Rectifier Diodes

     Diodes are the connection PN material that serves primarily as a rectifier. P-type material into the anode side while the N-type material into the cathode. Depending on the polarity of the voltage given to him, the diode can act as a switch is closed, if the anode gain a positive voltage while katodenya get a negative voltage. And apply as a switch opens when the anode have a negative voltage while the cathode get a positive voltage. This condition occurs only in the ideal diode-conceptual. In diode factual (real), it is necessary voltage greater than 0.7 V (for diodes made ​​of silicon) on the anode to the cathode for the diode to conduct electrical current. Voltage of 0.7 V is called a barrier voltage. Semi-conductor diode there are two kinds of silicon and germanium. In general that is used is silicone, which is not a conductor material and not insulators but have properties between them. A diode is divided into two parts, namely N-type silicon and silicon-type P. N-type manufacturing process with a chemical process called doping, this material is made ​​to have the free electrons in larger quantities. P-type doping is obtained by a different process in order to get a lot of holes. Hole shift from one atom to another atom in the silicon material. It is common to assume a free electron in a silicon N (anode) and holes in silicon P (cathode) as the carrier flow.

Picture 1. Meeting P-N is an insulator

 

     Regional meetings between P and N called the meeting to form a PN diode. At the meeting, free electrons from silicon material to fill holes in material N P, so this area is no more free electrons and holes so that the silicon becomes an insulator.

Picture 2. Symbols and physical form diodes

Picture 3. Given diode reverse bias

     If the diodes are reverse bias (+ to the N and - to P), see figure 3, the diode does not deliver because of the expanding PN meeting, see Figure 3. When the diodes are forward biased (+ to P and - to N), see figure 2.5a, then the insulating area does not appear that deliver diode, see figure 4.

Picture 5. Given diode forward bias