一、what is capacitor？
In popular understanding, a capacitor is a 'container for storing charge', which is usually referred to as a capacitor, and is generally represented by the letter C. The most common components in our daily life are ceramic capacitors and electrolytic capacitors.
二、What are the units of capacitors?
Commonly used basic capacitance unit is F (farad)
mF (millifarad)
μF (microfarads)
nF (Nafa)
PF (Pico method)
三、How to convert the unit of capacitance
Most capacitors are around 0.1 to 0.01μF in size
1μF= 10^(-6)F
1 farad (F) = 1000 millifarads (mF) = 1000000 microfarads (μF)
1 microfarad (μF) = 1000 nanofarads (nF) = 1000000 picofarads (pF)
四、Capacitor's capacity value labeling method
1、Mixed alphanumeric standard
Use 2-4 digits and a letter to indicate the nominal capacity, where the number indicates the effective value and the letter indicates the unit of the value. Letters sometimes indicate both units and decimal points. As shown below:
2、Direct notation without units
This method is represented by 1 - 4 digits and the capacity is in pF. For example, when the digital part is greater than 1, the unit is pico-farad, and when the digital part is greater than 0 and less than 1, the unit is micro-farad (mF). For example, 3300 means 3300 picofarads (pF), 680 means 680 picofarads (pF), 7 means 7 picofarads (pF), and 0.056 means 0.056 microfarads (mF).
3、Digital representation of capacitor capacity
Generally, three digits are used to indicate the size of the capacity. The first two digits are the significant digits of the nominal capacity of the capacitor. The third digit represents the number of zeros after the significant digits, and their unit is pF. As shown below:
4、Color Code Representation of Capacitors
The color code representation is to use different colors to represent different numbers. The color and identification method are the same as the resistance color code representation, and the unit is pF.
5、Error in capacitance
There are two ways to express capacitor capacity error. One is to mark the absolute error range of capacitance directly on the capacitor, that is, direct representation. Such as 2.2 ± 0.2pF.
Another way is to mark the letter or percentage error directly on the capacitor. The percent errors indicated by letters are: D for ± 0.5%; F for ± 0.1%; G for ± 2%; J for ± 5%; K for ± 10%; M for ± 20%; N for ± 30%; P Indicates ± 50%. If the capacitor is marked with 334K, it means 0.33 mF, and the error is ± 10%; if the capacitor is marked with 103P, it means that the capacitance variation range of this capacitor is 0.01 - 0.02 mF, and P cannot be mistaken for the unit pF.
Another way is to mark the letter or percentage error directly on the capacitor. The percent errors indicated by letters are: D for ± 0.5%; F for ± 0.1%; G for ± 2%; J for ± 5%; K for ± 10%; M for ± 20%; N for ± 30%; P Indicates ± 50%. If the capacitor is marked with 334K, it means 0.33 mF, and the error is ± 10%; if the capacitor is marked with 103P, it means that the capacitance variation range of this capacitor is 0.01 - 0.02 mF, and P cannot be mistaken for the unit pF.