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

Find the current flow through resistor using thevenin''s, Find the current ...

Find the current flow through resistor 12 Ω using Thevenin's Theorem.

Each cells is connected 4 rows, 20 cells with emf 1.45V and internal resist...

20 cells with emf 1.45V and internal resistance 0.5Ω for each cells is linked 4 rows which every rows having of 5 cells in series. Load resistance 15Ω is connected to the battery.

Find the line current after the addition of capacitor bank, Q. Find the lin...

Q. Find the line current after the addition of capacitor bank? A 60-Hz, three-phase motor draws 25 kVA at 0.707 lagging power factor from a 220-V source. It is desired to impro

Basic principles of electrical engineering, What is ideal and real sources?...

What is ideal and real sources? Source conversion? Nodal voltage method for d.c circuit?

Find the sending end voltage and sending end current, A 3-phase transmissio...

A 3-phase transmission line is 200km long. The line has a per phase series impedance of 0.25+j0.45 Ω/km and shunt admittance of j7.2 μS/km. The line delivers 250MVA, at 0.6 lagging

Commutation in dc machines, Currents induced in armature conductors of a d....

Currents induced in armature conductors of a d.c. generator are alternating. To make their flow unidirectional in the external circuit, we need a commutator. Moreover, these curren

Low-pass electronic filter, Low-pass electronic filter: The capacitors...

Low-pass electronic filter: The capacitors and inductors are the reactive elements of the filter. The number of elements ascertains the order of the filter. In this situation,

What is the function of the signal in 8086, What is the function of the sig...

What is the function of the signal in 8086? BHE signal means Bus High Enable signal. The BHE signal is made low when there is some read or write operation is carried out. i.e.

Need of microphone in telephone hand set, Q. Need of Microphone in telephon...

Q. Need of Microphone in telephone hand set? Microphone: For all practical purposes, microphone is transmitter for telephone. The microphone converts acoustical signals in the

Wireless and communication, With a maximum excess delay of and a chip durat...

With a maximum excess delay of and a chip duration of , the multipath components fall in delay bins. This means that we experience leakage of energy between chips and the channel i

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