| 摘要 |
PURPOSE:To obtain a small-sized high voltage measuring apparatus having high impact resistance, by constituting the same so as to detect voltage through a dynamic capacitor consisting of an electrode to be measured and a detection electrode. CONSTITUTION:When voltage to be measured is applied to an input terminal 1, charge corresponding to the voltage to be measured is in an electrode 22 to be measured and a detection electrode 23 constituting a dynamic capacitor 2. The induced charge of the capacitor 2 increases or decreases with the change in capacity and the charge in the side of the electrode 23 repeats inflow and outflow through a gate resistor 3. As a result, AC voltage corresponding to the voltage to be measured is generated in the gate of FET5 and subjected to impedance conversion by FET5 and a source resistor 6 to be outputted to a terminal 8 through a capacitor 7. This output signal receives AC amplification and the amplified signal is subjected to DC conversion through a rectifier circuit and a smoothing circuit to be subsequently sent in a display apparatus consisting of a light emitting diode, a liquid crystal and a fluorescent tube through an A/D converter.
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