In this project a protoype circuit which can switch on the device when the light falls on it. For this I will use LM358 IC which is operational amplifier. I have made the circuit with LDR and few more components. But when I interchange the LDR with photodiode, phototransistor and transistor (L14F1) my circuit works well without changing any other components. Before understanding the circuit which I have developed, first let’s have a look on the components used in the circuit.LM358 consists of two independent, high gain operational amplifiers in one package. Important feature of this IC is that we do not require independent power supply for working of each comparator for wide range of power supply. LM358 can be used as transducer amplifier, DC gain block etc.
Heat sensor senses the heat present around the sensor. When temperature rises above the set value, it will indicate the presence with the help of glowing LED. This heat sensor circuit can be used in kitchen or inside your PC. If your kitchen appliances or PC are over heated, it may be possible that…
This simple circuit will act as a warning alarm whenever the temperature of a device exceeds above the safety level. This circuit can be used to monitor the heat built inside the devices like your PC, inverters, CD player etc. As excessive heat may affect the sensitive component and may lead to permanent damage. The main advantage of this circuit is its compactness that’s why it can be easily install in the device itself. This circuit will also give you power on indicator of a device with the help of blinking LED. Therefore it attract your attention that device is on. This circuit uses a negative temperature coefficient (NTC) as a sensor to sense the heat. This circuit can be operated on wide range of temperature vary from 5V to 12V.
In 1910 Frank W. Wood made a board which can display number and after several modifications today it’s called 7-segment display. It is available in two configurations: common cathode and common anode. All the 8 LED terminals have their one end internally shorted and linked with the middle pins such that it serves as a common terminal (cathode or anode). 7 led are used to form the digits while the 8thone is for the dot which helps in identifying the correct orientation. It is widely used in digital clock, calculator, electronic meters and various other applications where numerical display is required. It can be used in place of dot matrix displays which are more complex than seven segment display. Seven segment displays can also be used to display some alphabets. Seven segment displays is a group of Light emitting diode (LED) arrange in figure of 8 pattern.
Relay is a very important device now days. They are used in various circuits and many of us have problem of how to use a relay. With the help of this article I have tried to explain two things firstly the Working of relay and secondly how to use a relay. As we know relay is a device which is used to provide connection between two or more points or device in response to the input signal applied. In another words relay provide isolation between the controller and the device as we know devices may work on AC as well as on DC. However, they receive signals from microcontroller which works on DC hence we require a relay to bridge the gap. Relay is extremely useful when you need to control a large amount of current or voltage with small electrical signal.
Are you ready to make your first project? If the answer is YES then you are at the right place to learn all the basics about building your project. So let’s start: Before making a new project, you require some basic tools and knowledge of how to use them to complete your project. Most important and commonly used tool which you require is soldering iron and soldering wire. You will also need some more tools like wire-cutters, wire-strippers and a pair of small pliers. Some other tools are also useful although they are not essential at starting stage. If you are beginner or doing soldering for first time, we will suggest you to use solder iron of power rating between 15-25 watts which is suitable for most of the soldering work. Higher watt soldering iron is also available in market. Keep in mind higher wattage iron does not mean that it will melt the solder wire fast.
Many of us design PCB with the information available on internet but sometimes it becomes difficult to understand the terms used in designing. In this article I have tried to explain the common terms which are used while designing PCB. PCB stands for printed circuit board. Different types of PCB materials are available in markets. Most commonly used are FR-1, FR-2, CEM-3, CEM-1 (FR=Flame Retardant and CEM= Composite Epoxy Material).Everything which you draw is on layer. Each layer has different physical properties. For example top layer is used to draw the component layout, bottom layer or inner layer are used for making connection between components and many more are also present.
Different kinds of PCB design software’s are available in market and according the requirement different users used different software. Like I am comfortable in designing my PCB on Eagle and my vendors who fabricate the PCB does not have Eagle than what will happen? Hence to bridge the gap between the PCB designer and manufacture we use gerber file. Gerber file contain information about the PCB like what will be the pad size, drill size, name of component etc. With the help of gerber file information obtained and manufacture feed the data into their machinery to manufacture PCB. The most common format that is used today is RS-274-X. But before using always check with the board manufacture. It is a good practise to check your layout before manufacturing because once it has been fabricated you cannot correct your mistake. Or it may happen that PCB will not be of any use this will lead to wastage of time and money both.
This circuit can be used in various projects where we require the counting. Like in doctors’ clinic or hospitals, in restaurants, in customer care offices where long queue is there and we want to stop the rush at the counter. This system is very effective where man power is less. In this you have to provide a token to the person and the person has to wait for its turn which can be displayed on the 7 segment display. With the help of this circuit we can maintain the silence and the person will also be informed about their turn.This circuit is based on 4026, a Johnson counter IC commonly used in digital display. It has a 5 stage Johnson decade counter with decoder which convert the Johnson code to a 7 segment decoded output
I am designing a circuit which can be controlled by TV or AC remote. For that I have purchase TSOP1738 with few more components from market. And I assemble my circuit carefully, then also I am not getting the desire output. I again rechecked my assembled circuit with the circuit diagram and I don’t find…
It is a simple circuit with the help of which you can control the speed of DC motor. You can also use it control the speed of windscreen wipers used in automobiles or it can be used in toys. Easy to install because of less components used and works well on wide range of power supply from 5V to 12V. This circuit is based on single IC that is NE555 which work as a-stable multi-vibrator. In this mode 555 timer is not stable and its output is continuously changes from low to high or from high to low. This continuous change from one state to another (high to low and then back to original state) produces a continuous square wave output.
The circuit described below is used to on and off the motor just by clicking your TV or AC remote. This low cost circuit is based on IR sensor, transistor with few more components to “on” the relay and a motor is connected with the relay which also become “on”. After receiving the second pulse motor become “off”. You can control your motor from 5-7 meters range. It can be operated with all most all the remotes present in home as it works on 38Khz frequency. You do not require to move from your place, just press the remote device become “on” and “off” respectively by getting signals from remote. The circuit also provides you the visual indication (“on” or “off”) of the device with the help of LED.
The project described below is a small model of traffic light which we daily see in our life on street. With this circuit you can control two way traffics. There will be lights on both sides, like there is red light on one side and green light will be present aautomatically on another side. It will also have yellow light to alert the passengers or drivers that now there signal are going to open.CD4017 is a 16 pin CMOS decade counter/ Divider. It take clock signal from the clock input and turn on the 10 output in sequence, each time when it receives clock input pulses.4072 is a dual 4 input OR gate. Output of OR gate goes high when any of the input goes high and if all input is low then output is also low7432 is a quad 2 input OR gate. In this also output goes high when any of the input is high and goes low when all inputs are low. 7432 contains 4 individual OR gate on single IC.
The doorbells produce a ringing alert sound so that the resident comes to know that there is somebody at the door. Many homes have two doors for entering. So, sometime it become confusing for the resident to find out on which door visitor is present. This project on doorbell circuit produces two different sounds and can be used simultaneously on both the doors. This circuit also gives a visual indicator so that deaf person can also know. For this we use different color LED for different door so that it becomes easy to know whether the visitor is present on front door or rear door. This simple circuit is based on transistor, diode, resistor and switches with few more components. Resistor is a two terminal passive component used to control the flow of current into the circuit.
CD4033 is a Johnson counter IC commonly used in digital display. It has a 5 stage Johnson decade counter with decoder which converts the Johnson code to a 7 segment decoded output. This means it will convert the input into numeric display which can be seen on 7 segment display or with the help of LED’s.Advantage of this IC is it can be operated at high voltage of 20V because it is highly sensitive and it can detect EMF presence in the atmosphere and it is sensitive to static charge also.When you touch the input terminal with finger, counter get’s started.Therefore care should be taken while using it. It can be used in various applications like in 7 segments decimal display circuit, in clocks, timer etc.
There are times when it is difficult to judge the distance while reversing the car or while parking. If someone is there to help you that is great but in situations when you are driving alone then what will you do? Or you are a new driver and cannot judge the distance? This circuit will solve all these problems. You can easily install at the back side of your car. Operated at 5V power supply and can also recharge batteries. You can also use them as shadow alarm at doors to protect your car. When shadow of a intruder fall on it will also give you alarm. This alarm will provide you the musical sound that’s why it will not tease your ears. Main components of this circuit areLM358 IC, LDR, UM66 IC, speaker and few more discrete components.LM358 consist of two independent, high gain operational amplifier in one package. Important feature of this IC is we do not require independent power supply for working of each comparator for wide range of power supply.
The circuit described here stops the musical sound when darkness is detected like when you put your hand above the sensor. This circuit can be used as morning alarm. Install it on your window so when the light falls on it will start giving you melodious sound to wake up. In night you can use it to switch off the light of staircase. When you switch off the light of your room with little modification like you can connect relay at output (in place of speaker) to off the bulb. This circuit can be operated with pencil cell as it require less only 3V for its operation. It can easily be mounted because of number of components used in circuit are quite small. LDR is a device whose sensitivity depends upon the intensity of light falling on it.
Seven segment displays nowadays are commonly used in place of dot matrix display. They have found their use in places like microwave or fancy toaster oven or the same on washing machine but before using them in all these places you need to interface the 7 segment display with microcontroller or some more hardware will be required. But with the basic knowledge of 7 segments display you can use it in front of your shop or you can display your name on it. 7 segment displays numbers from 0 to 9 and some alphabets.7 segment display are labelled a to g and decimal point is usually known as DP. DP is the common point. In common cathode display they are connected to ground and rest pin are connected to supply. Similarly in common anode DP are connected to supply and rest are connected to ground. You can also use more than one display according to your requirement.
While driving car, Before taking a turn it is a good practise to use the indicator, which will not only alert the other vehicle driver nearby you but reduces the chances of accident as well. But if your vehicle indicator is not working well then you can use this simple circuit. In night many accident took place because of less traffic, high speed and casual driving. We forget to use indicator and speeding vehicle behind you or from opposite side does not get time to slow or stop their vehicle. Therefore the use of indicator is always required in driving and while turning. This small circuit can also be used for two wheeler even in bicycle. Main advantage of this circuit is, it will not only give a visual indicator but also give you a buzzer sound while turning left or right.
Water level controllers are quite common nowadays. This circuit is based on popularly used IC555 IC. Water level controller circuits have these advantages: Mostthe circuit only display the amount of water present in circuit, but this circuit will “on” and “off” the motor according to the level of water present in tank. It will not automatically stop the motor when tank is fill but it will “on” the motor when water in tank reaches below a specific point. It can be easily installed in over headed tanks because of less components used in circuits. It prevents the wastage of water due to over flow of tank. Can be operated with the help of 12V battery or adaptors (converts 230V AC to 12V DC) readily available in markets.