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

Astigmation control, Astigmation control: In most modern oscilloscopes the...

Astigmation control: In most modern oscilloscopes there is an additional focusing control marked Astigmation . This is used to correct an effect which exactly is analogous to

Meters and measurements, The subject of electrical measurements is such a l...

The subject of electrical measurements is such a large one that entire books have been written on the topic. Only a few basic principles will be introduced here. Practical measurem

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

Analog, why h parameter used in low frequency transistor amplitfier

why h parameter used in low frequency transistor amplitfier

Short note on armature reaction., Armature Reaction in DC Generator:  Arma...

Armature Reaction in DC Generator:  Armature reaction is the effect of magnetic flux set up by armature current upon the distribution of flux under the main poles.

Define branch prediction logic in pentium, Define branch prediction logic i...

Define branch prediction logic in Pentium. Branch prediction logic in Pentium: The Pentium microprocessor utilizes branch prediction logic to decrease the time required for a

Determine the all-day efficiency, Q. A transformer has its maximum efficien...

Q. A transformer has its maximum efficiency of 0.9800 when it delivers 15 kVA at unity power factor. During the day it is loaded as follows: 12 hours 2 kW at power factor 0.5

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