The **C20-R068** is a specific model of an **NTC (Negative Temperature Coefficient) Thermistor**, commonly manufactured by companies like TDK/EPCOS or similar electronic component suppliers. It is primarily used for temperature measurement and compensation. --- ### 1. Key Technical Specifications The "C20" typically refers to the physical disc size/series, and "R068" denotes its resistance value. | Parameter | Specification (Typical) | | :--- | :--- | | **Component Type** | NTC Thermistor | | **Resistance at 25°C ($R_{25}$)** | 68 Ohms | | **Tolerance** | $\pm$ 5% to $\pm$ 20% (depending on specific grade) | | **Material** | Metal Oxide Ceramic | | **Mounting Type** | Through-hole (Leaded) | | **Operating Temp Range** | -55°C to +155°C | --- ### 2. Physical Characteristics * **Form Factor:** It is a leaded disc-type component, often coated with epoxy resin or phenolic resin for environmental protection. * **Leads:** Usually features kinked or straight tinned copper wires for PCB mounting. * **Dimensions:** The "20" often implies a disc diameter in the range of 3mm to 5mm (size varies by manufacturer standards). --- ### 3. Electrical Behavior As an **NTC** device, its resistance is inversely proportional to the temperature: 1. **Low Temperature:** The device maintains a higher resistance (68 Ohms at room temperature). 2. **High Temperature:** As the device heats up (due to ambient air or current flow), the resistance drops significantly. 3. **B-Value:** This component is characterized by a "B-constant," which determines the slope of the resistance-temperature curve. --- ### 4. Common Applications Due to its 68-Ohm resistance and thermal properties, the C20-R068 is used in: * **Inrush Current Limiting:** Protecting circuits from a surge of current when power is first applied. * **Temperature Sensing:** Used in household appliances (toasters, coffee makers) to monitor heat. * **Temperature Compensation:** Adjusting the behavior of other components in a circuit that might drift as they get hot. * **Automotive Electronics:** Monitoring engine or cabin temperatures. --- ### 5. Symbol and Identification In a circuit diagram, it is represented by a resistor symbol with a diagonal line or a specific "t°" marking. ```text Standard Symbol: / ----|/_|---- / t° ```