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ENGG1015 Tutorial

Pro-Project Laboratory and Project

No class (Supplementary notes, may be obsolete,

NOT for examination)

Learning Objectives

Give a draft plan for the project

Identify components that can be used in the pre-project labs and project (i.e. Build a Rube Goldberg Machine)

Identify electrical safety rules, electrical units, electrical symbols rules

Electrical Safety

5-10 ma can cause death

Skin resistance can range from 1kΩ for wet skin to 500kΩ for dry skin.

Death can result from as low as 50 volts

Body can sense 9 volts under the right conditions

Report TA or technician for any emergency case

Electrical Units

Voltage (V): volts (µv → kv)

Current (I): amperes (amps), milliampere (ma 10-3)

Resistance (R): ohms Ω, k-ohms (k 103), meg ohms (m 106)

Capacitance (C): farad, microfarad (µf 10-6), nanofarad (nf 10-9), picofarad (pf 10-12)

Inductance (H): henry, millihenry, microhenry

Frequency (freq.): mhz, ghz 109

Electrical Symbols

speaker

Switches in the Pre-project Lab

Solid State Relay (SSR)

Voltage controlled switch (Vin+ - Vin-)

Isolate the input stage (weak current) with the driving stage (strong current)

Vin+

Vin-

Vout+

Vout-Vin+Vin-

Vout+ Vout-

Input stage Driving stage

Input stage

with sensor

Driving stage

with driver(s)

Switches in the Pre-project Lab

Magnetic reed switch

Normal opened (NO)

Normal closed (NC)

Work with a magnet

Small current

QTI optical sensor

Sensed by infrared (IR)

Correct (small) current

Need an external resistor (10K)

Switches in the Pre-Project Lab

Relay switch logic

NO: Input “ON”, Output “ON”

NC: Input “ON”, Output “OFF”

Knowledge for the Pre-Project Lab

From circuit diagram to implementation

Knowledge for the Pre-Project Lab

From circuit diagramto implementation

Knowledge for the Pre-Project Lab

Terminal Board

Sensor / Switch

Motor / Driver

Wire to power supply

Wire color scheme (red (DC), black (GND), yellow, blue, green)

SS relay

Resistor

V = IR

Resistor parameters: resistance, tolerance and

power rating

Resistors are color coded

Standard Values: 10 12 15 18 22 27 33 39 47 56 68 82

Common tolerance: ±5%, ±1%

Variable resistors: pots

Why is high voltage used in power lines?

Resistor Color Code

Resistor Color Code

To distinguish left from right there is a gap

between the C and D bands.

band A is first significant figure of component value (left side)

band B is the second significant figure

band C is the decimal multiplier

band D if present, indicates tolerance of value in percent (no color means 20%)

Resistor Color Code

For example, a resistor with bands of yellow,

violet, red, and gold

First digit 4 (yellow), second digit 7 (violet),

followed by 2 (red) zeros: 4,700 ohms.

Gold signifies that the tolerance is ±5%

The real resistance could lie anywhere between

4,465 and 4,935 ohms

Digital Multi-meter (DMM)

Important debugging tool

Voltage DC: 2mv-1000v

Voltage AC: 2vac-750vac

Current: 2ua-10A

Resistance: 2-2m

BJT: beta test

Diode test

Power Requirements

Power (voltage) supplies that used in analog and digital circuits

+5v for digital circuits,

+15v, -15v for analog,

-5v, +12v, -12v also used

+3.3v

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Hints for the project

1. Be Safe!

2. Save your time and effort

3. Meet the requirement Five stages in series

Limited stock, limited components

Start: Press the button End: Pop up the balloon

4. Robust design

5. Try something crazy/creative

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Hints for the project

Clear alignment Come up a project theme

Christmas? Theme Park? Letter World?

Set up a common goal You want a A/C/E? You want to have fund?

Set up a group working session Make everyone will contribute

Set up schedule and milestone

Practical? Find out the allowed resources

(Electrical) components, time, skills, number of stages

Think and evaluate some actions/mechanisms Robust? Fancy? Difficult in implementation? Difficult to link to other

mechanisms? Any (easier) alternatives if the mechanisms fail?

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Questions for inspirations

(4W1H) Who/When/What/Why/How

How to push/pull/move/rotate the object?

How to trigger the switch/sensor?

How to do counting?

How to do switching?

How to pop up the balloon?

How to use the fan?

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Electrical switches

On/Off switch

Two terminals for lighting and two terminals for switching

NO

Reed switch Non-contact switch

Operated by magnetic flux NC/NO

Touch switch Contact switch

Operated by pressing NC/NO

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Electrical switches

Solid state relay switch Circuit isolation

Controlled by input PE

NO

Double pole, double throw (DPDT) relay Timer: different time scale /

different switching mode

Relay: circuit isolation

Controlled by input PE

Need a socket

NC/NO

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Electrical sensors

QTI sensor

Blocking sensor

Need a connection cable

Rotation VR

Rotation sensor

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Electrical drivers

Speaker Sound/vibration generation

Solenoid Magnetic controlled valve Switch off normally

Cooling fan Wind movement

Motor Rotation movement / moving

Lamp / LED Lighting effect Connect LED with a resistor

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Jointing

Board

12"x48“ (Base), 2"x48“, 1"x48"

Bracket (Angle/Straight)

Strong fix joint between boards

Different size

Hinge

Movable joint between boards

Cable tie and cable mount

Weak fix joint betweencomponents

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Miscellaneous

Terminal board

Connecting between wires and electrical components

Metal ball

Stages triggering

Metal pulley, sloted wheel

eye hook, Wheeled castor

Pulley, conveyor belt, sling …

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Order purchasing

Fill in a order purchasing form

Get the component from the technician after one week

Limited stock, limited budget, limited parts

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Projects from 2011 Class

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Projects from 2011 Class