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

Explain modulation and sampling, Q. Explain Modulation and sampling? Mo...

Q. Explain Modulation and sampling? Modulation is the process whereby the amplitude (or another characteristic) of a wave is varied as a function of the instantaneous value of

Pn diode, PN Diode The current-voltage characteristics are of major ...

PN Diode The current-voltage characteristics are of major concern in the learning of semiconductor devices with light entering like a third variable in optoelectronics devic

Define the term causality lti system, Define the term Causality LTI System ...

Define the term Causality LTI System Any practical LTI system operating in real time must be "causal" which means that its impulse response {h[n]} must satisfy h[n] = 0 for n

Inverting integrator circuit, Q. Consider the inverting integrator circuit ...

Q. Consider the inverting integrator circuit shown in Figure. Let C = 0.4µF and R = 0.1M. Sketch v o for a period of 0.5 s after the application of a constant input of 2 V at the

Four quadrant chopper or class e chopper , Four  Quadrant Chopper or Class...

Four  Quadrant Chopper or Class E chopper                                                                    Figure class E chopper circuit  Mode I When

Sketch ro versus vgs, Q. Sketch g m versus v GS for a JFET with I DSS = ...

Q. Sketch g m versus v GS for a JFET with I DSS = 10 mA, V P = 3V, V A = 100 V, and v DS = 10 V. See what happens if V A →∞. Also sketch r o versus v GS .

Determine flux in the central limb, Determine flux in the central limb: ...

Determine flux in the central limb: For the magnetic circuit shown in Figure the value of flux in the right limb is 0.48 m Wb and the number of turns wound on the central limb

Motor control , Normal 0 false false false EN-IN X-NO...

Normal 0 false false false EN-IN X-NONE X-NONE MOTOR CONTROL

Function of circuit - breaker, Q. Function of circuit - breaker, difference...

Q. Function of circuit - breaker, difference between circuit breaker and 'isolator'? Ans: The function of circuit breaker is to break the electrical continuity in the event o

Explain nodal analysis procedure, Nodal analysis procedure: 1.  Verify ...

Nodal analysis procedure: 1.  Verify the number of common nodes and reference node within the network. 2.  Assign current and its direction to every distinct branch of the n

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