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

Calculate the gross torque developed for a flux, Q. A four-pole, dc seriesm...

Q. A four-pole, dc seriesmotor has a lap-connected, two-layer armature winding with a total of 400 conductors. Calculate the gross torque developed for a flux per pole of 0.02 Wb a

What are the types of write operations used in 8253, What are the different...

What are the different types of write operations used in 8253? There are two types of write operations in 8253 (1) Writing a control word register (2) Writing a count val

Demodulation of ssb signals, Demodulation of SSB signals also requires the ...

Demodulation of SSB signals also requires the use of a phase-coherent reference. Figure shows the general configuration to demodulate the SSBsignal.Asmall carrier component, which

Define hysteresis, Define Hysteresis Hysteresis is the 'lagging' effect...

Define Hysteresis Hysteresis is the 'lagging' effect of flux density B whenever there are changes in the magnetic field strength H. When an initially unmagnetized ferromagnetic

Define sigma-delta analog to digital converters, Define Sigma-Delta Analog ...

Define Sigma-Delta Analog to Digital Converters? Sigma-Delta ADCs have the benefit of being implemented almost totally in the digital domain.  They are extremely reliable, high

Explain protected mode addressing, Explain protected mode addressing. ...

Explain protected mode addressing. This addressing permits access to data and programs located as the first 1M byte of memory, with in the first 1M byte of memory. Addressing

Determine the motor current and speed, A dc series motor is connected to a ...

A dc series motor is connected to a load. The torque varies as the square of the speed.With the diverter-circuit open, the motor takes 20 A and runs at 500 r/min. Determine the mot

Components of gis, Components of GIS: 1.  Software: GIS software gi...

Components of GIS: 1.  Software: GIS software gives the functions and tools required to store, analyze, and show geographical information. The key software elements are:

Variable capacitors, how can I simulate air variable capacitors in cst simu...

how can I simulate air variable capacitors in cst simulator?

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