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

Determine frequencies that is in the spectrum analyze, Two sine waves along...

Two sine waves along with periods of 10 ms and 30 ms are added to generate a single waveform. A spectrum analyzer is utilized to examine the frequency contents of the waveform. Wha

Starting methods for polyphase induction motors, Starting Methods for Polyp...

Starting Methods for Polyphase Induction Motors When high starting torques are required, a wound-rotor induction motor, with external resistances inserted in its rotor circuits

Critical rate of rise of voltage - thyristor , Critical Rate of Rise of Vol...

Critical Rate of Rise of Voltage It  depends on  the junction temperature higher  the junction  temperature lower  the critical rate of  rise of  voltage. It is also known  as

Power diode - power semiconductor devices , Power Diode A power diode i...

Power Diode A power diode is a two terminal, anode a and cathode K and  two layer P  and  N  junction devices. A PN  junction normally  formed  by allowing  diffusion and epita

Explain current-to-voltage amplifier, Q. Explain Current-to-Voltage Amplifi...

Q. Explain Current-to-Voltage Amplifier? The basic circuit is shown in Figure, which is similar to that of an inverting amplifier. The - input is connected directly to a curren

Power of the signal transmitted by powerful cell phones, What is the power ...

What is the power of the signal transmitted by powerful cell phones? Ans) The powerful cell phones can transfer a signal of 3 watts.

Explain hysteresis loop, Explain Hysteresis loop. Hysteresis loop: In...

Explain Hysteresis loop. Hysteresis loop: In a ferromagnetic material, the flux density B raises while external applied magnetic field H to it is raised. When the saturation

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

What are the different types of mosfet transistors, Q. What are the differe...

Q. What are the different types of MOSFET transistors ? The metal-oxide semiconductor field-effect transistor (MOSFET) is a three-terminal active device which has many applicat

Role of central and state governments, Role of Central and State Government...

Role of Central and State Governments The subsequent roles of Central and State Governments are envisaged in the Act: The Central Government will Notify rules

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