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 IS in the given circuit, Q. Given that V 0 = 10 V, determine IS ...

Q. Given that V 0 = 10 V, determine IS in the circuit drawn in Figure.

Magnetic circuits, Magnetic circuits To  see  how  this   is  used   i...

Magnetic circuits To  see  how  this   is  used   in  practice, consider a coil of N turns wound onto a closed ring shaped former with a very high (note:    r (steel) = 200

Signals & systems, transformation of independent variable e.g. time related...

transformation of independent variable e.g. time related explaination

Defective metering and meter reading errors, Defective Metering and Meter R...

Defective Metering and Meter Reading Errors Defective Metering Tampered, slow running, stalled, damaged meters are a cause of huge losses to the utility. The electromecha

Determine the current needed in the coil to produce a flux, Q. Consider the...

Q. Consider the magnetic circuit shown in Figure. Assume the relative permeability of the magnetic material to be 1000 and the cross-sectional area to be the same throughout. Deter

Determine the rectified load voltage, Consider the circuit of Figure (a) wi...

Consider the circuit of Figure (a) with v S (t) = 10 cos ωt. Use the piecewise-linear model of the diode with a threshold voltage of 0.6 V and a forward resistance of 0.5  to dete

find the sending end voltage and current, A 3-phase transmission line is 2...

A 3-phase transmission line is 200km long. The line has a per phase series impedance of 0.25+j0.45 Φ/km and shunt admittance of j7.2ΦS/km. The line delivers 250MVA, at 0.6 lagging

Matlab coding for powerflow analysis of fast decoupled metho, please give t...

please give the source coding of fast decoupled method

Compute the theoretical and practical frequency, Q. An RG-139/U rectangular...

Q. An RG-139/U rectangular waveguide is given to have dimensions a = 0.8636 mm and b = 0.4318 mm. Compute the theoretical and practical frequency ranges of operation for the guide.

Dc machines, what is working of dc machines?

what is working of dc machines?

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