ACS712 Current Sensor Module 5A 20A 30A - High Accuracy Power Monitoring

ACS712 Current Sensor Module | Hall-Effect Bidirectional Current Sensor Breakout Board with Analog Output for Precise DC / AC Power Monitoring on Arduino, STM32 and Raspberry Pi Designs

The ACS712 Current Sensor Module is the Hall-effect current sensor on a ready-to-use breakout board — the standard solution for adding current measurement to Arduino, STM32, ESP32, or Raspberry Pi designs without designing your own shunt-resistor + amplifier topology. Available in 5A, 20A, and 30A variants to match your application's current range.

Hall-effect sensing means galvanic isolation between the measured circuit and the MCU side — important for safety in high-current applications. Operates on 5V power supply and outputs 185 mV per ampere (5A variant) as an analog signal centred on VCC/2 (no current = 2.5V output, positive current pushes output up, negative current pushes output down). Compatible with any ADC input — Arduino's 10-bit ADC reads the output directly, no signal conditioning required. Compact 31mm × 13mm PCB fits in space-constrained designs.

Typical Applications

• Power monitoring — measuring current draw of motors, LEDs, heating elements, solar panels.
• Battery management — monitoring charge / discharge current on Li-ion / lead-acid battery packs.
• Smart home energy meters — DIY whole-house or appliance-level power monitoring.
• Motor control protection — overcurrent detection on BLDC / brushed DC motor drives.
• Solar charge controllers — measuring panel current and battery charge current.
• Educational electronics projects — teaching current measurement and Hall-effect sensing.

ACS712 Module Specifications

FAQ — ACS712 Current Sensor Module

Q: Which variant should I choose (5A / 20A / 30A)?
A: Pick the smallest variant that comfortably handles your max expected current — smaller variants have higher sensitivity (mV per A) and better resolution. 5A variant: 185 mV/A. 20A variant: 100 mV/A. 30A variant: 66 mV/A. For 2A applications, the 5A variant gives the best resolution.

Q: Can I measure AC current with it?
A: Yes — the Hall-effect bidirectional sensing captures both directions, so AC current shows as a sinusoidal output around the VCC/2 centre. Sample with a fast ADC + RMS calculation in firmware to get the RMS current value.

Q: Why VCC/2 centre output instead of GND?
A: Bidirectional sensing — current can flow in either direction. Positive direction pushes output above VCC/2, negative direction pushes it below. This way a single 5V ADC can read both polarities without a level shifter. Subtract VCC/2 in firmware to get signed current.

Q: Bulk pricing for production runs?
A: Yes — email contact@lys-sz.com with your quantity for tier pricing on educational kits or production deployments.

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Production OEMs stocking ACS712 by the reel? Email contact@lys-sz.com for bulk pricing. Worldwide shipping from our Shenzhen warehouse.