The 0.28 Inch 0–100V Three-Wire DC Voltmeter is a compact digital voltage display module designed to measure and show DC voltage in real-time. It features a bright 3-digit 7-segment LED display and uses a simple three-wire connection system, making it perfect for battery monitoring, power supply projects, DIY electronics, and DC voltage testing applications.
Core Module Features
• Display Type: 0.28 inch 3-digit LED digital display
• Measurement Type: DC voltage measurement
• Measuring Range: 0V – 100V DC
• Wiring Type: Three-wire (power + measurement)
• Readout: Real-time voltage display
Electrical & Interface
• Operating Supply Voltage: 3.0V – 30V DC (module power input)
• Measurement Voltage Range: 0V – 100V DC
• Current Consumption: ~10mA – 20mA (typical)
• Input Impedance: High impedance for minimal loading
• Polarity: DC only (reverse polarity can damage the module)
Wiring Details (3-Wire Connection)
• Red Wire: +V supply (3V–30V)
• Black Wire: GND / negative supply
• Yellow/White Wire: Voltage sensing input (+) to measure
Note:
• The measured voltage negative must be common with the module GND.
Performance & Accuracy
• Display Resolution: 0.1V (typical)
• Refresh Speed: Fast response for real-time readings
• Suitable for: Batteries, chargers, DC adapters, power rails
• Reliable Digital Output: No calibration needed for regular use
Physical & Integration
• Ultra-compact size for panel mounting
• Lightweight design with easy wire connection
• Perfect for enclosures, DIY test rigs, and portable devices
Applications
• Battery Voltage Monitoring (12V / 24V systems)
• DC Power Supply Voltage Display
• Solar Charging and DC UPS monitoring
• Robotics and embedded system voltage check
• DIY electronics panels and control boxes
Pro Tip
• For measuring above 30V, still power the module using 5V/12V supply (red-black) and connect high voltage only on sensing wire
• Always share ground between power source and measured source
• Use heat shrink on wires for safe long-term installation
Package Includes
• 1 × 0.28 Inch 0–100V DC Digital Voltmeter Module (Three-Wire)