A. A dc chopper with a free-wheeling diode feeds a dc motor with an armature inductance of 15 mH and resistance of 12. The dc source voltage is 200 V. The ON time and OFF time are 2 ms and 0.5 ms respectively. Determine the armature current when the back Emf of the motor is 155 V. Also draw the power circuitry.

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Speed control of a 140 V, 1.68 kW DC motor single phase thyristor full wave AC-DC It is made by the converter. AA supply voltage 220 V (rms) Is 50. In the converter It is assumed that there is no loss. The armature resistance of the DC motor is = 0.417 Q. Very a large inductance is connected in series with the motor. The motor voltage constant is = 0.0964 V/rpm. The motor can be considered as a permanent magnet DC. According to this, a) Draw the driver (converter-motor) power circuit. b) Calculate the nominal current of the motor. c) Supply voltage, supply current, converter output voltage for ignition angle a = 30 ° and Draw the waveforms for the converter output current. d) = 950 rpm and for nominal current, d1) The firing angle of the converter, d2) Effective value of supply and thyristor current, d3) Supply power factor, calculate.

For the given circuit below, a step down transformer gives an RMS voltage of 230 V/ 10.2-0-10.2 V with a load resistance of 2.2 Kiloohms. Assume Silicon diodes are used. Determine the Peak Inverse Voltage of the diode. D, SCT RL D. llle ண