PSI Frequency Inverters

PSI Frequency Inverters are welding control units that combine a weld timer and matched power supply in one enclosure for resistance welding applications.The series is available with medium-frequency inverter or thyristor power-stage designs, along with air-cooled and water-cooled configurations for driving welding transformers. The integrated timer supports spot welding, projection welding, repeat-mode operation for manual guns, and seam or roll-seam welding processes. Welding programs can be built from as many as three programmable time blocks, including preheat, weld, and postheat sections, with optional impulse and current-slope functions for shaping the weld cycle. Up to 256 programs can be stored, allowing different weld schedules to be assigned across many weld points. Process regulation includes phase-angle control and constant-current control, which can also be combined within the same schedule. Independent current monitoring supports programmable tolerance limits, timeout supervision, and automatic spot repetition when current falls below the required level. Additional functions include electrode wear management, current and force stepping, wear prewarnings, proportional-valve force control, force profiling, and protocol or diagnostic logging. Configuration and diagnostics are handled through the BOS-5000 PC interface, with communication available through a serial link or optional fieldbus and discrete I/O connections for PLC and robot integration.