Page 28 - Electrician - TT (Volume 2)
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ELECTRICIAN - CITS





               Fig 7
























           Zener diode: This diode specially designed for voltage regulation. A wide range of voltage regulated zener diodes
           are available.
           It is a PN junction diode doped heavily for  regulation purpose. It has a normal VI characteristic when it is forward
           biased. But the characteristic are changed abruptly when it is connected in reverse bias.
           In the reverse bias condition a leakage current in the order of Microamps will flow. When the reverse voltage
           reaches to a particular designed voltage a sudden breakdown known as avalanche breakdown happens.

           When a heavy current flows at constant voltage, the voltage continue to remain constant. Further increase in
           voltage, the current suddenly increases. Fig 8 shows the reverse characterises of zener diode.


               Fig 8











































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                                    CITS : Power - Electrician & Wireman - Lesson 60-69
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