Spread time - power semiconductor devices , Electrical Engineering

Assignment Help:

Spread Time (ts)

During  spread time anode  voltage  falls from 10% Ia  to the  on state  voltage  drop  and anode  current  rises  from 90% Ia  to final  value  of anode  current i ,e Ia in this period whole  charges injected from   gate spreads over the entire section of  cathode and anode  current  reaches at steady state  condition.

There the total turn on time  ( ton ) can be written  as

Ton = td + Ir + ts

In these  intervals td tr and ts the rise time is high  a s compared to other. If  rise time it  is reduced beyond  a limit thyrisotr may get destroyed because rate of  rise  of anode  current  may be  large  as compared to the spread velocity of charges and this  may forms a  local  hot spot on the cathode surface of SCR. Turn on  time depends on gate  current. It can be  reduced by using  higher  value of gate  currents.

 


Related Discussions:- Spread time - power semiconductor devices

Decimal to binary conversion, Decimal  to binary Conversion To conver...

Decimal  to binary Conversion To convert a decimal  number to binary  any one  of the followings  two methods  can be used. Methods1 : This  is very common  methods of co

Find the corresponding energy, Q. Consider a pair of coupled coils as shown...

Q. Consider a pair of coupled coils as shown in Figure of the text, with currents, voltages, and polarity dots as indicated. Show that the mutual inductance is L 12 = L 21 = M by

Explain node-voltage and mesh-current analyses, Explain Node-voltage and me...

Explain Node-voltage and mesh-current analyses? The node-voltage and mesh-current methods, which complement each other, are well-ordered systematic methods of analysis for solv

What do you mean by conditional selection, Q. What do you mean by Condition...

Q. What do you mean by Conditional selection? Conditional selection: When a marker is instructed to create a connection from a given incoming trunk to a given outgoing trunk, t

Automatic frequency control , Discuss the requirement for automatic gain co...

Discuss the requirement for automatic gain control in AM receiver and automatic frequency control in FM. How are these 'control' voltage formed and used?

Show the familiar electric sources, Q. Show the familiar electric sources? ...

Q. Show the familiar electric sources? Batteries and ac outlets are the familiar electric sources. These are voltage sources.An ideal voltage source is one whose terminal volta

Determine the i-v characteristic of the network, Determine the i-v characte...

Determine the i-v characteristic of the network shown in Figure by the use of breakpoint analysis.

Electronics circuits 1, Explain and drive the expression for fixed bias and...

Explain and drive the expression for fixed bias and potential divider.

Show example on residential wiring, Q. A person, while driving a car in a c...

Q. A person, while driving a car in a cyclone and waiting at an intersection, hears a thumping sound when a power line falls across the car and makes contact with the chassis. The

Define resistance strain gauge, Q. Define Resistance Strain Gauge? Mech...

Q. Define Resistance Strain Gauge? Mechanical and civil engineers routinely employ the dependence of resistance on the physical dimensions of a conductor to measure strain. A s

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