Welding system with reversible drive motor control
AssigneeUnion Carbide Corporation
InventorTibor E. Toth
Life of this patent
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Abstract
Electric welding system having a governor control for regulating the speed of the electrode drive motor and for controlling the direction of motor rotation in response to voltage and current welding parameters such that during welding the motor is driven in a forward direction toward the workpiece and under the control of a weld speed potentiometer whereas during a short circuit condition and at termination of the welding operation the motor direction is reversed.
Claims6
An electric welding system including an electrode, a workpiece, a power supply connected in series circuit relationship with said electrode and workpiece, a drive motor for feeding said electrode relative to said workpiece and a governor control system for controlling the speed and direction of rotation of said drive motor, said governor control system comprising:
- a source of driving potential;
- a bi-directional circuit including a first circuit drive means for connecting said source of driving potential across said drive motor in a first direction and a second circuit drive means for connecting said source of driving potential across said drive motor in a second direction opposite said first direction;
- means for generating a current signal in response to the presence of current in said series circuit;
- means responsive to arc voltage for generating a first voltage signal when the arc voltage is above a predetermined magnitude and a second voltage signal which varies in magnitude in proportion to variation in arc voltage;
- means for generating a direction signal having a first logical output state in response to the presence of said first voltage signal and having a second logical output state in response to the absence of said first voltage signal;
- logic means for enabling said first and second circuit drive means in response to the logical output state of said direction means;
- first adjustable means for providing a first speed control signal;
- second adjustable means for providing a second speed control signal;
- speed control means for controlling the speed of the motor in response to said second voltage signal and to said first and second control signals;
- and
- transfer circuit means responsive to said current signal and said first voltage signal for inhibiting either said first speed control signal or said second speed control signal such that when said current signal is present in the absence of said first voltage signal said second speed control signal is inhibited and when both said current and voltage signals are present said first speed control signal is inhibited.
Dependencies are inferred from the claim text.