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

Home energy management.., I need help to build a circuit diagram for home e...

I need help to build a circuit diagram for home energy management.It includes load controllers,a central system in which we should programme all of the control commands,and a two w

Major advantages of fet transistors over bjt transistors, Q. What the major...

Q. What the major advantages FET transistors over BJT transistors? a. BJT transistor (bipolar junction transistor) is a bipolar device - the prefix bi-revealing that the conduc

Calculate critical angel and fundamental gaussian mode, (1) An argon ion la...

(1) An argon ion laser, emitting light at a wavelength of 488nm with a beam divergence of 150 firad, is used to illuminate the moon. (i) Assuming the earth-to-moon distance is 3

Amplifiers with feedback, Q. Amplifiers with Feedback? Almost all pract...

Q. Amplifiers with Feedback? Almost all practical amplifier circuits include some form of negative feedback. The advantages gained with feedback may include the following: •

Explain the power transmission lines, Explain the Power Transmission Lines ...

Explain the Power Transmission Lines Transmission and distribution of electric power is accomplished by using overhead lines or underground cables. Overhead lines are normally

Indirect addressing , Indirect Addressing In this  addressing  mo e al...

Indirect Addressing In this  addressing  mo e also ne  of the  operands is the  stored in the memory. The memory  address of the  operand  is specified  by the  register pair.

What is traffic intensity, Q. What is Traffic Intensity? Traffic Inten...

Q. What is Traffic Intensity? Traffic Intensity: Traffic load on a given network may be on local switching unit, interoffice trunk lines or other common subsystem. For analyti

Measures for improving joints and connection, Measures for Improving Joints...

Measures for Improving Joints and Connection 1. Spacing of poles: The spacing between poles (for overhead lines) is also an important requirement. Long spans will result in

Dc machines, how unbalanced effect in wave winding is considered to be bala...

how unbalanced effect in wave winding is considered to be balanced?

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