The **Seeed Studio Grove AC-Voltage Sensor** is a specialized module designed for safely measuring single-phase AC voltage. It's part of the convenient Grove ecosystem, which uses standardized connectors to simplify prototyping and reduce wiring errors. The module uses a small-scale voltage transformer to step down a high AC voltage to a safe, low-level signal that can be read by a microcontroller's analog input. This method provides robust **electrical isolation**, which is a crucial safety feature when working with high-voltage AC circuits. It's a perfect tool for home automation, power monitoring, and educational projects involving AC power, offering a simple and secure way to interact with the electrical grid.
✨ Key Features and Benefits
- Non-invasive Measurement: Measures voltage without direct contact with the primary circuit, ensuring safety.
- High Electrical Isolation: The transformer-based design provides complete galvanic isolation from the high-voltage AC source.
- Grove System: Uses the standardized Grove connector, eliminating the need for complex wiring and soldering.
- Analog Output: Provides an analog voltage signal proportional to the measured AC voltage.
- Wide Application Range: Suitable for measuring typical residential AC voltages (e.g., 120V or 220V).
- Compact Design: Small form factor makes it easy to integrate into projects with limited space.
- Safety-focused: Designed with multiple safety features to protect both the user and the equipment.
🔧 Material and Construction Details
| Component | Material | Description |
|---|---|---|
| Main Sensor | Voltage Transformer | The core component for stepping down the AC voltage |
| PCB | FR-4 (Grove-compatible) | The main circuit board with the 4-pin Grove connector |
| Connectors | Grove Connector & Screw Terminals | For quick plug-and-play and secure wiring to the AC source |
| Resistors & Capacitors | SMD Components | Used for signal conditioning and filtering the transformer output |
| Indicator LED | LED | May be included to indicate power status |
📚 Use Cases and Applications
- Home energy monitoring systems
- Smart power strips and outlet control
- Building automation and power distribution monitoring
- Educational demonstrations of AC electricity
- DIY power analyzers and wattmeters
- Monitoring power grid stability and voltage fluctuations
🔍 Technical Specifications
| Specification | Details |
|---|---|
| Operating Voltage | 5V DC (for the Grove board) |
| Input Voltage Range | Varies by specific module, typically up to 250V AC |
| Output Signal | AC Voltage (e.g., 0-5V or 0-1V) |
| Interface | Analog Output via Grove connector |
| Isolation Voltage | High isolation for safety (e.g., > 4000V) |
| Accuracy | Depends on the internal circuitry and calibration |
🔌 Connection Diagram
| Module Pin | Function | Arduino/MCU Connection |
|---|---|---|
| VCC | Power Input | 5V |
| GND | Ground | GND |
| SIG | Analog Output | Analog pin (e.g., A0) |
| NC | Not Connected | Leave unused |
| AC Terminal (+) | AC Voltage Input (+) | Connect to one AC line |
| AC Terminal (-) | AC Voltage Input (-) | Connect to the other AC line |
🧼 Calibration & Maintenance
The Grove AC-Voltage Sensor requires software calibration for accurate readings. You need to read the analog output signal and perform an RMS (Root Mean Square) calculation in your code to get the actual voltage. To calibrate, measure the AC voltage with a multimeter and adjust your software's scaling factor until the calculated value matches the multimeter reading. The module is maintenance-free; ensure all connections are secure and the module is protected from dust and moisture. The Grove connector is robust but should not be subjected to excessive force.
⚠ Safety Information
This module deals with high-voltage AC. **Never** touch the AC terminals when the module is powered on. Always disconnect the power before making any connections. Despite the electrical isolation, a fault in the system can be extremely dangerous. This module is intended for educational and hobbyist use under proper supervision. Do not use it as a standalone safety device in a commercial or life-critical application.
👍👎 Pros & Cons
| Pros | Cons |
|---|---|
| Extremely safe due to high isolation | Cannot measure DC voltage |
| Simplified wiring with Grove connectors | Requires complex RMS calculation in software |
| Ideal for measuring standard AC line voltage | Accuracy can be influenced by input frequency |
| Compact and easy to use | Not designed for measuring very low AC voltages |
🅿 Product Images:
