Under controlled conditions a diode's current is modelled by the equation : Question 1 I, = 1,(exp(kV)-1) where Io is the diode current, V the 'forward biased diode voltage, Is is the reverse leakage current and k is a diode specific constant. a) For the diode characteristics shown in Figure Qla determine its model constants Is and k. Diode Current (mA) 3 1 -1 -0.2 -0.1 0.1 0.2 D.3 0.4 D.5 0.6 0.7 0.8 0.9 1 Diode Voltage M Figure Qla: Diode Characteristics

Draw and identify all the types of diode clippers (series and parallel) and clampers. Provide one solved problem each and the reference for each clipper/clamper circuit example.

A single phase – half wave controlled rectifier with freewheeling diode is supplying a load consisting series connected a resistor and an inductance from a 70.7V (RMS), 50HZ sinusoidal AC source. The firing delay of the thyristor is 90° and the load values are R=102, L=0.1 H. Define the load current expression and draw the load current by calculating for first two periods. And calculate the average values of the load voltage and current.

Write the following for a Semiconverter rectifier with RL load: a) Draw the circuit diagram, supply voltage and the output voltage waveform. b) Explain why there is no negative output voltage even without freewheeling diode. c) Derive the expression for average output voltage.