B.E. III Sem Electrical Engineering

III SEMESTER

3EE1. POWER ELECTRONICS - I

 

Unit1. PN JUNCTION DIODES: Open-circuited p-n junction and space charge region. The biased p-n junction, volt-ampere characteristics, cutin voltage and effect of temperature on V-I characteristics. Minority carrier density distribution in (i) a forward biased junction and (ii) a reverse biased junction. Diode capacitances. Junction diode switching times and characteristics.
OTHER DIODES: Avalanche breakdown and zener breakdown. Working principles of zener diodes, photo-diodes, light emitting diodes, solar cell and varactor diodes.


Unit2. ANALYSIS OF DIODE CIRCUITS: Diode as a circuit element, load line, small signal diode model and large signal diode model. Analysis of half wave and full wave single-phase rectifiers, peak inverse voltage. Various types of filters, their analysis and applications. Voltage multipliers, clipping and clamping circuits.


Unit3. BIPOLAR JUNCTION TRANSISTORS (BJTs): p-n-p and n-p-n transistors, transistor current components. Common base (CB) and common emitter (CE) configurations: input & output characteristics, current gains: alpha & beta. Transistor operating regions: active region, saturation region and cutoff region. Common collector configuration. BJT biasing and dc models. Thermal stability and stabilization techniques. Small signal models: h-parameters and hybrid pie models. BJT as a switch. Minority carrier concentration in the base for cutoff, active and saturation conditions, transistor switching times and characteristics. Transistor ratings.


Unit4. FIELD EFFECT TRANSISTORS: Construction, working, V-I characteristics and transfer characteristics of JFET. MOSFET: Enhancement type and depletion type: construction, working, V-I characteristics, and transfer characteristics. DC analysis of FETs. FET as a voltage variable resistor. FET small signal models. FET as a switch. CMOS.


Unit5. SMALL SIGNAL AMPLIFIERS: Analysis of BJT and JFET amplifiers at low frequency: input and out resistances, voltage and current gains. Frequency response of common emitter transistor amplifier at high frequency. Miller’s theorem and its dual. Cascaded BJT amplifiers. Darlington pair and Bootstrapped Darlington circuit.