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

Design the synchronous sequential circuit for state diagram, Design the Syn...

Design the Synchronous Sequential Circuit for State Diagram Illustration: - We wish to design the synchronous sequential circuit whose state diagram The kind of flip-f

Osillators.., what ie the use of mutual inductance in a hartley oscillator

what ie the use of mutual inductance in a hartley oscillator

What are the basic operations of mosfet, Q. What are the basic operations ...

Q. What are the basic operations of  MOSFET? The gate to source voltage is set to zero volts by the direct connection from one terminal to the other,and a voltage Vds is applie

Lead acid accumulators with electrical equipment, Lead Acid Accumulators : ...

Lead Acid Accumulators : These are the most common storage batteries which can deliver a heavy current when short-circuited. There are also many other hazards with these accumulat

Determine lower and upper cut-off frequency, Q. In an amplifier, the maximu...

Q. In an amplifier, the maximum voltage gain is 1500 and occurs at 1kHz. It falls to 1060.5 at 20kHz and at 20Hz. Determine (i) lower cut-off frequency (ii) upper cut-o

Classify the different types of insulating materials, Classify the differen...

Classify the different types of insulating materials with reference to their limiting safe temperatures for use. On the basis of insulating materials and their limiting safe te

Superposition Theorem, Help using superpositions find voltage across all re...

Help using superpositions find voltage across all resistor

Block diagram of digital control system, The block diagram of Figure is a f...

The block diagram of Figure is a functional representation of a type of digital control system, in which G and H serve the same function as in any feedback system. Note that the er

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