Do you want to build a circuit that blinks a light? This inverter-based circuit is simple, and it’s small enough to fit a breadboard.
Apart from the inverter, it only uses standard basic electronic components.
Below you’ll find the complete circuit diagram and component list.
The Circuit Diagram
In the lessons, you learned that you needed an inverter for this circuit. But there’s one important point if you want to build this:
You need to use a Schmitt-triggered inverter. It’s an inverter where the voltage at which it switches from LOW to HIGH is higher than the voltage for switching from HIGH to LOW.
You’ll find the complete circuit diagram below.
The numbers next to each pin in the diagram represent the pin number on the integrated circuit. Click here for the pinout of the 74C14 IC.
The Components You Need
| Part | Value | Note |
|---|---|---|
| – | – | Breadboard |
| U1 | 74C14 | Hex Schmitt Trigger Inverter |
| C1 | 100μF | Polarized capacitor |
| R1 | 10 kΩ | Standard Resistor |
| R2 | 470 Ω | Standard Resistor |
| LED | – | Standard output light-emitting diode |
These are pretty standard components that you can get from most places that sell parts for building electronics. I’ve creates a page with a list of where to buy electronic components.
Not sure how to build this circuit on a breadboard? Learn how to use a breadboard.
Below you can see a video of the circuit I built:
Did you build it? How did it go?
Let me know in the comments below.
Ed says
May 27, 2019 at 8:29 pmHi
I’m looking to build a Star Trek TNG TRICORDER light and sounds,
But I’m not sure how to do it. Any information you could share, would be much appreciated. Or where I could find that information. They used to sell them on eBay, but I cannot find any.
bruce hull says
July 22, 2019 at 1:14 amstill struggling with the blinking light. My energy source is a solar light for area lighting with a 3.7 volt Li-ion 800 mAh rechargeable battery. it’s currently reading 2.11 volts. I’m not sure on the pin outs of the inverter. Actually I would love a pin out on the schematic.
Bruce says
May 30, 2019 at 9:24 pmGreat information. I’m looking to have a LED blink but I want the LED to slowly light and then slowly go off. In a two second cycle loop. Any suggestions?
AlbeOutlaw176 says
June 2, 2019 at 2:39 pmYes I have a Comment why don’t you build it step by step show how to build it not just to show it light up ?
bruce hull says
June 19, 2019 at 6:16 pmOK, list the parts and where I can get them. I would have loved this sixty years ago but right now I want to finish my prioject AND I do see future projects that wil required me to dig a bit deeper.
admin says
June 20, 2019 at 2:17 pmHi Bruce,
Here’s a page with several options on where to buy the components from:
https://www.build-electronic-circuits.com/buy-electronic-components/
Best,
Oyvind
Niladri Patra says
June 26, 2019 at 1:23 pmHi,
I want to make 3v LED Flash light with LDR.
This type of light is using fishing purpose in sea.
Regards
Niladri
Ben says
July 12, 2019 at 8:45 pmI am still unsure about how the voltage interacts with the inverter. If I track the current, it leaves the positive pole of the 9V and travels directly to the inverter (at the input labelled 14). I assumed that this was the power supply to the inverter and would be constant. And that this voltage would exit through the output labelled ‘7’ and return to the battery. Is this an activating voltage that would then cause the inverter (with no initial voltage at the input labelled ‘1’) to output a voltage at ‘2’, which would loop around and cause the inverter to switch, initiating the on/off loop? Sorry if this is confusing…
admin says
July 15, 2019 at 11:51 amThe pins 14 and 7 are for powering the inverter. When the output is HIGH, it’s from here the output gets its voltage and current, yes.
bruce hull says
July 22, 2019 at 11:26 pmOK…update. I triple checked the schematic and used a couple of combinations. First I used a 9 Volt battery with the solar light and later on LED and in both setups I got a strong resulting illumination. I then used the solar panel with the 2.1 volts with both LET setups and got a average illumination result. The appears to be a slight flickering of the lights but it is very low and fast. Hard to detect at first. What is next?
Bruce
admin says
July 24, 2019 at 11:59 amCheck out the datasheet for the chip:
https://www.mouser.com/ds/2/308/mm74c14-1193355.pdf
From there you can see that the chip needs at least 3V. So 2.1 will probably give unreliable results.
bruce hull says
July 25, 2019 at 9:21 pmI appreciate your response and that makes sense regarding the voltage level but I had the same results when I substituted a nine volt battery as the power source. My power source is a yard light that comes on at night and goes off during day light hours. The light works fine in the constantly on position but I can’t get the slow on and off that I need for my project. Any suggestions as to possible substitution?
admin says
July 29, 2019 at 5:23 pmAre you saying that your circuit is not blinking when you use a 9V battery? One potential error is that the LED draws too much current. Try replacing the resistor in series with the LED with 2000 ohms.
If it’s still not working, measure the battery voltage when it’s connected to the circuit. If it’s less than 9V, you might have a battery that is almost dead. Try replacing with a new one.
bruce hull says
July 30, 2019 at 6:35 pmnew 9 v battery. I really need to get this to work with the solar panel so the batteries will recharge. the rechargeable batteries are 3.7 V. back to the drawing board.
bruce hull says
July 30, 2019 at 6:39 pmSo basically for this project to work as designed I need to use the solar panel (Wal Mart outdoor light) Which is powered by a 3.7 Li-ion battery. There’s lots of sunlight in south Mississippi. Will that work with your design?
admin says
August 14, 2019 at 4:12 pmThe circuit in this article should work fine with voltages above 3V. But you might need to adjust the resistor for the LED.
bruce hull says
August 23, 2019 at 2:36 amIt Works but it is blinking a little too fast. What rate resistor do I need to use instead of the 470?
admin says
August 23, 2019 at 9:40 amIt’s the 10k resistor or the capacitor you need to change to change the speed. You can for example try doubling the resistor value to 20k.
The 470 resistor sets the brightness of the LED.
Garry Cronin says
August 23, 2019 at 11:39 amhi Oyvind,
I notice in your “Basic Electronic Components” ebook you provide a schematic for a Blinking LED using a 555 Timer IC. Can you compare and contrast the pro’s and con’s of building it that way, compared to the way you show here in this article please?
thanks
– Garry
admin says
August 30, 2019 at 1:36 pmThe inverter uses less components. But other than that, for blinking an LED they’re pretty much the same.