Automatic street light using ldr
- 1. Automatic Street Light control using LDR
- 2. Group Members Compiled by : 16BEC0066 - NIKHIL SHARMA 16BEC0653 - VIPIN S RAKARADDI Submitted to – Mrs . Sangeetha A
- 3. Contents Introduction Circuit Diagram Hardware Requirement Description of Hardware Working Bread-board Mounting PCB Mounting Conclusion
- 4. Introduction Many of the people have a phobia of darkness, so to assist them in such situation, we have explained a simple circuit. It will automatically turn on street light in the way of LEDs or bulb coupled with relay. Working this circuit is very much easy and also the power consumed by the circuit is very low because of the very few components used in the circuit.
- 6. Components: Diodes - 4 Resistor R1 (10 K) – 1 Resistor R2 (3300 E) – 1 Resistor R3 (1 K) – 1 Variable Resistor VR1 (10 K) – 1 Capacitor C1 (470uF) – 1 Capacitor C2 (200uF) - 1 LDR – 1 Transistor T1 (BC548) – 1 Relay-1 LED-5
- 7. Description of Hardware : (1) LDR: Sensitivity depends on intensity of light. Resistance of LDR decrease with increase in intensity of light and vice-versa.
- 8. (2) Resistor: It is a passive component having two terminals that are used to manage the current flow in the circuit. A current that flows via a resistor is directly proportional to the voltage that appeared into resistor. Two types: (1) Fixed value resistor (2) Variable resistor
- 9. (5) BC548 Transistor : It is a general purpose silicon, NPN, bipolar junction transistor. It is used for amplification & switching purpose. Here, for switching purpose it is biased so that it remains on if there is signal at its base , other- wise it is completely off.
- 10. Bridge rectifier A diode bridge is an arrangement of four (or more) diodes in a bridge circuit configuration that provides the same polarity of output for either polarity of input. When used in its most common application, for conversion of an alternating current (AC) input into a direct current (DC) output, it is known as a bridge rectifier. A bridge rectifier provides full wave rectification from a two-wire AC input, resulting in lower cost and weight as compared to a rectifier with a 3-wire input from a transformer with a center tapped secondary winding. The essential feature of a diode bridge is that the polarity of the output is the same regardless of the polarity at the input.
- 11. Capacitors A capacitor is a passive two terminal electrical component that stores electrical energy in an electric field. The effect of a capacitor is known as capacitance. While capacitance exists between any two electrical conductors of a circuit in sufficiently close proximity, a capacitor is specifically designed to provide and enhance this effect for a variety of practical applications by consideration of size, shape, and positioning of closely spaced conductors, and the intervening dielectric material.
- 12. Working of Automatic Street Light Controller Switch Circuit: The working of circuit is very much easy to understand. In this circuit, we used transformer which will basically convert the high voltage at input into small voltage. After it we put bridge rectifier which will convert ac into dc current and provide pure dc current. In this LDR and VR1 form one potential divider . Here transistor is also placed which will basically act as switch. Transistor will be operating in cutoff and saturation mode to act as switch.
- 16. PCB mounting
- 17. Advantages: No man power required. Simple Construction. Efficient method. Less Consumption of electrical energy. Less maintenance. Cheap and economical.
- 18. Conclusion: In coming days, this will prove a great boon to the world, since it will save a lot of electricity of power plants that gets wasted in illuminating the street lights. As the conventional sources are depleting very fast, then it`s time to think of alternatives.
Editor's Notes
- #8: LDR is a device whose sensitivity depends upon the intensity of light falling on it. When the strength of the light falling on LDR increases the LDR resistance decreases , while if the strength of the light falling on LDR decreased resistance incresed. In the time of darkness or when there is no light, the resistance of LDR is in the range of mega ohms, while in the presence of light or in brightness in decrease by few hundred ohms.