Students make smart circuits that automatically turn on and off lights according to the light

It is the creative idea of ​​Nguyen Minh Quan and Van Viet Thien Kim - students of Chu Van An Secondary School, Hue City.

Sharing with us, Nguyen Minh Quan, said: "Today, with the development of science and technology, there are many smart electrical devices as well as many automation circuits that have been born to help serve. best for human life ".

Model of smart and economical circuit design application at Chu Van An Secondary School.

However, in fact, in many parts of our country, these electrical equipment and circuits have not been applied, people must manually control. Some electric circuits have a very long and night-time lighting such as street lights, park lights, schools, offices . These circuits consume a great amount of power and require users to close off during the times. early morning or dark night.

Some electric circuits apply smart devices such as the lighting circuits of the routes with time relays to automatically control the lights over time. However, this circuit still has the disadvantage of not correcting the seasonal time difference.

Therefore, Minh Quan and Thien Kim came up with the idea of smart circuits, which can automatically turn on and off under light and save electricity.

The circuit has a light sensor, when it is dark, the circuit will automatically turn on and when it is bright, the circuit will automatically disconnect without human adjustment. The time relay is preset for the circuit at a fixed time, after that time, the circuit automatically switches to a new state and maintains that state until the power is cut. The circuit also has a potentiometer that regulates the increase or decrease of voltage for the circuit, the power meter for power consumption and the aptomat to shut off the power.

Diagram of installation of equipment and materials.

Thien Kim said the operation principle of the circuit is quite simple. When opening the power switch, the light source signal, with 220V current current, is supplied for the light sensor. When it gets dark, the light sensor works for the current running into pins 7 and 8 of the time relay. Then pin number 5 of the relay performs the task of supplying voltage to lights D1 and D2, making these two lights turn on. After a predetermined time, pin 6 of the time relay acts on the potentiometer.

At this time, the potentiometer will adjust the pressure drop to make the 2 lights dimmed, the power of the lamp is reduced compared to the rated power, the power consumption is lower than at the beginning. When it is bright, the light sensor stops working, no current is supplied to the circuit, lights D1 and D2 turn off.

The smart circuit of both of you is one of four subjects awarded the first prize at the Youth Competition for Children and Children in Thua Thien Hue Province for the 11th time, in 2018.

Prof. Dr. Tran Huu Dang, Chairman of the Association, Head of the Organizing Committee, highly appreciated the creativity and applicability of this topic.

"This smart and energy-efficient circuit can be used extensively in homes, such as fencing circuits, garden circuits, or it can be used in schools' corridors. or . in public circuits such as street lights and parks " , Professor Tran Huu Dang commented.