JPS61151469A - Condenser type rotary electrostatic voltmeter - Google Patents

Abstract

PURPOSE:To make it possible to discriminate even polarity in addition to applied charge, by a method wherein a high voltage generation apparatus is mounted in a condenser type rotary electrostatic voltmeter and high voltage is generated after a charged article to be measured was measured while the charge quantity generated in the fixed electrode of the electrostatic voltmeter by measurement is changed. CONSTITUTION:When a responsive plate 2 is directed toward a charged article to be measured, charge having the same polarity as the charge applied to the charged article to be measured is generated in a fixed electrode 1. A movable electrode 4 rotated against the force of a coil spring 6 and a graduations plate 10 shows the electrostatic voltage or electric field intensity of the charged article to be measured. Next, high voltage is generated at a high voltage terminal 13 by a high voltage generation apparatus 11 using a piezoelectric element. Charge is moved to the fixed electrode 1 charged with low voltage by corona discharge and the polarity of charge is judged by the increase and decrease of an indicator 9.

Description

[Detailed Description of the Invention] A capacitor-type rotating electrostatic voltmeter that measures electric field strength or electrostatic voltage of a measured object using Coulomb force has a simple structure, is sensitive, behaves in accordance with theory, and is sensitive to lines of electric force. Because there is no processing or amplification, the measurements are extremely reliable. On the other hand, one essential drawback is that the polarity of the charge on the charged object to be measured cannot be determined.

The present invention enables a capacitor-type rotary electrostatic voltmeter to determine the polarity of the charged charge of a charged object to be measured as needed without losing the advantages of measurement using Coulomb force. In other words, a high voltage generator is built into a capacitor-type rotary electrostatic voltmeter, and after measuring a charged object, the high voltage generator is activated as necessary, and the generated high voltage is generated by corona discharge or electrostatic induction. A charge is applied to the fixed electrode of the capacitor type rotary electrostatic voltmeter, the amount of charge generated on the fixed electrode is changed by measurement, and the polarity of the charge on the charged object to be measured is determined by the movement of the pointer that fluctuates according to the change. It has been made possible.

In this case, consideration must be given to optimizing the amount of charge transferred from the high voltage generator to the fixed electrode.

'-This invention will be explained with reference to specific examples and drawings.

Reference numeral 1 in the figure represents a fixed electrode, which is connected to the sensitive plate 2 through a conductive wire 3. The movable electrode 4 is held by a shaft 5, which is rotatably held by plackets 7 at both ends thereof. The inner end of a spiral spring 6 is fixed to the shaft 5, and the outer end of the spiral spring is fixed to a support arm 8.

Further, a pointer 9 is attached to the shaft 5, and the movement of the pointer 9 can be read from the scale of a scale plate 10. Although this specific example uses a piezoelectric element as the high voltage generator 11, it may be a high voltage generator using a battery.

The ground side of the high voltage generator is coupled by a conductor 14 to the bracket 7, which is the ground side of the electrostatic voltmeter. By pushing the push rod 12, a high voltage is generated at the high voltage end 13.

The operation of this capacitor type rotary electrostatic voltmeter will be explained. When attempting to measure the voltage of an electrical object to be measured or the electric field intensity thereof, the sensitive plate 2 is directed toward the charged object to be measured. Then, due to electrostatic induction, a charge with a polarity opposite to that of the charged object to be measured is generated on the sensitive plate 2, and the fixed electrode 1, which is connected to the sensitive plate 2 by the conductor 3, is charged with the charged object to be measured. A charge of the same polarity is generated.

To simplify the explanation, it is assumed that the charged object to be measured is positively charged. Then, the sensitive plate 2 becomes negative, and the fixed electrode I
is positively charged. Movable electrode 4 close to fixed electrode 1
A negative charge is generated on the movable electrode 4, and due to the attractive force generated between this negative charge and the positive charge on the fixed electrode, the movable electrode 4
rotates the shaft 5 against the drag of the spiral spring 6 and moves the pointer attached to the shaft 5 to indicate the scale on the scale plate 10, thereby measuring the electrostatic voltage of the charged object to be measured or the measurement thereof. You can know the electric field strength at a point.

The present invention provides means for dealing with the case where the polarity of the charge of the charged object to be measured is not known at the time of the above-mentioned measurement.In this specific example, a high voltage generator 11 using a piezoelectric element is provided. is provided, and by pushing the push rod 12, the high voltage end 13
high voltage is generated. In this case, assuming that a positive high voltage is generated at the high voltage end 13, pressing the push rod 12 generates a positive high voltage at the high voltage end 13.
Charge is transferred to the fixed electrode 1, which is provided at a low voltage near zero, by corona discharge. In this case, since the fixed electrode 1 is positively charged, the high voltage end 13
Due to the movement of more positive charges, the amount of charge on the fixed electrode 1 increases, and the indication on the pointer 9 increases. It can be seen that the polarity of the charge on the fixed electrode 1 is the same as the polarity of the charge on the high voltage end 13, and therefore the polarity of the charge on the charged object to be measured is the same as the increase in the indication of the pointer. That is, in this case, it can be seen that the charged object to be measured is positively charged.

When the charged object to be measured is negatively charged, a positive charge is generated on the sensitive plate 2 and a negative charge is generated on the fixed electrode 1.
In this case, by pushing the push rod 12, the indication of the pointer 9 is decreased. Therefore, it can be seen that the charged object to be measured is charged with a charge opposite to the charge at the high voltage end 13, that is, a negative charge.

The amount of charge transferred from the high voltage end 13 must be set appropriately depending on the capacitor type rotary electrostatic voltmeter.

[Brief explanation of the drawing]

The figure is a perspective view showing an embodiment of the invention.

Claims (1)

[Claims] A capacitor-type rotary electrostatic voltmeter with the movable electrode side as the ground side has a built-in high voltage generator, which is activated as necessary, and the generated high voltage is transmitted through corona discharge or electrostatic induction. By acting on the fixed electrode of the capacitor-type rotary electrostatic voltmeter, the amount of charge generated on the fixed electrode is changed by measuring the charged object to be measured, and the polarity of the charge on the charged object to be measured can be determined. A capacitor-type rotating electrostatic voltmeter.