Midterm Examination 2
(Due: June 14, Friday 1 Hour 15 minutes
Instructor: Dr. Ying-Khai Teh)
Instruction: Please answer all FIVE questions. You must show your working steps to get the full
credit. Please allocate sufficient time to prepare your answer in a single file PDF, and complete
uploading process of the file to Canvas.
First Name:
Last Name:
Red ID #:
Questions Scores
1
2
3
4
5
Total
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, Question 1: 3% for each sub-question except the last sub-question, 20%
a) Consider a full-wave peak rectifier fed by a 50-Hz sinusoid having a peak value Vp = 200 V.
Assume the load resistance R = 10 kΩ and the diode is ideal. Maximum rated diode surge current
IDMAX=2A.
i) Find the value of the capacitance C in μF that will result in a peak-to-peak ripple voltage of 3 V.
Vr = Vp / 2fCR
3 = 200/(2×50×C×10k)
C = 66.67μF
ii) Find peak diode current iD in µA.
𝑽𝑷 𝟐𝟎𝟎
𝑰𝑳 = = = 𝟐𝟎 𝒎𝑨
𝑹 𝟏𝟎𝒌
𝒊𝑫,𝒑𝒆𝒂𝒌 = 𝑰𝑳(𝟏 + 𝟐𝝅√𝑽𝑷/𝟐𝑽𝒓)
(𝟐𝟎𝟎)
𝒊𝑫,𝒑𝒆𝒂𝒌 = 𝟐𝟎𝒎 (𝟏 + 𝟐𝝅√ ) = 𝟕𝟒𝟓𝟓𝟐𝟎µ𝑨
𝟐×𝟑
iii) Calculate FOM2 (Figure-of-Merit 2, defined in on the project 1 description) of diode used in this
rectifier circuit. FOM2=peak diode current / Maximum rated diode surge current.
𝒊𝑫,𝒑𝒆𝒂𝒌 𝟕𝟒𝟓. 𝟓𝟐
𝑭𝑶𝑴𝟐 = = = 𝟎. 𝟑𝟕𝟐𝟖
𝒊𝑫𝑴𝑨𝑿 𝟐𝟎𝟎𝟎
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