Answer Happy

(d) In the CE164 laboratory activities, you built a DC power supply unit (PSU) designed to deliver 5.5V DC output for an AC input of 240Vms and 50Hz. The PSU had four main stages. i) Draw a diagram including all four stages in the PSU, labelling each stage according [3%] to its main function and showing the approximate voltage wave shape at the output of each stage. ii) Suppose that a certain load connected to the PSU requires 15V peak-to-peak to [3%] come out of the rectification stage. What will have to be the peak-to-peak transformer secondary voltage (Vsec-pp) to deliver this voltage? Also what number of turns is required in the secondary to obtain the Vsec-pp you calculated? Assume that we are using a bridge rectifier, and that the primary has 500 turns. Use the practical' diode model. iii) Where in the block diagram you drew above would a Zener diode be most useful? [5%] Explain why, including a description of how a Zener diode would perform the desired function. Use the Zener diode's V-I characteristic curve in Fig. 2.d and refer to the relevant labelled points in your explanation. VR ܚܐ ܂ IR