Download Proposal to conceive, design, prototype, and evaluate a Light

Proposal to conceive, design,
prototype, and evaluate a Light
Sensitive Dimmer to minimize power
consumption
by Cody Coleman, Tshiamo Lechina, and Tatiana Mamaliga
Summary
In order to minimize the consumption of electrical energy used for lighting, we propose to
conceive, design, prototype, and evaluate a switch that senses the brightness of natural light and
varies the intensity of the light bulbs used to light the rooms. Our team met multiple times to
brainstorm and discuss several ideas to come up with a final design, which is using a light sensor
and a dimmer switch to regulate the amount of power that light bulbs use. Our Light Sensitive
Dimmer should be able to sense the brightness of natural light outside the windows and adjust the
amount of energy used to power the bulbs. These requirements will be addressed by the dimmer
switch that will vary the intensity of the light bulbs based on the input that it will receive from the
light sensor located by the window. There's no considerable risk to the user of our device; in a case
of device failure, the light will just turn off . When implemented, the Light Sensitive Dimmer will
contribute to the world economy by saving money on energy used for lighting.
Introduction
A Light Sensitive Dimmer is of significant importance to the world. It is commonly observed that a
lot of energy is wasted at times when the lights are turned on during the day, even when there is
enough daylight pouring through the windows. However, most of electricity comes from
nonrenewable sources of energy (i.e. coal), and it is costly, which affects both the environment and
the economy. To solve this problem, this project is to conserve the energy that is often wasted by
the unnecessary use of lights during the day. In addition to the requirement that it sense the
brightness of natural light outside the windows and adjust the amount of energy used to power the
bulbs, this device should also
satisfy the following requirements:
●It should not expose anyone to undue hazards;
●It should not occupy a large area in the room;
●It should not interfere with the main electrical circuit of the building so as to damage it;
●It should be optional to use;
●It should be for individual-room use;
●The product must have a small ecological footprint, both in terms of the materials used to
construct the product and the labor required to produce the product.
Background
Energy Model
The light sensor by the window will estimate the amount of natural sunlight that comes into the
room, and will send an impulse to the dimmer switch, making it adjust how bright the bulbs should
be. We analyzed the amount of energy lost in a hypothetical situation that the lights are left on from
7am to 5pm in ESG as follows:
about one hundred of 100 W Fluorescent light bulbs in ESG
Estimated Energy used by the bulbs in one day:
Energy=Power *Time
=100 W*10 hrs*3600 sec=3.6 MJ for one bulb
for 100 bulbs:
3.6 MJ*100=360 MJ
over one semester:
12 weeks * 5 days * 360 MJ=2.16*10^10 J
Cost of this energy:
Amount of electricity used in one day costs 100*100 W*10 hrs=100kWhrs
Over one semester: 12 weeks * 5 days * 100kWhrs=6000kWhrs
Cost of electricity in Massachusetts: 16.6 cent per kWhr
in one semester the cost of that electricity would be: 6000kWhrs*$.166 = $998
~ $1000
Safety Analysis
When constructing a device to conserve electrical energy used to light rooms, as required by our
project, one needs to consider several factors. The device should prevent exposure to undue
hazards, it should not interfere with the main electrical circuit of the building so as to damage it, it
should not be imposed on the consumer, and it should have a small ecological footprint, both in
terms of the materials used to construct the product and the labor required to design the product.
We regard these safety requirements with highest priority when considering the Light Sensitive
Dimmer, and we will take them into strong account. Moreover, there's no considerable risk to the
user of our device because we are going to use insulated connected wire, and other safe materials to
construct it; in a case of device failure, the light will just turn off.
Aesthetics and ergonomics
For our design the Aesthetics and ergonomics requirement is not going to be a concern. The Light
Sensitive Dimmer will not occupy a large area in the room and will consist of a central unit which
will coordinate light sensors and dimmer switches in different rooms.
Materials and labor costs
The materials that we are going to use for the Light Sensitive Dimmer as well as the estimated
corresponding
prices are:
-light sensor--$55.00
-dimmer switch--$49.99
-wiring--$20
estimated total cost: about $124.99 ~ $125
Methods
Design overview:
The Light Sensitive Dimmer will consist of a light sensor and a dimmer switch connected together
with wiring and programming tools. The light sensor will detect the amount of brightness that the
room receives from natural lighting and will send an input to the programmed dimmer switch. The
dimmer switch will then associate the data with a specified intensity and will give out a
corresponding amount of energy to the bulbs.
Design Selection
There were a number of ideas that we came up with while thinking of a device that will save
energy. Each of us contributed to picking the one design that we chose to proceed with by ranking
the following factors about each design as illustrated on table 1 below. Since the main objective is
to reduce energy footprint, the factor, “will reduce a lot of energy” was ranked out of a maximum
of 6 points, while the other factors were ranked out of 3 points. By popular vote, the switch that
adjusts intensity of light depending on the brightness of sunlight turned out to be the design we
picked for our project. We evaluated our design choice according to several criteria, as illustrated in
Table 2.
Possible
Designs
Team
Technical
member slum dunk
s
(3)
ranking
Personal
Interest
(3)
Will save lots Time
of energy
commitment
(6)
(3)
Total
Switch that
Cody
2
turns charger
Tatiana 2
of computer
Tshiamo 2
off when
battery is full
1
4
1
26
3
4
0
2
4
1
Roof Top
Garden
Cody
2
3
4
0
Tatiana
3
1
5
0
Tshiamo 1
1
4
0
Solar Paint to Cody
3
convert solar
Tatiana 3
energy to
Tshiamo 3
electrical
3
6
0
2
6
0
2
6
1
Switch that
adjust
intensity of
light during
the day
Cody
3
3
5
2
Tatiana
3
3
5
2
Tshiamo 3
3
5
1
Box that
insulates hot
pot to soften
food before
cooking
Cody
2
1
4
3
Tatiana
3
2
4
3
Tshiamo 2
3
4
3
24
35
38
34
Table 1: Ranking of different factors to consider when choosing one design from all the proposed
designs.
Design FRDPARRC
Functional
Requirement
s
Design Parameters
Analysis
Research
Risks
Countermeasur
es
Conserves
energy by
dimming
or turning
off lights
when
there is
enough
sunlight in
the room
Light sensing
device will collect
information about
brightness of
sunlight, and send it
to dimmer switch,
which will dim the
light of lamp
6000 kW/hours
of energy
per semester
can be wasted
on lights that
are left on
unnecessarily
during the day
A photodiode
can produce a
voltage
depending on
the intensity of
light it is
exposed to. A
dimmer switch
produces
different
brightness in
attached lamp
depending on
how much
input voltage
there is in part
of its circuit. A
photodiode can
therefore be
used together
with a dimmer
switch to
control
intensity of
light coming
from lamp
Integrating
dimmer switch
with wiring of
building could
cause fires if
not done
properly.
A dimmer
switch can be
made
separately and
used with a
lamp, and not
connected to
the building
lights
safe
Small scale
prototype- could
make dimmer
switch and not
connect it to
building circuitry.
With a small
device
connected to
one lamp it
will be easy to
detect any
faults, and any
faults will be
less dangerous
to the user
compared to a
large device
integrated to
the whole
building circuit
Risks of
electrocution
could result if
one touches
the conducting
wires on
dimmer switch
circuit.
The exposed
metal in
dimmer switch
circuit can be
covered with
electric tape
Ergonomics
and
aesthetics
The device will be
small and compact.
It should be able to
fit on the window
sill
If the device is
kept in the
room it will
respond to
light produced
by the lamp, to
make sure it
only responds
to sunlight it
should be
made such that
it can be kept
by the window,
behind the
blinds
economical
Budget restraintunder $200
Estimated cost
of device is
$125.00
A photodiode
detects any
visible light,
not only the
one from the
sun, so even
light from the
lamp will
make it
produce a
voltage
Table 2 Design FRDPARRC
Qualifications of primary investigators
As first year MIT students, this year, we have had the experience of building a device that keeps
coffee hot for two hours, and one that heats water using solar energy. Additionally, each of us has
built several projects in high school, as part of the curriculum as well as during summer programs
and other extracurricular activities.