CCE 301L Final, Spring 2012

CCE 301L: Electronics Laboratory Final Exam Dr. Adel Chit (Beirut) Dr. Fadi Fayad (Saida) Dr. Adel Chit (Zahle) AMERICAN UNIVERSITY OF SCIENCE & TECHNOLOGY DEPARTMENT OF COMPUTER AND COMMUNICATIONS ENGINEERING CCE 301L: Electronics Laboratory Fall Term 2011-2012 Final Exam April 21, 2011 Student Name: __________________________ ID Number: _______________ CLOSED BOOK (90 Minutes) IT IS IMPORTANT THAT YOU READ AND UNDERSTAND THE FOLLOWING: Questions are not allowed during the examination. If you believe that there is ambiguity in a specific question, simply write your own assumptions and proceed with the answer. The CHEATING penalty will result in an F in the course. Mobile Phones are strictly prohibited in the examination hall. Programmable Calculators are not allowed in this exam. Borrowing of any material is not permissible. Write your Name and ID Number in the indicated space of the question booklet. You may use the back of any page of for scratch or for your answers. Do not detach any sheet from the question booklet. This exam consists of 2 pages. Make sure that you have the correct number of pages. THE WHOLE EXAM SHOULD BE MADE ON THIS QUESTION BOOKLET ANY OTHER SUBMISSION IS NOT GOING TO BE GRADED YOU NEED TO SHOW ALL OF YOUR WORK TO GET COMPLETE CREDIT. Good Luck! Problem Points 1 : 05 2 : 20 3 : 15 4 : 10 5 : 15 6 : 25 7 : 10 SCORE /100 1 CCE 301L: Electronics Laboratory Final Exam Dr. Adel Chit (Beirut) Dr. Fadi Fayad (Saida) Dr. Adel Chit (Zahle) Question #1 (5 points) Find the output voltage of the following amplifier: a. An op amp without negative or positive feedback (comparator) has at its positive input +3 V and at its negative or inverting input +4 V. Determine the output voltage Vout of this comparator. (2.5 points) b. Same question as a. but +3 V is feeding the inverting input and +4 its positive or non inverting input. (2.5 points) Question #2 (20 points) Design a voltage stabilizer with 220 V 20% as voltage input and 220 V 5% as voltage output. You have to show your calculation for all circuit(s) in your answer. Specially the control circuit must be drawn for three transformer-tapes in details. Question #3 (15 points) Design two-stage amplifier circuit for low frequency indicating the value of all components. (50<Av<100; no load) Question #4 (10 points) Draw a common-emitter amplifier followed by a Darlington circuit. Indicate the value of Av and Ai. Explain the purpose of this combination. Question # 5 (15 points) Design an electronic circuit that automatically-dims the light of an AC lamp as a function of the external daylight. You can use the LDR (light dependent resistor) as a light sensor. Draw and explain the designed circuit. Remark: The resistance of an LDR is very high, sometimes as high as 1 MΩ, but when it is illuminated with light its resistance drops dramatically. Question # 6 (25 points) Design an automatic 220V AC / 12V DC battery charger based on a voltage comparator that compares between the battery voltage and a reference voltage provided by a Zener diode. Draw and explain the complete designed circuit. Question # 7 (10 points) Design a sine wave oscillator for a frequency equal to 5000 Hz. Show your complete calculation. 2