The datasheet details for the YL-105 adapter board usually include: Input Voltage: 5V DC (can be powered directly from an Arduino's 5V pin). On-board Regulator:
“Never ignore the fine print,” Aris said, tapping the familiar YL105 datasheet. “It’s not just a list of numbers. It’s the story of what can go wrong—and how to win.” yl105 datasheet
| | 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 | The datasheet details for the YL-105 adapter board