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Friday, February 9, 2018
Sunday, July 10, 2016
Working of Refrigerator & Refrigeration Principle
Refrigeration technology is commonly used in domestic and industrial applications. This video gives a detailed and logical introduction to the workings of refrigerators using the vapor compression cycle.
The Basic Principle
The basic principle of refrigeration is simple. You simply pass a colder liquid continuously around the object that is to be cooled. This will take heat from the object. In the example shown, a cold liquid is passed over an apple, which is to be cooled. Due to the temperature difference, the apple loses heat to the refrigerant liquid. The refrigerant in turn is heated due to heat absorption from the apple.
It is clear that, if we can produce cold liquid refrigerant continuously, we can achieve continuous refrigeration. This simple fact forms the core of the refrigeration technology. We will next see how this is achieved.
Components of Refrigerator & Working
An inside view of a refrigerator is shown.
Fig.2 An inside view of a refrigerator
It has 4 main components: compressor, condenser, evaporator, and throttling device. Of these components, the throttling device is the one that is responsible for the production of the cold liquid. So we will first analyze the throttling device in a detailed way and move on to the other components.
Throttling Device
The throttling device obstructs the flow of liquid; cold liquid is produced with the help of this device. In this case, the throttling device is a capillary tube. The capillary tube has an approximate length of 2 m and an inside diameter of around 0.6 mm, so it offers considerable resistance to the flow.
Fig.3 A Capillary tube: This results in sudden drop in pressure and temperature
For effective throttling at the inlet, the refrigerant should be a high-pressure liquid. The throttling device restricts the flow, which causes a tremendous pressure drop. Due to the drop in pressure, the boiling point of the refrigerant is lowered, and it starts to evaporate. The heat required for evaporation comes from the refrigerant itself, so it loses heat, and its temperature drops. If you check the temperature across the throttling device, you will notice this drop.
It is wrong to say that the throttling is a process. We know only the end points of throttling, that is, the states before and after throttling. We don’t know the states in between, since this is a highly irreversible change. So it would be correct to call throttling a phenomenon rather than a process.
Evaporator - Heat Absorption Process
The next phase is simple: this cold liquid is passed over the body that has to be cooled. As a result, the refrigerant absorbs the heat. During the heat absorption process, the refrigerant further evaporates and transforms into pure vapor. A proper heat exchanger is required to carry the cold refrigerant over the body. This heat exchanger is known as an evaporator.
Fig.4 Cold liquid is passed through a heat exchanger know as evaporator for absorbing heat from the refrigerator
So we have produced the required refrigeration effect. If we can return this low-pressure vapor refrigerant to the state before the throttling process (that is the high-pressure liquid state), we will be able to repeat this process. So first step, let’s raise the pressure.
Compressor
A compressor is introduced for this purpose. The compressor will raise the pressure back to its initial level. But since it is compressing gas, along with pressure, temperature will also be increased. This is unavoidable.
Fig.5 A compressor is used to raise pressure of the refrigerant
Now the refrigerant is a high-pressure vapor. To convert it to the liquid state, we must introduce another heat exchanger.
Condenser
This heat exchanger is fitted outside the refrigerator, and the refrigerant temperature is higher than atmospheric temperature. So heat will dissipate to the surroundings. The vapor will be condensed to liquid, and the temperature will return to a normal level.
Fig.6 Condenser heat exchanger is fitted outside the refrigerator so it will reject heat to the surroundings
So the refrigerant is back to its initial state again: a high-pressure liquid. We can repeat this cycle over and over for continuous refrigeration. This cycle is known as the vapor compression cycle. Refrigeration technology based on the vapor compression cycle is the most commonly used one in domestic and industrial applications.
Refrigeration Accessories
You can find more details on refrigerator components here. Evaporators and condensers have fins attached to them. The fins increase the surface area available for convective heat transfer and thus will significantly enhance heat transfer.
Fig.7 Fins attached to the condenser and evaporator
Since the evaporator is cooling the surrounding air, it is common that water will condense on it, forming frost. The frost will act as an insulator between the evaporator heat exchanger and the surrounding air. Thus it will reduce the effectiveness of the heat removal process. Frequent removal of frost is required to enhance the heat transfer. An automatic defrosting mechanism is employed in all modern refrigerators.
More on Compressor
Apart from raising the pressure, the compressor also helps maintain the flow in the refrigerant circuit. Usually, a hermetically sealed reciprocating type compressor is used for this purpose. You might have noticed that, your household refrigerator consumes a lots of electricity compared to the other devices. In a vapor compression cycle, we have to compress the gas; compressing the gas and raising pressure is a highly energy intensive affair. This is the reason why the refrigerator based on the vapor compression refrigeration technology consumes a lot of electricity.
Coefficient of Performance
The heat and power transfer happening in a vapor compression refrigeration circuit is shown below.
Fig.8 Energy interaction happening in a refrigeration system
A simple energy balance of the system yields the following relationship.
It is often required to evaluate performance of a refrigerator or compare between different refrigeration technologies. A term called Coefficient of Performance (C.O.P) helps in doing this. To understand this term completely, we need to know what is the input and output of a refrigeration system. What we need from a refrigerator is the cooling effect. Or QABSORBED is the output of a refrigeration cycle. Input to the refrigerator is the power given to the compressor. So the term C.O.P can easily be defined as output by input and is expressed as follows.
The Basic Principle
The basic principle of refrigeration is simple. You simply pass a colder liquid continuously around the object that is to be cooled. This will take heat from the object. In the example shown, a cold liquid is passed over an apple, which is to be cooled. Due to the temperature difference, the apple loses heat to the refrigerant liquid. The refrigerant in turn is heated due to heat absorption from the apple.
It is clear that, if we can produce cold liquid refrigerant continuously, we can achieve continuous refrigeration. This simple fact forms the core of the refrigeration technology. We will next see how this is achieved.
Components of Refrigerator & Working
An inside view of a refrigerator is shown.
Fig.2 An inside view of a refrigerator
It has 4 main components: compressor, condenser, evaporator, and throttling device. Of these components, the throttling device is the one that is responsible for the production of the cold liquid. So we will first analyze the throttling device in a detailed way and move on to the other components.
Throttling Device
The throttling device obstructs the flow of liquid; cold liquid is produced with the help of this device. In this case, the throttling device is a capillary tube. The capillary tube has an approximate length of 2 m and an inside diameter of around 0.6 mm, so it offers considerable resistance to the flow.
Fig.3 A Capillary tube: This results in sudden drop in pressure and temperature
For effective throttling at the inlet, the refrigerant should be a high-pressure liquid. The throttling device restricts the flow, which causes a tremendous pressure drop. Due to the drop in pressure, the boiling point of the refrigerant is lowered, and it starts to evaporate. The heat required for evaporation comes from the refrigerant itself, so it loses heat, and its temperature drops. If you check the temperature across the throttling device, you will notice this drop.
It is wrong to say that the throttling is a process. We know only the end points of throttling, that is, the states before and after throttling. We don’t know the states in between, since this is a highly irreversible change. So it would be correct to call throttling a phenomenon rather than a process.
Evaporator - Heat Absorption Process
The next phase is simple: this cold liquid is passed over the body that has to be cooled. As a result, the refrigerant absorbs the heat. During the heat absorption process, the refrigerant further evaporates and transforms into pure vapor. A proper heat exchanger is required to carry the cold refrigerant over the body. This heat exchanger is known as an evaporator.
Fig.4 Cold liquid is passed through a heat exchanger know as evaporator for absorbing heat from the refrigerator
So we have produced the required refrigeration effect. If we can return this low-pressure vapor refrigerant to the state before the throttling process (that is the high-pressure liquid state), we will be able to repeat this process. So first step, let’s raise the pressure.
Compressor
A compressor is introduced for this purpose. The compressor will raise the pressure back to its initial level. But since it is compressing gas, along with pressure, temperature will also be increased. This is unavoidable.
Fig.5 A compressor is used to raise pressure of the refrigerant
Now the refrigerant is a high-pressure vapor. To convert it to the liquid state, we must introduce another heat exchanger.
Condenser
This heat exchanger is fitted outside the refrigerator, and the refrigerant temperature is higher than atmospheric temperature. So heat will dissipate to the surroundings. The vapor will be condensed to liquid, and the temperature will return to a normal level.
Fig.6 Condenser heat exchanger is fitted outside the refrigerator so it will reject heat to the surroundings
So the refrigerant is back to its initial state again: a high-pressure liquid. We can repeat this cycle over and over for continuous refrigeration. This cycle is known as the vapor compression cycle. Refrigeration technology based on the vapor compression cycle is the most commonly used one in domestic and industrial applications.
Refrigeration Accessories
You can find more details on refrigerator components here. Evaporators and condensers have fins attached to them. The fins increase the surface area available for convective heat transfer and thus will significantly enhance heat transfer.
Fig.7 Fins attached to the condenser and evaporator
Since the evaporator is cooling the surrounding air, it is common that water will condense on it, forming frost. The frost will act as an insulator between the evaporator heat exchanger and the surrounding air. Thus it will reduce the effectiveness of the heat removal process. Frequent removal of frost is required to enhance the heat transfer. An automatic defrosting mechanism is employed in all modern refrigerators.
More on Compressor
Apart from raising the pressure, the compressor also helps maintain the flow in the refrigerant circuit. Usually, a hermetically sealed reciprocating type compressor is used for this purpose. You might have noticed that, your household refrigerator consumes a lots of electricity compared to the other devices. In a vapor compression cycle, we have to compress the gas; compressing the gas and raising pressure is a highly energy intensive affair. This is the reason why the refrigerator based on the vapor compression refrigeration technology consumes a lot of electricity.
Coefficient of Performance
The heat and power transfer happening in a vapor compression refrigeration circuit is shown below.
Fig.8 Energy interaction happening in a refrigeration system
A simple energy balance of the system yields the following relationship.
It is often required to evaluate performance of a refrigerator or compare between different refrigeration technologies. A term called Coefficient of Performance (C.O.P) helps in doing this. To understand this term completely, we need to know what is the input and output of a refrigeration system. What we need from a refrigerator is the cooling effect. Or QABSORBED is the output of a refrigeration cycle. Input to the refrigerator is the power given to the compressor. So the term C.O.P can easily be defined as output by input and is expressed as follows.
Air Conditioning Circuit and Cycle Diagram
The component at #1 in this air conditioning circuit and cycle
diagram is the compressor.
The compressor is the heart of the system; it keeps the refrigerant flowing through the system at specific rates of flow, and at specific pressures.
It takes refrigerant vapor in from the low pressure side of the circuit, and discharges it at a much higher pressure into the high side of the circuit.
The rate of flow through the system will depend on the size of the unit,
And the operating pressures will depend on the refrigerant being used and the desired evaporator temperature.
The component at #2 in this air conditioning circuit and cycle diagram is the condenser.
The red dots inside the piping represent discharge vapor.
The solid red color represents high pressure liquid refrigerant.
Most air cooled air conditioning and refrigeration systems are designed so that the refrigerant will condense at a temperature about 25 to 30 degrees above outside ambient air temperature.
When the hot refrigerant vapor discharged from the compressor travels through the condenser, the cool air flowing through the condenser coil absorbs enough heat from the vapor to cause it to condense.
If the outside air temperature is 80 degrees, the system is designed so that the temperature of the refrigerant, right at the point where it first condenses, will be about 105 to 115 degrees.
Why do we want the refrigerant to condense at this relatively high temperature?
So that the air will be very cold relative to the temperature of the discharge vapor,
Which will allow the latent heat energy in the vapor to transfer over to that relatively cold air,
And cause the refrigerant to condense.
This transfer of heat from the vapor to the flowing air is what makes hot air blow out of your air conditioner's condensing unit.
At this stage in the air conditioning circuit and cycle diagram, high pressure liquid refrigerant will flow down the liquid line, through a filter drier that is designed to prevent contaminants from flowing through the system, and on to the metering device.
The metering device, component #3 on this air conditioning circuit and cycle diagram, is the dividing point between the high pressure and low pressure sides of the system,
And is designed to maintain a specific rate of flow of refrigerant into the low side of the system.
If the wrong capacity of metering device is used, or if there is a problem with the metering device,
An incorrect quantity of refrigerant will flow into the evaporator.
When the refrigerant passes through the metering device, it drops from about 225 psi to about 70 psi,
It also drops in temperature from about 110 degrees to about 40 degrees,
It starts evaporating immediately,
And it wouldn't be too inaccurate to imagine it acting like warm soda when you shake the bottle and pop the top off.
It shoots out into the evaporator foaming, bubbling, and boiling,
And remember, it's at a low pressure, so it's only boiling at about 40 degrees F.
And that brings us to the evaporator, component #4 in the air conditioning circuit and cycle diagram.
There will be relatively warm air flowing over the evaporator coil, lets say about 80 degrees.
The air conditiong system is designed so that the refrigerant will evaporate in the evaporator at a temperature of about 40 degrees, so that it will be cold compared to the warm air flowing over it.
The system is designed so that the heat in the warm air flowing over the evaporator will be absorbed by the cold evaporating refrigerant.
This cools the air flowing over the evaporator, and is the reason cold air blows out of your air conditioner.
I hope this air conditioning circuit and cycle diagram has helped you understand air conditioning systems, and once again, feel to copy it and print it out.
Performance Testing
Compound Gauge (Low Side)
•The compound gauge derives its name from its function. It will register both pressure or vacuum.
•All air conditioning systems can, under certain conditions, drop from a pressure into a vacuum on the low side. It is necessary that a gauge be used that will show either pressure (psi and kPa) or inches of mercury vacuum (Hg.).
•The vacuum side of the gauge must be calibrated to show 0 to 30 inches (0 to 762 mm) Hg. The pressure side of the gauge must be calibrated to register accurately from 0 pressure to a minimum of 60 psi (414 kPa).
•The maximum reading of the pressure should not exceed 160 psi (1103 kPa). Practically all readings of the low side of the system will be less than 60 psi (414 kPa) with the system in operation.
High Pressure Gauge (High Side)
•The high pressure gauge is used to determine pressures in the high side of the system.
•The gauge is calibrated to register accurately from zero pressure to a minimum of 300 psi (2070 kPa).
•A few systems operate under high head pressure during normal operation conditions. This is why the high pressure gauge should have a reading of at least 600 psi (4140 kPa).
Gauge Manifold
•The gauge manifold mounts the high and low side gauges and connects the gauges into the high and low sides of the system by means of test hoses.
•The gauges connect to the upper part of the manifold through holes drilled and tapped to a 1/8-inch pipe thread.
•Test hose connectors below the gauges on the lower side of the manifold direct the refrigerant through the manifold to the gauges to obtain pressure readings.
•A center test hose connector on the lower side of the manifold is connected to both pressure gauges and the test hoses by a passage in the manifold.
•Refrigerant flow into the high and low side is controlled by a shutoff hand valve at each end of the manifold.
Basic Refrigeration Cycle
Theory of Refrigeratiion Cycle
Principles of Refrigeration
•Liquids absorb heat when changed from liquid to gas
•Gases give off heat when changed from gas to liquid.
For an air conditioning system to operate with economy, the refrigerant must be used repeatedly. For this reason, all air conditioners use the same cycle of compression, condensation, expansion, and evaporation in a closed circuit. The same refrigerant is used to move the heat from one area, to cool this area, and to expel this heat in another area.
•The refrigerant comes into the compressor as a low-pressure gas, it is compressed and then moves out of the compressor as a high-pressure gas.
• The gas then flows to the condenser. Here the gas condenses to a liquid, and gives off its heat to the outside air.
•The liquid then moves to the expansion valve under high pressure. This valve restricts the flow of the fluid, and lowers its pressure as it leaves the expansion valve.
•The low-pressure liquid then moves to the evaporator, where heat from the inside air is absorbed and changes it from a liquid to a gas.
•As a hot low-pressure gas, the refrigerant moves to the compressor where the entire cycle is repeated.
Note that the four-part cycle is divided at the center into a high side and a low side This refers to the pressures of the refrigerant in each side of the system
Monday, June 27, 2016
Sunday, March 10, 2013
How to change USB drive icon ?
Are you tired of seeing that old and classic USB icon in My Computer ?
Do you wish to change your USB thumb drive’s icon to something cool and amazing ? In this article I will teach you the simple and cool computer trick to change USB drive icon of any pen drive.
To make you aware what this trick is all about, let us take an example of CDs. Sometimes when you insert any branded CD or DVD in your optical drive of your computer, you must have seen that drive icon of CD/DVD ain’t the default icon, which used to come earlier. Instead, the icon shown next to drive name in My Computer is similar to brand logo of CD or DVD which you had purchased. That’s what this article is all about, in this article you will learn to make your own ICON and set it to default icon of your USB Pen drive and make it look cool.
So, here we go,
Initial steps of changing USB drive icon :
Take or create one square image which you want to set as thumb drive icon exactly of 60×60 or 90×90 pixels
Convert your image into .ICO extension file
Once you have followed above step and your image of .ico extension is ready, you have to follow the next section
To change icon of USB drive, follow the given steps :
Step 1: Insert your USB thumb drive in your computer
Step 2: Open your USB pen drive from My Computer and paste the .ico file which you created earlier in root directory(and not in any folder) of your pen drive.
Step 3: Once you have pasted the .ico image in your thumb drive, rename the same image to fav.ico
Step 4: Launch Notepad and type the following code in Notepad
Step 5: Once you have type-in the above code in Notepad, save the file in your USB pen drive with file type as All files and save the file with name autorun.inf in thumb drive. Again, save the file in root directory and NOT in any folder of your pen drive.
That’s it, now the next time when you will insert your pen drive in computer, you will find it appearing with the icon which you pasted in it earlier.
If you face any issue when performing this trick and need help or if you want to share you experience with this trick, please do leave a reply.
Enjoy!
Do you wish to change your USB thumb drive’s icon to something cool and amazing ? In this article I will teach you the simple and cool computer trick to change USB drive icon of any pen drive.
To make you aware what this trick is all about, let us take an example of CDs. Sometimes when you insert any branded CD or DVD in your optical drive of your computer, you must have seen that drive icon of CD/DVD ain’t the default icon, which used to come earlier. Instead, the icon shown next to drive name in My Computer is similar to brand logo of CD or DVD which you had purchased. That’s what this article is all about, in this article you will learn to make your own ICON and set it to default icon of your USB Pen drive and make it look cool.
So, here we go,
Initial steps of changing USB drive icon :
Step 1: Insert your USB thumb drive in your computer
Step 2: Open your USB pen drive from My Computer and paste the .ico file which you created earlier in root directory(and not in any folder) of your pen drive.
Step 3: Once you have pasted the .ico image in your thumb drive, rename the same image to fav.ico
Step 4: Launch Notepad and type the following code in Notepad
[AutoRun]
ICON=fav.ico
Step 5: Once you have type-in the above code in Notepad, save the file in your USB pen drive with file type as All files and save the file with name autorun.inf in thumb drive. Again, save the file in root directory and NOT in any folder of your pen drive.
That’s it, now the next time when you will insert your pen drive in computer, you will find it appearing with the icon which you pasted in it earlier.
If you face any issue when performing this trick and need help or if you want to share you experience with this trick, please do leave a reply.
Enjoy!
How to disable autorun feature ?
You must be thinking why an article on – Steps to disable autorun feature ? Well, there is no harm in thinking that way but there is surely a harm by keeping autorun feature enabled.
If you go and ask you security expert to tell something about autorun feature then he will say It’s better not to have one. The biggest threat to computer, as you know are viruses and spyware. Most of the computer get infected from viruses because of connecting infected pen drive or loading infect disc. There are viruses of type called autorun viruses. These type of viruses get executed automatically withing a seconds of getting host pen drive connected to an uninfected computer i.e. they start automatically.
These viruses make copy of themself in your computer and infect it severely. They are able to automatically execute themselves because of autorun feature of Windows. In this article you will learn way of disabling Autorun Feature in your PC.
Before going ahead I want to inform you that the few person of Windows don’t come with Group Policy Editor(GPEDIT) preinstalled, and since this is important for this tweak I want you to first press WinKey+R and type gpedit.msc,,
To disable autorun feature and stay protected from autorun viruses, follow the given steps :-
Step 1: Goto Start and then goto Run or press WindowsKey+R on your computer
Step 2: Type gpedit.msc and then press Enter key
Step 3: Local Group Policy Editor window will appear on your screen
Step 4: Now Expand Computer Configuration -> Administrative Templates, by using navigation panel present on left side and select option System under it
For few operating system Turn off Autoplay appears in Windows components instead of System
Step 5: Look for option Turn off Autoplay in Right hand side of window
Step 6: Right click on Turn off Autoplay option and select properties or click edit
Step 7: Now enable the option – Turn off Autoplay on
Step 8: Make sure All drives option is selected in drop down menu
Step 9: Click on Apply
Step 10: Click on OK button
That’s it! You have now disabled autorun feature in your computer and you will be about safe from autorun viruses. But don’t forget that performing this trick will protect you from all the viruses, it’s just a small measure you took and therefore keep updating your Antivirus program regularly.
If you go and ask you security expert to tell something about autorun feature then he will say It’s better not to have one. The biggest threat to computer, as you know are viruses and spyware. Most of the computer get infected from viruses because of connecting infected pen drive or loading infect disc. There are viruses of type called autorun viruses. These type of viruses get executed automatically withing a seconds of getting host pen drive connected to an uninfected computer i.e. they start automatically.
These viruses make copy of themself in your computer and infect it severely. They are able to automatically execute themselves because of autorun feature of Windows. In this article you will learn way of disabling Autorun Feature in your PC.
Before going ahead I want to inform you that the few person of Windows don’t come with Group Policy Editor(GPEDIT) preinstalled, and since this is important for this tweak I want you to first press WinKey+R and type gpedit.msc,,
Step 1: Goto Start and then goto Run or press WindowsKey+R on your computer
Step 2: Type gpedit.msc and then press Enter key
Step 3: Local Group Policy Editor window will appear on your screen
Step 4: Now Expand Computer Configuration -> Administrative Templates, by using navigation panel present on left side and select option System under it
For few operating system Turn off Autoplay appears in Windows components instead of System
Step 5: Look for option Turn off Autoplay in Right hand side of window
Step 6: Right click on Turn off Autoplay option and select properties or click edit
Step 7: Now enable the option – Turn off Autoplay on
Step 8: Make sure All drives option is selected in drop down menu
Step 9: Click on Apply
Step 10: Click on OK button
That’s it! You have now disabled autorun feature in your computer and you will be about safe from autorun viruses. But don’t forget that performing this trick will protect you from all the viruses, it’s just a small measure you took and therefore keep updating your Antivirus program regularly.
Thursday, March 7, 2013
ELECTRONICS STREET LIGHT SWITCH
Here is a simple, expensive and easy to use electronics street light switch using LDR and NE555. The working of this circuit is truly based on light sensing, i.e. automatic turn it on in night (no sunlight available) and turn It off at sunshine (sunlight available).
In this power supply section the work of step-down transformer is done by register R1 and further rectification to change into 9.1V dc is by diode D1 and zener diode ZD1. The output voltage across zener diode is further filtered by capacitor C1 and C2.
The another section of street light is switching section built around light-dependent register LDR1 with the help of transistor T1 through T3 and timer IC NE555 (IC1), where LDR1 is used as sensor of this switching circuit.As in day time the resistance of LDR1 remain low but it is reverse in night time i.e. high resistance is offered by LDR1. For this property of LDR1 the timer IC used in this circuit is as inverter. So, high input at pin 3 is provided by low input at pin 2 and vice-versa. Lastly, this inverter is used to turn street bulb B1 on with the help of triac (triac is activated).
The transistor T1 and T2 is remain cut-off to make pin 4 and pin 8 of IC1 low due to light fall on LDR1 during day time. Due to this transistor T3 is also cut-off and trigger voltage is not received by IC1 through pin 2. As a result the output voltage at pin 3 is low which does not activate triac and the street bulb does not glow.
Circuit Description of Electronics street light switch
As electronics street light switch is a switching circuit so, for more detail we can divide this circuit into two section i.e. power supply and switching circuit.In this power supply section the work of step-down transformer is done by register R1 and further rectification to change into 9.1V dc is by diode D1 and zener diode ZD1. The output voltage across zener diode is further filtered by capacitor C1 and C2.
The another section of street light is switching section built around light-dependent register LDR1 with the help of transistor T1 through T3 and timer IC NE555 (IC1), where LDR1 is used as sensor of this switching circuit.As in day time the resistance of LDR1 remain low but it is reverse in night time i.e. high resistance is offered by LDR1. For this property of LDR1 the timer IC used in this circuit is as inverter. So, high input at pin 3 is provided by low input at pin 2 and vice-versa. Lastly, this inverter is used to turn street bulb B1 on with the help of triac (triac is activated).
The transistor T1 and T2 is remain cut-off to make pin 4 and pin 8 of IC1 low due to light fall on LDR1 during day time. Due to this transistor T3 is also cut-off and trigger voltage is not received by IC1 through pin 2. As a result the output voltage at pin 3 is low which does not activate triac and the street bulb does not glow.
PARTS LIST
Resistors (all ¼-watt, ± 5% Carbon)
R1 = 10 KΩ/10-watt
R2 = 33 KΩ
R3 = 39 KΩ
R4, R6, R7 = 10 KΩ
R5 = 100 Ω
Capacitors
C1, C5 = 0.1 µF
C2 = 1000 µF/25V
C3 = 10 µF/25V
C4 = 0.01 µF
Semiconductors
IC1 = NE555 timer IC
T1, T3 = BC548
T2 = 2N2222
ZD1 = 9.1V/0.5V
D1 = 1N4001
Triac1 = BT136
LED1 = RED color
Miscellaneous
LDR1 = light-dependent resistor
F1 = Fuse, 5A
B1 = 100W/ 230V AC
SW1 = On/off Switch
NOKIA UNIVERSAL CODES
NOKIA
Nokia Universal Codes
Code Description :
These Nokia codes will work on most Nokia Mobile Phones
(1) *3370# Activate Enhanced Full Rate Codec (EFR) – Your phone uses the best sound quality but talk time is reduced my approx. 5%
(2) #3370# Deactivate Enhanced Full Rate Codec (EFR) OR *3370#
(3) *#4720# Activate Half Rate Codec – Your phone uses a lower quality sound but you should gain approx 30% more Talk Time.
(4) *#4720# Deactivate Half Rate Codec.
(5) *#0000# Displays your phones software version, 1st Line : Software Version, 2nd Line : Software Release
Date, 3rd Line : Compression Type.
(6) *#9999# Phones software version if *#0000# does not work.
(7) *#06# For checking the International Mobile Equipment Identity (IMEI Number).
(#pw+1234567890+1# Provider Lock Status. (use the “*” button to obtain the “p,w”and “+” symbols).
(9) #pw+1234567890+2# Network Lock Status. (use the “*” button to obtain the “p,w”and “+” symbols).
(10) #pw+1234567890+3# Country Lock Status. (use the “*” button to obtain the “p,w”and “+” symbols).
(11) #pw+1234567890+4# SIM Card Lock Status. (use the “*” button to obtain the “p,w” Go to Topand “+” symbols).
(12) *#147# (vodafone) this lets you know who called you last.
(13) *#1471# Last call (Only vodofone).
(14) *#21# Allows you to check the number that “All Calls” are diverted to
(15) *#2640# Displays security code in use.
(16) *#30# Lets you see the private number.
(17) *#43# Allows you to check the “Call Waiting” status of your phone.
(18) *#61# Allows you to check the number that “On No Reply” calls are diverted to.
(19) *#62# Allows you to check the number that “Divert If Unreachable (no service)” calls are diverted to.
(20) *#67# Allows you to check the number that “On Busy Calls” are diverted to.
(21) *#67705646# Removes operator logo on 3310 & 3330.
(22) *#73# Reset phone timers and game scores.
(23) *#746025625# Displays the SIM Clock status, if your phone supports this power saving feature “SIM Clock Stop
Allowed”, it means you will get the best standby time possible.
(24) *#7760# Manufactures code.
(25) *#7780# Restore factory settings.
(26) *#8110# Software version for the nokia 8110.
Go to Top
(27) *#92702689# Displays – 1.Serial Number, 2.Date Made, 3.Purchase Date, 4.Date of last repair (0000 for no
repairs), 5.Transfer User Data. To exit this mode you need to switch your phone off then on again. ( Favourite )
(28) *#94870345123456789# Deactivate the PWM-Mem.
(29) **21*number# Turn on “All Calls” diverting to the phone number entered.
(30) **61*number# Turn on “No Reply” diverting to the phone number entered.
(31) **67*number# Turn on “On Busy” diverting to the phone number entered.
(32) 12345 This is the default security code.
press and hold # Lets you switch between lines
NOKIA5110/5120/5130/5190
IMEI number: * # 0 6 #
Software version: * # 0 0 0 0 #
Simlock info: * # 9 2 7 0 2 6 8 9 #
Enhanced Full Rate: * 3 3 7 0 # [ # 3 3 7 0 # off]
Half Rate: * 4 7 2 0 #
Provider lock status: #pw+1234567890+1
Network lock status #pw+1234567890+2
Provider lock status: #pw+1234567890+3
SimCard lock status: #pw+1234567890+4
NOKIA 6110/6120/6130/6150/6190
IMEI number: * # 0 6 #
Software version: * # 0 0 0 0 #
Simlock info: * # 9 2 7 0 2 6 8 9 #
Enhanced Full Rate: * 3 3 7 0 # [ # 3 3 7 0 # off]
Half Rate: * 4 7 2 0 #
NOKIA3110
IMEI number: * # 0 6 #
Software version: * # 0 0 0 0 # or * # 9 9 9 9 # or * # 3 1 1 0 #
Simlock info: * # 9 2 7 0 2 6 8 9 #
NOKIA 3330
*#06#
This will show your warranty details *#92702689#
*3370#
Basically increases the quality of calling sound, but decreases battery length.
#3370#
Deactivates the above
*#0000#
Shows your software version
*#746025625#This shows if your phone will allow sim clock stoppage
*4370#
Half Rate Codec activation. It will automatically restart
#4370#
Half Rate Codec deactivation. It will automatically restart
Restore Factory Settings
To do this simply use this code *#7780#
Manufacturer Info
Date of Manufacturing *#3283#
*3001#12345# (TDMA phones only)
This will put your phone into programming mode, and you’ll be presented with the programming menu.
2) Select “NAM1″
3) Select “PSID/RSID”
4) Select “P/RSID 1″
Note: Any of the P/RSIDs will work
5) Select “System Type
” and set it to Private
6) Select “PSID/RSID” and set it to 1
7) Select “Connected System ID”
Note: Enter your System ID for Cantel, which is 16401 or 16423. If you don’t know yours,
ask your local dealer for it.
 Select “Alpha Tag”
9) Enter a new tag, then press OK
10) Select “Operator Code (SOC)” and set it to 2050
11) Select “Country Code” and set it to 302 for Canada, and 310 for the US.
12) Power down the phone and power it back on again
ISDN Code
To check the ISDN number on your Nokia use this code *#92772689#
Nokia Universal Codes
Code Description :
These Nokia codes will work on most Nokia Mobile Phones
(1) *3370# Activate Enhanced Full Rate Codec (EFR) – Your phone uses the best sound quality but talk time is reduced my approx. 5%
(2) #3370# Deactivate Enhanced Full Rate Codec (EFR) OR *3370#
(3) *#4720# Activate Half Rate Codec – Your phone uses a lower quality sound but you should gain approx 30% more Talk Time.
(4) *#4720# Deactivate Half Rate Codec.
(5) *#0000# Displays your phones software version, 1st Line : Software Version, 2nd Line : Software Release
Date, 3rd Line : Compression Type.
(6) *#9999# Phones software version if *#0000# does not work.
(7) *#06# For checking the International Mobile Equipment Identity (IMEI Number).
(#pw+1234567890+1# Provider Lock Status. (use the “*” button to obtain the “p,w”and “+” symbols).
(9) #pw+1234567890+2# Network Lock Status. (use the “*” button to obtain the “p,w”and “+” symbols).
(10) #pw+1234567890+3# Country Lock Status. (use the “*” button to obtain the “p,w”and “+” symbols).
(11) #pw+1234567890+4# SIM Card Lock Status. (use the “*” button to obtain the “p,w” Go to Topand “+” symbols).
(12) *#147# (vodafone) this lets you know who called you last.
(13) *#1471# Last call (Only vodofone).
(14) *#21# Allows you to check the number that “All Calls” are diverted to
(15) *#2640# Displays security code in use.
(16) *#30# Lets you see the private number.
(17) *#43# Allows you to check the “Call Waiting” status of your phone.
(18) *#61# Allows you to check the number that “On No Reply” calls are diverted to.
(19) *#62# Allows you to check the number that “Divert If Unreachable (no service)” calls are diverted to.
(20) *#67# Allows you to check the number that “On Busy Calls” are diverted to.
(21) *#67705646# Removes operator logo on 3310 & 3330.
(22) *#73# Reset phone timers and game scores.
(23) *#746025625# Displays the SIM Clock status, if your phone supports this power saving feature “SIM Clock Stop
Allowed”, it means you will get the best standby time possible.
(24) *#7760# Manufactures code.
(25) *#7780# Restore factory settings.
(26) *#8110# Software version for the nokia 8110.
Go to Top
(27) *#92702689# Displays – 1.Serial Number, 2.Date Made, 3.Purchase Date, 4.Date of last repair (0000 for no
repairs), 5.Transfer User Data. To exit this mode you need to switch your phone off then on again. ( Favourite )
(28) *#94870345123456789# Deactivate the PWM-Mem.
(29) **21*number# Turn on “All Calls” diverting to the phone number entered.
(30) **61*number# Turn on “No Reply” diverting to the phone number entered.
(31) **67*number# Turn on “On Busy” diverting to the phone number entered.
(32) 12345 This is the default security code.
press and hold # Lets you switch between lines
NOKIA5110/5120/5130/5190
IMEI number: * # 0 6 #
Software version: * # 0 0 0 0 #
Simlock info: * # 9 2 7 0 2 6 8 9 #
Enhanced Full Rate: * 3 3 7 0 # [ # 3 3 7 0 # off]
Half Rate: * 4 7 2 0 #
Provider lock status: #pw+1234567890+1
Network lock status #pw+1234567890+2
Provider lock status: #pw+1234567890+3
SimCard lock status: #pw+1234567890+4
NOKIA 6110/6120/6130/6150/6190
IMEI number: * # 0 6 #
Software version: * # 0 0 0 0 #
Simlock info: * # 9 2 7 0 2 6 8 9 #
Enhanced Full Rate: * 3 3 7 0 # [ # 3 3 7 0 # off]
Half Rate: * 4 7 2 0 #
NOKIA3110
IMEI number: * # 0 6 #
Software version: * # 0 0 0 0 # or * # 9 9 9 9 # or * # 3 1 1 0 #
Simlock info: * # 9 2 7 0 2 6 8 9 #
NOKIA 3330
*#06#
This will show your warranty details *#92702689#
*3370#
Basically increases the quality of calling sound, but decreases battery length.
#3370#
Deactivates the above
*#0000#
Shows your software version
*#746025625#This shows if your phone will allow sim clock stoppage
*4370#
Half Rate Codec activation. It will automatically restart
#4370#
Half Rate Codec deactivation. It will automatically restart
Restore Factory Settings
To do this simply use this code *#7780#
Manufacturer Info
Date of Manufacturing *#3283#
*3001#12345# (TDMA phones only)
This will put your phone into programming mode, and you’ll be presented with the programming menu.
2) Select “NAM1″
3) Select “PSID/RSID”
4) Select “P/RSID 1″
Note: Any of the P/RSIDs will work
5) Select “System Type
” and set it to Private
6) Select “PSID/RSID” and set it to 1
7) Select “Connected System ID”
Note: Enter your System ID for Cantel, which is 16401 or 16423. If you don’t know yours,
ask your local dealer for it.
 Select “Alpha Tag”
9) Enter a new tag, then press OK
10) Select “Operator Code (SOC)” and set it to 2050
11) Select “Country Code” and set it to 302 for Canada, and 310 for the US.
12) Power down the phone and power it back on again
ISDN Code
To check the ISDN number on your Nokia use this code *#92772689#
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