First, the understanding of inductance
Inductance is a kind of nonlinear components, the current through the inductance can not be mutation, so for mutation current it will show a high resistance state, it is in the circuit main role: choke, filter, shock, tuning and so on.So how do you read the inductance value?
Ii. Identification of inductance
The basic units of inductance include heng (H), mH and uH, which are converted into 1H=1000mH and 1H=1000000uH.So how does the inductor read its value? What are the methods?
1. Direct marking method
Direct marking method this method is relatively clear to see the size of the inductance, the nominal inductance value is directly marked on the inductance body with Numbers and text symbols, and the letters behind the inductance unit represent the deviation.For example, plug-in i-type inductance and UU common mode inductance are mostly represented by this identification method.
2. Literal notation
The literal symbol method is composed of Numbers and literal symbols. According to certain rules, the nominal value and deviation value of inductance are marked on the inductance.This notation is usually used for small power inductors in nH or pH with "R" and "n" for decimal points, respectively.As shown in the figure below, an inductance is represented by a literal notation, where 4R7 represents inductance 4.7 microns H.
3. Color coding
The color method of inductance is similar to the color method of resistance.
When the color ring is used to mark, the end of the end of the inductor is the end of the ring, and the other end is the first ring.
Coloring ring logo in the above unit of resistance is the ohm (Ω), the inductance is micro heng mu (H), generally have said the third ring and the fourth, the first two digits are significant figures, third is ratio.
If there's a fourth, that's the error level.Nominal inductance value is represented by color code as shown in the following table.
Color standard method is more common in plug-in color ring inductance, as shown in the figure below
4. Digital representation
Digital notation is a bit like literal notation, except that it USES three digits to represent the inductance, starting with the left digit, the first two digits are significant digits, and the last digit represents the number of significant digits followed by "0", the unit is micheng (muh), more often seen in small power patch inductance.As shown in the figure, the inductance labeled "220" is 22 microns H.
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Post time: Aug-24-2019