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ELE1502 Electronic Circuits ~ Assignment 2

25 May

ELE1502 Electronic Circuits ~ Assignment 2

Due : – 19/05/2017 [100 marks]
This assignment is about two separate circuit sketches that you have been given
by your supervisor to check (analyse), build and test. You have been asked to
give him a brief report with some recommendations on each circuit.

 

Circuit 1 : – Power Supply Development (40 marks)
Analysis –
You are required to first do some analysis, particularly around range of output
voltage achievable with the adjustment range of the potentiometer connected to
the LM317 under full 100mA load. (3 marks)
Further analysis is required of the suitability of the major capacitor C1 for the
designed power supply load of 100mA at the extremes of the range of the output
voltage (as per variable setting). Do a comparison check for the crossed out
value of 100uF. What does this tell you? (3 marks)
Build & Test –
You need to build the circuit on your prototyping breadboard and take some
measurements with a multimeter (DMM). (Avoid measuring current with your
DMM (unless you have a more expensive one that is fuse protected) – rather
measure voltage across a resistance and calculate the current I = V/R)
Attach a pic (or video clip) of your built circuit showing a measurement (existing

 

in your results table) on your connected DMM. (10 marks)
a) Measure the input voltage and output voltage of the power supply circuit,
for both extreme settings of the potentiometer AND for output currents of

 

0mA and 100mA. (10 marks)
b) By either using the lowest AC voltage range on your DMM or by using a
capacitor coupled speaker so you can hear it, see if you can detect any
ripple (a.c.) voltage on your d.c. output under all the conditions of part a).
[Connect a grounded speaker to the PSU output via a series capacitor of
about 100uF (watch out for cap polarity! – wear safety glasses).]

(5 marks)
c) From your observations in a) and b), what recommendations do you
have? Prove these by performing appropriate tests. (5 marks)
Note: The report should include tabulated results, a fully redrawn schematic
with all final component details shown (4 marks), observations and
recommendations. This should fit on an A4 sheet.

Circuit 2 : – Comparator and Logic Circuit (60 marks)
Analysis –
Considering Circuitry of SECTION X :
Scrutinise the circuit and gain and understanding of its intended operation. Do
this by identifying the sub-circuit blocks. (5 marks)
By including datasheet information where needed, calculate expected voltages at
points A, B and C for the extreme settings of the potentiometer. Also, calculate
the voltage from the potentiometer (threshold) at A, at which you expect the
comparator’s output to change. What role does the switch SW1 play? Determine
any expected timing values in the circuit. (10 marks)
Considering Circuitry of
SECTION Y :
By looking at the datasheet of the 4017, work out and explain the expected
behaviour of this section of circuitry. (5 marks)
Build & Test –
Build the SECTION X circuit on your prototyping breadboard and include building
the MONITOR circuit, connecting its input T to SECTION X’s output Q. Take the
following measurements using your DMM and a timer (smart handheld device?):
(Tip : Use a wire to simulate the switch SW1 and briefly close the “switch”
before each measurement.)
[Note – Attach a pic/video clip of your built circuit showing a measurement
(existing in your results table) on your connected DMM.] (10 marks)
a) Using the DMM measure the voltages at A, B and C. Tabulate results to
easily compare to your expected values from your analysis. Also record
the threshold voltage at A for when the comparator output changes.
(10 marks)
b) By watching the LED in the MONITOR circuit, measure any timing you
observe under the various input conditions set by the potentiometer at A.
Explain how the switch SW1 effects the circuit’s operation. (5 marks)
Build the
SECTION Y circuit on your prototyping breadboard. Disconnect your QT connection and connect Q to S and R to T. Set the potentiometer to the
minimum. When powered up, briefly close the switch SW1. Then adjust the
potentiometer upwards and note what happens to SECTION Y. Record your
observations. How does it compare to your expectations? (10 marks)
Note: The report should include tabulated results, a fully redrawn schematic
with all sections connected and all final component details shown (5 marks),
observations and recommendations. This should fit on two sides of an A4
sheet.

 
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Posted by on May 25, 2017 in Academic Writing

 

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