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

Transmission and distribution, A three-phase transposed line is composed of...

A three-phase transposed line is composed of one conductor per phase with flat horizontal spacing of 11 m as shown in Figure 1(a). The conductors have a diameter of 3.625 cm and a

Circuite theory, In real life, transformers have losses which cause their b...

In real life, transformers have losses which cause their behaviour to deviate from the ideal. Explain the reasons for this non-ideal behaviour

Constant frequency system, Constant Frequency System In this  system c...

Constant Frequency System In this  system chopping period  T is kept constant but the  on time T om is varied. This  system is also referred to pulse with modulation or time

Process of amplitude modulation, Q. Process of Amplitude Modulation? In...

Q. Process of Amplitude Modulation? In AM the message signal is impressed on the amplitude of the carrier signal. There are several different ways of amplitude modulating the c

Machine-tool process to drill or punch holes, Q. Explain Machine-tool proce...

Q. Explain Machine-tool process to drill or punch holes? Figure depicts an elementary system, including the input, digital processor, drill-positioning mechanism, and sampled-d

Explain working of encoders, Explain working of Encoders? Encoding is t...

Explain working of Encoders? Encoding is the process of forming an encoded representation of a set of inputs, and it is the converse of the decoding operation. An encoder is a

Hamming window and zero padding, This question investigates the effect of e...

This question investigates the effect of extending the data set with zero-padding & of the appropriate time in the workflow to apply a window function. To get finer resolution in t

Explain the significance of the coupling capacitor, Q. Explain the signific...

Q. Explain the significance of the Coupling capacitor and the RE - CE circuit. The function of the coupling capacitor is to isolate the amplifier input circuit from the source.

Sketch the timing diagram for a 4-bit ripple counter, Q. Sketch the timing ...

Q. Sketch the timing diagram for a 4-bit ripple counter which uses T flip-flops.

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