This instructable is about making a basic light intensity meter without using Arduino or any other micro controller or programming. The light intensity meter displays different levels of light intensity with different colours of LED's. The red LED indicates normal light, red and yellow LED indicate high intensity and green along with red and yellow indicates very high intensity. This is a project for beginners, and requires very basic knowledge and skill of electronics and soldering. This circuit is completely original and designed by me.
The light intensity meter can be installed anywhere due to its small size. Install it in your room or your garden or just keep it on your study table.
Step 1: Video
Before moving ahead you can have a look at the video. It shows the working and the process of making the prototype.
Step 2: Material Required
- LDR X1
- LED's X3 (red, yellow, and green. One each)
-100 ohms resistor X1
-47 ohms resistors X1
- Breadboard X1
- Breadboard wires
- Jumper wires ( male to female )
- Perforated PCB
- Wire peeler
- Soldering iron
Step 3: Trial, Error and Testing.
To get the perfect outcome and the resistance combination, many different resistors values were tested in
different light conditions. The resistor values were also chosen by considering the difference in resistance of each of the LED of the different colour. It was observed that red LED had the least resistance, whereas the yellow LED had the most resistance, hence affecting the choice of order of LEDS and the resistors.
Step 4: Making the Prototype on Breadboard
To make the prototype follow the video and the circuit provided in the pictures.
Step 5: Making the PCB and Soldering
If you want to make the circuit permanent, then start soldering the components, following the pictures. First place the LEDS and solder them along with resistors. Green should be soldered to the 100ohms resistor and yellow should be soldered to the 47 ohms resistor.
Step 6: Box
To make the box I have used EVA sheet of 4mm thickness. All the pieces are joined together using a rubber adhesive.The dimensions of the box are-