Fixed bias with emitter resistor, Electrical Engineering

Assignment Help:

Fixed bias with emitter resistor:

711_Usage.png

Figure: Fixed bias with emitter resistor

The fixed bias circuit is changed through attaching an external resistor to the emitter. This resistor establishes negative feedback which stabilizes the Q-point. From the voltage law of Kirchhoff, the voltage across the base resistor is

VRb = VCC - IeRe - Vbe.

From the law of Ohm, the base current is

Ib = VRb / Rb.

The manner feedback controls the bias point is like this. If Vbe is stay constant and temperature get increases, emitter current also increases. Though, a larger Ie increases the emitter voltage Ve = IeRe, in turn which decreases the voltage VRb across the base resistor. A lower base-resistor voltage drop decreases the base current that results in less collector current since Ic = ß IB. Collector current and emitter current are related through the Ic = α Ie with α ≈ 1, thus an increase in emitter current with temperature is opposed, and operating point is kept stable.


Related Discussions:- Fixed bias with emitter resistor

Show quantization error, Quantization Error Sampling followed by quanti...

Quantization Error Sampling followed by quantization is equivalent to quantization followed by sampling. Figure illustrates a message signal f (t) and its quantized version den

Commercial fm radio broadcasting, Q. Commercial FM radio broadcasting? ...

Q. Commercial FM radio broadcasting? Commercial FM radio broadcasting utilizes the frequency band of 88 to 108 MHz for the transmission ofmusic and voice signals. The carrier

Application of electrochemical grinding, Explain the working principle, Sur...

Explain the working principle, Surface finish, material removal, accuracy,advantages and application of Electrochemical Grinding(ECG). (a) In electro chemical machining of pure

Terms with respect to d.c machine, Q.  Define coil pitch, Back pitch, fron...

Q.  Define coil pitch, Back pitch, front pitch, pole pitch, commutator pitch, resultant pitch, Multiplex winding and degree of Re-entrant of a winding, with respect to a D.C. mach

Back to back test of tranformer, what is the advantage and disadvantage of ...

what is the advantage and disadvantage of back to back test of transformer

Motor., if load is removed so which motor will run fast? series or shunt?

if load is removed so which motor will run fast? series or shunt?

Circuit theory ., it''s 3 assignments and each assignment have 7 questions ...

it''s 3 assignments and each assignment have 7 questions so each assignment have 1 hour when I open it I have only 1 hour to finish it I can show him or her the practice question t

Transistor, what is bias compensation

what is bias compensation

Identify a variety of security threats, Each year the University computer s...

Each year the University computer society holds a „virtual fair? in Second Life in order to raise money for charity. The main attraction at the event is a lucky dip, where attendee

Sketch the output waveform for the synchronous counter, Q. Consider a serie...

Q. Consider a series-carry synchronous counter with T flip-flops shown in Figure in which the AND gates carry forward the transitions of the flip-flops, thereby improving the speed

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