the inductor through the primary windings by current in a second direction and discharging the inductor to charge the capacitors. The switch is operated by a power factor control circuit at a frequency greater than about 18 kHz.

Abstract: A single phase power supply module for electric arc welders and plasma arc cutters comprising: a single phase input stage; positive and negative output terminals; a full wave rectifier connected to the input stage for rectifying the single phase voltage at the input stage; a buck converter type power factor correcting circuit for controlling current flow from the input stage to the rectifier, which buck converter has an output capacitor regulated to an intermediate voltage in the range of 100-150 volts; and, a high speed DC to DC converter having an internal transformer coupling applying voltage across the output terminals and means for regulating the applied voltage to an output voltage in the range of 0-113 volts. The module is universal and several can be connected in parallel, in series or to switch networks to construct several welders or cutters.

Abstract: In a switching type power supply for use in an electric arc welder or plasma cutter, of the type having an output transformer with a primary winding in a series circuit DC source with a selected voltage and a switch, either single or tandem, with a conductive on state to pass a current pulse through the primary winding in a first electrical direction and a non-conductive off state disconnecting the DC voltage source from the winding and a large filter capacitor across the DC input voltage source, the improvement comprising: a snubber network for transferring energy due to the leakage inductance of the primary winding to the filter capacitor when the switch is shifted from the on state to the off state where the snubber network includes a storage capacitor with a diode controlled resonant charging circuit so the winding is in a tank circuit with the storage capacitor to charge the storage capacitor in a charging cycle when the switch shifts from the on state to the off state and a diode controlled discharging

Abstract: A single phase power supply module for electric arc welders and plasma arc cutters comprising: a single phase input stage; positive and negative output terminals; a full wave rectifier connected to the input stage for rectifying the single phase voltage at the input stage; a buck converter type power factor correcting circuit for controlling current flow from the input stage to the rectifier, which buck converter has an output capacitor regulated to an intermediate voltage in the range of 100-150 volts; and, a high speed DC to DC converter having an internal transformer coupling applying voltage across the output terminals and means for regulating the applied voltage to an output voltage in the range of 0-113 volts. The module is universal and several can be connected in parallel, in series or to switch networks to construct several welders or cutters.

Abstract: A control circuit is provided for the output of a high frequency inverter of the type having an output transformer with a core, primary windings and a secondary winding with two sections for creating a first secondary current pulse of electrical current in one section when the primary windings magnetizes the core and a second secondary current pulse in the other of the secondary sections when the primary windings remagnetizes the core. By alternating switch means for passing current through the primaries to magnetize and remagnetize the core at a preselected rate the output current pulses are provided by the two sections of secondary windings. The control circuit of the present invention involves a modification of the output transformer secondary stage. A first auxiliary winding is connected to one of the secondary sections to create an auxiliary current pulse as the core of the transformer is magnetized.

Abstract: A self-starting, non-latching, pulse modulator which will function as an analog divider of first and second input quantities, or as a linear pulse period modulator responsive to one of the quantities, or as a linear pulse frequency modulator responsive to the other of the quantities, depending upon how the first and second input quantities are controlled. The first input quantity is connected to charge a capacitor. The second input quantity is compared in a first comparator with the voltage across the capacitor. A second comparator compares the voltage across the capacitor with a reference voltage. The outputs of the first and second comparators are connected, respectively, to the first and second inputs of a flip-flop which has its first output connected to a monostable multivibrator. The second output of the flip-flop and the output of the monostable multivibrator are both connected so that either one can momentarily activate a discharge circuit for discharging the capacitor.

Abstract: A network protector relay produces a close signal entirely from sequence components based on the magnitude and phase relationships between the positive sequence component of the phase-to-ground voltages on the network side of the protector and the positive sequence component of the phasing voltages. The close signal may be inhibited by either the presence of the negative sequence component of the phase-to-ground voltages on the network side of the protector or if a trip contact is closed. The trip contact will be closed under certain specified conditions which make it advantageous to prevent manual closing of the contacts.

Abstract: Pilot protective relay apparatus for high-voltage, three-phase alternating current transmission lines which provides the functions of an electromechanical pilot-wire protective relay, without the necessity of having a continuous, metallic conductor connected between the points to be compared. The protective relay apparatus is completely solid state, making trip decisions based upon three separate comparisons of the near and far line current conditions represented by line current derived single-phase voltage signals. The three comparisons indicate the magnitude of the phasor difference, the magnitude of the phase angle, and the relative average absolute magnitudes.

Abstract: Protective relay apparatus which includes monitoring and detecting functions related to subsynchronous currents in a three-phase electrical power system. The monitoring function provides signals related to the positive sequence component of any subsynchronous current flowing at a monitored subsynchronous frequency. The detecting function is responsive to the signals provided by the monitoring function, distinguishing between subsynchronous currents due to self-excited oscillations, and those due to transient oscillations, to provide a timely trip signal for a circuit breaker in either instance.

Abstract: Multi-stage current operated power supply including linear transformer coupled to AC power lines and provides positive and negative regulated output progressively charged during each half cycle of input current while maintaining ampere-turns balance.

Abstract: Apparatus for protecting a power system or a portion thereof against the effects of subsynchronous current oscillations is disclosed. A signal representative of or proportional to the subsynchronous current is developed via synchronous modulation and bandpass filter techniques. This signal is fully rectified to produce a waveform from which information can be garnered from both the positive and negative half-cycles.A peak holding and peak status circuit then compares successive peaks of the rectified signal, which circuit is adapted to recognize only those peaks having increasing amplitude. The output of the peak holding and peak status circuit is utilized by three comparator circuits which individually employ differing reference voltage levels for overall evaluation purposes.