Solar Alarm Clock




This is a simple circuit that uses two solar panels to power a small toy motor. I placed the motor inside my bike bell so that it would ring every time direct sunlight would hit the panels.

This will be part of a performance/ video documentation, in which I will map out my dreams on my room's coffee table, right under the window. I will place the clock in different spots on the table, circle it, and write down the a description of the dream and also the time it took place. The idea is to find out if there's a pattern and relationship between the time of the morning I wake up and the kind of dream I have.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: :: Constructing the Circuit

Just follow the diagram below to construct your circuit. You will need the following components:

- (2) 2N3906 transistors
- (1) 2N3904 transistor
- (1) 2N 2222 transistor
- (1) 1381S integrated circuit
- (1) 3300 uF 2.5V capacitor *
- (1) circuit board
- (1) 100 kOM resistor
- (1) 1000 kOM resistor
- (1) 0.5w Series Glass-sealed Zener Diode
- (1) small motor
- (2) two small solar panels

  • Depending on the amount of capacitors you use, the length of the "ring" and its frequency will change (the more capacitors, the longer the "ring", the slower the frequency).

Step 2: :: Designing the Encasing

I created this encasing from an existing cardboard box that had tabs on its longer side. Any type of design can work, just make sure the slit for the motor and the bell will motor is securely held under the bell and that its close to the wall.
You can also use any kind of bell; my bike bell created a purring, soft sound.

Step 3: :: Add It All Together!

So once you put it all together, you just need to make sure that the bell is very close to the wall of the bell.
That's all!

Be the First to Share


    • CNC Contest

      CNC Contest
    • Make it Move

      Make it Move
    • Teacher Contest

      Teacher Contest

    7 Discussions


    9 years ago on Introduction

    i need help for my project.. i want to do this..


    9 years ago on Step 1

    can i use DIY solar cell in this?


    10 years ago on Introduction

    Solar engines rock! too bad i can't get any of the 1381's around here... and other type or solar engines are very touchy. Isn't a 2N3904 and 2N2222 pretty much the same thing? You could make your parts list more consistent to your schematic, you listed a 1000 kOhm resistor (1MOhm) and the schematic displays a 1000 Ohm resistor (1k). Long live to analog electronics! Please post a video.


    10 years ago on Introduction

    Oh, this is nice. not at all what I expected. I clicked it expecting another microcontroller based clock, and found it's solar powered, built with common components so anyone could make it and it wakes you up with the sun. good job.