Tips for testing electricity with a test pencil
In addition to measuring whether the object is charged or not, the low-voltage tester (tester for measuring 220v) can also be used for some other auxiliary measurements.
1. Judging the induction current When measuring a long three-phase line with a general test pen, even if the three-phase AC power supply lacks one phase, it is difficult to determine which power line is missing a phase. The reason is that the line is long and parallel lines There is an inter-line capacitance between the wire and the wire, so that a certain wire that lacks a phase generates an induction, and makes the neon tube of the electric pen shine. At this time, you can test the neon of the electric pen and connect a small capacitor of 1500p (the withstand voltage should be greater than 250v), so that when the live line is tested, the electric pen can still emit light as usual; Dimly bright, according to which it can be judged whether the measured power supply is induced electricity.
2. Identify whether the AC power supply is in the same phase or out of phase. Hold a test pen in each hand, stand on an insulating object, and touch the two pens to the two wires to be tested at the same time. If the neon tubes of the two test pens are not too bright, It means that the two wires are in the same phase. If the neon tubes of the two test pens emit very bright light, it means that the two wires are out of phase.
3. Distinguish between alternating current and direct current. When the alternating current passes through the test voltage, the two poles in the neon tube will light up at the same time; and when the direct current passes through, only one pole in the neon tube will light up.
4. Distinguish the positive and negative poles of the direct current. Connect the test pen between the positive and negative poles of the direct current. The bright end of the neon tube is the negative pole, and the non-lit end is the positive pole.
5. Use a tester to test whether the DC is grounded and determine whether it is positive or negative. In a DC device that requires ground insulation, a person stands on the ground and touches the DC with a tester. If the neon tube lights up, it means that the DC is grounded; if If the neon tube is not lit, there is no direct current grounding. When the tip of the test pen lights up, it means that the positive pole is grounded. If the pole at the end of the pen is lit, it means that the negative pole is grounded.
6. As a neutral wire monitor Connect one end of the test pen to the neutral wire and the other end to the ground wire. If the neutral wire is disconnected, the neon tube will light up.
7. Make household appliance indicator lamps. Take out the neon tube and resistor from the electric test pen, connect the two components in series and connect them between the live wire and the neutral wire of the power line of the household appliance. When the household appliance is working, the neon tube will light up.
8. Determine whether the object has static electricity. Hold a test pen around an object and test it. If the neon tube lights up, it proves that there is static electricity on the object.
9. Roughly estimate the voltage With the electric test pen that you often use, you can roughly estimate the voltage level according to the intensity of the neon tube’s light when measuring the electricity. The higher the voltage, the brighter the neon tube.
10. Judging whether the electrical contact is good. If the neon tube light source flickers, it indicates that a certain thread is loose, poor contact or unstable voltage.
11. To determine the high voltage of the TV, hold the electric pen close to the high voltage nozzle, and the neon tube is bright and there is high voltage
