| 摘要 |
<p>PURPOSE:In a glow discharge heater comprising main electrodes and an auxiliary electrode, to prevent sharp current rise on arcing and prevent the transfer from glow discharge to arc discharge by providing a zero voltage arcing circuit between the electrodes. CONSTITUTION:In a glow discharge heater, an A-C voltage from a main power source 4 is applied across main electrodes 1 and 2. With a switch 9 closed, a high- voltage wave from a boosting transformer 6 (used for auxiliary power source) is fed across an auxiliary electrode 3 and the main electrodes 1-2 to effect a minor-current pilot glow discharge, which triggers a flow discharge between the main electrodes for heating. A zero-voltage arcing circuit 11 in an auxiliary power circuit comprises: a differentiation circuit comprising a transistor 17, a capacitor 19, and a resistor 20; a full-wave rectifier circuit 21; and a triac 24. The circuit 11 feeds voltage across the auxiliary electrode 3 and main electrodes from the zero point of the voltage wave applied across the main electrodes 1 and 2.</p> |
