Light sensor can be an unfamiliar term for many people. In our daily life, we sometimes need to switch on some electric light (bulbs / tubes etc.) after sunset or rather when outside is dark. And again we switch off them in the morning after sunrise or after we wake up. These can be your main gate lights of residence, garden lighting, street lights, common passage lights in apartment, in parking space or the signage of your shop. As a common practice we do this manually. Hence it always involves manual intervention. We waste electric energy as the light is not required the moment outside ambient light is available through natural source. However, we can very easily automate this switching process. The solution to this is LDR Switch or Light Sensors.
What is LDR / Light Sensor?
Full form of LDR is Light Dependent Resistor. Also, this sensor is known as Photosensor or Photo cell. This is type of sensor which detects the intensity of the light falls on it and it’s resistor value changes with the change of light intensity. The semiconductor material property shows this characteristics.
Simple LDR Switch For Our Use
LDR switch is easily available nowadays. You can readily buy these switches online. You simply need to connect this LDR switch in series to your existing circuit. Alternatively, you can replace your existing normal switch with this LDR switch. This way your circuit will be totally automated. However, I shall still recommend that you also keep the existing manual switch for a second option in addition to connecting LDR switch in series. Below diagram can help you to understand the connection process.
Additionally, remember to check the light switch rating for the ampere or load wattage capacity before buying. If you connect load more than the rated capacity of LDR switch, then it will burn. Also find more such interesting home automation ideas here.