The Theoretical Design

IntroductionTheoretical Design Requirements

Marking Criteria

1

Introduction• In industry one is expected to prove that an idea will work by simulating

the idea using relevant software and/or by building a prototype.• The simulation is usually omitted only if suitable simulation software is

unavailable or if certain sections of the circuit simply cannot be simulated (e.g. the actual code for a microcontroller).

• With this in mind it, is COMPULSORY to design a circuit diagram for the project prototype. This is the circuit/s that you intend building / demonstrating for your actual project for this subject.

• Prepare the Theoretical Design document containing all circuit diagrams, calculations, component selections and simulation results.

• You may not purchase components/parts for the prototype until your Theoretical Design has been accepted and passed by the NMMU mentor.

• A sub minimum of 50% is needed for this assessment.

2

Theoretical Design Requirements• Create a MS Word document that contains the following:

1. Cover Page– Title of the project, student name and number, and mentor’s name.

2. Schematic Diagram– Complete a full schematic diagram of the proposed project– Use a CAD package (MultiSim, Protel), MS Word, MS Visio or by hand

(and then scanned into the document)– You don’t have to provide a schematic diagram of the power supply if

an external supply is going to be used.– In the case where a development/controller board (MultiPIC, Arduino,

RS232 IO Controller, etc.) is going to be used, only the board’s I/O and Supply pins have to be indicated by a block in the schematic. A complete circuit of the board is not required.

3

Theoretical Design Requirements cont.3. Circuit Description and Calculations– If possible, break the full schematic diagram into smaller sections and

explain each section’s circuit. Otherwise give a description of the full circuit’s operation.

– Show all calculations that were used to design each section of the full schematic diagram (resistor values, wattages, currents, voltages etc.)

– Show tables and figures from datasheets when more specialized components are used, or when you want to prove a certain formula or operation of a component.

4. Application Specific Components (if applicable)– Provide a description and reasons for selecting the application specific

components for this application. These will normally be the more specialized components.

– Also mention alternatives available and a reason(s) for your choice.

4

Theoretical Design Requirements cont.5. Simulation Results (if applicable)– Where possible, test your schematic design in a simulation package

(MultiSim) and verify that the circuit will work.– Provide evidence of this with screen captures etc.– Do simulations on smaller sections of the circuit if the complete circuit

cannot be simulated at once.– Simulation of actual code for microcontrollers will be difficult. Show

simulations of the interfacing circuits then in these cases.

5

Theoretical Design Requirements cont.6. Software Planning (compulsory for Microcontroller and PC based projects)– Complete all preliminary flowcharts for the control software (use MS

Visio, MS Word, or by hand).– Indicate a draft representation of all the graphical user interfaces (GUI)

for PC based projects.– Indicate a overall view of LCD messages and menu systems for

Microcontroller based projects. – A draft communication protocol description must also be provided in

the case of Microcontroller/PC communication projects.• The document does not have to be ring-binded and can simply be stapled.• Attach a copy of the Marking Sheet to the cover page and fill in your

student name and number on the sheet.• Email a copy of this document to your NMMU mentor.

6

Theoretical Design Requirements cont.• These are the minimum requirements for the document, you can add

more information if you want.• The document does not have to be ring-binded and can simply be stapled.• Attach a copy of the Marking Matrix to the cover page and fill in your

student name and number on the sheet.• Email a copy of this document to your NMMU mentor.

7

Marking Criteria

8

Theoretical Design Marking MatrixSurname: Student No:

Section Weight 0 1 2 3 4 Mark out of 4 Weighted Result

1 1

Original Design and or, Technical Modification Considerations

None Very basic, too

simplistic

Less than 50% of the technical aspects

regarding design or modification considered

Most of the technical aspects regarding

modification or design considered

All technical aspects of considered and accounted for

2 1Design Calculations, Programming and or, Design Considerations

None Between 0 and 2 50% present and

correct Between 2 and 4 Complete, correct and realistic

Each student must present either Alternative 1, or Alternative 2

3 2

Alternative 1, Design Simulation

None

Partly functional simulation, missing fundamental details

Partly functional simulation, showing

various plots, missing significant details

Completely functional simulation, showing

various plots as deemed appropriate, missing

minor details

Completely functional simulation, showing

input and output signals including various plots as deemed appropriate,

good logical layout

4 2

Alternative 2, Explanation of Functional Components as an alternative to Design Simulation

None

Student knows very little about the technical aspects of the project. Few reasonable and logical assumptions

have been made.

Explanation of each component of the

project is not comprehensive. Some reasonable and logical

assumptions have been made.

Explanation of each component of the

project is comprehensive. Small omissions regarding

assumptions.

Explanation of each component of the

project is comprehensive.

Reasonable and logical assumptions have been

made

Percentage

Total (out of a max of 16)