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
Explain the working of BJT Amplifiers? The purpose of electronic amplifiers is essentially to increase the amplitude and power of a signal so that either useful work is done or
What are the Disadvantages of using robots - They can find it difficult to deal with 'unusual' circumstances for example a door is missing from a car waiting on the paint spra
Explain the suitability of copper that is used as electrical conducting materials. Copper : Pure annealed is utilized for the winding of electrical machines. High pur
Competition and Non-conventional energy: Competition: The tariff policy bolsters competition through making it mandatory for a distribution licensee to procure power by
Q. What is Frequency Translation and Product Modulation? The basic operation needed to build modulators is the multiplication of two signals. Whenever sinusoids are multiplied,
Q. Show the Characteristics of General - Purpose Capacitors? The working voltage for a capacitor is generally specified by themanufacturer, thereby giving the maximum voltage t
Q. Discuss the essentials of an oscillator? The essential components of an oscillator are (i) Tank Circuit: It consists of inductance coil(L) connected in parallel with ca
Q. What is a darlington pair? The Darlington circuit consists of two cascaded emitter followers with infinite emitter resistance in the first stage.
Self-inductance and the induced e.m.f Inductance is the name given to the property of a circuit whereby there is an e.m.f induced into the circuit by alter of flux linkages pro
Question: a) Give one reason why a "subroutine" could be written into the body of the main program. b) With the help of the diagram below, write down the sequence of the ni
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