Sensors make any project fun and easy to fabricate and operate. There are a huge variety of sensors that exist in the electronics market. And we get the decision to pick the correct sensor for our activities or requirements. In any case, nothing is better than creating your own DIY sensor to work with a wide scope of micro-controllers so you have the specific circuit to create that best fits your requirements for your project. Right now, we are going to make a dark light indicator sensor (or day and night indicator sensor) which will show if there is a dim or light in the environment. A few utilizations of this circuit, are road light controlling, home/office light controlling, day and night indicators, and so on.
The figure underneath shows two circuit diagrams of light and dark sensors utilizing LM358 IC with a 20k variable resistor, a photoresistor diode, and a few other components.
Hardware Components
The following components are required to make Light Dark Sensor Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Op-amp IC | LM358 | 2 |
| 2. | Resistor | 10K, 470R | 2, 2 |
| 3. | LDR | – | 2 |
| 4. | LED | – | 2 |
| 5. | Variable Resistor | 20K | 2 |
| 6. | DC Power Supply | 3-12V | 1 |
LM358 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of LM358
Dark Sensor Circuit
Light Sensor Circuit
Working Explanation
The working of these two circuits is simple and straightforward. The first circuit is a dark sensor; that will show visual signs by enacting a LED when the preset level is set by the 20K variable resistor. The second circuit is a light sensor that will initiate the output LED when the light reaches a preset level set by the 20K variable resistor.
The affectability of the circuit can be additionally expanded by trying different estimated values of 10K resistor and variable resistor. The circuit can work with any voltage ranges from 3V to 30V. The LED current constraining resistor must be expanded if the working voltage is higher than 12 volts is utilized.
Applications and Uses
It is applicable in the following areas:
- Street light controlling
- Home and office light controlling
- Day and night indicators
- It can likewise be used as an emergency indicator in light-sensitive areas
