Pilot arc circuit for a contact start plasma torch

A contact start plasma system, comprising:

• means for supplying electrical power to a contact start plasma arc torch for operation in a pilot arc mode and a transferred arc mode;
• and
• means for automatically disconnecting power to the pilot arc mode of the torch though a passive pilot arc circuit to facilitate an automatic transfer from the pilot arc mode to the transferred arc mode by reducing a pilot current towards zero as a pilot capacitor in the pilot arc circuit becomes more charged, such that the pilot arc circuit opens and the pilot current stops flowing through the pilot arc circuit when the pilot capacitor becomes essentially fully charged.

A power source for a contact start plasma arc system, comprising:

• a power supply for supplying electrical power to a torch for operation in a pilot arc mode and a transferred arc mode;
• and
• a passive pilot arc circuit for automatically disconnecting power to the pilot arc mode, the passive pilot arc circuit comprising a pilot capacitor that automatically disconnects the pilot arc circuit to facilitate an automatic transfer from the pilot arc mode to the transferred arc mode by reducing a pilot current towards zero as the pilot capacitor in the pilot arc circuit becomes more charged, such that the pilot arc circuit opens and the pilot current stops flowing through the pilot arc circuit when the pilot capacitor becomes essentially fully charged.