Static v- i characteristics - power semiconductor devices , Electrical Engineering

Assignment Help:

Static V- I Characteristics

A thyristor  works in  three basic  modes

a.Reverse  blocking mode

b.Forwards  blocking  mode and

c.Forward  conducting  mode

In reverse  blocking  mode cathode is made  positive  with respect to anode  and gate  circuit  remains  open as shown  in figure  in this  mode junctions  J1 and J3 are seen  to be reverse  biased and junction J2 is forward  biased. A very  small  current  flows.

1517_Characteristics.PNG

                             Figure(a) reverse blocking  mode (b)forwards blocking  mode  (c)forward  conducting mode

An avalanche breakdown  occurs  at junction J1 and J3. When  reverse voltage  is increased and  reverse  current  increase  rapidly  as shown in figur.

In forward  blocking  mode anode is positive  with respect to cathode and gate is  opened. Since  the junctions J1 and J3 are forward biased whereas junction J2 is reverse biased. Hence  a small  leakage current  flow  called forward  leakage  current. When  forward  voltage  is increased junction J2 will have  avalanche  breakdown  at a  voltage named forward  break over voltage  vBo.  

In  forward  conduction mode  anode  is made  positive with  respect to  cathode  and gate is  also made  positive with respect  to cathode. As positive  gate  voltage  is applied   between gate and  cathode at a particular  forward  anode  voltage junctions  J2 comes in  forwards bias  from reverse bias  condition and a  forwards anode  current flow  in the  circuit  with very small  voltage drop  across  the thyristor.

 


Related Discussions:- Static v- i characteristics - power semiconductor devices

Customer indexing scheme, Customer Indexing Scheme: Customer indexing ...

Customer Indexing Scheme: Customer indexing and asset codification system provides a platform to enable the utilities to generate verifiable and validated data of consumers an

Explain working of inverting amplifier, Q. Explain working of Inverting Amp...

Q. Explain working of Inverting Amplifier? One common op-amp circuit is shown in Figure. For the case of finite voltage gain Ao of an op amp that is otherwise ideal, the output

Illustrate frequency-shift keying, Q. Illustrate Frequency-shift keying? ...

Q. Illustrate Frequency-shift keying? Digital transmission by FSK is a nonlinear modulation method that is appropriate for channels that lack the phase stability needed to perf

Show the dialling circuit, Q. Show the Dialling Circuit? Dialling circu...

Q. Show the Dialling Circuit? Dialling circuit enables subscriber to output signals representing digits, and this enables caller to enter destination telephone number. Dialling

Explain the construction of a mosfet, Explain the construction of a MOSFET....

Explain the construction of a MOSFET. Draw the symbols and diagrams of both P-channel and N-channel MOSFET. As JFET and MOSFET also have source, drain and gate. Its gate is ins

What is program counter, Program counter holds the address of either the fi...

Program counter holds the address of either the first byte of the next instruction to be fetched for implementation or the address of the next byte of a multi byte instruction, whi

What is centralized spc, Q. What is centralized SPC? In centralized con...

Q. What is centralized SPC? In centralized control, all control equipment is replaced by a single processor which should be quite powerful. It should be capable of processing 1

Calculate the hysteresis loss in joules per cycle, Q. In plotting a hystere...

Q. In plotting a hysteresis loop the following scales are used: 1 cm = 400 At / mand 1 cm=0.3 T. The area of the loop for a certain magnetic material is found to be 6.2 cm 2 . Calc

Classify the materials based on the energy bands, Classify the materials ba...

Classify the materials based on the energy bands and explain them. Classification of materials based on energy bands: With reference to various band structures demonstrate

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd