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

Nor gate - introduction to microprocessors , NOR Gate NOR means NOT OR ...

NOR Gate NOR means NOT OR . it complements the  output  of an OR  gate.  The symbol  of Nor  gate in fig. (a) shows that a Nor  gate  comprises  of an OR  gate followed  by a N

What minimum value of coupling resistance, Q. It is desired to have a sag o...

Q. It is desired to have a sag or tilt of no more than 10% when a 50Hz square wave is impressed on an amplifier stage. The output circuit resistance is Rv=1K. What minimum value of

Determine the nyquist sampling interval - radar system, Consider an S band ...

Consider an S band (3 GHz) radar with a rotating aperture antenna with a width of 3 m.  Suppose the antenna rotates at a rate of one rotation every 10 seconds.  Assume the 3 dB bea

Connection of shunt capacitors - across individual customers, Connection of...

Connection of Shunt Capacitors - Across Individual Customers The most appropriate manner of improving PF of the distribution system and thereby reducing line losses is to link

Determine what is the minimum required sampling rate, 1. An analog informat...

1. An analog information signal, whose maximum frequency is 6000Hz, is to be transmitted using a PCM system. The quantization error must not exceed the 1 % of the peak-to- peak an

Discuss the characteristics of embedded systems, Problem : a) What is a...

Problem : a) What is an "Embedded System"? Discuss the characteristics of Embedded Systems. b) Describe three downfalls of "Embedded Systems". c) Explain the difference b

Simulation of a standard ic linear regulator, 1.    Introduction The ob...

1.    Introduction The objective of this assignment is to design and evaluate a stabilised discrete linear power supply. The power supply requires to be designed according to t

There are many advantages of plc - stepper motor , There are many advantage...

There are many advantages of PLC a.The PLC  was specifically designed for harsh  conditions with  electrical  noise magnetic fields vibration  extreme temperatures or humidit

Factors affecting frequency response of an amplifier, Q. What is their rela...

Q. What is their relation with gain? What are the factors affecting frequency response of an amplifier? Some amplifiers should be "flat" across a band of frequencies. In other

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