Yl105 Datasheet -

int relayPin = 7; void setup() pinMode(relayPin, OUTPUT); digitalWrite(relayPin, LOW); // relay off initially

void loop() digitalWrite(relayPin, HIGH); // turn relay ON delay(2000); digitalWrite(relayPin, LOW); // turn relay OFF delay(2000); yl105 datasheet

If the jumper is installed, the relay activates when IN = LOW. The wiring is identical, but logic is reversed. int relayPin = 7; void setup() pinMode(relayPin, OUTPUT);

Whether you are automating your home, building a robot, or designing a safety cutoff, the YL105 offers a reliable bridge between the fragile world of microcontrollers and the demanding realm of high-power electronics. Always respect the voltage ratings, adhere to proper wiring practices, and consult the SRD-05VDC-SL-C and PC817 datasheets for deeper technical insight. Always respect the voltage ratings, adhere to proper

| | Min | Typ | Max | Unit | |---------------|---------|---------|---------|----------| | Supply Voltage (VCC) | 4.5 | 5.0 | 5.5 | V DC | | Input High Voltage (IN - HIGH mode) | 3.0 | 5.0 | 5.5 | V | | Input Low Voltage (IN - LOW mode) | 0 | 0.8 | 1.5 | V | | Input Current (IN pin) | – | 5 | 15 | mA | | Relay Coil Current | – | 70 | 90 | mA | | Total Module Current | – | 85 | 110 | mA | Relay Contact Ratings (Load Side) | Load Type | Voltage | Max Current | |---------------|-------------|------------------| | Resistive AC | 250V AC | 10A | | Resistive DC | 30V DC | 10A | | Inductive AC | 250V AC | 7A | | Inductive DC | 30V DC | 5A | Warning: Do not exceed these ratings. The relay may weld shut or catch fire. 4. Timing Characteristics (Switching Speed) For applications requiring high-speed switching (e.g., dimming, pulse control), the relay’s mechanical nature limits operation. Refer to these timing specs:

When working with AC mains voltage (110V/230V), take all necessary safety precautions. Use insulated enclosures, avoid live testing, and never leave the module powered while unattended. Need more technical specifics? Leave a comment or refer to the component-level datasheets linked in Section 9. Happy switching!

Introduction In the world of electronics and microcontroller projects (Arduino, Raspberry Pi, ESP8266, STM32), the ability to control high-power devices—such as lamps, motors, solenoids, and pumps—using low-power logic signals is essential. The YL105 is one of the most popular and widely available single-channel relay modules designed precisely for this purpose.