Oscillator-stabilizer of a welding arc (OSSD) is a device for non-contact excitation of a welding arc when welding with a non-consumable (tungsten) electrode in an inert gas medium ( argon , helium or a mixture thereof) both on direct and alternating current.
Modern OSSD - devices of serial connection to the welding current source.
The principle of operation of the OSSD is to convert an alternating voltage of the 50 Hz supply network to high-frequency short-duration pulses of excitation of the welding arc.
The OSSD consists of an output rectifier, a stabilized power source, a control circuit, a storage capacitor charge circuit, a high-voltage pulse shaper, an output high-voltage transformer, a current sensor, and a gas valve.
The alternating voltage of the network supplied to the input of the input rectifier is rectified and fed to the charge circuit of the storage tank, which provides a charge of the tank at a time determined by the control circuit. Upon reaching a certain voltage on the capacitance, the control circuit, after the mains voltage passes through 0 V, generates a control pulse to the high-voltage pulse shaper. Due to the discharge of the storage capacitance to the primary winding of the transformer - shaper of the high-voltage pulse, a high-voltage pulse is formed in the shock excitation circuit. The control circuit opens the valve and forms a delay in switching it off at the end of the weld, thus providing gas protection for the weld during the welding process and after the end of the welding process.
Oscillator output voltage parameters: voltage from 2000 to 6000 V, frequencies - from 100 Hz to 500 kHz. Operation at the indicated frequencies may interfere with surrounding electronic devices. Therefore, oscillators must be registered with local telecommunication inspection authorities.