Transcript Slide 1

Theme: A Safe Environment
There is an increased awareness of the importance of safety in
the home for both adults and children. Items such as personal
alarms, child locks, burglar alarms, warning devices,
temperature alarms etc. help to create a safer environment.
Design Brief:
With reference to the above theme, design and make a device
that will improve personal safety in the home. The device must
incorporate a mechanical or electrical or electronic system.
Theme: A Safe Environment
There is an increased awareness of the importance of safety in
the home for both adults and children. Items such as personal
alarms, child locks, burglar alarms, warning devices, temperature
alarms etc. help to create a safer environment.
Design Brief:
With reference to the above theme, design and make a device
that will improve personal safety in the home. The device must
incorporate a mechanical or electrical or electronic system.
I have decided to carry out some research on the following
topics:
• Personal Alarms
• Burglar Alarms
• Child Locks
(1) Analysis, Research & Investigation:
Safety Concerns for!
Elderly
Children
Fire!
Handicapped
Warning
Devices /
Alarms?
Security!
Single
People
I have decided to focus on the handicapped environment!
(1) Analysis, Research & Investigation:
Safety Concerns for!
Elderly
Hearing
Disability
Handicapped
Visually
Impaired
Wheelchair
Bound
(1) Analysis, Research & Investigation:
Associated Problems:
Hearing
Disability
• awareness of caller - door bell / knocking!
• telephone ringing
• television / radio
• cooker alarm
• smoke alarm
• intruder
• dog barking
I have decided to investigate a visual/vibrating indicator
to indicate to the impaired hearing that someone is at
the door.
(1) Analysis, Research & Investigation:
I have decided to carry out some research on the following areas:
• Personal Alarms
• Burglar Alarms
• Warning / Signalling Device
The number of personal attacks particularly on the elderly
and young women is quite frightening in today's society.
Therefore there is a need for some type of small convenient
device that could be easily carried, triggered with ease and would
send out a loud audible tone to catch the attention of passers-by!
(1) Analysis, Research & Investigation:
A Domestic Burglar Alarm:
The idea of an intruder alarm is to simply try and deter a
potential burglary occurring at your premises, and to an
extent research shows that it works. A burglar does not
want any attention; his/her aim is to access the property
with as little fuss as possible. If the alarm system is
triggered or activated a loud sound attracts attention!
Warning Device:
I may consider researching some type of warning or
signalling devices such as hazzard lights – safety –
tractors, cycling, walking etc. or a device to aid the
handicapped?
(1) Analysis, Research & Investigation:
Design 1: Existing Solutions
This alarm is designed to be worn around the neck or
strapped to the wrist for convenience. It is very
compact, small in size and quite robust. The casing is
made from ABS, nylon etc, and the manufacturing
process is probably injection moulded however this
shape could be easily made using the school vacuum
forming machine and using rigid polystyrene plastic.
The shape or design is quite simplistic and uninspiring.
Design 2: Existing Solutions
This personal attack alarm opposite also performs
exactly the same function producing a high pitched
sound dB120 for a short time warning off an attacker
or an alarm! I like the relief detail that I feel enhances
the visual impact!
(1) Analysis, Research & Investigation:
Design 3: Existing Solutions
Specification – (must do’s)
Compact, lightweight, plastic casing, robust, aesthetically
pleasing, relatively low cost etc..
This alarm is designed to activate when the cord is pulled.
The cord is easily accessible. The cylindrical shape lends
itself to accommodate the round batteries. This design is
very small and probably quite comfortable to wear around
the neck. The wearer can be assured that the device is
always readily at hand and not left in the handbag or in the car!
(1) Analysis, Research & Investigation:
A Domestic Burglar Alarm:
This diagram shows the different
locating zones in and around the
home for the many different
alarm devices that could be fitted
to help provide better security –
sensors, motion detectors,
monitor
(1) Analysis, research & investigation - existing products
An existing product in the market
place:
Evo D413 Wireless
Flashing Door Bell Kit
for the hard of hearing
The Evo D413 is a wireless door bell/flasher
system for use throughout the home and garden.
The bell push is fitted to your door like any
conventional door bell, but the chime/flasher unit
is wireless making it fully portable up to a range
of 200 metres. This system is also designed with
the hard of hearing in mind with a flashing light
built in for use instead of the chime.
I like the range that this device provides however
the LED light output may be difficult to see and
the circuit appears to be quite complex!
(1) Design Specification: Door-Bell / Security:
Type of device will require either something flashing or moving?
Some type of Mechanical or Electronic system.
My Design Brief:
My intention is to design and manufacture a device
which will signal to a partial hearing person that
someone is at the door. I also wish to include a
security alarm that indicates an intruder has entered
the property.
(1) Design Specification: Door-Bell / Security:
Design Specification:
• the device should be operated by a standard door-bell push button;
• when the button is pressed the device should continue to operate for
a minimum of 10 -15 seconds;
• the visual output signal must be easily seen indicating someone at
the door;
• a visual signal must indicate should an intruder enter the house;
• if the device is operated by electronics it should be powered by low
voltage d.c. (less than 12V);
• the device should be easily manufactured in the school workshop;
• the product should be attractive, easily serviced and maintained;
• the product should be strong and withstand sudden shocks.
(1) Design Specification: Door-Bell / Security:
Design Specification continued:
• the product / device should hold a TV remote control;
• the unit should be compact, stable and match the room surroundings;
• the product should be environmental friendly.
(2) Project Management:
Proposed Timeframe: Time: - 49 class periods to complete the portfolio & manufacture
the product;
Budget: - I have estimated that 10 euro should cover the total
production costs;
However my research will be helpful when costing materials and
my chosen design may also impact on the final cost.
Circuit 1: Systems Design Ideas
Pros:
• a very simple circuit which
provides
oscillating sound and flashing
light / LED
Cons:
• operator might only press the
door button momentarily
• Needs to sound and flash for
at least 10
seconds
A very basic electronic circuit design
Circuit 2: systems design ideas
Pros:
• a very simple latching circuit
which uses a relay to create a
latch
• Light will continue to flash
until the door is opened (SW
2)
• No electricity is used until the
switch (SW1) is pressed
Cons:
• when no one at home light
will continue to flash and
sound - power wastage
• Relays can stick over a period
of time
A basic electronic circuit design
Circuit 3: systems design ideas
Pros:
• a simple latching
circuit using a thyristor
• Light will continue to
operate until the door
is opened (SW 2)
• This circuit design is
more reliable than a
relay
Cons:
• when no one at home
light will remain on
wasting battery power.
A basic electronic circuit design
Circuit 4: systems design ideas
Pros:
• this basic circuit
design uses a
capacitor to keep the
light flashing for
approximately 10
seconds
Cons:
• capacitor timing tends
to be inaccurate
• slight current drain
through LED and
transistor.
A basic electronic timer circuit design
Circuit 5: systems design ideas
This circuit provides a delayed visual indication when a door bell switch
is pressed. In addition, a DPDT switch can be moved from within the
house which will light a lamp in the door bell switch. The lamp can
illuminate the words "Please Wait" for anyone with walking difficulties.
Circuit 4: systems design ideas
This circuit also satisfies the conditions for the security / door bell situation:• SW 2 ‘on’ LED D1 flashes;
• capacitor charges and provides current to the LED for approximately
15 seconds;
• If SW 3 micro / proximity switch (fitted into the door) is activated D2
flashing LED indicated an intruder has entered.
Circuit 5: optimum electronics systems design
This circuit also satisfies the conditions for the security / door bell situation:• SW 1 ‘on’ and SW 3 door bell ‘on’ Bulb BL1 ‘on’;
• thyristor latches keeping BL1 ‘on’ indicating someone at the door;
• SW4 pressed BL1 ‘off’ current by-passes thyristor switching this
component to its insulating state;
• If SW 2 micro / proximity switch (fitted into the door) is activated D3
flashing LED indicates that an intruder has entered.
Circuit 5: optimum electronics systems design
PCB converted using Circuit Wizard
(3) Design Ideas: Security / Door Bell Indicator
Location of unit?
Near the TV as this would be central in the room? The casing should also be a
decorative unit / product;
Worn on body would be ideal but this would require infrared / radio which is too complex an
electronic system.
My Design Brief:
My intention is to design and manufacture a device which will signal to a partial hearing
person that someone is at the door. I have decided to design the systems casing or
housing as a TV remote control holder or stand as this often is in a convenient location
and easily seen in the living room. An output light will indicate when someone is at the
door. I also intend to design some type of security alarm to indicate that an intruder has
entered the house.
(3) Design Ideas: Security / Door Bell Indicator
Location of unit:
Near the TV as this would be central in
the room?
Caller calls at the door
and rings bell
The unit is placed near the TV
In a central location.
a) A flashing light signal
indicates that someone
Is at the door
b) A flashing light of a different colour flashes A TV remote holder/stand
Could be duel purpose?
if an intruder enters the house.
(3) Design Ideas: Security / Door Bell Indicator
Location?
Alarm!!
An intruder has entered
Someone at the door
I feel the best location for this product is near the TV which tends
to be the focal point in the living room.
Concepts: Early Ideas Casing Design
supporting the TV remote control
Side view
end view
Some type of stand made
from acrylic plastic?
Concepts: Early Ideas Casing Design
supporting the TV remote control
Gouging from a solid piece
Of wood
Concept 1: Early Ideas Casing Design
Holder for the TV remote control
Designing from a solid block of wood
Concept 1: Solid Modelled - 3D CAD
Casing made from solid beech
This design could be manufactured using
the CNC. Access for the battery & pcb will
must be considered!
I may decide to manufacture this design Using
the press-mould method.
Concept 2: Solid Modelled - 3D CAD
Concept 2: Solid Modelled - 3D CAD
The remote control sits on the
acrylic rest & the large LED
provides the flashing output when
someone rings the door bell.
I drew my inspiration from the
shape / profile of the remote control.
Concept 3: Solid Modelled - 3D CAD
This a simplistic casing design that may
be vacuum formed or press moulded.
The remote control is located in the recess.
Inspiration taken from …!!!
(3) Selection of Optimum Solution / justification
Justification:
I have selected this design as it satisfies all the points raised in my
specification:the device should be operated by a standard door-bell push button;
My electronic circuit demonstrates that when the door is forced open or when
the door bell is pushed flashing light/s provide a signal to the user;
when the button is pressed the device should continue to operate for
a minimum of 10 seconds;
The capacitor in my circuit acts like a battery and provides current to flow to
the output for a required time;
the visual output signal must be easily seen indicating someone at the door;
I have inserted flashing LED’s into the TV remote control and I find they are
easy to see particularly when placed on the TV remote stand centrally in the
room;
(3) Selection of Optimum Solution / justification
a visual signal must indicate should an intruder enter the
house;
When an intruder forces the door open the proximity or micro switch /
magnet in the door holding the switch open is released and makes
contact bring the circuit on – flashing LED ‘on’;
if the device is operated by electronics it should be powered by low
voltage d.c. (less than 12V);
The device is powered by a d.c. 12V battery;
the device should be easily manufactured in the school workshop;
All the making process using acrylic plastic such as drilling, filing,
bending, gluing etc can be carried out in the workshop;
the product should be attractive, easily serviced and maintained;
I feel the product looks good because of the contemporary design
and the colourful acrylic material and I also feel it fits into the
domestic environment quite well.
Concept 3 sketch development:
I will require some type of
robust stand and base
to house the remote securely?
Some type of fabricated
housing would conceal
the battery and pcb and
add stability?
Concept sketch development:
I like the idea of a housing so I have designed this simplistic
shape. I have used a cylinder cut and faced on the centre
lathe and sawn in two for the semi-circular end and glued
this to the formed ‘u’ shape. This part is transparent so that
the pcb and battery are visible. I thick this will provide a
modern look!
3D CAD: Solid Model of my chosen design
assembled view
exploded view
Optimum Solution
Optimum Solution:
Partial Hearing / Security & Door Bell Indicator
master / re-set
switch
Manufacturing
(4) Working Drawings
(4) Working Drawings
(4) Working Drawings
Materials & Production Planning:
Manufacturing Processes
Time approx,
1
Manufacture of pcb by chemical bath or
CNC - surface machining
Class periods
1
2
Assembly & soldering of pcb / testing
1-2
3
CAD drawings of former/mould
design (not a manufacturing process)
3
4
CNC Manufacture of former
1
5
Hand finishing/sanding of former
1-2
6
Vacuum forming of former
1
7
Manufacture of bezel for split mould
1-2
8
Assembly of casing
1
9
Testing the finished product
1
10 Evaluations – write-up!
Materials & Production Planning:
Part:
Materials & Processes:
1
Base
Acrylic / plastic / fabrication
2
Collar
Acrylic / plastic / fabrication
3
Top
Acrylic / plastic / fabrication
4
Stand
Acrylic / plastic / fabrication
7
pcb
Copper clad board
8
Pcb mount
9
LED’s
5
6
10 PPP 3 Battery
11
Liquid solvent cement
3 x 5mm LED’s
PPP 3 Battery
Environmental Impact:
As I stated earlier the material that I intend using for my housing
design is acrylic plastic. Plastics are made from oil which is a
fossil fuel and unfortunately as the price of oil increases then so
will the cost of plastics. Another disadvantage of this type of
plastics is that acrylic is not biodegradable and therefore plastic
takes many years to disintegrate. However many types of plastics
can be recycled and have alternative uses. Sign makers use
acrylic because it is easily to machine, is lightweight and does not
corrode. Off-cuts can be used for school projects.
An alternative material would have been wood which I had thought
of. Certain types of wood can look well and could easily blend in
with domestic surroundings. Wood can also be recycled, reused
for heating and is biodegradable.
Production Realisation:
Evaluation & critical reflection:
I was quite pleased with the visual appearance of the finished
model and I enjoyed making the product. However I feel I am
now just ready to start all over again and do a better job! My
research materials helped me and the reference materials I
collected inspired the final design. Google images is great for
looking at other ideas / existing products particularly of TV
remote control holders. I also researched mobile phone
holders to get ideas.
The acrylic plastic was quite easy to cut, file, glue and polish
and overall I had no problems using this material.
Fortunately no finishing was required on this material just
polishing the edges on the ‘buff’. The liquid solvent cement
was clean and easy to use in the assembly of the stand.
Evaluation & critical reflection:
My teacher showed me how to use the burette opposite which
applies the liquid solvent cement precisely.
Bending the acrylic was also quite easy I used the hot wire
bending machine for sharp bends and the strip heater for the
larger radii.
I struggled with my time management despite having a plan.
If I was involved in a major project like this again I would plan my
time better!!
In the future the TV may be developed to include some type of
house security indicator providing a signal when an intruder has
enter the property?
Location: Partial Hearing / Security / Door Bell Indicator
TV remote control holder / plus a security alarm and door-bell indicator.
Alternative Solution: Idea 2:
Partial Hearing / Security & Door Bell Indicator
Idea 2:
Manufacturing
Alternative Solution: Idea 3:
Partial Hearing / Security & Door Bell Indicator
Idea 3:
Manufacturing
Research:
Partial Hearing
Door Bell Indicator
- House Security!
Analysis, research & investigation - existing products
www.deaf.ie/IDSinfo/Deaftech.htm
International Deaf Logo
www.kimododreams.com/lette/?cat=6
http://www.mitedu.freeserve.co.uk/Circuits/Misc/deafdoorbell.htm
www.homecontrols.com/.../pgrfnbr/503/sesent/00
answers.yahoo.com/question/index?qid=20070528..
http://www.angelfire.com/co3/NCFS/science/dangerousdecibels.html