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

Evaluate the voltage gain, Q. On a CD amplifier R s = 4k?, µ =50 and r =35...

Q. On a CD amplifier R s = 4k?, µ =50 and r =35k?. Evaluate the voltage gain A v . A v = V o /V i = µRs / (µ+1)Rs + r

Evaluate the voltage source, Q. For the capacitor shown in Figure connected...

Q. For the capacitor shown in Figure connected to a voltage source, sketch i(t) and w(t).

Substations, How to calculate Electrical losses by transformation

How to calculate Electrical losses by transformation

Shunt capacitors, Shunt Capacitors Line losses owing to poor PF can be...

Shunt Capacitors Line losses owing to poor PF can be decreased through improving the PF. Overall improvement in the operating condition can be brought about through reducing t

Key performance indicators in business, Key Performance Indicators in Busin...

Key Performance Indicators in Business Significance of Key Performance Indicators (KPIs) in the business of power especially within a change environment due to partial deregul

Development of PLC- controlled crystallization model, 1.Describe the techno...

1.Describe the technological process of crystallization. 2. Compose the requirements to developed crystallization model.stion..

What do you mean by number systems, Q. What do you mean by Number Systems? ...

Q. What do you mean by Number Systems? The Digital circuits are inherently binary in nature, but numerous types of representations of numerical data are in use. The represen

Effect of feedback on dynamic response and bandwidth, Q. Effect of feedback...

Q. Effect of feedback on dynamic response and bandwidth? Let us consider the block-diagram representation of the open-loop system shown in Figure 16.2.5(a), whose direct transf

Absorption of radiation and stimulated emission, Absorption of radiation ...

Absorption of radiation If an atom is initially in a lower state 1, it can rise to a higher stare 2 by absorbing a quantum of radiation. Photon of frequency v where E 1 and E

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