Circuit Flow Process

Generally, the circuit given by the demonstrator is shown as diagram above. Actually this circuit is act as auto switch, which can switch the load on or off automatically. For this circuit, the light dependent resistor (LDR) will give the command to the 555 timer IC. The command is send to the timer when got shadow or no lights fall on the LDR. The timer will receive the command on the pin 2, which is trigger input. The timer will process the input and give the output to the relay. The timer required a period of time to receive the input and a period the time to process the output. The time can be calculated by multiplied the resistor (R₂) with the capacitor (C₁) and In3. The output command will control the coil on the relay, which it can switch on the load or switch off the load. The load will switch off when no light fall on the LDR and switch on when got the light flow on the LDR.

Daily report (2/10/09)

Activities:
-Try to stimulate the given circuit using the circuit maker again.
-The circuit constructed is testing again before starting the soldering work.
-Try to find out the problems and obstacles during the testing and try to solve it.

Place:
Laboratory 1st year for Electric and Electrical (Faculty Engineering and Building Environment)

Date:
2 Oktober 2009

Time: 10.30am-12.30pm
3pm-5pm

Task leader:
Chong Kim Soon

Assistant:
Yii Wen Wen

Working flow process:

This is the fourth day we doing our project. First, we started to stimulate the given circuit using circuitmaker again. Unfortunately, the lucky star seem like don’t stand at our side, the problems we faced yesterday still occur. Without any hestitation, we skipped stimulation part and going on other works in order to save our times.

Before soldering, we test the circuit we constructed yesterday again. After testing no problems, we started our soldering jobs. Basically, soldering work is quite challenging and exciting and somehow our hand may shake when soldering the components. But still the soldering work is managed to finish in times.

The component which is construct on the copper board.

The process of solidering

Then, we tested the circuit again. LED is observed for its brightness. Successfully, LED is on with the red colour lamp then the circuit is considered successful.

Finally, we troubleshooting the circuit and the stimulation part in order to solve the problems we obtained.

*RUSH…RUSH… RUSH!!! Whole day full with rush and hurry!! Since the laboratory don’t open on Saturday and Sunday, we need to rush to the end today in order to complete our laboratory’s works. Thanks for everyone who giving any help and cooperation to us in completing our works~

Tomorrow will be a brand new day for all of us, just wait and feel what will be the amazing things will happen and it may change your whole life!!

Daily report (1/10/09)

Activities:
-Stimulate the given circuit using the software(circuit maker).
-Construct the given circuit using the equipments provided in the laboratory.
-Compare the results with the stimulation values.
-Try to find out the problems and obstacles during the testing and try to solve it.

Place:
Laboratory 2nd year for Electric and Electrical ( Faculty Engineering and Building Environment)

Date:
1 Oktober 2009

Time: 10.30am-12.30pm
2.30pm-5pm

Task leader:
Chong Kim Soon

Assistant:
Yii Wen Wen

Working flow process:

First, we construct the given circuit using the circuit maker to obtain the theoretical values. However, we unsuccessful to stimulate the circuit because the relay part cannot operate in normal way. It take quite long time for us to find the problems and we decided to do hardware first then will settle the stimulation part after that.

We construct the hardware of the circuit and testing using the equipments IDL and testing. LED which as an output is observed for its brightness. If LED is on with the colour lamp then the circuit is considered successful.

Getting the actual value of the component .

This picture which show all the equipment that we used.

Construct the circuit on the breadboard.

Finally, we make the hardware successfully been constructed. We troubleshooting the circuit and the stimulation part in order to solve the problems we obtained.

*What an tiring day!! But the lucky is we manage to get the output LED to light up. And about the stimulation part and the soldering work, left it for next day’s worries.

The earth will still going on even though you face some obstacles in your life~
The only way to manage the obstacles well is to having an optimistic mind~
Hopefully the lucky star will bless us all with its special power *^^*

Description of the circuit components

General description

This circuit is build by using resistor, capacitor, relay, high speed diode, 555 IC timer, and light dependent resistor (LDR).
The main component of this circuit is the 555 IC timer. This timer will control the entirely circuit which it will making the circuit be a switch.

Component description

555 timer IC

Diagram A

Diagram B

Generally the 555 timer IC is an integrate circuit (chip) as show as above diagram A and also the pin number in the diagram B. It use in implementing a variety of timer and multivibrator application. Depending on the manufacture, the standard 555 package include over 20 transistor, 2 diode and 15 resistor on a silicone chip installed in an 8 pin mini dual-in-line package (DIP-8). The internal schematic is show as below.

Explanation of the pin of the IC

Nr.	Name	Purpose
1	GND	Ground, low level (0V)
2	TRIG	A short pulse high-to-low on the trigger starts the timer
3	OUT	During a timing interval, the output stays at +VCC
4	RESET	A timing interval can be interrupted by applying a reset pulse to low (0V)
5	CTRL	Control voltage allows access to the internal voltage divider (2/3 VCC)
6	THR	The threshold at which the interval ends (it ends if U.thr → 2/3 VCC)
7	DIS	Connected to a capacitor whose discharge time will influence the timing interval
8	V+, VCC	The positive supply voltage which must be between 3 and 15 V

Normally the 555 timer IC has three operating mode that is :

(A) Monostable mode

In this mode, the 555 function as a “one-shoot”. Application include timers missing pulse detection, bouncefree switches, frequency divider, capacitance measurement, pulse-width modulation (PWM) etc.

(B) Astable mode

Free running mode : the 555 can operate as an oscillator. Uses include LED and lamp flashers, pulse generation, logic clocks tone generation, security alarms, pulse generation, logic clocks, tone generation, security alarms, pulse position modulation, etc.

(C)Bistasble modes or Schmitt trigger

The 555 can operate as a flip-flop, if the DIS pin is not connected and no capacitor is used. Uses include bouncefree latched switches, etc.

High-speed diode

For this circuit, we are using the 1N4148 high-speed switching diodes fabricated in planar technology, and encapsulated in hermetically sealed glass SOD27 (DO-35) packages. This diode contain maximum speed 4ns, maximum continuous reverse voltage 100V, maximum repetitive peak reverse voltage 100V, and maximum repetitive peak forward current 450mA which get from the data sheet.

Light dependent resistor (LDR)

Light Dependent Resistors are very useful especially in light/dark sensor circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000000 ohms, but when they are illuminated with light resistance drops dramatically.

Relay

A relay is an electrical operated switch. Electrical current through the coil of the delay creates a magnetic field that attracts a leaver and changes the switch contacts. The coil current can be on or off so relays have two switch position and they have to switch position and they are double-throw ( changeover ) switches.The general concept of this circuit diagram is shown as below.

Actual relay design’s diagram is also shown as below.

For this mini project, we are using 5-pins relay. A 5-PIN relay has a single control circuit, but two separate current paths for the switch: one when the relay is de-energized (OFF – no current through the coil) and the other the energized (ON – current is flowing continuity. When the 5-PIN relay is de-energized (OFF), pins 4 and 5 have continuity. When the relay is energized (ON), pins 3 and 5 have continuity.

Problem statement of the project~~

Problem statement :
The purpose of this circuit is we need to use application of the light sensor and the timer component to switch to another load in the faster speed. The light sensor circuit that can act as the switch for the circuit and also for the load, it can switch the circuit and the load on and off in a faster speed. This circuit most probably is designed for the security system and the trigger camera. This is because the circuit can detect the change of the light by using the sensor in order to give the instruction for the load and let the load to operate it function.

*We should really appreciate this application since this application bring lots of advantages to us in making our lives easier~ Thanks for the inventor!!!

Main + sub-objectives of the project~

Main objective :
To learn and apply the function of 555 timer IC in the real world application

Sub-objectives:
a)To learn the function and the operation of the 555 timer IC.
b)To investigate the flow and the functionality of the circuit.
c)To learn simulating the circuit by using the software.
d)To work the project in a team and finish it systematically.
e)To learn to work out the project in the lab by using the component according to the given circuit diagram

Daily report (30/9/2009)

Activities:
-Discuss about the main,sub-objective,and problem statement of the mini project.
-To find the solution for the main, sub-objective and problem statement.
-To find the additional source and information about the project.
-Take the components and measure the true value of the resistance and capacitance.
-Update the blog.

Place:
Faculty Engineering and Environment Building

Date:
30 September 2009

Time:
11.00am-12.30pm

Task leader:
Yii Wen Wen

Assistant:
Chong Kim Soon

Working flow process:
First, we start to discuss about the main and sub-objective of the mini project. We refer to the information we found from the internet and textbook to understand the flow of the circuit and the application of the circuit.

After that, we take our components from the laboratory. Then, we measure the true value of the resistance and the capacitance. Besides, we take some photo for the components and some photo when we measure the resistance and capacitance.

Finally, we update our blog by uploading the pictures and the main, sub-objectives and the problem statement of our mini projects.

Tomorrow we will try to stimulate the circuit in the circuitmaker and trying the functionality of the circuit in the lab.

Wish the process of the our project can be moving on very well~~

Daily report (29/9/2009)

Activities:
-Discuss with each other to create a blog.
-To add the information into the blog and email it to the demonstrator.
-To find the source and information for the project.
-To find the solution for the main, sub-objective and problem statement.

Place:
Perpustakaan Tun Seri Lanamg (PTSL)

Date:
29 September 2009

Time:
8.00pm-9.30pm

Task leader:
Yii Wen Wen

Assistant:
Chong Kim Soon

Working flow process:
First, we starting to discuss the way to create the blog and the name for the blog URL. After that we start the do the theme and the basic information of our blog. The blog URL’s name and the theme was settle while the information of the project was upload by Chong Kim Soon.

After that, we try to find the information about the project from the internet and we also find some reference from the book in the PTSL. We are trying to understand the working process of the circuit.

For the main, sub-objective and the problem statement, we both agree to
complete it by tomorrow, because we both are not familiar with some part
of the component inside the circuit diagram.

*First day of starting to do the mini project, quite exciting and worrying about the processing of the project, but we will sure put all our effort in this project in order to make it sucessfully~~

YEAH, let start the LIGHT SENSITIVE TRIGGER project!!

INTRODUCTION OF THIS BLOG

This blog is described about the KL2092 Electrical and Electronics Laboratory 1 project. Chong Kim Soon (A121937) and Yii Wen Wen (A122674) are in charge of this project. We are undergraduate student from National University of Malaysia (UKM) and taking course Electrical and Electronic Engineering. We will upload the working flow process and the daily report into this blog.

The title of this project is Light Sensitive Trigger. The circuit is shown as below. The circuit contains capacitor, resistors, light dependent resistor (LDR), diode, and the relay. We will explain of this circuit in deeply for the coming post.