Introduction: 555 Timer Delay Circuit

About: MAGNUM TECHNICAL ACADEMY is an education institute, that base its activities to the enrichment and enhancement of technical knowledge to her students, through a practical justification of the explained theorie…

The use of time delay switching, and the effects; once its not integrated in a system where needed, cant be over emphasized.

We have taken through this course, to explain the essence and use of time delay switching in electronics and electrical engineering.

Step 1: Review the YouTube Video

The step to step DIY video is presented on the YouTube ,you can watch it.

Step 2: Overview

We classified the topology of developing a time delay switch circuit into three.

- The first topology, utilizes passive electronics components.

- The second topology,which uses integrated circuits chips, such as the 5 5 5 timer I C chip. We will focus on this topology in this video.

- The third and last topology,which uses a micro-controller chips, where in our development was AT-mega 3 2 8, which is commonly found in Arduino board.

We will delve directly into the second topology,and see how it can be configured.

Step 3: Operations

5 5 5 timer I C is a versatile electronics chip,one can easily come across. Its uniqueness is got from its capacity of acting in different ways such as,
- oscillator
- timer
- memory space and many more preset you can make.

The 2nd topology unlike the 1st topology, its easy to implement,and if you have not read the 1st topology, I will recommend you do so, in order to grasp the fundamentals of TIME DELAY SWITCHING.

Back to the 2nd topology, 5 5 5 I C chips can be configured in two modes which are

- Astable mode and
- Mono-stable mode

Step 4: Astable Mode

In astable mode,the I C functions to generate an oscillating signal, that can be preset using the RC coupling. Which include R1,RV1,and C2.

From the setup we have on the bread board, the I C is configured in astable mode, and you can see the led showing the oscillation. The oscillation coming out of the output pin 3 of the chip have the red LED glow once the signal goes HIGH and the yellow LED glow once the signal goes LOW.

The fraction of time the output the output is high is given by the mathematical formula as shown.
T high/ T high-T low
The relationship is what is called DUTY CYCLE. More about that on another video.

The frequency of the oscillation can be adjusted by varying the potentiometer.
As you can see, as the resistance is adjusted,the speed and the frequency changes.

This is all you need to know for now about astable mode.

Step 5: Monostable Mode

In mono stable mode, the chip acts as a timer.
The process of the timing function is best understood using the chip internal circuit diagram.

We wont delve into that in this video,since we will publish an explanatory video specially for the chip.

Mono stable circuit offers only one stable state,when triggered at the pin 2. the duration for the triggered state is dependent on the values of RV1 and C2 , from the circuit.
With the circuit presented, the maximum time the chip can delay is 1 minute and 10 secs using this formula…

In configuring 5 5 5 timer I C in any mode, it is recommended to use 10 kilo ohm to 14 mega ohm resistor and capacitor value of 100 pico farad to 1000 micro farad for optimal performance.
We will develop the circuit by ,first assembling the components.
Next, withe the presented circuit, we start to implement…

After soldering, we have the system look like this...

Step 6:

Step 7: Test

We connect the circuit to the generator system switch and test the delay performance, setting the delay to 1 minute.
The circuit worked exactly as per design, and that makes it amazing.

Step 8: Recommendation

You can always set the duration to longer time less than 4 hours. As that is the extent the chip can go.

Remember to check the previous topology and the next topology which we made using ARDUINO.

Step 9: Thought Share

Which of this topology is your preferred choice in terms of,

-Low cost
-And easy adjustment

Leave your answer in the comment box below.
If you find this video of help leave a like, and share your thought with us on the comment box, as we will love to go through them.

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