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

Crt and cro, working principle of crtand block diagram of cro

working principle of crtand block diagram of cro

Determine the energy, Q. Consider a pair of coupled coils as shown in Figur...

Q. Consider a pair of coupled coils as shown in Figure of the text, with currents, voltages, and polarity dots as indicated. Show that the mutual inductance is L 12 = L 21 = M by

Designated consumers - features of energy conservation, Designated Consumer...

Designated Consumers - Features of Energy Conservation The Act gives the list of designated consumers, which involves the energy intensive industries, Railways, Port Trust, Tr

Architecture of 8085 microprocessor, Architecture of 8085 Microprocessor ...

Architecture of 8085 Microprocessor The 8085  microprocessor  is an 8 bit  general purpose microprocessor. 8 bit  processor  means it can  read write  and process 8 bit  data

Find the current Flow, Q. A charge q(t) = 50+1.0t C ?ows into an electric c...

Q. A charge q(t) = 50+1.0t C ?ows into an electric component. Find the current ?ow.

Explain working of inverting amplifier, Q. Explain working of Inverting Amp...

Q. Explain working of Inverting Amplifier? One common op-amp circuit is shown in Figure. For the case of finite voltage gain Ao of an op amp that is otherwise ideal, the output

Evaluate phase difference between voltage and current, Evaluate Phase diffe...

Evaluate Phase difference between voltage and current: An inductive coil of reactance 15.7 Ω and resistance 32 Ω is connected in series with a capacitor of reactance 79.5 Ω. T

Determine the maximum length, Q. If the line of Problem 15.1.3 is made of c...

Q. If the line of Problem 15.1.3 is made of copper whose resistivity ρ = 1.72×10 -8 ·m, determine the maximum length that can be used if losses are not to exceed 3 dB when f = 3

Induction motor, A very widely used alternative form of synchronous motor i...

A very widely used alternative form of synchronous motor is the  ' indu c tion motor'. This has the advantage that it does not require an auxiliary motor to run the rotor up t

Vector calculus in electromagnetic theory, can you please briefly explain a...

can you please briefly explain about significance of the word direction in vectors with some valid points

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