Control circuit for a welding device

A control circuit for a welding device for establishing a weld time duration and controlling the time duration completion of a power circuit to the welding device comprising first and second connection means for connecting said control circuit to a power source, a welding transformer having primary and secondary windings thereof, said primary winding having first and second terminals thereon, a control transformer having primary and secondary windings thereof, said primary winding having first and second terminals thereon, said first terminal of the primary winding of the control transformer being connected to said first terminal of the primary winding of the welding transformer and to said first connection means, said second terminal of the primary winding of the control transformer being connected to second connection means, a trigger circuit portion connected across said secondary winding of the control transformer, said trigger circuit portion including operator actuatable means and means for producing a trigger output signal in response to actuation of said operator actuatable means, said means for producing a trigger output signal including a pulse generator for generating periodic signals and gate means, said gate means being responsive to the generation of a periodic signal at a time when said operator actuatable means are actuated to produce a trigger output signal, control status means capable of being in one of two control states and including a bistable device with first and second input means, said first input means operatively connected to said trigger circuit portion to receive said trigger circuit output signal, said bistable device being responsive to receipt of said trigger output signal of said trigger circuit portion to establish a first control state in said control status means, a timing circuit portion connected in parallel with said trigger circuit portion across said secondary winding of the control transformer, said timing circuit portion including timing means and operator adjustable means for selecting and establishing a weld time interval, said timing means including means for detecting the control state of said control status means and time passage means responsive to detection of the first control state of said control status means for generating a time interval output after the passage of an amount of time equal to the selected weld time interval established by the selective adjustment of said operator adjustable means, said second input means of said control status means connected to said timing circuit portion to receive said time interval output, said bistable device being responsive to receipt of said time interval output of said timing circuit portion to establish a second control state in said control status means, a gating circuit having gate input means connected to said second terminal of the primary winding of the welding transformer and gate output means connected to said second connection means, said gating circuit including control input means connected to said control status means to detect the control state thereof and other means responsive to detection of said first control state of said control status means for completing a circuit between said gate input means and said gate output means, said circuit completion enabling current to flow through said primary winding of said welding transformer so long as said control status means is in said first control state, means responsive to establishment of said first control state in said control status means for preventing the production of more than one trigger output signal for each activation of said operator actuatable means, and a high-pass RC filter circuit having an input connected to said operator actuatable means and an output connected to said gate means, said responsive means for preventing the production of more than one trigger output signal for each activation of said operator actuatable means including means to alter the time constant of said filter circuit.