{"id":16461,"date":"2024-11-01T12:53:00","date_gmt":"2024-11-01T07:23:00","guid":{"rendered":"https:\/\/www.electronicsforu.com\/?p=16461"},"modified":"2024-12-01T23:14:52","modified_gmt":"2024-12-01T17:44:52","slug":"street-light-controller","status":"publish","type":"post","link":"https:\/\/www.electronicsforu.com\/electronics-projects\/street-light-controller","title":{"rendered":"Street Light Controller"},"content":{"rendered":"
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\"EFY<\/figure><\/div>\n\n\n

Traditional Street lighting systems frequently suffer from problems such as false activation and a lack of precise control. This paper provides a unique street light controller that addresses these restrictions.<\/p>\n\n\n\n

Street Light Controller Circuit Setup<\/strong><\/h2>\n\n\n\n

The circuit is built around popular op-amp<\/a> IC 741 (IC1), 14-bit ripple counter CD4060 (IC2), SCR BT169, BC557 and other components. IC1 along with LDR<\/a>1 enables IC2, which drives transistor T1 into conduction. IC2 is also used to trigger SCR1 to switch on the street light. Removal of trigger turns the light \u2018off.\u2019<\/p>\n\n\n

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\"Street<\/a>
Street light controller with a switching circuit<\/figcaption><\/figure><\/div>\n\n\n

IC CD4060 has an inbuilt oscillator around its pins 9, 10 and 11. Pin 12 is the master reset (MR) control. The oscillator is disabled when pin 12 is high and enabled when pin 12 is low.<\/p>\n\n\n\n

Circuit Operation<\/strong><\/h3>\n\n\n\n

In daytime, i.e., when light is falling on LDR1, its resistance decreases and the high output at pin 6 of IC1 cuts off pnp transistor T1 and disables IC2. At this stage, SCR1 remains untriggered to switch off the street light.<\/p>\n\n\n\n

At night, i.e., when no light is falling on LDR1, its resistance increases and low output pin 6 of IC1 drives pnp transistor T1 into conduction. This enables IC2 and its internal oscillator starts oscillating.<\/p>\n\n\n\n

After a preset time, pin 14 (Q7) of IC2 goes high and SCR BT169 is triggered through resistor R9 and diode D3. This energizes RL1 and street light is turned on. This time interval can be varied by connecting the gate of SCR1 to pins 6, 13, etc of IC CD4060 (not shown in Fig. 1).<\/p>\n\n\n\n

Transistor T2, which is normally conducting, is driven into non-conduction when output pin 3 (Q13) of IC2 goes high, which de-energizes relay RL1 to switch off the street light. This time can be adjusted with the varying preset resistor VR2.<\/p>\n\n\n

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\"Pin
Pin configurations of SCR and transistors<\/figcaption><\/figure><\/div>\n\n\n

Put simply, the street light turns \u2018on\u2019 when Q7 of IC2 goes high and \u2018off\u2019 when Q13 goes high, provided pin 12 of IC2 remains low.<\/p>\n\n\n\n

Also Check:<\/strong>\u00a0Reference Design For A Solar Powered Street Light<\/a><\/p>\n\n\n\n

Construction and Testing<\/strong><\/h2>\n\n\n\n

The circuit works off regulated 12V DC. You can assemble it on any general-purpose PCB and enclose in a suitable cabinet. The mains AC terminal for the street light is connected to the normally-open (N\/O) contact of relay<\/a> RL1, so the street light turns on when the relay energized.<\/p>\n\n\n\n

Core Advantages<\/strong><\/h2>\n\n\n\n