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

Applied electronics, What is coupling? Explain the types of coupling

What is coupling? Explain the types of coupling

Explain keyboard interfacing to 8088 through 8279, Explain keyboard interfa...

Explain keyboard interfacing to 8088 through 8279 . The 8279 is a programmable keyboard and display interfacing component which scans and encodes up to a 64-key keyboard and con

Define some applications of digital counters, Define some Applications of D...

Define some Applications of Digital Counters? Digital counters are extremely useful in many applications. They can be effortlessly found in digital clocks and parallel-to-seri

Hybrid parameters, Hybrid parameters (or) h - parameters:- If the ...

Hybrid parameters (or) h - parameters:- If the input current that is denoted as i 1 and output Voltage that is denoted as V 2 are takes as independent variables, input v

Dc charging and discharging circuit, The circuit shown below is a DC chargi...

The circuit shown below is a DC charging and discharging circuit. a.  At t = 0 sec, switch S1 is thrown to position 1 ("pos1"). Write the mathematical expressions for and .

Phasor relation between different voltages and currents, Phasor relation be...

Phasor relation between different voltages and currents: In the capacitive circuit of Figure, find 1.      Impedance, 2.      Resultant current, 3.      Power factor,

Show the direct connection or one to one topology, Q. Show the Direct conne...

Q. Show the Direct connection or one to one topology? In the one to all topology, there is a path between every node and every other node. The number of paths required is defin

What is the per-unit slip at full load, Q. A three-phase, 60-Hz induction m...

Q. A three-phase, 60-Hz induction motor runs at almost 1800 r/min at no load, and at 1710 r/min at full load. (a) How many poles does the motor have? (b) What is the per-unit

Equivalent circuit of a polyphase induction machine, Equivalent Circuit of ...

Equivalent Circuit of a Polyphase Induction Machine The inductionmachinemay be regarded as a generalized transformer inwhich energy is converted and electric power is transferr

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