Original WCS2720 Hall Effect based Linear Current Sensor (0-20A)

🔍 Overview
The WCS2720 is a Hall-effect based linear current sensor designed to measure DC (and low-frequency AC) current without direct electrical contact.
Measurement range: 0 to 20A (typically bidirectional ±20A in some configurations)
Output: Analog voltage proportional to current
Type: Non-invasive (magnetic sensing)
👉 It provides electrical isolation between measured circuit and output signal.
⚙️ Working Principle
The sensor operates based on the Hall effect:
1. 🔌 Current Flow
Current passes through an internal conductor path inside the sensor
2. 🧲 Magnetic Field Generation
Flowing current generates a magnetic field around the conductor
3. 📡 Hall Sensing
Internal Hall sensor detects this magnetic field
Produces a Hall voltage proportional to current
4. 🔄 Signal Conditioning
Built-in amplifier converts Hall voltage → linear analog output
👉 Output voltage directly corresponds to measured current.
📊 Measurement Characteristics
Current Range
0 to 20A (unidirectional)
Some versions support:
±20A (bidirectional measurement)
Sensitivity
Typically ~100 mV/A (approximate, model-dependent)
Linearity
Highly linear output across range
⚡ Electrical Characteristics
Supply voltage: 5V (typical)
Output voltage:
Centered around midpoint (≈2.5V at 0A for bidirectional type)
Low internal resistance (minimal power loss)
🔗 Output Interface
Analog Output
Voltage proportional to current
Example behavior:
0A → ~2.5V (bidirectional type)
Positive current → voltage increases
Negative current → voltage decreases
👉 Requires ADC for digital processing.
🧠 Internal Features
✔ Electrical Isolation
No direct electrical connection between:
Measured current path
Output signal
✔ Low Power Loss
Very low conductor resistance
Minimal heat generation
✔ Fast Response
Suitable for real-time monitoring
✔ Compact Integrated Design
Combines:
Conductor
Hall sensor
Amplifier
🔄 Operating Behavior
✔ Real-Time Current Measurement
Continuous analog output
✔ Bidirectional Detection (if supported)
Detects:
Charging current
Discharging current
✔ Temperature Influence
Slight drift with temperature
Internal compensation reduces error
🌡️ Environmental Characteristics
Works across typical operating temperatures
Stable under normal electrical conditions
⚠️ Limitations
Accuracy affected by:
Temperature drift
External magnetic fields
Lower precision compared to:
Shunt-based sensors (for very small currents)
Requires calibration for precise measurement
🔌 Typical Pin Configuration
VCC → 5V supply
GND → Ground
OUT → Analog voltage output
IP+ / IP− → Current input terminals
🧩 Functional Role
The module acts as a:
Current sensor (non-contact type)
Analog current measurement device
Isolation-based sensing element
🏁 Summary
The WCS2720 Hall Effect Current Sensor is a reliable and isolated current measurement solution that:
Uses Hall-effect magnetic sensing
Measures up to 20A current
Provides linear analog voltage output
Offers electrical isolation and low power loss
Is suitable for real-time current monitoring in DC systems