Question

a) The DC power supply below is connected to a 110 V RMS, 50 Hz AC mains. The transformer has turns ratio N, : N2 = 10 : 1, and the diodes have forward voltage drop 0.7 V, and the regulator has dropout voltage 1.8 V. We require V 5 V. OUT =2 A GND 110 V rms O A R V Va VC 50 Hz N2 N i. Given the transformer has turns ratio Nį: N2 = 10: 1 what is the peak value of v2? ii. Assuming a first order model for the diodes, with forward voltage drop 0.7 V, what is the peak value of vc? i. The voltage regulator has dropout voltage 1.8 V. If we require VL = 5 V, what is the minimum acceptable value for vc? iv. What is the minimum value of C to ensure the power supply can deliver 2 A with Vi = 5 V? v. If we use C = 4700 /uF, what is the average value of vc? vi. If we use C = 4700 uF and the power supply is delivering 2 A at 5 V, how much power is dissipated in the voltage regulator on average?

Answer 1

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