Voltage Sensor Module 25V

🔍 What this module is
The Voltage Sensor Module (0–25V) is a simple analog sensor used to measure DC voltage using microcontrollers like Arduino or ESP32.
👉 It does NOT directly measure high voltage
👉 It uses a voltage divider circuit to reduce voltage safely
⚙️ Working Principle
The module scales down input voltage using resistors
Converts:
0–25V input → 0–5V output
This output is read by Arduino analog pin
➡️ Internally uses a resistor divider (30kΩ + 7.5kΩ)
⚙️ Key Specifications
Input Voltage Range: 0 – 25V DC
Output Voltage: 0 – 5V (safe for Arduino)
Resolution: ~0.00489V (10-bit ADC)
Output Type: Analog
Operating Voltage: 3.3V–5V
🔌 Pinout
Input Side (High Voltage)
VCC / + → Positive voltage to measure
GND / - → Ground
Output Side (Microcontroller)
S (Signal) → Analog pin (A0 etc.)
+ → 5V / 3.3V
- → GND
🧠 Formula to Calculate Voltage
Since voltage is divided by 5:
Vinput=Vanalog×5V_{input} = V_{analog} \times 5Vinput​=Vanalog​×5
👉 Example:
If Arduino reads 2V, actual voltage = 10V
💡 Applications
🔋 Battery voltage monitoring
⚡ Power supply measurement
🚗 Automotive voltage sensing
🌞 Solar panel monitoring
🔌 IoT energy systems
⚠️ Important Notes (Very Important)
❌ Do NOT exceed 25V input → may damage Arduino
❌ Measures only DC voltage (not AC)
❌ Cannot measure negative voltage
⚠️ For ESP32 (3.3V ADC): max measurable ≈ 16.5V
🆚 When to use this vs other sensors
Sensor
Use Case
Voltage Sensor (25V)
Simple voltage measurement
INA219 / INA260
Voltage + current + power
ZMPT101B
AC voltage measurement
👍 Why it's useful
Very cheap & simple
No complex library needed
Perfect for beginners + quick projects