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Traffic light control system project simulation

Traffic Light Control System Design Project Traffic lights, also known as traffic signals, traffic lamps, traffic semaphore, signal lights, stop lights and robots, and also known technically as traffic control signals are signaling devices positioned at road intersections, pedestrian crossings and other locations to control competing flows of traffic. The first manually operated gas lit traffic light was installed in 1868 in London, though it was short-lived due to explosion. The first safe, automatic electric traffic lights were installed in the United States starting in the late 1890s Traffic lights alternate the right of way accorded to road users by displaying lights of a standard colour (red, yellow, and green) following a universal colour code. In the typical sequence of colour phases: the green light allows traffic to proceed in the direction denoted, the yellow light provides warning that the signal will be changing from green to red. Actions required by drivers v...

Operation of relay types

What is relay? It is switch that provides the safety to an electrical circuits from the abnormal conditions. Relay has two parts which is NO ( normally open ) and NC ( normally close ).  NO means the circuit are normally open, In this conditions the electric supply does not passes through the circuit due to the open circuit conditions. This type of relays are use in mechanical devices like hoist and manipulator for controlling. NC means the circuit is normally close, In this conditions the electric current can flow through the circuit due to the circuit is close And this relay coil is use as On switches in mechanical devices like hoist and manipulators.

Programming temperature sensor with microcontroller

Interfacing LM35 temperature sensor with PIC microcontroller An LM35 temperature sensor senses the temperature and produces Analog signals which is fed to a microcontroller which interprets the result. The microcontroller used here contains an Analog to Digital Converter (ADC) which receives the signals from the LM35 and produces a corresponding digital signal and the value of the temperature displayed on an LCD. Application: Room temperature control Egg incubator Dryers e.g. cocoa dryers, Green agriculture, etc. Materials: An LM35 A PIC 16F877A Two relays 2 transistors BC549 2 protective diodes (fly-back diodes) A Fan A heater A 16x2 LCD Supply DC 5/12V, AC 230V Circuit diagram of LM35 temperature sensor interface with microcontroller The circuitry is shown below Operation Lets control the temperature such that if the temperature is less than 25 degree Celsius, the heater is put ON and the fan OFF. If the temperature is about 25 degree Celsius, the...

Interfacing a relay using a microcontroller

Interfacing a relay circuit with a PIC microcontroller We are going to see how to interface a relay to a PIC micro controller. But before that, you need to know what is a relay. A relay is a switching device which permits the switching of a load in a circuit or to a supply. The advantage of using a relay is due to the fact that, this device can permit the switching of high loads in circuits. Before interfacing a relay in a circuit, the relay must be chosen to suit the supplying circuit and the required load. For example, th ere are relays which operate at 5V, 6V, 12V, etc. and having a maximum load current and voltage rating. Materials PIC 16F877A, 5V relay, 5V DC source, 1 BC547 transistor, 1 diode 1N4148, 230V AC load (heater), 230V AC source, 8MHz Crystal Oscillator, 2 ceramic capacitors, 2 resistors, 1 push button. Circuit diagram of relay with microcontroller The circuit diagram is shown below. The relay is connected to PORTC of the microcontroller at Pin...

What is Touch Potential?

What is Touch potential? You often came across the term step and touch potential, but you never new what's all about. Grab it now. Touch potential is the potential generated across a conductive body or object to the earth, when the conductive body contacts or touches a live wire. So, current flow through the conductive body from the live wire to the earth.  This can occur due to earth failure and inappropriate earthing in an installation. Other causes exist. To illustrate this, we are going to see some common examples. How touch potential is generated 1) A person touching a poorly earthed conductive part during earth failure. E.g touching the metallic part of towers, machines, etc during earth failure. 2) Live TV media antenna buses mistakenly touching live wires in transmission lines. 3) Excavators and lifters mistakenly touching a transmission line Those are just some few examples of how touch potential is generated. So, electrical tec...