Automatic light/dark activated systems have very common utilities in day to day life. For example, street lighting at night, morning alarm, automatic emergency [[wysiwyg_imageupload::]]light, dark activated buzzers and so on. The project explained here can be used in several such systems. This circuit has a sensor component which works in response to the ambient light condition. The output of this sensor is compared with a set reference value and whenever the light condition changes from dark to light or light to dark, the output goes high. In this project, the surrounding illumination is observed by a light dependent resistor (LDR) which acts as a sensor for the circuit. The voltage drop across this LDR corresponds to a particular intensity of light. Read on more to find out how the circuit is made and how it works.
Today many accidents occur because everyone is in hurry and we do not see the signal and crosses the railway line. So to solve this we can install this simple circuit which will give an red indicator when train is nearby and green indicator when train goes away from platform. For this we are using the reed switch as sensor.An indication of red and green light is done with the help LED. You can also modify this circuit to use bulb in place of LED so that it can be seen from distance.
Battery level indicator will let you know the status of battery of a device just by glowing the number of LED’s. For example four LED’s are glowing means battery capacity is 40 percent. You can use this circuit with your inverter or with your car battery; it will give you indication about your battery status. So before your battery dies you can recharge it.Advantage of this circuit is it does not require power supply; it will take power supply from the battery of the device itself. This simple circuit is based on single IC LM3914 with few more discrete components. LM3914 is a monolithic integrated circuit which senses the analog voltage and derives 10 LED’s providing a linear analog display.
The water level indicator is used to measure the level of water present in the tank. This circuit not only indicates the amount of water present in overhead tank [[wysiwyg_imageupload::]]but it also gives an alarm when the tank is full. Water level indicator gives you an indication on 7 segment display by displaying E, P and C for empty, partially fill and completely fill, respectively.Water level indicator also gives you a display in the form of LED connected to it, you can also connect different color LED to distinguish the level of water present in it.The circuit is built around two IC’s namely 7408, 7404, 7 segment common cathode display and few more components. IC7408 is Quad two input AND gate and IC7404 is a hex inverting gate.
The circuit depicted in the article can be used as an indicator in vehicles. Here two identical circuits are used one for left and the other for right. This project can [[wysiwyg_imageupload::]]be installed in our vehicles when the indicators are not working. Even in Bi-cycles at the place of inbuilt indicators that works manually.IC555 is the most versatile chip and it is (can be) used in all most every kind of application because of its multifunctionality. As we know it’s on chip multivibrator means with IC555 one can design astable, monostable, bistable multivibrators. Its main applications are to generate timings, clock waveform, generate synchronizing signals, square wave oscillator and many more. Read more to find out how the circuit is designed and how it can be made to work.
The project illustrated below helps to find out nearby person or vehicle and make them visible to one another. It can be used in various applications for [[wysiwyg_imageupload::]]pedestrians, runners, bicyclists, motorcyclists, vehicles etc.Most of the time during the night when the roads are badly lit the risk of accidents increases. Sometimes it happens that our vehicle breaks down and we need help. In such conditions this reflector can be used which automatically gets turned ON when it receives light from another vehicle passing nearby. The circuit is based on 555 timer IC and uses a NE555 version of it. Keep on reading to find out how the circuit is designed and how it works.
Embedded Systems are widely used nowadays. Applications of the embedded system are innumerable. One such application as discussed here is Lift Overload Indicator. As the name implies, it restricts the elevator from transporting a number of people above the maximum prescribed limit.The indicator used here is RGB led to indicate the warning signs. Moreover, it also displays the net number of people in the elevator using an LCD in 4-bit mode. The counting of the person is accomplished by using two IR sensors. We know that using the three primary colours Red, Blue and Green, any secondary colour can be obtained. The RGB led uses the same principle. Different colours are generated by mixing of different intensities of the three primary colours. Keep on reading to find out how the project is assembled and tested.