The success of any creation is often dependent on the foundations it is built upon, be it the strength of a character, depth of a building’s foundations or the extent of a tree’s roots. Much in the same way, the success of any electronic device depends on what it is built on. The motherboard of any electronics device serves as a playground and a host to every form of electrical signal that performs some function for the equipment. A Printed Circuit Board doesn’t just connect electrical components using etched copper pathways, but also provides mechanical strength to it. Printed Circuit Boards are found in almost all of the commercial products as a packaging medium as building blocks.
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.
In this project a mobile/battery charger is made by using voltage divider rule. Voltage divider is also known as a potential divider. Potentiometer having two resistor in it is the best example of a voltage divider rule. This charger has reference voltage lower than the input voltage. Using voltage divider any voltage can be derived by it by passing high voltage than the voltage we want. This is because output voltage which comes out is always lesser. Voltage dividers are used for adjusting the level of a signal, for bias of active devices in amplifiers and for measurement of voltages. A Wheatstone bridge and a multimeter both include voltage dividers. A potentiometer is used as a variable voltage divider in the volume control of a radio, in finding temprature, in battery charger, in loud speaker etc.