WELDING APPARATUS.

摘要

Stick and stud welding apparatus which utilizes a microprocessor (30) and related, RAMs (32) ROMs (33) and peripheral interface devices (3 1, 32, 35) to control the welding parameters. The ideal desired weld current and weld cycles in the case of stud welding can be selected depending upon the mode of operation and/or stud conditions. The program for the microprocessor instructs the microprocessor to periodically compare the actual welding current to the ideal current, compute the difference and alter the phase firing time of an SCR bridge to compensate or adjust the welding current to the ideal current. In the case of stud welding mode, the program further instructs the microprocessor to reference the selected number of cycles, compute the total energy delivered across the stud and workpiece gap from actual current, welding terminal voltage and time and enlarge the number of actual weld cycles to a given percentage of that initially selected to provide a total energy input to the stud as selected. In the stud mode, the pilot arc current and cycles may likewise be selected and controlled. Such parameters as pilot arc current, pilot arc cycles, main welding current, main welding current cycles, total energy, welding terminal voltage and error occurrence are displayed visually by means of lights (28) and/or written printout (29).