2. High-voltage electroscope: High-voltage electroscope is mainly used to test high-voltage electrical equipment with the ground voltage above1000 V ... There are three types of devices widely used: luminous, acousto-optic and wind-driven.
Electroscope is an instrument that detects whether an object is charged or not and roughly estimates the number of charges. When the tested object touches the conductor at the top of the electroscope, its own charge will be transferred to the foil in the glass bell jar. Because the same charges repel each other, the foil will automatically separate and form a certain angle.
According to the unfolding angle of two foils, the charged amount of the object can be estimated. In fact, this is the electric field force on the foil, including the repulsion of the same name charge on the foil and the attraction of the different name charge on the inner wall of the container.
If a metal box is used instead of a glass bottle to shield static electricity, a metal rod and a utensil are used to lead out wires to measure the potential difference between two points, and a balance is used to quantify the results, the electroscope can be transformed into a more accurate electrometer.
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Troubleshooting of electroscope;
1, press the test button on the high-voltage electroscope, and the alarm sound of the pointer-type high-voltage megohmmeter is very small. Measure the ground voltage 9V of HD 140 1 1BP ⑦ with a voltmeter, and the peripheral components of HD1401BP are normal. It is found that the transistor Q2 has poor performance, so it is replaced by A9014.
2. Press the test button on the high-voltage electroscope, and the ceramic chip and LED do not give an alarm.
According to the fault phenomenon, it is judged that the flat rubber-sheathed flexible cable with front-end induction is damaged by detecting the source trigger control circuits Q 1, R 1, R2 and R3. Check the above components with multimeter, and they are all normal. Then check the peripheral components of HD 140 1 1BP, and no problems are found, so it is judged as HD65438.
3. Press the watch-type near-current alarm on the high-voltage electroscope, and the test button shows that the LED flashes intermittently as normal. If there is no alarm sound on the piezoelectric ceramic sheet, check that Q3, R 10, R 1 1 and L are all normal. The connection line between the piezoelectric ceramic chip and the circuit board is good. Replace the piezoelectric ceramic piece and remove the fault.
The rheostat and device of the electric slide wire of high-voltage electroscope must be checked regularly. When using, handle with care, and don't shake or shake violently. It should be placed in a fixed cabinet, not in damp, power test wires or dirty places, and avoid placing the ultra-low frequency high voltage generator in an environment containing corrosive air (such as acid, alkali and other gases). High-voltage electroscope should be tested once every six months.
If the shell of electric indicator is found to be defective, and the insulating rod has obvious cracks and other defects, it is not suitable for preventive test and should be replaced in time.
4. Press the test button on the high-voltage electroscope, and the alarm is normal, but the sound alarm does not ring when the electroscope is used to check electricity.
Press the test button on the high-voltage electroscope, and the ceramic chip and the sliding indicator LED will alarm normally, indicating that the internal circuit and driving circuit of HD1401BP, piezoelectric ceramic chip and LED are normal, and the fault triggers the control circuit of the previous induction detection source. Check Q 1, R 1 and R2 with a multimeter, and find that the resistance of R2 becomes 4m. ?
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