A long light power control circuit

At dawn, light illuminates the photosensitive resistor RL, causing its resistance to decrease. This switch IC (2) exhibits a high electrical footprint. When light is present, the relay K does not activate. At night, in the absence of light, the photosensitive resistor RL has high resistance, leading to a low voltage level at pin 2 of the IC. As a result, the IC conducts, activating relay K, which closes its normally open contacts K-1, allowing the lamp to illuminate.

The circuit described utilizes a photosensitive resistor (commonly known as a light-dependent resistor, or LDR) to control the operation of a lamp based on ambient light conditions. During daylight hours, the LDR's resistance decreases significantly, preventing the associated switch IC from activating the relay. This results in the lamp remaining off, conserving energy during times when it is not needed.

In contrast, at night or in low-light conditions, the resistance of the LDR increases, which causes the voltage at pin 2 of the switch IC to drop to a low level. This change in voltage level triggers the IC to enter a conductive state. Consequently, the relay K is activated, closing its normally open contacts (K-1). This action completes the circuit to the lamp, allowing it to turn on and provide illumination.

The switch IC is designed to handle the electrical characteristics of the circuit, ensuring reliable operation while minimizing power consumption. The relay serves as an interface between the low-power control signal from the IC and the higher power requirements of the lamp, allowing for safe operation without direct electrical connection between the two.

In summary, this circuit effectively automates lighting control based on environmental light levels, enhancing convenience and energy efficiency. The integration of the photosensitive resistor with the switch IC and relay provides a straightforward yet effective solution for automatic lighting applications. At dawn, the light is irradiated onto the photosensitive resistor RL, it reduces resistance This switch ICs (2) exhibits high electrical foot. I. lC end, the relay K does not s uck desk, lamp does not light. To r night, dark, darken, the photosensitive resistor RL was high resistance, so lC VJ (2 pin level goes low .IC conduction, the relay K assault units, which normally open contacts K-l cut Taiwan, lamps bright.