Arc welding current control apparatus

Claim 2

A power regulating network comprising a load including an energizable winding, first input connections adapted to be energized from a source of electrical energy, an energy storage element, regulating means, a first network connecting said storage element to said input coNnections, said first network including said regulating means whereby rate of change in the energy stored in said storage element may be regulated, second input connections adapted to be energized from a source of electrical energy, a second network energized from said second input connections and including said energizable winding and a circuit controlling means for controlling the energy supplied to said energizable winding, means connecting said circuit controlling means to said first network for actuation of said circuit controlling means as a function of the magnitude of the energy stored in said storage element, said regulating means having a portion thereof responsive to an operating condition of said load when said load is in an energized condition, said portion being effective to alter said regulating means as a function of the magnitude of said operating condition and thereby change the magnitude of the energy supplied to said energizable winding.

Claim 3

The combination of claim 1 in which said operating condition is the potential across said energizable winding.

Claim 4

The combination of claim 1 in which said operating condition is temperature.

Claim 5

The combination of claim 3 in which said regulating means includes impedance means and said portion of said regulating means alters the magnitude of the impedance of said impedance means.

Claim 6

The combination of claim 4 in which said impedance of said regulating means decreases in magnitude with an increase in temperature of said load.

Claim 7

The combination of claim 1 in which said load comprises a saturable reactor having an alternating potential winding and a unidirectional potential control winding, said energizable winding being said unidirectional potential control winding, a second pair of input terminals adapted to be energized from a source of alternating potential power, a pair of output terminals, and third circuit means connecting said second pair of input terminals to said pair of output terminals and including said alternating potential winding of said reactor.

Claim 8

The combination of claim 6 in which said first input connections are energized with a series of pulses of electrical energy and said alteration of said regulating means acts to alter the instant in each said pulse of said series that said circuit controlling means is effective to initiate the flow of energy to said energizable winding.

Claim 9

The combination of claim 7 in which said operating condition is temperature and in which said portion of said regulating means is a negative temperature characteristic impedance device whereby the time interval between the start of each said pulse and the time said initiating is decreased with increase in temperature of said load.

Claim 10

The combination of claim 7 in which said operating characteristic is the potential across said energizing winding and in which said portion of said regulating means increases the time interval between the start of each said pulse and the time of said initiation in response to an increase in the RMS potential across said energizing winding.

Claim 11

The combination of claim 8 in which said regulating means comprises a voltage limiting element and a pair of impedance elements connected in series with each other, said storage element and said regulating means being connected in shunt with said voltage limiting element.

Claim 12

The combination of claim 10 in which said means which connects said circuit controlling means to said first network includes a unijunction transistor type device having a pair of base electrodes and an emitter, said base electrodes being connected to be energized by the potential appearing across said voltage limiting element and one of said pair of said impedance elements.

Claim 13

In a welding apparatus, a plurality of main input terminals adapted to be energized from a source of polyphase electrical energy, a polyphase transformer having primary and secondary windings, a polyphase current controlling reactor having a plurality of current conducting windings, a Polyphase rectifier having polyphase input terminals and unidirectional power supplying terminals, circuit means connecting said primary windings to said main input terminals and connecting said secondary windings through a first plurality of said current windings to said polyphase input terminals of said rectifying network, a current regulating network having a pair of input terminals and a pair of output terminals and a rectifying network, said rectifying network having alternating potential input terminals connected for energizations from said main input terminals and having unidirectional potential terminals, said regulating network further including a switching means and an R/C controlled network having a resistor series connecting with a capacitor, circuit means connecting said unidirectional terminals to a designated winding of said current windings through said switching means, said R/C network being connected to said unidirectional terminals for energizations of its said capacitor thereby, said network including a voltage responsive switch having an output circuit and a control circuit, said control circuit being connected to said R/C network whereby its potential is changed as a consequence of a change in potential, said capacitor to render its associated output circuit conductive, said switching means being connected to said output circuit of said voltage responsive switch whereby said switching means is rendered effective to energize said designated winding of said windings of said reactor as a consequence of the conduction of said voltage responsive switch, and means including said switching means for terminating the energization of said unidirectional winding means of said reactor, and means thermally associated with said reactor and said R/C network and effective to decrease the R/C time constant of said R/C network with an increase in temperature of said reactor whereby to compensate for increase in the impedance in at least one of said reactor windings.

Claim 14

In a welding apparatus, a plurality of main input terminals adapted to be energized from a source of polyphase electrical energy, a polyphase transformer having primary and secondary windings, a polyphase current controlling reactor having a plurality of current conducting windings, a Polyphase rectifier having polyphase input terminals and unidirectional power supplying terminals, circuit means connecting said primary windings to said main input terminals and connecting said secondary windings through a first plurality of said current windings to said polyphase input terminals of said rectifying network, a current regulating network having a pair of input terminals and a pair of output terminals and a rectifying network, said rectifying network having alternating potential input terminals connected for energizations from said main input terminals and having unidirectional potential terminals, said regulating network further including a switching means and an R/C controlled network having a resistor series connecting with a capacitor, circuit means connecting said unidirectional terminals to a designated winding of said current windings through said switching means, said R/C network being connected to said unidirectional terminals for energizations of its said capacitor thereby, said network including a voltage responsive switch having an output circuit and a control circuit, said control circuit being connected to said R/C network whereby its potential is changed as a consequence of a change in potential, said capacitor to render its associated output circuit conductive, said switching means being connected to said output circuit of said voltage responsive switch whereby said switching means is rendered effective to energize said designated winding of said windings of said reactor as a consequence of the conduction of said voltage responsive switch, and means including said switching means for terminating the energization of said unidirectional winding means of said reactor, and means thermally associated with said reactor and said R/C network and effective to decrease the R/C time constant of said R/C network with an increase in temperature of said reactor whereby to compensate for increase in the impedance in at least one of said reactor windings.

Claim 15

The combination of claim 12 in which said reactor includes a plurality of separate flux conducting iron paths, each said iron path having first and second legs, said first plurality of said windings of said reactor being alternating current conducting windings and being individually wound about said first legs, said designated winding being a unidirectional current conducting winding for supplying control flux to said iron paths and being wound about all of said second legs and said one reactor winding being said unidirectional current conducting winding.

Claim 16

The combination of claim 12 in which said regulating network includes a first and a second voltage dropping element and a voltage limiting element connected in series and in the order named between said unidirectional potential terminals, said series connected resistor and capacitor being connected in parallel with said voltage limiting element, said voltage responsive switch being a unijunction type switch having three terminals, a first pair of said three terminals defining at least in part its said control circuit and a second pair of said three terminals defining at least in part its said output circuit, said second pair of said three terminals being connected in shunt with said capacitor, and said first pair of said three terminals being connected in shunt with said voltage limiting element and at least said second voltage dropping element.

Claim 17

The combination of claim 14 in which there is provided a pair of load terminals, said reactor includes a plurality of separate flux conducting iron paths, each said iron path having first and second legs, said first plurality of said windings of said reactor being alternating current conducting windings and being individually wound about said first legs, said designated winding being a unidirectional current conducting winding for supplying a control flux to said iron paths and being wound about all of said second legs, said one reactor winding being a unidirectional current winding fOr supplying control flux to said iron paths and being wound about all of said second legs, said one reactor winding being said unidirectional current winding, said winding having a second unidirectional current winding wound about all of said second legs, and means connecting said second unidirectional winding between one of said unidirectional power supplying terminals of said polyphase rectifier and one of said load terminals, the other of said load terminals being connected to the other of said unidirectional power supplying terminals of said polyphase rectifier.

Claim 18

An energizing network for an inductive load comprising a pair of input terminals adapted to be energized from a source of alternating potential, a first rectifier having alternating potential terminals and unidirectional potential terminals, means connecting said alternating potential terminals to said input terminals, a pair of output terminals adapted to be connected to an inductive load, a discontinuous control type switch having a control circuit and a main circuit, said control circuit being effective to initiate conduction of said main circuit and ineffective to terminate conduction of said main circuit, means connecting said output terminals to said unidirectional terminals and including said main circuit, and control means operatively connected to said input terminals for energization by power derived from said input terminals, said control means including timing means effective to energize said control means for rendering said main circuit conducting, and an energy storage device connected between said alternating potential terminals.

Claim 19

An energizing network for an inductive load comprising a pair of input terminals adapted to be energized from a source of alternating potential, a first rectifier having alternating potential terminals and unidirectional potential terminals, means connecting said alternating potential terminals to said input terminals, a pair of output terminals adapted to be connected to an inductive load, a discontinuous control type switch having a control circuit and a main circuit, said control circuit being effective to initiate conduction of said main circuit and ineffective to terminate conduction of said main circuit, means connecting said output terminals to said unidirectional terminals and including said main circuit, and control means operatively connected to said input terminals for energization by power derived from said input terminals, said control means including timing means effective to energize said control means for rendering said main circuit conducting, and an energy storage device connected between said alternating potential terminals.

Claim 20

The combination of claim 16 in which an asymmetrical current controlling device is connected between said output terminals, said asymmetric device when conducting reactive derived current having a lesser potential dropped thereacross than the potential dropped across a circuit which extends between said output terminals through said main circuit and said rectifier.

Claim 21

The combination of claim 17 in which said switch is a semiconductor device having a P-N junction in its main circuit and in which said rectifier is a full wave network and includes a regenerative current circuit connected to conduct current between said unidirectional terminals in shunt with said alternating potential terminals, said regenerative current circuit including at least one semiconductor diode rectifier, and in which the threshold drops of said main circuit and of said regenerative current circuit is greater than the potential drop across said asymmetric device.

Claim 22

The combination of claim 18 in which said rectifier is a full wave rectifier, said regenerative circuit has two legs and each said leg including a pair of series connected semiconductor diodes, and said asymmetric device is a semiconductor diode rectifier poled to conduct current in the same direction between said output terminals as said regenerative circuit.

Claim 23

The combination of claim 19 in which there is provided a power transformer having primary and secondary winding means, a full wave power rectifier, a saturable core reactor having alternating current winding means and a direct current control winding means, an input circuit for said primary winding means adapted to be energized with alternating potential, a power circuit connected between said secondary winding means and said power rectifier and including said alternating current winding means, means operatively connecting said input terminals to said input circuit for energization of said first rectifier with single phase alternating potential energy, and means connecting said control winding means to said output terminals.

Claim 24

The combination of claim 20 in which said control means includes a unijunction type semiconductor device having a plurality of terminals, means connecting a first pair of said plurality of terminals of said unijunction type device to said unidirectional potential terminals of said first rectifier, said timing means including a resIstance means series connected with a timing capacitor, a second pair of said plurality of terminals of said unijunction type device being connected across said timing capacitor, and means connecting said second pair of said terminals of said unijunction type device to said control circuit of said switch.

Claim 25

The combination of claim 21 in which said control means includes a voltage dropping means and a voltage limiting element connected in series between said unidirectional terminals of said first rectifier, said series connected resistance means and timing capacitor being connected in shunt with said voltage limiting element and said first pair of terminals of said unijunction type device being connected across a circuit comprising a portion of said voltage dropping means series connected with said voltage limiting means.

Claim 26

The combination of claim 22 in which said control means includes a temperature sensing means arranged in heat exchange condition with at least one of said windings of said reactor and effective to decrease the time required to change said timing capacitor and the consequent actuation of said switch by said unijunction type device whereby to compensate for the temperature change in said reactor.

Claim 27

A power regulating network comprising a load including an energizable winding, first input connections adapted to be energized from a source of electrical energy, a phase shifting circuit, a first network connecting said storage element to said input connections, said first network including said phase shifting circuit, second input connections adapted to be energized from a source of electrical energy, a second network energized from said second input connections and including said energizable winding and a circuit controlling means for controlling the energy supplied to said energizable winding, means connecting said circuit controlling means to said first network for actuation of said circuit controlling means as a function of the delay afforded by said phase shifting circuit, said phase shifting circuit having a portion thereby responsive to an operating condition of said load when said load is in an energized condition, said portion being effective to alter the delay provided by said phase shifting circuit as a function of the magnitude of said operating condition.

Claim 28

A power regulating network comprising a load including an energizable winding, first input connections adapted to be energized from a source of electrical energy, a phase shifting circuit, a first network connecting said storage element to said input connections, said first network including said phase shifting circuit, second input connections adapted to be energized from a source of electrical energy, a second network energized from said second input connections and including said energizable winding and a circuit controlling means for controlling the energy supplied to said energizable winding, means connecting said circuit controlling means to said first network for actuation of said circuit controlling means as a function of the delay afforded by said phase shifting circuit, said phase shifting circuit having a portion thereby responsive to an operating condition of said load when said load is in an energized condition, said portion being effective to alter the delay provided by said phase shifting circuit as a function of the magnitude of said operating condition.

Claim 29

The combination of claim 24 in which said operating condition is the potential across said energizable winding.

Claim 30

The combination of claim 24 in which said operating condition is temperature.

Claim 31

The combination of claim 24 in which said load comprises a saturable reactor having an alternating potential winding and a unidirectional potential control winding, said energizable winding being said unidirectional potential control winding, a second pair of input terminals adapted to be energized from a source of alternating potential power, a pair of output terminals, and third circuit means connecting said second pair of input terminals to said pair of output terminals and including said alternating potential winding of said reactor.

Claim 32

The combination of claim 27 in which said first input connections are energized with a series of pulses of electrical energy and said alteration of said phase shifting circuit acts to alter the instant in each said pulse of said series that said circuit controlling means is effective to initiate the flow of energy to said energizable winding.

Claim 33

The combination of claim 28 in which said operating condition is temperature and in which said portion of said regulating means is a negative temperature characteristic impedance device whereby the time interval between the start of each said pulse and the time of said initiating is decreased with increase in temperature of said load.