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

Determine the energy fluence - fluence rate, 1. The photon fluence rate is ...

1. The photon fluence rate is 10 7 photons mm -2 sec -1 for a beam of γ rays. One fourth of the photons have energies of 100 keV, one half have energies of 80 keV and the remain

Determine frequency of rotor current, A 3 phase, 6 pole induction motor is ...

A 3 phase, 6 pole induction motor is rated at 400hz, 150v, 10h.p., 3% slip at rated power output. The windage and friction loss is 200w at rated speed. With the motor operating at

Calculate the armature current, A DC shunt motor rotating at 1560 RPM is su...

A DC shunt motor rotating at 1560 RPM is supplied from a 240-V source. The line current supplied to the motor is equal to 27 A. The shunt field resistance of the motor is equal to

TRANSFORMER, what are the characteristics of transformer?

what are the characteristics of transformer?

Mode 2 - boost converter, Mode 2 In this  mode transistor  gets turne...

Mode 2 In this  mode transistor  gets turned off by  the negative output  of PWM  current  flows  through  inductance L diode D then  divide into two  parts one flows through

Name the flag bits available in 8085 microprocessors, Name  the flag bits a...

Name  the flag bits available in 8085 microprocessors. The 8085 microprocessor has five flags to show  five different  types  of data conditions .they are zero(Z),carry(CY),Sig

Sources of power dissipation in cmos logic, Describe the three main sources...

Describe the three main sources of power dissipation in CMOS logic. Hence calculate the power dissipated in a CMOS ASIC of 40,000 gates operating at a frequency of 133MHz with a s

Give the classification of oscillators, Q. Give the classification of oscil...

Q. Give the classification of oscillators. Discuss the frequency stability of oscillators. Oscillators are classified in the following different ways. 1. According to the wa

Matlab simulation, Simulate and compare BER of QPSK system and 4-QAM system...

Simulate and compare BER of QPSK system and 4-QAM system without grey coding Eb/No=0.2.4.6.8.10

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