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

What do you mean by negative impedance converter, Q. What do you mean by Ne...

Q. What do you mean by Negative Impedance Converter? The op-amp circuit of Figure causes a negative resistance R in between the input terminal and ground. In the more general

Rahul, in 8085 name the 16 bit registers

in 8085 name the 16 bit registers

Measuring with an oscilloscope, 1. Introduction : Theory:   The ...

1. Introduction : Theory:   The voltage measured across a load follows the Ohm's law which says that the current passing through a conductor between two points is direct

Explain basic input output system function call, Discuss BIOS function call...

Discuss BIOS function call with one example. BIO stands for Basic Input Output System: This is a set of programs to give most basic low-level services as services keyboard, s

Electric discharge machining process, Describe the following in Electric di...

Describe the following in Electric discharge Machining Process(EDM). a) Dielectric fluids & their characteristic b) Electrodo feed Control c) Flushing System

Explain shockly''s equation and its significance, Q. Explain shockly's equa...

Q. Explain shockly's equation and its significance in plotting the transfer characteristics ? The linear relationship does not exists in the output of the JFET, the relationshi

Find the turns ratio, Q A60-Hz, 100-kVA, 2400/240-V(rms) transformer is use...

Q A60-Hz, 100-kVA, 2400/240-V(rms) transformer is used as a step-down transformer from a transmission line to a distribution system. Consider the transformer to be ideal. (a) Fi

Determine the mmf of the exciting coil, Q. For themagnetic circuit shown in...

Q. For themagnetic circuit shown in Figure, neglecting leakage and fringing, determine the mmf of the exciting coil required to produce a flux density of 1.6 T in the air gap. Them

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