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

Security alarm system, In this Project you will simulate a Security Alarm s...

In this Project you will simulate a Security Alarm system using the Quick flash board. A switch is placed as shown in the figure below. The main goal of this project is: Task 1:

Explain dielectric current, Dielectric: Insulator that is used among th...

Dielectric: Insulator that is used among the two plates of a capacitance is called as dielectric.  Electric field exists in the dielectric and the flux density depends on th

Excitation, excitation in an ac generator

excitation in an ac generator

find the thevenin and norton equivalent circuits, The output port of the o...

The output port of the one-port is defined by terminals A and B. Given: R 1 = 10 k_, R 2 = 20 k_, R 3 = 10 k_, and R 4 = 10 k_ V 1 = 20 V and I1 = 0.8 mA a) Find the T

Obtain expressions for the open-loop voltage gain, Q. Consider the op-amp c...

Q. Consider the op-amp circuit shown in Figure and obtain expressions for the open-loop voltage gain at (a) low and (b) high frequencies. Also determine relations for the 3-dB poin

State diagram for a typical von neumann machine, Question: a) Give the ...

Question: a) Give the instruction cycle state diagram for a typical Von Neumann machine. b) Give two diagrams to differentiate between a Memory and CPU connections. c) Co

Mould casting, Mould Casting: Plaster Moulding : In this method, the...

Mould Casting: Plaster Moulding : In this method, the mould is prepared in gypsum or plaster of paris. In practice, the plaster of paris is mixed with tale, asbestos, fibers

How linear sweep voltage is generated, Q. With a suitable block circuit, sh...

Q. With a suitable block circuit, show how linear sweep voltage is generated ? The above figure shows a basic sweep waveform generator. The switching action of the switch

Multiple tariff meters or tou meters, Multiple Tariff Meters or TOU Meters ...

Multiple Tariff Meters or TOU Meters Time of use metering facilitates load control and planning on the part of utilities. This is efficiently achieved using a concept known as

Types of meter test, Types of Meter Test A meter should pass the subse...

Types of Meter Test A meter should pass the subsequent two types of tests: Type Tests Routine Tests Meters are calibrated such in which the whole

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