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

How does a mosfet amplify electrical signals, Q. How does a MOSFET amplify ...

Q. How does a MOSFET amplify electrical signals? While a minimum requirement for amplification of electrical signals is power gain, one finds that a device with both voltage an

Electrical/electronic engineering project, i need a project creating in ele...

i need a project creating in electronic/electrical engineering at HNC level, 3000 words Harvard referencing. it can be about anything in this field or i can give a suggestion

Evaluate a single-stage transistor amplifier, Design and using Pspice, eval...

Design and using Pspice, evaluate a single-stage transistor amplifier amplifier to meet the following specifications: * Power supply - 12V dc. · *Voltage gain - 120 when Vin

Transistor as a switch, Transistor as a switch: Transistors are genera...

Transistor as a switch: Transistors are generally employed as electronic switches, for both of the high power applications including switched-mode power supplies and low power

What is the purpose of clock signal in an 8086 system, What is the purpose ...

What is the purpose of clock signal in an 8086 system? 8086 needs clock signal with 33%duty cycle from some external operations.8086 processor needs 5 MHZ clock signal

Define characteristics of discrete time systems - linear, Define Characteri...

Define Characteristics of Discrete Time Systems - Linear? A discrete-time system is said to be linear if it obeys the principles of superposition. That is, the response of a li

Resonance, i want to plot a system current transfer matrix element vs frequ...

i want to plot a system current transfer matrix element vs frequency curve.how can i draw it?any suggestion.

Compute the pull on the plunger, Q. A sectional view of a cylindrical iron-...

Q. A sectional view of a cylindrical iron-clad plunger magnet is shown in figure. The small air gap between the sides of the plunger and the iron shell is uniform and 0.25 mm long.

Calculate rotor copper losses, A 20 h.p. , 3 phase, 400 volt, 60 hertz, 4 p...

A 20 h.p. , 3 phase, 400 volt, 60 hertz, 4 pole induction motor delivers full load at 5% slip. The mechanical rotational losses are 400W. Calculate (a) The electromagnetic torqu

What do you mean by induction, Q. What do you mean by Induction? The es...

Q. What do you mean by Induction? The essentials for producing an emf bymagneticmeans are electric andmagnetic circuits,mutually interlinked. Figure (a) shows a load (or sink o

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