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
12. A capacitor is to be constructed so that its capacitance is 0.2µF and to take a p.d. of 1.25kV across its terminals. The dielectric is to be mica which, after allowing a safety
how capacitor works as transducer?
Q. What is the basic working of Decoders? An n-bit binary code is capable of encoding up to 2 n distinct elements of information. A decoder is a combinational network that decode
Q. For the 4-bit D/A converter of Figure, calculate: (a) The maximum analog output voltage. (b) The minimum analog output voltage. (c) The smallest detectable analog outpu
Is there an opto-coupler that has a blocking voltage, VRRM, of greater than 800 volts? Perhaps, 1200 or 1600 volts? The manufacturer?
A moving coil galvanometer consists of a coil in a uniform magnetic field B o, suspended fro a fibre of torque constant C, current I produces a deflection O=nAB o i/c where n is
1. A very narrow laser beam in air is shone into a sphere of solid glass that has a uniform refractive index n>1 and radius ? . The beam makes an angle a in air with the normal to
advantage and disadvantage of alloying steel with silicon
importance of electromechanical energy conversion and device in electrical engineering
a) Draw robot configuration. b) Explain the significance of end effectors. c) Define the terms (i) accuracy (ii) Repeatability (iii) Work volume (iv) Control Reso
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