| 摘要 |
PURPOSE:To eliminate the need for a special independent power source and to simplify the constituting of circuits by grounding the center tap of the secondary winding of a transformer, and converting a voltage induced between the ground and an electrode into a direct current and then applying it to the electrode itself. CONSTITUTION:The center tap 1a of the secondary winding of the transformer 1 is grounded and an AC voltage which is about a half as high as the voltage across the secondary winding is induced at the electrode 5. A current flows to charge a capacitor 11 in positive half cycles of this AC voltage and flows to a diode 10 in negative half cycles. Then, when the voltage of the capacitor 11 reaches the voltage of constant voltage characteristics of a varistor 9, the current of the varistor 9 increases and the charging current does not flow to the capacitor 11 any more, so that the constant DC voltage of the electrode 5 is applied. Consequently, the need for the special independent power source is eliminated and the circuit constitution is simplified. |
