I think of a puzzle and an idea came to my mind to create a puzzle using some electronics component such as resistors, LED's, diodes etc. Here I am going to make a puzzle using electronics circuitry. I am only going to use 1K ohm resistors in the whole circuitry. The puzzle is that, you see the 9 header pins on the breadboard. The task is that you have to choose combination of two pins by touching the battery connector terminals to the header pins at which both the LED's glow brightest. If you find it in one chance then you will be the winner. To make the puzzle hard you can cover the circuit with a box except the header pins and limit the chances to 1 or 2. I will show you how to make a cover for the circuit in the last steps of this instructable. So, let's start............

Step 1: Tools and Materials Required.

1. 1K ohm resistor- 10.

2. Male header pins- 9.

3. IN4007 diodes- 2.

4. Green LED-2.

5. Breadboard-1.

6. A small piece of thin wire.

7. Hard paper.

8. White paper.

9. Scissor.

10. 9V battery-1

11. Battery connector-1

12. Glue.

Step 2: Circuit Diagram.

First of all make the circuit diagram in any circuit designing software as shown in the image or simply follow the above circuit diagram. Here, I use Circuit Wizard. According to the above diagram I am going to place the components on the breadboard.

Step 3: Placing the First Four Resistors on the Breadboard.

First of all take a breadboard as shown in the image. Now, place the first resistor as in the second image. Now, place the other resistors as shown in third and fourth image.

Step 4: Placing Diode and Other 1K Ohm Resistors.

Place the diode as shown in the first image. Now in series of that diode place a resistor of 1K ohm as shown in second image. Now, place other two 1K resistors as shown in the third and fourth image.

Step 5: Placing Other Resistors and the Last Diode.

Place a 1K resistor as shown in the first image. Now, place another resistor as shown in the second image. Now, place the diode as shown in the third image.

Step 6: Placing the Green LED's and the Last 1K Resistor.

Now, place the long pin of the both LED's to the diode as shown in the first and the second image. Now, place the last 1K resistor as shown in the third image. Here, I use a different colour 1K resistor but don't get confused it is a 1K resistor(color bands or you can say color coding is same).

Step 7: Placing the Four Header Pins on One Side of the Breadboard.

The first image shows you how the male header pins look like. Place the first header pin as shown in the second image. Now, place the other header pins as shown in the third, fourth and fifth image.

Step 8: Placing the Header Pins on the Other Side of the Breadboard.

Now, move the breadboard 180 degree so that the other side of the breadboard is in front of you. Now, place the header pins as shown in the first, second, third and fourth image.

Step 9: Making the Puzzle a Little Bit Tough.

Again rotate the breadboard to 180 degree's. Now, take a piece of thin wire and connect it's one end to the final resistor's leftmost pin as shown in the first image. Now, connect the second end of the wire in between the first diode we placed before as shown in the second image. Now, connect a header pin to that point as shown in the third image.

Step 10: First Step in Making the Box to Hide the Circuit.

Take a hard paper and cut and fold it in appropriate dimensions as shown in second and third image. But keep in mind that when we put that box over the breadboard then the box touches the breadboard as shown in the fourth image.

Step 11: Second Step in Making the Box to Hide the Circuit.

Make a hole in the box such that both the LED's appear at the top of the box as shown in the first and the second image. Now, our circuit is hidden. In the next step we decorate the box.

Step 12: Finalizing and Decorating the Box.

Cut the hard paper as shown in the first image. Now, stick the white paper as shown in the second image. Now, make the box as shown in the third and the fourth image. Now, take a piece of black paper and stick it on the box as shown in fifth and sixth image. In the next step I am going to hide the circuit with this box.

Step 13: Hiding the Circuit.

Hide the circuit as shown in the first image. But, be sure that all the header pins are visible. Now, decorate the box as shown in the second image.

Step 14: Completing the Puzzle.

Take a 9V battery and battery connector as shown in the first image. Now connect the connector to the battery. Our puzzle is completed. Now, you see the 9 header pins on the breadboard. The puzzle is that you have to choose combination of two pins by touching the battery connector terminals to the header pins at which both the LED's glow brightest. Interesting part is that in how many chances one can find the correct terminals.

Step 15: Tips to Make the Puzzle Harder.

To make the puzzle harder connect more header pins outside the box such that the probability of finding the correct pair decreases. Enjoy the puzzle with your friends!