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

Static scherbius drive - motor control , Static  scherbius  Drive B...

Static  scherbius  Drive By using  this scheme, below and above  synchronous speed can be obtained for an induction motor. There are  two possible  configurations to obtain  s

Role of erc - salient features of nep, Role of ERCs: A National Elect...

Role of ERCs: A National Electricity Policy is one of the key instruments for providing policy guidance to the Electricity Regulatory Commissions in discharge of their functio

Name 5 different addressing modes, The five addressing modes are given belo...

The five addressing modes are given below: Immediate, Register, Direct, Implied addressing modes           Register indirect,

Input offset current of operational amplifier, Q. Input offset current of o...

Q. Input offset current of operational amplifier? The adverse effect of the input bias current mentioned would be nulli?ed if both inputs were connected to equal resistances (o

Dc motor starting, DC Motor Starting When voltage is applied to the arm...

DC Motor Starting When voltage is applied to the armature of a dcmotorwith the rotor stationary, no emf is generated and the armature current is limited only by the internal ar

Basis of the electric solenoid actuator, There is a force on the plunger re...

There is a force on the plunger required to do to move it into or out of the gap and work must be done by or against this force. The conservation of energy dictates that the change

Determine the power angle delta, A synchronous motor has the following para...

A synchronous motor has the following parameters per phase. E=2kv, Eo=5kv, X2=3ohms, and I=700amps. Draw the phasor diagram and determine (a) power angle delta, (b) active po

Diode circuits, Diode Circuits: Prob. (a) Draw the piecewise linear v...

Diode Circuits: Prob. (a) Draw the piecewise linear volt ampere characteristic of a p n diode. What are the circuit models for the ON state and the OFF state. (b) Determ

Properties of a semiconductor, Properties of a semiconductor: What pr...

Properties of a semiconductor: What properties of a semiconductor are determined from a Hall effect experiment ? Sol. The Hall Effect experiment is used to determine th

Difference, Difference between bootstrip sweep circuit and Miller sweep ci...

Difference between bootstrip sweep circuit and Miller sweep circuit

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