Spread time - power semiconductor devices , Electrical Engineering

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.

 

Posted Date: 4/2/2013 3:44:00 AM | Location : United States







Related Discussions:- Spread time - power semiconductor devices , Assignment Help, Ask Question on Spread time - power semiconductor devices , Get Answer, Expert's Help, Spread time - power semiconductor devices Discussions

Write discussion on Spread time - power semiconductor devices
Your posts are moderated
Related Questions
Q. Explain the working of a darlington pair? This is two transistors connected together so that the current amplified by the first is amplified further by the second transistor

Q. A shift register can be used as a binary (a) divide- by-2, and (b) multiply-by-2 counter. Explain. Q. Show a block diagram of a 4-bit shift-right register using JKFFs.

Q. Explain Mesh - Current Method? This complements the nodal-voltage method of circuit analysis. A set of independent mesh-current variables that implicitly satisfy the KCL equ

Q. With a circuit diagram explain how a transistor in common-base configuration amplify signals.  The common-base terminology is derived from the fact that the base is common t


Q. The flux-density distribution produced in a two - pole synchronous generator by an acexcited field winding is B(θ, t) = B m sin ω 1 t cos θ Find the nature of the armatur

I want to know how can i make transformerlass power supply 220v to 48v (8A) and 220v to 24v (8A)

Q. For the mechanical spring-mass-friction system shown in Figure, the differential equation relating the force F(t) and the velocity u(t) is given by  where M is themass,D


wave form of half wave rectifier with rl load