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

Signals and spectral analysis, Q. Signals and spectral analysis? Figure...

Q. Signals and spectral analysis? Figure shows the functional block diagram of a signal-processing system. The information source may be a speech (voice), an image (picture), o

What are magnetic materials, Magnetic materials (A) provide path to ma...

Magnetic materials (A) provide path to magnetic flux. (B) are good insulators. (C) are semiconductors. (D) None. Ans: Magnetic materials provide path to

Hybrid parameters, Hybrid parameters (or) h - parameters:- If the ...

Hybrid parameters (or) h - parameters:- If the input current that is denoted as i 1 and output Voltage that is denoted as V 2 are takes as independent variables, input v

Advantages of an rc coupling over a direct coupling, Q. What are the advant...

Q. What are the advantages of an RC coupling over a direct coupling? Draw a basic Rc coupling network and explain. Figure -RC-coupled transistor amplifier The network

What do you mean by noise, Q. What do you mean by Noise? In any communi...

Q. What do you mean by Noise? In any communication system there are usually two dominant factors that limit the performance of the system: 1. Additive noise, generated by el

Electric machines, a shunt motor supplied at 230V rms runs at 900rev/min wh...

a shunt motor supplied at 230V rms runs at 900rev/min when the armature current is 30A.the resistance of the armature circuit is 0.4 ohms.find the armature input

Define the operation of real mode interrupt, Define the operation of real m...

Define the operation of real mode interrupt. Operation of Real mode interrupt: While the microprocessor completes executing the current instruction, this determines whether a

Transmission, what are the grond clearance for 220KV overhead transmission ...

what are the grond clearance for 220KV overhead transmission lines?

Name the materials used in case of fuses, Name the materials used in case...

Name the materials used in case of Fuses . Also give reasons. Fuses : For rewirable fuses, copper-tin and lead-tin alloy is used. For HRC and cartridge fuses silve

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