Development of a system to Control Electrical Lights and Fans using TV Remote

This competency demonstration report discusses the development of a system to control electrical lights and fans using TV remote. It covers the project background, objectives, distinctive activity, identified issues and solutions, and project review. The report also includes the project group, the author's responsibilities, and collaborative work.

COMPETENCY
DEMONSTRATION REPORT
Career Episode 3

CE 3.1 Project Information
Name of the project: Development of a system to Control Electrical Lights and Fans
using TV Remote
Location of the project: [PLEASE FILL]
Project Duration: [PLEASE FILL]
Organization: [PLEASE FILL]
Role and Designation during the time: Team Member
CE 3.2 Project Background
CE 3.2.1 Characteristics of the project
Automation using the electronics have become the trend and I was looking forward for
the development of a product that could be utilized in the households for the remote management
of the electric appliances. I suggested the entire team for the delivery of a project that could
allow the control of the home appliances using the TV remote as it is widely available. I
developed the system that follows the linear profile through providing the regulation against the
input power supply. It could be used for regulating the power supply considering the variations
in the frequency of the power supply and manage the products without any additional
considerations. I controlled and used the RMS voltage adjustments for controlling the speed or
intensity of the load and controlled them using the triac circuitry through manipulating the firing
angle. I also calculated the voltage supply, monitored the identified change, and compensated
through changing the instance of firing the triac trigger pulse accordingly.

CE 3.2.2 Objectives developed for the project
I was playing the role of the lead team member in the project and hence the prior activity
was to set a path that is smooth and reliable for the rest of the team members in manner to make
sure that the delivery could be managed in an efficient and effective manner. I developed the
following set of the objectives:
 To develop a system that can control the speed or intensity of the electric fans and
lights using the general TV remote.
 To build and design a controller that is capable of controlling the fans and lights
using the serial port interface.
 To develop a sophisticated automated and remote system for controlling the
household appliances.
 To manage the team and establish an efficient and effective communication
between the different team members.
 To manage the project of the budget low as minimum as possible and make sure
that the product could be made easily and widely available for the common users.
CE 3.2.3 My area of work
I had to develop a smooth path and allow the different sectors of work for every
individuals involved in the project. I managed to divide the project into eight major components
including power supply, RD232 driver, IR receiver circuit, zero crossing detector, intensity
regulation in relation to the main voltage variation, IR decoder, Triac firing pulse generation and
TRIAC. I allotted the rest of the team members for the first five sectors and every individual

was responsible for managing the delivery of those activities. I kept the project simple and
related every activity with other for the management and delivery of the project objectives. I took
the responsibility of rest of the three activities those were of same importance as the others. I
programmed and managed the microcontrollers, IR receiver, and circuit of the entire system.
CE 3.2.4 Project Group
CE 3.2.5 My responsibilities throughout the project
As the team leader, I had great responsibility for assuring that the project is being
delivered successfully and all the objectives and scope of the project could be met efficiently. I
also considered the other team members’ association, contribution, and their comfort throughout
the project for assuring that the project could be managed smoothly. I was totally focused
towards my technical and management of the entire project and so, I followed proper document

related jobs for tracking all the ongoing activities in manner to keep a comparison or baseline of
the project. I made sure that the baseline of the project has minimum difference and so, either I
was on time for every activity or ahead of the rime without altering the expected changes in the
project.
CE 3.3 Distinctive Activity
CE 3.3.1 Comprehending the theory of the project
I used the general principle of the power controlling through the application of the
electronic knowledge and made sure that the expected operations could be delivered in an
efficient and effective way. I kept the system independent of the frequency of incoming power
supply in addition to the regulation providing against the input voltage supplies. Intensity of a
light bulb (resistive load) or speed of a fan (inductive load) is related to the RMS voltage
supplied, which can be controlled by the firing angle of the triac according to
Vrms = Vm/21/2(1- θ/Pi)0.5
I used the following block diagram for the development of the path that could possibly be
helpful and effective in motivating the employees towards the final delivery of the project:

The above figure can be described as the following statements:
• Power supply consisting of 230V/9V transformer, bridge rectifier, filter and 5 V
regulator
• RS232 level shifter for RS232 commands.
• IR receiver for TV remote control
• ADC for measuring the unregulated voltage as a measure of mains RMS value
• Zero crossing detector for generating time reference for triac firing pulses 1
• Triac circuitry (followed by load)
• A 40-pin and 20-pin microcontroller have been used to modulate the software and
hardware development.

CE 3.3.2 Engineering knowledge and skills applied in the project
I had three sections to complete the project and make sure that the final delivery of the
project that includes the IR decoder, Triac Firing Pulse Generation, and TRIAC. I used IC6, 20-
pin microcontroller AT89C2051 in manner to allow the system to receive the commands from
the IR receiver and the RS232 receiver. It was helpful and effective in decoding the output of the
IR receiver through command bits sampling in the IR signal those were being received from the
remote and set the port’s bit 1 accordingly. I assigned the following switches of the remote
control in manner to regulate the loads of the home appliances:
1. Switch 1: switch ON the second load.
2. Switch 2: switch ON the first load.
3. Switch 3: switch OFF the second load. Volume up: To increase the intensity of
the first load.
4. Switch 4: switch OFF the first load.
5. Channel up: decrease the intensity of the first load.
6. Volume down: increase the intensity of the second load
7. Channel down: decrease the intensity of the second load.
CE 3.3.3 Identified issues and their solutions
I identified that at the initial testing the system was not functioning properly as the
control of the load was not being made. There was the connection problem, as the links of the
soldering was not made properly and so, the remote was not functioning properly. I cleaned all

the connections and re-soldered all the connections that allowed the current to flow in the circuit
again and all the functions were being operated normally. I also identified that the team
management and the flow of the activities was not being managed properly and hence, I
developed proper documentation of the projects in manner to make sure that the zero crossing
detector output can be used for setting the triac firing pulses’ instants. Thereafter, I processed the
ADC output for supply voltage variation and shift the firing pulses; as it was required. The
following flow chart can explain the functioning and operating of the solution, I adopted:
CE 3.3.5 Plan to produce creative and innovative work
I used the TRIAC circuit that is a three terminal semiconductor those I used for
controlling the current in either directions. In basics, I used two SCRs back to back with the
common gate. I used it considering the supply to the triac, as it is an AC signal and will always
turn of the voltage supply whenever the applied voltage reaches to the zero at the end of the

current half-lifecycle. I used the triac for directly controlling the percentage of the power of the
half-cycle that has been applied to the load. For the instance, when the pulse is turned on and is
applied at some controllable point after the initiation of every half cycle, the direct control over
the percentage power could be gained.
CE 3.3.6 Collaborative work
Every individual was of same importance for the successful delivery of the project and
had contributed in the successful development project. I can comment that the team members
had contributed equally in the development of the project and delivered all the necessary
objectives for meeting the overall outcome of the project.
CE 3.4 Project Review
CE 3.4.1 Project Overview
I was successful in controlling the fan speed and intensity of the light bulbs through the
development of this system. I made sure that the system follows the linear profile and would be
capable of providing the regulations against the Input Power Supply Voltage. I contributed in the
development of the system that can allow the individuals to control the home appliances output. I
used PCB Printed circuit board for the implementation of the system as well.