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(IELM110)[2009](s)midterm~1910^_543.pdf
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COMPUTING IN INDUSTRIAL APPLICATIONS
IELM 110 Spring 09
Mid-term examination

Duration: 2 hours
Please answer ALL questions
(Mark allocations are shown with the questions. Total mark is 100)

Read carefully the following instructions:
1.
This is an open-book examination

2.
Please keep to the point.

3.
Answers must be in complete sentences (bullet points with correct grammar are also acceptable).

4.
Accompany your answers with ALL necessary assumptions and explanation

5.
You are advised to read ALL the questions before you start to answer them. (Hints: allocate your efforts according to the marks)


Name: ______________________(ID: ____________)
Answer ALL questions (mark allocations are shown)
Question 1
Q1) As shown below is a circuit that is supposed to carry out the following function:
As the IR light beam is interrupted, the double-acting single-ended cylinder will retract. Otherwise, the cylinder will remain extended.

As an engineer, will you certify that this circuit is working? Yes or No? [2 marks]

If you think there are problem(s), please explain what the problem(s) are?
and give the correct drawing either by marking on the above figure (make sure you put
your name and ID on this page and hand in your examination paper with your
answer book or redrawing the corrected circuit diagram in your answer book.
(Hint: there are more than one problem) [14 marks]

Question 2 Q2a) You have been given the following components (there is no need to use all of them), please design an alarm system so that when the capacitive proximity sensor is activated (by the hand of a thief), the single-acting cylinder will continuously extend and retract as long as the proximity sensor remain activated. Once the proximity sensor is de-activated (i.e., the thief put his/her hand away from the proximity sensor), the cylinder will stop moving. When your circuit is powered-up initially and the proximity sensor is not activated, the cylinder should not move.
. one limit switch: LS1 . one single-acting cylinder (same as the single-acting cylinder used in IA lab) . one 3/2 valve and one 5/2 valve (same as the 3/2 and 5/2 valves used in IA lab) . one power supply and lots of wires . one compressed-air supply and pneumatic tubes . one capacitive proximity sensor (same as the capacitive proximity sensor used
in IA lab)
Please draw the circuit diagram using correct symbols. [12 marks]
p.1 of 3 Name: ______________________(ID: ____________)
Q2b) You have been given the following components (there is no need to use all of them), please design a metal detecting system so that when the inductive proximity sensor is activated (e.g., by placing a metal block near the inductive proximity sensor), the double-acting cylinder will continuously extend and retract as long as the proximity sensor remain activated. Once the proximity sensor is de-activated (i.e., the metal block has been moved away from the