Automatic light switch turns off light for convenience, safety and to save money. Some devices are fixed in connection with the timers to automatically turn off light. Such appliances save your money and energy. They help make home more comfortable and secure.
You need to think about the problem you want to solve before installing an automatic light switch. Motion detector lights can provide security to dark areas outside your home; one need to time the light when required to light.
How the automatic light operates
The sensitive automatic light connection is intended for connection to the supply of 220v. The circuit connects a lamp of 220v when the night falls and automatically cuts the connection once the day light falls. The switch is made without relay so that to prevent problems with electric arc and the noise that results from inductance contacts and coil.
Automatic light switch extracts the power from the main supplier of 220v through C4, R10, D3, C3 and D2. It is fed by a voltage source D1 with 8.2v which is the circuit used to measure light, R2`-P1. At lower intensity LDR,s resistance,R2, becomes more and P1 voltage decrease. When switch S1 is disconnected, R3-C2 time that is constant makes the gate volts of T1 to differ slower than R2 resistivity. This is important to prevent circuit from reacting at a rapid change of the ambient intensity of light .
One need to be cautious as there are more points connected at 220v; therefore it is good to input a good insulation. Ensure that you don’t repair the circuit when it is already having a connection to the main.
Timer switch have buttons that turns on a light for a present amount of time. If you want to keep the light for an extended period of time, you can set the controls with a touch of another button.
Therefore an automatic switching light is efficient especially in energy saving, this saves money in return. The light turns on when required depending on the set time and off when that time lapses.