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

Compound motor , Compound motor It is possible to arrange for part of...

Compound motor It is possible to arrange for part of the field  coil to be in series with the armature and part in parallel   This gives rise to a motor with a mix

Transmission, what are the grond clearance for 220KV overhead transmission ...

what are the grond clearance for 220KV overhead transmission lines?

Power, why do we use commutator?

why do we use commutator?

Design a pulse generator, To design a VI that can also be used as a Sub VI ...

To design a VI that can also be used as a Sub VI in another VI. The title of the VI will be Pulse Generator. The output from the VI will be of the type Analogue Waveform and

External frequency compensation of operational amplifier, Q. External Frequ...

Q. External Frequency Compensation of operational amplifier? For applications requiring a more extended high-frequency response, there are op amps with no internal compensation

Explain working of presentation layer, Q. Explain working of Presentation L...

Q. Explain working of Presentation Layer? This is concerned with format of the data represented, in order to overcome difference in representation of information as supplied to

What are the different types of patrolling, Q. What are the different types...

Q. What are the different types of Patrolling? When these are adopted? What are points to be considered while preparing the charts? Ans.- Types of Patrolling. 1. Keyman's

Ultrasonic Sensor Help for Seventh Grader, What are ultrasonic sensors made...

What are ultrasonic sensors made of? What is a good online source to find information on a basic level about ultrasonic sensors?

Describe watch dog timer and reaction timer, a. Given a timer with a termin...

a. Given a timer with a terminal count and a clock frequency of 10 MHz measure the following: (i) Range & Resolution (ii) Terminal count values needed to measure 3ms interval

Thevenin equivalent circuit, The circuit below will be most efficiently ana...

The circuit below will be most efficiently analyzed by obtaining the Thevenin equivalent circuit for the circuit to the left of the points (a-b) on the schematic. The capacitor is

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