top of page
100K Ohm NTC 3950 Thermistor

100K Ohm NTC 3950 Thermistor

₹50.00Price
🌡️ 100K Ohm NTC 3950 Thermistor — Detailed Explanation
🧠 What is it?
A NTC Thermistor is a type of resistor whose resistance changes with temperature.
👉 NTC means Negative Temperature Coefficient, which means:
  • As temperature increases → resistance decreases
The “100K 3950” specifies its key characteristics.
🔍 Meaning of “100K 3950”
1. 100K Ohm
  • Resistance at 25°C = 100,000 Ω (100kΩ)
2. 3950 (Beta Value)
  • A constant that defines how resistance changes with temperature
  • Based on the Steinhart–Hart equation
👉 Higher Beta → steeper resistance change
⚙️ How It Works
  • Made from semiconductor materials
  • Temperature change affects charge carriers
  • This changes resistance
📉 Behavior:
  • Cold → High resistance
  • Hot → Low resistance
📉 Temperature–Resistance Relationship
Where:
  • R(T)R(T)R(T): Resistance at temperature TTT
  • R0R_0R0​: Resistance at reference temperature T0T_0T0​ (usually 25°C)
  • BBB: Beta value (3950)
  • TTT: Temperature in Kelvin
🔌 Typical Circuit (Voltage Divider)
To use with a microcontroller:
VCC
│
[ Fixed Resistor ]
│-----> Output (to ADC)
[ Thermistor ]
│
GND
👉 Output voltage changes with temperature → read using ADC
📊 Key Specifications
  • Resistance: 100kΩ @ 25°C
  • Beta value: 3950
  • Temperature range: -40°C to +125°C
  • Type: NTC (Negative coefficient)
  • Accuracy: typically ±1% to ±5%
🧠 Important Characteristics
1. Non-linear Response
  • Not linear like digital sensors
  • Requires calculation or lookup table
2. High Sensitivity
  • Very sensitive to small temperature changes
3. Fast Response
  • Small size → quick thermal response
🚀 Applications
  • 🌡️ Temperature measurement
  • 🔋 Battery temperature monitoring
  • 🖥️ CPU thermal control
  • 🏠 HVAC systems
  • 🚗 Automotive sensors
  • 🔌 Power supply protection
✅ Advantages
  • Low cost
  • High sensitivity
  • Small size
  • Fast response
⚠️ Limitations
  • Non-linear output
  • Requires ADC + calculations
  • Accuracy depends on calibration
  • Self-heating can affect readings
💡 Example Use with Arduino
Steps:
  • Create voltage divider
  • Read analog value (ADC)
  • Convert voltage → resistance
  • Use equation (or library) → temperature
🧪 Real-Life Example
In a laptop:
  • Thermistor detects CPU temperature
  • Resistance drops as temperature rises
  • System increases fan speed
🔍 Practical Tips
  • Use a precision resistor (1%) in voltage divider
  • Avoid placing near heat sources unless intended
  • Use averaging in code to reduce noise
Quantity
bottom of page