DC voltage stabiliser operating on arc welding current - has series inductor-resistor in circuit with fast clipping diode forming DC=DC converter having output present only during existence of arc

摘要

The welding current between outer terminals is converted into a first DC voltage between intermediate terminals, becoming a second DC voltage between inner terminals while the welding arc is in being. High-frequency components are suppressed by a choke, voltage-dependent resistance and fast clipping diode. The remaining HF peaks are eliminated by a Zener diode, and a relay is energised. When the DC voltage exceeds the Zener voltage, a capacitor is charged and this relay is short-circuited by a transistor. A second relay energises a LED to indicate that the electronic circuits are not powered. From the second DC voltage a stabilised 05supplyisproducedattheoutputterminalsbya voltage-controlled oscillator and saturated FET with a saturable inductor.