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

Determine the input resistance between terminals of circuit, Q. Consider Fi...

Q. Consider Figure of the weighted differencing amplifier. Let R 3 = R 1 and R 4 = R 2 . Determine the input resistance between terminals a and b of the circuit.

Classify feedback control systems according to purpose, Q. Classify Feedbac...

Q. Classify Feedback control systems according to purpose of the system? • Position control systems. Here the output position, such as the shaft position on a motor, exactly fo

Lki load register pair immediate instruction , LKI  Load Register pair  ...

LKI  Load Register pair  Immediate  Instruction This instruction is used to copy or  load  16 bit  data specified  in the  instruction  directly into  the register pair. The i

Calulation of hv/lv ratio to reduce the line loss, kindly send us the formu...

kindly send us the formula and C program for performance improvement of distribution system using HV/LV ratio. REGARDS ANUJ AGARWALA

Introduction to microprocessors , Normal 0 false false fals...

Normal 0 false false false EN-IN X-NONE X-NONE

What do you mean by heat sink?, Q. What is a heat sink? List the factors, w...

Q. What is a heat sink? List the factors, which determine its efficiency. To reduce the chance of thermal runaway, the rise of temperature at the collector junction to a danger

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

Calculate the diameter of the core, A step index multi mode fibre along wit...

A step index multi mode fibre along with numerical aperture of 0.2 supports approximately 1000 modes at an 850µm wavelength. Calculate a) What is the diameter of the core? b)

Give some applications of constantan, Give some applications of constantan....

Give some applications of constantan. Constantan is an alloy of nickel and copper. It is used in thermocouples, motor starters and precision resistors.

Thevenins theorem, advantages and disadvantages of thevenins theorem

advantages and disadvantages of thevenins theorem

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