Download Night Light Name : Class : My Learning Outcomes How did you feel

Night Light
Name :
Class
_______________________________
: ________________________________
My Learning Outcomes
How did you feel that you achieved your learning Intention?
Fully (3)
Week
1
Week
2
Week
3
Week
4
Week
5
Week
6
Week
7
Week
8
Week
9
Partially (2)
Not At All (1)
Night Light
Situation
When told to switch off my light at night I sometimes wish that I could
have the light on for a little while longer. Light at night helps me get to
sleep and comforts me in the dark.
Design Brief
Design and make a ______________________
Specification
Now make a list of some of the things that a good Night Light will have or
will do. This is called a specification.
Function (What must it do ?)
_______________________________________
_______________________________________
Appearance (What should it look like ?)
_______________________________________
_______________________________________
Quality (How well should it be made ?)
_______________________________________
_______________________________________
Safety (How safe is it ? )
_______________________________________
_______________________________________
Cost ( What is a reasonable price ?)
_______________________________________
_______________________________________
Electronic Circuit Symbols
In Technology and Design we can draw special pictures to show the
different things in an electronic circuit. These are called circuit symbols.
Some of these symbols are shown below.
Symbol
Name
Battery
Variable Resistor
Resistor
Switch
LED
Motor
Buzzer
Transistor
Light Dependant Resistor
Picture
Electronic Circuit Symbols – Work Sheet
Silly Sammy does not know what each of the circuit symbols mean. Can you
help him match the symbols to the electronic components.
Symbol
Name
Battery
Variable Resistor
Resistor
Switch
LED
Motor
Buzzer
Transistor
Light Dependant Resistor
Picture
Match The Components Shown below
Electronic Building Blocks
Electronic components are the building blocks that go together to build an
electronic circuit. You can use these building blocks to design and build the
circuit you want.
A circuit should have three main blocks : an Input, a Control and an Output.
This can be seen as a block diagram like the one below.
INPUT
CONTROL
OUTPUT
INPUT: The INPUT part of the circuit senses and reacts to changes in
its surroundings. For example, changes in Temperature, the level of Light
or Moisture in the surrounding environment.
CONTROL: The CONTROL part of the circuit reacts to changes in the
Input and tells the Output part what to do. Eg: It controls the Output.
OUTPUT: The Output part of the circuit produces Sound, Light, Heat or
Movement. The Output part is switched on and off by the Control.
Input components are really variable resistors. Changes in their
resistance can be detected by the control part of the circuit.
Control Components detect changes in the input and react to control the
Output.
Output Components- Circuits are used to control Outputs. Outputs can be
Light, Sound, Heat or Movement.
INPUT COMPONENTS
Light Sensor
Temperature Sensor
Symbol
Moisture Sensor
Symbol
Symbol
CONTROL COMPONENT
Transistor
symbol
OUTPUT COMPONENTS
Light / Bulb
Symbol
Sound / Buzzer Movement / Motor
Symbol
Symbol
LED
Symbol
Speaker
Symbol
Transistors
What are they?
A Transistor is a very useful component for controlling a circuit. It can be
used to link the Input to the Output. For example a Transistor could be
used to link a light sensor (Input Component) to a lamp (Output
Component).
A Transistor has three legs. Each has a name.
The leg closest to and left of the tab is called the emitter.
The leg next to the emitter is called the base.
The third leg is called the collector.
The three legs must be connected the correct way in a circuit or the
Transistor will not work.
A Transistor is a kind of electronic switch. If electricity flows into the
base leg the transistor will switch on the outputs.
Transistors
How they work?
The activity on this sheet demonstrates how a transistor works.
Draw the Transistor circuit below using Livewire.
1. When the switch is open is the LED on or off ? ________
2. When the switch is closed is the LED on or off ? _______
3. Into which leg of the Transistor is the switch controlling the electric
current ? ____________
4. What is the purpose of the 1K Resistor in the circuit ?
_____________________________________________
The LED will only be lit if there is a complete circuit. To have a
complete circuit an electric current must be able to pass through the
Transistor from the Collector to the Emitter. This can only happen if
there is a voltage at the base of the Transistor.
Resistors
A resistor is a device which reduces the current flowing in a circuit. The
greater the resistance the smaller the current.
Electrical resistance is measured in ohms and the symbol for ohms is (Ω).
Think of water flowing in a hosepipe, if someone stands on the tube the
flow of water is reduced or even stopped. The more the tube is squashed
the greater the resistance and the smaller the flow of water.
Place Resistors X, Y and Z in the circuit shown below and observe the bulb.
1.
2.
3.
4.
With which resistor was the bulb brightest?
With which resistor was the bulb dimmest?
Which resistor had the most resistance?
Which resistor had the least resistance?
Resistors have four coloured bands which tell you the value of each
resistor and how accurate that value is. Below you can see what a resistor
actually looks like.
Resistors
As you know, resistors have different values. We can work out the value of
each resistor by looking at the four coloured bands that each resistor has
and by using a resistor table.
Resistor Table
1st Band
2nd Band
3rd Band
Black 0
Brown 1
Red 2
Orange 3
Yellow 4
Green 5
Blue 6
Violet 7
Grey 8
White 9
Black 0
Brown 1
Red 2
Orange 3
Yellow 4
Green 5
Blue 6
Violet 7
Grey 8
White 9
Black No zero’s
Brown
0
Red
00
Orange
000
Yellow
0000
Green
00000
Blue
000000
By using the resistor table above we can work out the value of the resistor
shown below.
Orange Orange Brown
If we look at the first colour of the resistor and also look at the first
band in the resistor table you will see that the number beside Orange is 3.
If we look at the second band in the resistor table and look at the second
colour which is also Orange you will see that the number beside Orange is
also 3. Now by looking at the third band on the resistor you will see that it
is Brown. The third band on the resistor table tells us how many Zero’s to
add. In this case we add 1 zero so our answer is
330 Ohms
or
330 Ω
Resistor Worksheet
Use your resistor table to work out the values of the resistors shown
below.
Red
Red
Brown
___________
Brown
Red
Black
_____________
Blue
Brown
Orange
_____________
Red
Red
Red
_____________
Using the resistor table work out the colours of the resistors shown
below:
330 ohms
__________________
27 ohms
__________________
1000 ohms
_____________________
67000 ohms
_____________________
Plastics
Plastics are a man-made (synthetic) material. They are made from crude
oil. There are many different types of plastic which have many different
properties. They can be rigid, flexible, hard, or soft, opaque or
transparent. However, all plastics can be divided into two groups depending
on how well they react to heat.
Thermosetting Plastics: These plastics are resistant to heat and once
formed into a shape they can not be reshaped. Items which are used near
heat such as saucepan handles or electrical fittings are usually made from
thermosetting plastics.
Thermoplastics: These plastics can be reshaped by heat. Once shaped,
they can be heated and reshaped again and again. These plastics can not be
used in situations where they will get hot or would change shape. Examples
include, Acrylic & Rigid Polystyrene
Questions:
1. What is the name of the plastic you used to make your project?
__________________________________________
2. What properties does this plastic have which makes it suitable for
this project?
__________________________________________
3. Is this plastic a Thermoplastic or Thermosetting Plastic?
__________________________________________
4. What machine did you use to shape your Plastic?
__________________________________________
Soldering
Soldering makes a permanent joint between two pieces of metal. It can be
used on most metals but not on aluminium. Solder is an alloy made up from
a mixture of tin and lead. A substance called flux is used with solder. Flux
cleans the surfaces to be joined. Multicore solder is hollow and has flux
inside it. Solder is melted using a soldering iron.
The soldering iron is tinned by putting a small amount of solder onto it.
It is very important that all work being
soldered is properly heated in order to
get a good joint which makes good
electrical contact. If a component is not
properly heated, molten solder may flow
around it but not actually bond onto it.
This is known as a dry joint
and electricity may not pass through it.
Some components such as LED’s can be easily damaged if they get too hot.
Printed Circuit Boards
Printed circuit boards (PCB’s) are plastic with copper lines. The
components are soldered not the copper.
1. Solder is an alloy - from what two metals is it composed?
________________________________________________
2. What type of materials can be joined by soldering?
________________________________________________
3. When soldering why is it important to heat all the components
properly?
________________________________________________
4. The PCB onto which you soldered your components is made from two
different materials. What are they and which is the insulator and
which is the conductor? ____________________________
Output
Light Emitting Diode (LED)
LED stands for Light Emitting Diode. An LED has two legs, positive and
negative. LED’s come in a variety of shapes and sizes. They can also be
found in a range of colours, usually red, green, yellow and amber.
LED’s are used a lot in electronics because they are very reliable and cheap
to run, as they use very little current.
Care must be taken when soldering. The legs must not get too hot or the
LED will blow. Care must also be taken that the legs of LED do not touch as
this will prevent the circuit from working.
Circuit Symbol
Negative leg
Positive Leg
There are two ways to identify the negative leg of an LED. The short leg is
negative, and the leg closest to the flat rim is also negative.
Products with LED’s
Evaluation
Now that you have completed your Night Light it is important that you
take time to evaluate it. To do this you will have to decide how well it
turned out, what worked well, what did not and what changes you would
make if you were doing it again.
To decide how well it turned out you must go back to your original
specification at the start of the project and decide if you managed to
meet the aims set out there.
Specification
It should ;
 Light up in the dark
 Be colourful and appealing
 Be strong and well finished e.g.
Finished to a high standard
 Be safe to use – (All electrical components concealed)
 Be user friendly – (Easy to use and understand)
 Be made for under £3.00
What do others think ?
In order to get a good evaluation of your product it is often a good idea to
get some other members of your class to give you their opinion of your
work. It is important that your classmates evaluate your work honestly and
fairly.
To help you evaluate your work please complete the evaluation sheet
provided, and pass it on to three of your classmates for their opinion.
Night Light Evaluation:
For each point of your specification score your project out of ten. Use the
guidelines below.
10 – 9
8–7
6–5
4–3
2–1
Excellent standard with no faults
Very good work with only a few faults
Average work with some mistakes
Work of a poor standard with many faults
Very poor, incomplete work.
Specification
My Score Pupil
No. 1
Pupil
No. 2
Pupil
No. 3
Light up in the dark
Colourful & Attractive
Strong & Good quality
finish
Safe to use
User Friendly
Made for under £3.00
Total Score
If you were to make this project again what would you do differently?
(Change the design, the materials, the colours)
Give a reason for your answer ?
_________________________________________________
_________________________________________________
_________________________________________________
________________________________________________
Assessment:
Name: ____________
AFL / Feedback
Night Light
Vacuum Forming and Cutting Rigid Polystyrene
V.Form:
Cutting:
1
2
3
4
5
6
7
8
9
10
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
Finishing Edge of Rigid Polystyrene
Finish:
O
O
O
O
O
O
O
O
O
O
Drilling Rigid Polystyrene
Drilling
O
Soldering
O
O
O
O
O
O
O
O
O
Soldering O
Components
Soldering O
PCB
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
Assembly
Assembly
of Project
O
Scale: 1 – 10 With 1 = Very Poor & 10 = Excellent
Total:
70