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

Explain about ''emitter follower'', Q. Explain about 'Emitter Follower'? ...

Q. Explain about 'Emitter Follower'? EMITTER FOLLOWER : An emitter follower circuit shown in the figure is widely used in AC amplification circuits. The input and output of the

Show applications for synchronous motors, Q. Show Applications for Synchron...

Q. Show Applications for Synchronous Motors? With constant-speed operation, power factor control, and high operating efficiency, three-phase synchronous motors are employed in

Electromagnetism, explain how can you find hysteresis loss from hysteresis ...

explain how can you find hysteresis loss from hysteresis loop

Triode mode, Triode Mode When   V GS   > V th   and   V DS...

Triode Mode When   V GS   > V th   and   V DS   GS   - V th ) The transistor is turned on, and a channel has been created that allows current to

Scr, What is finger voltage in a scr?

What is finger voltage in a scr?

Calculate the value in ohms of the rotor resistance, The synchronous speed ...

The synchronous speed of a wound-rotor induction motor is 900 r/min. Under a blocked-rotor condition, the input power to the motor is 45 kW at 193.6 A. The stator resistance per ph

What is the use of modem control unit in 8251, What is the use of modem con...

What is the use of modem control unit in 8251? The modem control unit handles the modem handshake signals to coordinate the communication among the modem and the USART.

Introduction to electronics, Explain the difference between a microprocesso...

Explain the difference between a microprocessor and an embedded microcontroller

Bi directional buffer 74ls245 , Bi Directional Buffer 74LS245 This types...

Bi Directional Buffer 74LS245 This types  of bi directional  buffer is required for data  bus as it has  to function as bi directional bus. The logic  diagram  of such  buffer i

DSP-chebyshev, Consider Chebyshev Type I versus Chebyshev Type II (also cal...

Consider Chebyshev Type I versus Chebyshev Type II (also called inverse Chebyshev) Ölters. Which one should be used based on the following criteria? (If there is no difference betw

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