| 主权项 |
1. A programmable polarity module that is electrically connectable to both a direct current power supply and to a welding gun that carries a first welding electrode and a second welding electrode, the programmable polarity module comprising;
a fixed positive polarity input lug and a fixed negative polarity input lug that, respectively, are electrically connectable to a fixed positive polarity output lug and a fixed negative polarity output lug of a direct current power supply; a first interchangeable polarity output lug and a second interchangeable polarity output lug that are electrically connectable to a welding gun that carries a first welding electrode and a second welding electrode; a first pair of silicon controlled rectifiers (SCR's) associated with the first interchangeable polarity output lug, the first pair of SCR's including a forward positive SCR, which is also associated with the fixed positive polarity input lug, and a reverse negative SCR, which is also associated with the fixed negative polarity input lug; a second pair of SCR's associated with the second interchangeable polarity output lug, the second pair of SCRs including a forward negative SCR, which is also associated with the fixed negative polarity input lug, and a reverse positive SCR, which is also associated with the fixed positive polarity input lug; and a controller that controls the first and second pairs of SCR's to assign either a positive or negative polarity to the first interchangeable polarity output lug and either a positive or negative polarity to the second interchangeable polarity output lug, the polarities of the first and second interchangeable output lugs being opposite of each other. |
