The **JC103C3R5/X** is a high-precision NTC (Negative Temperature Coefficient) thermistor, typically manufactured by Amphenol Advanced Sensors (formerly GE Sensing/Thermometrics). Below is a detailed breakdown of its specifications, electronic characteristics, and applications. --- ### 1. Key Technical Specifications The model number identifies specific resistance values and tolerance levels essential for circuit design. | Parameter | Specification | Description | | :--- | :--- | :--- | | **Resistance at 25°C** | 10,000 Ω (10k) | The base resistance value at room temperature. | | **Resistance Tolerance** | ±3.0% | The allowable deviation from the 10k rating. | | **Beta Value (B25/85)** | 3977 K | Defines the curve of resistance change over temperature. | | **Operating Range** | -40°C to +150°C | The environmental limits for safe operation. | | **Dissipation Constant** | ~2.0 mW/°C | The power required to raise the part's temperature by 1°C. | | **Time Constant** | ≤ 10 seconds | The speed at which the sensor reacts to temperature changes. | --- ### 2. Electronic Characteristics #### A. Negative Temperature Coefficient (NTC) As an NTC device, its electrical resistance **decreases** as the surrounding temperature **increases**. This relationship is non-linear and is calculated using the Steinhart-Hart equation or the Beta formula. #### B. Interchangeability The "JC" series is known for being "interchangeable," meaning units can be swapped in a circuit without requiring individual recalibration, provided the system accounts for the ±3% tolerance. #### C. Physical Construction * **Encapsulation:** Usually epoxy-coated for environmental protection. * **Leads:** Typically tinned copper or nickel wires for easy soldering onto PCBs. * **Small Form Factor:** Designed for point-sensing in tight spaces. --- ### 3. Application Use Cases This specific 10k thermistor is a standard in the industry and is used in the following ways: 1. **Temperature Compensation:** Offsetting the effects of temperature on other electronic components in a circuit. 2. **HVAC Systems:** Monitoring ambient air temperature or pipe temperature. 3. **Industrial Process Control:** Integrated into probes for monitoring chemical or mechanical heat. 4. **Battery Packs:** Sensing cell temperature during charging cycles to prevent thermal runaway. --- ### 4. Typical Voltage Divider Circuit To read the value with a microcontroller (like an Arduino), the JC103C3R5/X is typically placed in a voltage divider circuit. ```cpp // Basic logic for converting Analog Read to Resistance int sensorValue = analogRead(A0); float voltage = sensorValue * (5.0 / 1023.0); float resistance = (10000 * voltage) / (5.0 - voltage); // Further math is then applied using the Beta value (3977) to get Celsius. ``` ---