555 timer with LED time on= time off

Parts List

LM555 timer

6.8k ohms resistor

100k potentiometer

10micro farad capacitor

.01microfarad capacitor

LED

Schematic Diagram

 LM555 timer pin lay out

Assembly instructions

First start by inserting the chip into the breadboard. Next, make power and ground connections to the chip. It is typically a good habit to have red wire be exclusively power and black exclusively ground so if problems arise, you can easily pick out where power and ground is traveling but it is up to you of what you are going to use. Add the LED from pin 3 on the chip to ground. Insert the potentiometer anywhere on the board. Then wire pin 2 to pin 6. The 10μF capacitor can then be connected from pin 2 or pin 6 (because they are both connected with same wires) to ground. I used pin 2 because that side of the chip is closest to ground. Connect the .01μF capacitor from pin 5 to ground. Connect the potentiometer to pin 6 and pin 7. Pin 6 should be should be connected to the middle pin on the potentiometer and pin 7 should be connected to one of the outer pins. The final step is to add the resistor to the circuit. Then try plugging power from 3-9 volt battery into the board. If the LED seems to stay lit instead of blinking, that is okay. What the LED is really doing (in most cases) is blinking so fast that it seems to just stay lit. As you turn the potentiometer, the light should blink at different speeds.