Here is a simple circuit that flashes 2 LEDs alternately. It only uses a few basic components, so why don't you try it!

Step 1: Gather the Parts Needed.

Parts list:

  1. 2N3904 transistors x2
  2. 10µf caps x2
  3. Red LEDs x2
  4. 470Ω resistors x2
  5. 100kΩ resistors x2
  6. Assorted jumpers
  7. A breadboard
  8. 9V battery
  9. 9V battery clip

Step 2: The Schematic Diagram.

Follow the schematic diagram for this circuit.

Step 3: Insert the Transistors and Resistors.

Insert the 2 transistors in your breadboard like the one on the picture. Then, connect the emitters of the 2 transistors to the ground(negative) rail.

Connect the 2 100kΩ resistors to the bases of the transistors and the other end to a free rail.

Connect the 470Ω resistors to the collectors of the transistors and the other end to a free rail.

Step 4: Insert the Caps.

Insert the 2 capacitors as shown in the picture. Put the negative side of the caps on a free rail on the breadboard.

Step 5: Jumpers and LEDs...

Place jumpers as shown and noted in the pictures.

Connect jumpers from the positive rail of breadboard to the 100kΩ resistors.

Step 6: Connect the Battery.

Connect the battery to its respective rails and see if it blinks.

Congratulations, you have made your project!

<p>I love little electronics projects like this! </p>
<p>Thanks for your comment! I love simple projects like this!</p>
<p>Great, thank you.. was looking for a simple circuit to make a dummy alarm box led circuit from.. I wanted to run at 3V so I removed the 470 reisistors and changed to a 100 cap to slow them down again.. I'm using LED's with 2.7V forward voltage so should be ok.</p>
<p>its my project i m ist year computer engineering student...</p>
<p>i made it thanks bro!</p>
<p>This is the same circuit as this:</p><p><a href="https://www.instructables.com/id/Blink-LEDs-with-Discrete-Parts/" rel="nofollow">https://www.instructables.com/id/Blink-LEDs-with-Di...</a></p><p>But it is a classic. This reminds me to check and see if someone else hasn't posted the circuit I'm thinking about posting here next. Yup, it's been covered. So I don't need to bother.<br></p>

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