Before you start please read the following instructions carefully.
1. This assignment forms part of the formal assessment for this module. If you fail to reach the required standard for the assignment then you will be allowed to resubmit but a resubmission will only be eligible for a Pass grade, not a Merit or Distinction.
You should therefore not submit the assignment until you are reasonably sure that you have completed it successfully. Seek your tutor's advice if unsure.
2. Ensure that you indicate the number of the question you are answering.
3. Make a copy of your answers before submitting the assignment.
4. Complete all details on the front page of this TMA and return it with the completed assignment to your support centre via Blackboard.
5. Your tutor's comments on the assignment will be posted on Blackboard as a separate feedback sheet. Your assignment will not be returned to you.
Assessment Criteria
This assignment relates to the operation and evaluation of both linear an switched-mode power supply circuits and to the design a linear power supply to meet a given specification. The assignment forms Element I of the module's assessment criteria that covers in part Learning Outcomes 1 2 & 4 as indicated below.
Knowledge and Understanding
1. Demonstrate an understanding of a variety of electronic circuits including power supplies operational amplifier circuits and digital to circuits
Cognitive and Intellectual Skills
2. Choose appropriate circuit components for the design of electronic circuits.
Key Transferable Skills
3. Demonstrate the application of numerical skills to the solution of problems relating to digital and analogue devices and circuits.
1. A 230 V smoothed [but unregulated] power supply is required to meet the following specification:
- Output voltage 12 V
- Output current 2 A
- ripple factor < 0.024.
i) Sketch a suitable circuit.
ii) Making any reasonable assumptions specify suitable ratings and values for the:
- transformer
- bridge rectifier
- smoothing capacitor .
2. Calculate the output voltage range for the adjustable voltage regulator* circuit shown in FIGURE 1.
*Data sheet is in Blackboard/Assessment.
3. a) State the type of switching regulator shown in FIGURE 2, and briefly explain its operation.
b) In FIGURE 2, R1 = 10 kΩ Vref = 1.25 V and the duty cycle D is 30%. Determine:
i) the required value of R2 [select the nearest preferred value from the E24 series].
ii) the value of VIN.
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E24 series (tolerance 5% and 1%)
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10
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11
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12
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13
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15
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16
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18
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20
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22
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24
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27
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33
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33
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36
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39
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43
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47
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51
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56.
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62
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68
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75
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82
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91
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