In addition, we'll see some important points about the topic in DID YOU KNOW sections.
Whenever we rush toward any road that has a heavy flow of vehicles, we always follow some traffic rules. One of the most fundamental traffic rules is to follow the traffic lights. These traffic lights direct the vehicles to start or stop moving at the road according to our turn. These turns are decided by the Traffic Lights. The traffic Lights show the different colored lights and these lights turn on and off in a sequence. We know all these things, but we are revising these to get the logic behind the scene. we define the Traffic Lights technically as:
"The traffic lights are the combination of three LEDs colored as red, amber and green that are connected in a specialized circuit that gives the output from the LEDs in a specific format and this format is used to control the flow of traffic."
These LEDs are enclosed in a metallic body. Traffic Light signals are so useful that 99% of the countries use them. This makes the circuit one of the most fundamental and common circuits to understand.
There are many devices through which the Traffic Lights may be controlled. Out of which, two are common:
We have discussed the 1st method in our previous tutorial, Let's have a look at the next one.
before starting the simulation, let's have a look at its components briefly. The circuit of Traffic Lights uses a very common yet powerful device i.e, 555 Timer IC. The 555 Timer is so useful that it is said that annually, a billion of 555 Timers are produced and it is considered as the most popular IC of the year 2017. We introduce the 555 Timer as:
"The 555 Timer is a common 8 pins Integrated Circuit used in a variety of oscillation generators and Timers to generate a pulse of the signals that control the output sequentially."
In our experiment, we'll apply the Mono-stable Multi-vibrator mode of the 555 timer. The output of 555 Timer in this mode is in the form of a single pulse of current that has a specific length. This pulse is sometimes called the one-shot pulse.
The 4017 is the special IC that is usually coupled with the 555 Timer. It works on the pulse generated by the 555 Timer and the definition for the 4017 IC is given as:
Once the clock pulse of 4017 IC in the traffic Lights goes from low to high, the IC started its cycle again and we get a sequential Logic output. The pins 3 to 12 of the 4017 IC Counter are said to be the output pins of the 4017 and we'll connect the traffic lights with them.
DID YOU KNOW?????????????????????????????
It is said by AAA, the average American spends 58.6 hours every year waiting at the red light of traffic signal.
Component | Values |
C1 | 0.01uF |
C2 | 47uF |
C3 | 6.8nF |
R1 | 23k ohm |
R2 | 10k ohm |
R3 | 22K ohm |
R4 | 100k ohm |
R5 | 100 ohm |
R6 | 100 ohm |
So, today we saw a fantastic circuit in which we learned that what are the Traffic lights signal using 555 timer, how does the ICs of 555 timer and 4017 IC Counter work with each other to show the output of the Traffic Lights and we designed the circuit of 555 Timer Traffic Lights in Proteus ISIS. If you have any questions, you can contact us through the comment sections.DID YOU KNOW????????????????
The working speed of the Traffic Lights can be varied by changing the values of capacitors connected with pin 5 and 2 of the 555 Timer IC.
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