Capacitor charge and discharge circuit for fastener welding

A process for capacitor discharge fastener welding including the steps of:

• a) providing an input voltage source, a rectifier bridge receiving the input voltage source, at least two capacitor charge switches linked with the rectifier bridge, at least one capacitor linked with the at least two capacitor charge switches, at least two capacitor discharge switches linked with the capacitor and to welding output terminals;
• b) charging the at least one capacitor including closing the at least two capacitor charge switches when the at least two capacitor discharge switches are open;
• c) opening the at least two capacitor charge switches disconnecting the capacitor from the input voltage source;
• d) closing the at least two capacitor discharge switches allowing current from the capacitor to discharge through the output terminals;
• e) opening the at least two capacitor discharge switches cutting off a current path to the output terminals.

A capacitor discharge (CD) fastener welding circuit comprising:

• an input voltage source;
• a rectifier bridge of diodes receiving the input voltage source;
• at least two capacitor charge switches linked with the rectifier bridge;
• at least one capacitor linked with the at least two capacitor charge switches;
• at least two capacitor discharge switches linked with the capacitor and to welding output terminals;
• and
• a current sensor at the at least one capacitor sensing a current provided to the capacitor.