Patent ID: 9421634
Filing Date: 2016-08-23
CPC Classification: B23K

Claim Text:
1. A spot welding system comprising: a power supply module configured to generate a first current; a power delivery module configured to receive the first current from the power supply module and to generate a second current from the first current; a first electrode and a second electrode configured to resistively spot weld at least two weld pieces interposed between the first and second electrode by receiving the second current, thereby causing the resistance and temperature of the weld pieces to increase such that the weld pieces melt; and a voltage control module configured to receive a current reading indicating a value of the first current, estimate a resistance of the weld pieces as a result of the second current flowing through the weld pieces based on the value of the first current and independent of a voltage difference across the first and second electrodes, and determine a phase angle value for setting a voltage outputted by the power supply module based on the estimated resistance and a power profile that indicates an amount of power to be delivered by the power delivery module over a period of time, wherein the power supply module adjusts the first current based on the determined phase angle value.