The multimeter measures the resistance of the inductance of the color ring
The common pointer multimeter does not have a special device for testing inductors. We can only use this kind of multimeter to roughly measure the quality of inductors:
The resistance value of inductor is measured by R×1W of pointer multimeter. If the resistance value is very small (generally zero), the inductor is basically normal.If the measured resistance is infinity, the inductor has been damaged.
For inductors with metal shells (such as midweek), if the resistance value between the shell (shield) of oscillating inductors and each pin is detected, it is not infinity, but has a certain resistance value or is zero, then there is a problem with the inductor.
It is added that: in the detection of inductors, digital multimeter range selection is very important, it is best to choose a range close to the nominal inductance to measure, otherwise, the test results will have a large error with the actual value.
Because color ring inductors are non-standard components, unlike resistors, which can be easily detected, and some inductors do not have any marking, it is generally necessary to identify their inductance value by means of parameter marking on the drawing.
In the maintenance, be sure to use the same specifications and parameters of the original inductor for replacement.
How to measure the inductance of color ring
Inductance can be measured by LCR tester, which can measure inductance accurately and stably.If you do not have an LCR meter, you can also measure the inductance with an inductance capacitance meter like the one shown below.
Multimeter measurement of color ring inductance
The shape of the color ring inductor and the color ring resistance is similar, but the color ring inductor two sharp, large in the middle, and the lead connecting place is gradually tapering;And the resistance is obviously thick on both sides, thin in the middle, and very uniform, and the connection with the lead is a vertical section.
General color ring inductors are green background color, and resistance is generally brown yellow, blue or white background color.
The pointer multimeter detection inductor good or bad method: the pointer multimeter conversion switch is placed in Rx1 block, red and black meter pen each connect inductor any pin, according to the measured resistance value, can be specifically divided into the following three cases for identification:
(1) the measured coil or color code inductor resistance value is zero, its internal short-circuit fault.
(2) the needle rotation, the measured inductance resistance value reading, resistance value and winding inductor winding around the enameled wire diameter, the number of winding has a direct relationship, as long as the resistance value can be measured, it can be considered that the measured winding or inductance is basically normal.
(3) the hands do not move, the measured inductance resistance value is infinite, indicating its internal open circuit fault.
Matters needing attention in the use of color ring inductor
1. Inductance components, the core and winding wire are easy to cause the change of inductance due to the temperature rise effect. It is necessary to note that the body temperature must be within the range of use specifications.
2, inductor winding, after the current through the electromagnetic field is easy to form.When placing the components, be careful to keep adjacent inductors away from each other, or coil groups at right angles to each other, so as to reduce the amount of induction between each other.
3. Gap capacitance can also be generated between layers of inductors, especially multi-coil thin wires, which can cause high frequency signal bypass and reduce the actual filtering effect of inductors.
4. When measuring inductance value and Q value with the instrument, in order to obtain correct data, the test lead should be as close to the component body as possible.
You May Like:
Post time: Sep-04-2019