This voltage is used to create a high intensity arc inside the torch to ionize the gas, thereby producing the plasma. The nozzle and electrode constrict and maintain the plasma jet. Sequence of Operation The power source and arc starter circuit are connected to the torch via interconnecting leads and cables. These leads and cables supply the proper gas flow, electrical current flow and high frequency to the torch to start and maintain the process. A start input signal is sent to the power supply.
Gas flows through the nozzle and exits out the orifice.
There is no arc at this time as there is no current path for the DC voltage. Figure 2 click here for larger view 2. After the gas flow stabilizes, the high frequency circuit is activated. The high frequency breaks down between the electrode and nozzle inside the torch in such a way that the gas must pass through this arc before exiting the nozzle. Energy transferred from the high frequency arc to the gas causes the gas to become ionized, therefore electrically conductive.