The circuit of traffic lights in my opinion is a series of easy-hard-easy to make.
Where we are required to be able to condition the flame of three lamps by following the existing traffic regulations. If we use computer programming as a regulator of the third condition of the lights probably we will not spend too much time to make it. As an example with microcontroller programming or programming-based computer applications such as Visual Basic, Delphi and many others. But if you use a common electronic circuit components used may be somewhat time consuming to get the results you are fully in accordance with the conditions of traffic lights that use the streets.
Well ... if you're looking for examples of a series of simple traffic light above the range can I recommend to you. The working principle of a series of traffic light above is very easy to understand. The series of above use the output from IC up / down counter 74 190 as the producer output tercacah and then conditioned using logic gates so that the logic in accordance with the logic of the actual traffic light. Actually you can also use the IC counter ups as pencacahnya. Red lights are represented by the LED D1, D2 and yellow by green led by led D3.
LIST OF COMPONENTS:
Resistors: R1 (1 Kohm), R2, R3 and R4 (220 ohms) and VR1 (Potensio 10 K / 15 K)
Capacitors: C1 (100 UF)
Led: D1 (red), D2 (yellow) and D3 (green).
Integrated Circuit: IC1 (NE 555), IC2 (74LS190) and IC3 (74LS02)
HOW TO WORK AND ANALYSIS OF CIRCUIT LIGHT TRAFFIC:
To generate the signal used peggerak counter circuit astable circuit IC555.
R1, C1 and VR1 is a combination astable as a determinant of the speed of the clock signal to be inserted to the input counter and in the end will determine the length of time the flame of their lamps. The greater the value of the three clock cycles will stay longer and vice versa.
To obtain a combination of LEDs required only 2 bits output from the counter circuit.
Bit-3 from the output to the counter only be used as reset the enumeration.
The lamp was first lit the light yellow color, due to connect with the output Q1 of counter IC. Then followed by a red lamp that is connected to the output Q2. Then both (yellow and red) light simultaneously. The last green light will turn on its own.
The series of bit counter counts up with the sequence:
- 0 1 (light yellow light)
- 1 0 (red light)
- 1 1 (light yellow and red lights)
- 0 0 (light turned green, according to the nature of the gate NOR)
Examples of traffic light sequence apply only to one lane for traffic light circuit that uses more than one line then you can use the same circuit device and use a combination of gates as a liaison between the conditions of each lane. This means you should make a longer red light is illuminated on each other point for point which it operates. These conditions can be achieved by utilizing a combination of logic gates in a chain.