Hi All, I am Emmanuel Katto.

I'm trying to design a simple LED flasher circuit using a 555 timer IC. The goal is to create a circuit that flashes an LED on and off at a frequency of around 1 Hz. I've been searching online for tutorials and examples, but I'm having trouble understanding how to choose the correct resistor values and capacitor values for my circuit.

Here's my current design:

• 555 timer IC (IC1)
• 1kΩ resistor (R1) connected between pin 3 and pin 6
• 10kΩ resistor (R2) connected between pin 2 and ground
• 100nF capacitor (C1) connected between pin 2 and ground
• 1kΩ resistor (R3) connected between the LED and pin 3
• LED (D1) connected between the output of the 555 timer and ground

When I power the circuit, the LED doesn't flash at all. I'm not sure what's going wrong or how to adjust my design to get the desired flashing behavior.

Questions:

1. Is my circuit design correct, or am I missing something important?
2. How do I choose the correct resistor values (R1, R2, R3) for my circuit?
3. What is the optimal value for the capacitor (C1) to achieve a flashing frequency of around 1 Hz?

I would appreciate any help or guidance on how to troubleshoot and fix my design.

Thanks in advance!
Emmanuel Katto

 

Welcome to AAC.

First—a narrative of the hookup is not going to encourage anyone to help you vet your circuit. You need to draw a schematic.

Second—there are an endless supply of online 555 timer calculators that will give you the proper values for your circuit. AAC has a very complete page of tools here. It has everything you need to answer the questions you’ve asked and more.

If after visiting that page you have more specific questions, please do ask them. There are many people ready to help but if you make it hard for them (e.g.: narrating your wiring instead of drawing it out, asking open-ended and vague questions that appear easily answered by your own efforts) you will find few volunteers.

Take a look at the link above, if it fails to answer a question you have, come back and ask it with an explanation of why you can’t answer it with that information and I am certain you will find help immediately.

Again, welcome, thanks for joining us. Good luck!

 

When you are trying a circuit, you MUST work from a circuit diagram, and if you want help you MUST show the circuit diagram you are working from.

Your verbal description of your circuit translates to the following diagram, which will not work for a number of reasons, and I am sure is not what you intended to produce:

Even if you have only a poor photo of a hand-drawing of your circuit, it is infinitely better than a verbal description.

 

To answer your design queries, here is the datasheet for the 555.

https://www.ti.com/lit/ds/symlink/lm555.pdf

Selection of suitable components for astable operation is covered in section 7.4.2.

 

When I power the circuit, the LED doesn't flash at all.

The very first time I built an LED flashing circuit with the 555 mine didn't flash at all either. Well, not true. It was flashing ON and OFF so fast that it looked like it was on all the time.

As others are encouraging you - draw a schematic. If you can't do it electronically like on a computer you can still draw it on a piece of paper and take a picture of it. Then upload the picture.

 

I was able to easily construct a sketch of the circuit from the description, and it seems that both the power positive and negative connections were not stated. Actually, the written description is better than some of the wiring diagrams that have been presented by others in the past.
But certainly most of the folks here work best with actual circuit schematics.

 

Here's my current design:

• 555 timer IC (IC1)
• 1kΩ resistor (R1) connected between pin 3 and pin 6
• 10kΩ resistor (R2) connected between pin 2 and ground
• 100nF capacitor (C1) connected between pin 2 and ground
• 1kΩ resistor (R3) connected between the LED and pin 3
• LED (D1) connected between the output of the 555 timer and ground

How about a schematic instead of word salad?

This is what I got from @Ya’akov's link

That's a terrible "schematic" for anyone who hasn't memorized pin function... And a terrible symbol...

 

That's a terrible "schematic"

Sorry I didn't come up to your high standards of excellence.