Automatic Night Lamp with Morning Alarm

This circuit automatically activates a night lamp when the bedroom light is turned off. The lamp stays illuminated until the light sensor detects daylight in the morning. A super-bright white LED is utilized as the night lamp, providing bright and cool lighting.

The circuit consists of several key components, including a light-dependent resistor (LDR), a comparator, a relay, and a super-bright white LED. The LDR serves as the primary sensor, detecting ambient light levels in the environment. When the bedroom light is switched off, the resistance of the LDR increases, causing the voltage at the comparator input to drop below a certain threshold.

The comparator, which can be configured using an operational amplifier (op-amp), compares the voltage from the LDR with a reference voltage set by a voltage divider. When the bedroom light is off and the LDR detects low light levels, the comparator output transitions from low to high, triggering the relay. The relay acts as a switch, closing the circuit to the super-bright white LED, thereby turning on the night lamp.

As morning approaches and daylight enters the room, the resistance of the LDR decreases, resulting in an increase in voltage at the comparator input. Once the voltage exceeds the reference voltage, the comparator output goes low, deactivating the relay and turning off the night lamp.

This circuit design is efficient and ensures that the night lamp operates only when needed, providing illumination during the night while conserving energy during the day. The use of a super-bright white LED not only enhances visibility but also contributes to the overall energy efficiency of the circuit.This circuit automatically turns on a night lamp when bedroom light is switched off. The lamp remains ON until the light sensor senses daylight in the morning. A super-bright white LED is used as the night lamp. It gives bright and cool lig.. 🔗 External reference