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

Find the mmf needed to establish a magnetic flux, Q. Consider the toroid sh...

Q. Consider the toroid shown in figure made up of three ferromagnetic materials. Material a is nickel-iron alloy having a mean arc length la of 0.6 m; material b is medium silicon

Ldst, Design a logic circuit with 4 inputs A, B, C & D that will produce o...

Design a logic circuit with 4 inputs A, B, C & D that will produce output ‘1’ only whenever two adjacent input variables are 1’s. A & D are also to be treated as adjacent, impleme

Input offset voltage of operational amplifier, Q. Input offset voltage of o...

Q. Input offset voltage of operational amplifier? When both inputs are tied to ground, i.e., both differential-mode and common-mode inputs are zero, the output should be zero.

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

Single Phase Induction Motor, How do I connect a Capacitor on the machine i...

How do I connect a Capacitor on the machine if it has a start mechanism

Voltage regulator, Voltage regulator: A voltage regulator is an electr...

Voltage regulator: A voltage regulator is an electrical regulator intended to automatically keep a constant voltage level. A voltage regulator is an instance of a negative fee

Insulation resistance, how can we increase insulation resistance of sheet

how can we increase insulation resistance of sheet

Sod output - serial input output ports , SOD Output Serial output data ...

SOD Output Serial output data  single  bit can be sent  out through this pin using SIM  command  discussed in details in chapter8.

Role of a bus arbiter in a multiprocessor configuration, Discuss the role o...

Discuss the role of a bus arbiter in a multiprocessor configuration. Bus arbiter: It functions to resolve priority among bus masters and permits only one device at a time to

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