The 0.28-inch Mini Digital Voltmeter & Ammeter is a compact, dual-display power monitor designed for real-time tracking of voltage and current. At Electrapac, we recommend this "all-in-one" gauge for any DIY power supply, battery charger, or motor control project where precision monitoring is key.

Product Overview

This module features two bright, 3-digit LED displays (typically Red for Voltage and Blue for Current). Despite its tiny 0.28-inch profile, it can measure up to 100V DC and 10A of current. It includes a built-in shunt, meaning you can measure up to 10A directly through the board without needing an external bulky copper shunt.

Key Features for Electrapac Customers

• Dual Monitoring: View both Volts and Amps simultaneously on one screen—no need for a multimeter during operation.

• Built-in Shunt: Simplifies wiring for projects pulling up to 10A, saving space in your enclosure.

• Calibration Trimpots: Features two fine-tuning potentiometers on the back, allowing you to calibrate the readings against a professional multimeter.

• Snap-In Design: The plastic housing features side clips for easy "snap-in" mounting into a rectangular panel cutout.

• Reverse Polarity Protection: The operating power input is protected to prevent the module from burning out if wired backward.

Wiring Guide (5-Wire Setup)

To ensure your Electrapac meter functions correctly, follow this 5-wire logic:

The Thin Wires (Module Power):

• Thin Red: Connect to a 4V–30V DC source (to power the display).

• Thin Black: Connect to the Negative ground of the power source.

The Thick Wires (Current Measurement):

• Thick Red: Connect to the Negative side of your Load.

• Thick Black: Connect to the Negative side of your Power Source.

Note: The ammeter measures current on the low side (ground path). Incorrect wiring here is the #1 cause of damaged modules.

Primary Applications

• Variable Bench Power Supplies: Adding a professional digital readout to a custom LM2596 or XL6009 build.

• Solar Charge Controllers: Monitoring how much energy your panels are producing and pushing into a battery.

• Battery Discharge Testing: Viewing voltage sag and current draw in real-time for 18650 or Lead-Acid packs.

• E-Bike/Electric Scooter Gauges: Tracking battery level and motor draw during use.

• Car/Marine Audio: Monitoring 12V system health and amplifier current consumption.

Why Shop at Electrapac?

We source the 0.28" Dual Meter with high-quality LED segments that remain visible even in bright environments. At www.electrapac.com, we provide the diagnostic tools that give you total visibility into your electrical systems.