Simple LED Blink Circuit




About: Wood working and electrical engineering....oh yeah and building stuff

This instructable is to show you how to blink and a LED with a simple circuit. I feel like sometimes we get lost in the over complexities of micro controllers and this project is made to remind you that simple projects can still be done via analog means.

Step 1: What You Will Need

Step 2: Prototyping

This circuit is a free-running pulse generator. The pulse rate is determined by the capacitor and the time in between pulses is determined by the 1k ohm resistor(brown-black-red). Increasing or decreasing the value of the 1k resistor will change the span of time in between each flash. I recommend using a bread board to prototype the circuit so you can play around with the different values for the resistors and capacitors to find the speed of the flashing that you like.

Step 3: Finalizing the Prototype

This step is simply transferring the breadboard prototype onto a more permeant solution, like the perfboard shown here. I would recommend starting off with the IC socket then adding the nessary wires. Make sure the wires have insulation as it could cause a short and your LED wouldn't blink.

Step 4: Purpose of This Project

Alright ill admit it seeing an LED blink isn't that exciting. Its what you do with it. Adding a red Led to the eyes of a pumpkin or maybe even a santa hat. But something a bit more interesting is that this circuit could run a relay and with a relay you could power an entire string of christmas lights or a lamp for a haunted house. Since this project is very easy and cheap to make it could be a fun prank on a friend(or enemy) to put a bunch of them in their house. The possibilities are truly endless, But the main purpose of this projects was originally to show that you can still do some cool things without an arduino or raspberry pie.

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    4 Discussions


    1 year ago


    Uber late comer here. I an thinking of using this circuit to control directional light and 4 way flashers on a scale model. Instead of the USB could I use a 9v battery? I would also like to hook it up to two different switches. One an On/Off/On and the other a Push on Push off. Can I do that all through the same circuit?


    2 years ago

    im new in the eletronc hobby ill try it sims hard


    2 years ago

    I never thought of it like that, but yes you could use this circuit as a tester for other 555timers and LEDs.


    2 years ago

    Well your circuit is more then a simple blinking LED. You now also made a 555 chip tester. By simply pulling out the existing 555 chip and inserting an unknown one you can now determine good 555's from bad ones. And if you also use a socket for the LED, you can also use it as an LED tester. So one seemingly simple circuit becomes a testing project for other parts as well. Thumbs Up!