Inductor manufacturers always encounter various problems when testing inductors?
So do you know how to judge the quality of an inductor? Follow Gu Jing Xiaobian to learn!
1. Visual view:
Directly observe whether the pins of the inductor are disconnected, whether the magnetic core is loose, and whether the insulating material is damaged or charred.
2. Multimeter test:
In judging whether an inductor is good or bad, a multimeter resistance block is often used to test the on-off and resistance value of the inductor. Place the multimeter in the
Ω block, the red and black probes are connected to any leading out end of the inductor. At this time, the pointer should swing to the right. According to the measured resistance value, it can be distinguished in the following three cases.
(1) The resistance value of the tested inductor is too small. Clarify that there is a short circuit problem in the internal coil of the inductor. During the test operation, be sure to carefully zero the multimeter and carefully observe whether the position where the pointer swings to the right really reaches the zero position, so as to avoid misjudgment. When it is suspected that there is a short circuit problem inside the inductor, it is better to use R × 1 Ω gear shall be measured repeatedly for several times, so as to make correct judgment
(2) The inductor under test has a resistance value. The DC resistance value of the inductor is directly related to the wire diameter and the number of turns of the enameled wire used to wind the inductor coil. The thinner the wire diameter and the more turns, the greater the resistance value. Generally, use multimeter R × one
Ω gear measurement, as long as the resistance value can be measured, it can be that the measured inductor is normal.
(3) The resistance of the inductor under test is infinite. This phenomenon is easy to distinguish. It shows that there is an open circuit problem at the contact between the coil or lead out end and the coil inside the inductor.
3. Insulation test:
Insulation detection is mainly for inductors with iron core or metal shield. Place the multimeter in R * 1K gear and measure the resistance between the coil lead and the iron core or metal shield. Under normal circumstances, it is infinite (the gauge needle does not move), otherwise it indicates that the insulation of the inductor is poor. Have you all learned?