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How to Use KF-301 Relay: Examples, Pinouts, and Specs
Design with KF-301 Relay in Cirkit DesignerIntroduction
The KF-301 Relay is an electromagnetic switch module widely used in electronics for controlling high power devices and circuits using low power signals. It is particularly useful in situations where you need to control AC or DC loads with a microcontroller like an Arduino UNO. Common applications include home automation, industrial controls, and switching devices on and off remotely.
Explore Projects Built with KF-301 Relay
ESP-32 Controlled Relay Switching for AC Bulbs
This circuit consists of an ESP-32 microcontroller connected to multiple KF-301 relays, which are used to control several AC bulbs. The ESP-32's GPIO pins are used to send signals to the relays, which in turn switch the connected bulbs on or off. Additionally, rocker switches are connected to the ESP-32 to provide manual control inputs, and the entire system is powered by a 220V AC power source.
Open Project in Cirkit DesignerESP32-Based Relay Control System with Visual Indicators
This circuit uses an ESP32 microcontroller to control two KF-301 relays, which in turn switch power to two bulbs. An analog meter is connected in parallel with a red LED, possibly to indicate the status or measure the current. The entire circuit is powered by a 5V DC source.
Open Project in Cirkit DesignerESP32-Based Smart Environment Controller with Relay and Sensor Integration
This circuit features an ESP32 microcontroller interfaced with various sensors and modules, including an MLX90614 infrared temperature sensor, an HC-SR04 ultrasonic distance sensor, and an LCD display for output. A KY-019 relay module is controlled by the ESP32 to switch an AC source, with a PTC for circuit protection. Additionally, an AC-to-DC converter powers the ESP32 and a fan, indicating the circuit may be used for temperature-based control applications with visual feedback and actuation capabilities.
Open Project in Cirkit DesignerArduino and ESP32-CAM Based Fingerprint-Triggered Solenoid Lock System
This circuit is designed for a security or access control application, featuring an Arduino UNO interfaced with a fingerprint scanner for authentication and controlling a 4-channel relay module. The relays operate multiple solenoids powered by a 12V battery, and an ESP32-CAM module is included for potential image capture capabilities.
Open Project in Cirkit DesignerExplore Projects Built with KF-301 Relay
ESP-32 Controlled Relay Switching for AC Bulbs
This circuit consists of an ESP-32 microcontroller connected to multiple KF-301 relays, which are used to control several AC bulbs. The ESP-32's GPIO pins are used to send signals to the relays, which in turn switch the connected bulbs on or off. Additionally, rocker switches are connected to the ESP-32 to provide manual control inputs, and the entire system is powered by a 220V AC power source.
Open Project in Cirkit DesignerESP32-Based Relay Control System with Visual Indicators
This circuit uses an ESP32 microcontroller to control two KF-301 relays, which in turn switch power to two bulbs. An analog meter is connected in parallel with a red LED, possibly to indicate the status or measure the current. The entire circuit is powered by a 5V DC source.
Open Project in Cirkit DesignerESP32-Based Smart Environment Controller with Relay and Sensor Integration
This circuit features an ESP32 microcontroller interfaced with various sensors and modules, including an MLX90614 infrared temperature sensor, an HC-SR04 ultrasonic distance sensor, and an LCD display for output. A KY-019 relay module is controlled by the ESP32 to switch an AC source, with a PTC for circuit protection. Additionally, an AC-to-DC converter powers the ESP32 and a fan, indicating the circuit may be used for temperature-based control applications with visual feedback and actuation capabilities.
Open Project in Cirkit DesignerArduino and ESP32-CAM Based Fingerprint-Triggered Solenoid Lock System
This circuit is designed for a security or access control application, featuring an Arduino UNO interfaced with a fingerprint scanner for authentication and controlling a 4-channel relay module. The relays operate multiple solenoids powered by a 12V battery, and an ESP32-CAM module is included for potential image capture capabilities.
Open Project in Cirkit DesignerTechnical Specifications
Key Technical Details
- Operating Voltage (Coil): 5V DC
- Current Rating: 10A at 250V AC or 10A at 30V DC
- Switching Voltage: Up to 250V AC or 30V DC
- Switching Capacity: Up to 2500VA or 300W
- Operating Time: 10ms Release Time
- Release Time: 5ms
- Life Expectancy (Mechanical): 10,000,000 operations
- Life Expectancy (Electrical): 100,000 operations
Pin Configuration and Descriptions
| Pin Number | Description | Notes |
|---|---|---|
| 1 | Normally Open (NO) | Contact closes when coil is energized |
| 2 | Common (COM) | Connects to NO or NC depending on coil state |
| 3 | Normally Closed (NC) | Contact opens when coil is energized |
| 4 | Coil+ (VCC) | Connect to 5V supply |
| 5 | Coil- (GND) | Connect to ground |
| 6 | Input Signal (IN) | Trigger signal from microcontroller |
Usage Instructions
Connecting the KF-301 Relay to a Circuit
- Connect the Coil+ (VCC) pin to a 5V power supply.
- Connect the Coil- (GND) pin to the ground of the power supply.
- Connect the Input Signal (IN) pin to a digital output pin of a microcontroller.
- Connect the Common (COM) pin to the power line of the load you wish to control.
- Connect the Normally Open (NO) pin to the device you want to control. Use Normally Closed (NC) if you want the device to be powered until the relay is activated.
Important Considerations and Best Practices
- Ensure the load does not exceed the relay's maximum voltage and current ratings.
- Use a flyback diode across the relay coil to prevent back EMF when the coil is de-energized.
- Consider using a snubber circuit for inductive loads to prevent voltage spikes.
- Always ensure proper isolation between the low voltage control side and high voltage load side.
Example Code for Arduino UNO
// Define the relay control pin
#define RELAY_PIN 7
void setup() {
// Set the relay control pin as an output
pinMode(RELAY_PIN, OUTPUT);
}
void loop() {
// Turn on the relay by setting the control pin HIGH
digitalWrite(RELAY_PIN, HIGH);
delay(1000); // Wait for 1 second
// Turn off the relay by setting the control pin LOW
digitalWrite(RELAY_PIN, LOW);
delay(1000); // Wait for 1 second
}
Troubleshooting and FAQs
Common Issues
- Relay does not switch: Check the input signal and power connections. Ensure the control signal is reaching the relay's input.
- Intermittent operation: Verify that the contacts are not worn out and that the coil voltage is stable.
- Clicking sound but no action: This could indicate a problem with the contacts or insufficient power to the coil.
Solutions and Tips
- Ensure stable connections: Loose connections can cause intermittent operation or failure to actuate.
- Check the input signal: Use a multimeter to verify that the control signal is within the expected range.
- Replace if necessary: If the relay has reached its end of life due to extensive use, consider replacing it.
FAQs
Q: Can I control the KF-301 Relay with a 3.3V signal? A: The relay requires a 5V signal to reliably actuate. Use a level shifter if you're controlling it with a 3.3V microcontroller.
Q: Is it safe to switch AC loads with the KF-301 Relay? A: Yes, but ensure you have proper knowledge of working with high voltage and take necessary safety precautions.
Q: How can I extend the life of the relay? A: Minimize the load on the contacts, use snubber circuits for inductive loads, and avoid frequent switching if possible.