Neon Bubble Test Pen Lamp Lighting Principle
Electric test pen (also known as electric pen) is one of the commonly used electricians, which is used to determine whether an object is charged or not. Distinguish the live wire or neutral wire in the daily lighting circuit. Its measuring range is between 60~500V, and it has pen type and screwdriver type. It consists of neon tubes (commonly known as neon bulbs), resistors, springs, etc. When in use, the charged body passes through the electric pen, the human body and the earth to form a potential difference, which generates an electric field, and the neon tube in the electric pen will emit light under the action of the electric field. When using the electric pen, it must be held correctly. The female and middle fingers hold the insulating part of the electric pen, and the index finger presses the metal cap of the pen end. Before using the test pen, it must be confirmed that it is in good condition (test at the place where there is a power supply) before it can be used. When in use, it should gradually approach the measured object until the neon tube emits light to be in direct contact with the measured object. Because the resistance in the test pen is very large, the current flowing through the human body is very small, and people will not touch it... In addition, does the replacement position of the neon bubble resistance of the screwdriver type test pen have any effect on the luminous brightness? Whether it damages the components ?
---- is "Neon bulb and resistor replacement position". Some electric pens have indeed changed their positions. The electricity of the screwdriver contacts first passes through the neon bulb and then the resistance. Please briefly analyze why it is not damaged.
It will not affect the use of neon bulbs and resistors if they are connected in series or exchange positions
The working principle of the neon bulb in the fluorescent lamp is: 1. A curved bimetallic sheet (the thermal expansion coefficient of the two metals is different), which is an electrode. 2 The fixed end is used as another electrode. When the neon bulb is applied with voltage, the neon gas will emit light and heat, and the bimetallic sheet will stretch and contact the fixed electrode in this temperature environment, which is a working state and the circuit is connected. But after the circuit is turned on, the neon bulb will stop heating. The bimetallic sheet is in another temperature environment, the metal sheet will bend, and will be out of contact with the fixed electrode, and the circuit will be disconnected. Restore the original state.
