Switching characteristics, Electrical Engineering

Assignment Help:

Switching Characteristics

Switching  characteristics  of BJT  are shown  in figure. Due  to the presence of internal  capacitances BJT  cannot be  turned  instantly. Initially when base  emitter  voltage  is applied in CE  configuration leakage current  flows.  The collection current  begins  to rise after  some delay  time  and reaches at its  steady state  value. the time  from which  collector  current  starts  rising  to its  steady  state value  known  as rise time. BJT gets turned on in and collector emitter  voltages falls from  its maximum  value  forward voltage drop.

1431_Switching Characteristics.PNG

 

Till the forward  base  current is  maintained the BJT  remains in  on condition. As  the base emitter  voltage  is removed at a time t1 does not change for a  time ( there  its is  storage time in which the charges are removed from the base).  After  this time Ic begins to fall and collector voltage starts rising  for a time tf  ( fall time ) . in  fall time  decreases to leakage current  and voltage  rises  to vcc. Hence the turn off time  of BJT is  t off = ts +  tf. In conduction period of BJT a steady state  current  flows and  forward  voltage  drop  appears across the  collection emitter  junctions.

 


Related Discussions:- Switching characteristics

Conductometry experiment, why conductance is not zero at end pont? reply as...

why conductance is not zero at end pont? reply as soon as possible.

Discuss the disadvantages of an rc coupled amplifier, Q. Discuss the disadv...

Q. Discuss the disadvantages of an RC coupled amplifier? RC coupled amplifiers have a few disadvantages. The resistors use dc power and so the amplifier has low efficiency. The

FET, shockely equation?

shockely equation?

Show advantages of oscillators, Q. Show Advantages of Oscillators? Alth...

Q. Show Advantages of Oscillators? Although oscillations can be produced by mechanical devices (e.g. alternators), but electronic oscillators have the following advantages:

Explain the action of a pn-junction with bias, Q. Explain the action of a p...

Q. Explain the action of a pn-junction with bias. Consider both the forward bias and the reverse bias, and use sketches wherever possible.

Illustrate the components of flexible manufacturing system, What is FMS? Il...

What is FMS? Illustrate the components of Flexible Manufacturing System? Discuss the different kinds of Material Handling and Storage Systems?

Traditional Model - Performance Monitoring and Control, Traditional Model -...

Traditional Model - Performance Monitoring and Control The traditional model talks only about the finance and the financial accounting model. The output are published periodic

List few applications of microprocessor-based system, List few applications...

List few applications of microprocessor-based system. It is used: i. For measurements, display and control of current, voltage, temperature, pressure, etc. ii. For traff

Astable multivibrator circuit, how does this circuit work and what are th e...

how does this circuit work and what are th electrical components in it do?

What is the pipelining, A method used in advanced microprocessors where the...

A method used in advanced microprocessors where the microprocessor begins implementing a second instruction before the first has been done. That is, various instructions are in the

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