Design with Light Sensor w Relay in Cirkit DesignerThe XHM131 Light Sensor w Relay is a versatile electronic component designed to detect ambient light levels and activate a relay based on user-defined thresholds. This component is ideal for automating devices such as lights, fans, or other appliances, making it a popular choice for home automation, industrial applications, and DIY projects. Manufactured in China, the XHM131 combines a light-dependent resistor (LDR) for light detection and a relay module for switching high-power devices.
This circuit is a light-sensitive relay switch that uses a photocell (LDR) to control a 12V relay via a BC547 transistor. The relay is powered by a 12V battery, and the transistor acts as a switch that is triggered by the resistance change in the LDR, which is influenced by the ambient light level.
Open Project in Cirkit Designer
This circuit appears to be a light-activated switch controlling two bulbs using a 5V relay, with an LDR (Light Dependent Resistor) as the sensor. The relay is powered by a 48V to 5V converter, which is switched on by a 12V battery through an SPST toggle switch. The LDR's output is connected to the relay's input, enabling the relay to switch the bulbs on or off based on the ambient light level detected by the LDR.
Open Project in Cirkit Designer
This circuit is designed to monitor and control lighting based on ambient light levels and motion detection. It uses an Arduino UNO to read data from an LDR and two HC-SR501 motion sensors, and controls a 2-channel relay module to turn lights on or off. The system also measures current and voltage, displays these values on an LCD, and can be remotely controlled or monitored via the Blynk platform.
Open Project in Cirkit Designer
This circuit is designed to control an AC LED bulb using a 220V power source, with an infrared motion sensor and an MMWave radar sensor providing input signals. The two-channel relay is used to switch the LED bulb on and off based on the sensor inputs, while the ESP8266 microcontroller is likely programmed to process the sensor data and control the relay. A converter is included to interface between the sensors, microcontroller, and the relay, ensuring proper voltage levels.
Open Project in Cirkit DesignerThe XHM131 module has a total of 6 pins and terminals for input and output connections. Below is the pinout description:
| Pin/Terminal | Label | Description |
|---|---|---|
| 1 | VCC | Connect to a 5V DC power supply. |
| 2 | GND | Ground connection. |
| 3 | OUT | Digital output pin that indicates the light detection status (HIGH or LOW). |
| 4 | NC | Normally Closed terminal of the relay. |
| 5 | COM | Common terminal of the relay. |
| 6 | NO | Normally Open terminal of the relay. |
Below is an example of how to use the XHM131 with an Arduino UNO to control an LED based on ambient light levels.
// Define the pin connected to the XHM131 OUT pin
const int lightSensorPin = 2;
// Define the pin connected to the relay (NO terminal)
const int relayPin = 13;
void setup() {
pinMode(lightSensorPin, INPUT); // Set the light sensor pin as input
pinMode(relayPin, OUTPUT); // Set the relay pin as output
digitalWrite(relayPin, LOW); // Ensure the relay is off initially
Serial.begin(9600); // Initialize serial communication
}
void loop() {
int lightStatus = digitalRead(lightSensorPin); // Read the light sensor output
if (lightStatus == HIGH) {
// If light is detected, activate the relay
digitalWrite(relayPin, HIGH);
Serial.println("Light detected: Relay ON");
} else {
// If no light is detected, deactivate the relay
digitalWrite(relayPin, LOW);
Serial.println("No light detected: Relay OFF");
}
delay(500); // Add a small delay for stability
}
Relay Not Activating
Erratic Behavior
Relay Stuck in One State
Arduino Not Detecting Output
Q: Can the XHM131 detect specific light wavelengths?
A: No, the XHM131 uses an LDR, which responds to general ambient light levels and is not wavelength-specific.
Q: Can I use the XHM131 with a 3.3V microcontroller?
A: The module requires a 5V power supply, but the OUT pin can be connected to a 3.3V logic input with proper level shifting.
Q: Is the relay safe for inductive loads like motors?
A: Yes, but use a flyback diode across the load to protect the relay from voltage spikes.
This concludes the documentation for the XHM131 Light Sensor w Relay.