Diode is nothing but a valve. Before understanding what is diode first we need to understand what is valve? How it works?
See this image. This is a simple valve. As you can see, when there is no waterflow this door is remain closed and disconnect one side with another.
Case 1. If the water flow towards left to right this door get open by the flow pressure of water. Water will flow one side to another. Hope this is clear.
Case 2. Again here is no water flow. Everything is in silent stage. Now the door again closed as previously. Water flowing right to left, but the door remain closed, no movement. Why?
Here is the trick. Previously that door opened by pressure of water, now at this time, that same pressure preventing the door to get open.
This is how valves are made and how they work. They make anything to flow in one direction, and prevent to flow back on reverse direction.
Now coming to the point.
Diodes are work in this way. They are electronic valve. From rectifiers to zener, all are diodes. There are many, different types of diodes available in electronics.
What makes difference between them?
Well, as you now understand that diodes are same, all of them are valve. But some diodes are not only this simple valve, they are far from that. Like in zener diode you can open that door from another side and make it flow reverse.
That means diodes are use as a valve in electronics circuitry. Like making AC to DC, Blocking Reverse flow, Making Clamp circuitry etc.
Now coming to the next point how rectifiers actually make Ac to Dc?
That is not so complex either.
What is Ac?
It's specification hidden in his name. Alternating current. AC continuesly alternate it's polarity. AC goes like this:- " ~ "
As it's alternate polarity in time it generates frequency.
What is DC?
Dc or direct current is a flow of Electrons in one direction.
Dc look like this:- " -------------- "
As you can see a straight line. No polarity changes, so no frequency.
Now rectifier diode do the job for converting AC to DC.
This is a long story. Here is a short description-
Diode's anode cathode combination create n or negetive side and p or posetive side combination. N side have large number of Electrons and very few holes and for P side is vice versa.This is created by heat excitation or thermal excitation procedure or TEP. Now next step take place and it is quite interesting. free electrons from the n side will spread into p side and make a romantic combination with holes. They stick together. And they make +ve ion which is non movable from the n side. This romantic marriage is called as diffuse process. While few atoms on the p side are completely broken by heart and convert themselves as negative ions. Same thing happened on n side, they converted to positive ions. As a result of this massive incident, large number of positive ions and negative ions will accumulate on n and p side. It’s called depletion region. In physics, if there is positive and negative ions then static electricity born. This is called as barrier potential, as this acts as a barrier and block the flow of positive and negative ions across the diode junction.
This is a simple explanation of how they work and depending on that think where they are used. In electronics if you apply basic knowledge then you can understand what to use at where.
Shanghai Shanglang is a manufacturer spec ializedin different kinds of diodes, bridges rectifier.
We are an expert manufacturer specialized in rectifier diodes and bridge rectifier. Now we could produce diodes from STD, FR, HER, SF, UF, TVS , SMD, Zener, Schottky, Switching and 0.5A - 50A, MB,MBF,ABS,WOB, KBL, KBP, KBU, GBL, KBPC, DIP bridge rectifier.