Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Q. What is thermal runaway? State one method to prevent the same?
The effect of changes in leakage current (ICO) and current gain(b) on the dc bias point is given by the equation
IC = bIB + (1+b) ICO.
The collector current increases with the increase in temperature since b increases with increase in temperature.
ICO doubles in value for every 100 C increase in temperature.
This leads to increased power dissipation with further increase in temperature. Being a cumulative process it can lead to thermal runaway resulting in burn-out of the transistor. The self-destruction of an unstabilized transistor is called thermal runaway. However, if by some technique, IB is made to fall with increase in temperature automatically, then decrease in the term bIB can be made to neutralize the increase in the term (1+b)ICO, thereby keeping IC almost constant. This will achieve thermal stability resulting in bias stability.
Stabilization technique makes use of a resistive biasing circuit that permits such a variation of base current (biasing current) IB as to maintain the collector current IC almost constant in spite of variations in reverse saturation current ICO and b.
DT = Tj - TA = θPD
where, PD = power in watts dissipated at the collector junction
TA = ambient temperature
Tj = junction temperature
θ = constant of proportionality called thermal resistance
what is feedback?
Q. Explain the transfer characteristics in a few words ? The transfer characteristics are a plot of an output (or a drain) current versus an input controlling quantity. There i
Explain temperature dependence of electrical conductivity and resistivity in conductors. When the temperature is increased, there is a greater thermal motion in atoms that redu
Transistor Switching Circuit Design a) Sketchy a schematic diagram showing how a transistor can be used to control the operation of a relay b) Determine what is meant by ba
Explain the Cylindrical or Round Rotors? All synchronous machines have a similar stator design and it is actually the rotor construction that makes them different. The rotor is
Q. Draw the circuit of a common drain FET amplifier and explain. FET amplifier circuit The weak signal is applied between gate and source and amplified output is obtained
1. Introduction : Theory: The voltage measured across a load follows the Ohm's law which says that the current passing through a conductor between two points is direct
Q. What is positive clipper? Give 2 types of its applications ? In the series positive clipper, when the input voltage is positive, the diode does not conduct and acts an open
Q. Analyze the 2-bit R-2R ladder-network D/A converter, and corresponding to binary 01, 10, and 11, obtain the equivalent circuits and determine the analog output voltage as a frac
what is beta?
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd