The **FCR-25W-R** is a specific model of a **Fixed Chip Resistor**, commonly used in surface-mount technology (SMT) applications. Below is a detailed breakdown of its electronic components, specifications, and characteristics. --- ## 1. Component Identification The part number follows a standard naming convention used by manufacturers (typically like *Uniroyal* or *Yageo*), where each segment represents a physical or electrical attribute. ### Part Number Breakdown | Segment | Meaning | Detail | | :--- | :--- | :--- | | **FCR** | Series Name | Flame-Proof Carbon Film / Chip Resistor | | **25W** | Power Rating | 0.25 Watts (1/4 W) | | **R** | Packaging | Reel (Taped and Reeled for automated assembly) | --- ## 2. Technical Specifications The FCR series is designed for general-purpose electronic circuits requiring a compact form factor and reliable heat dissipation. ### Electrical Characteristics * **Resistance Range:** Typically available from $1\Omega$ to $10M\Omega$. * **Tolerance:** Common tolerances are $\pm 1\%$ (F) or $\pm 5\%$ (J). * **Maximum Working Voltage:** Generally rated around **200V to 250V** (depending on the specific case size). * **Operating Temperature:** $-55°C$ to $+155°C$. ### Material Composition 1. **Substrate:** High-purity Alumina ($Al_2O_3$) ceramic core for heat resistance. 2. **Resistive Layer:** A thin film of Carbon or Metal Oxide deposited on the substrate. 3. **Protective Coating:** Epoxy or glass layer to protect against moisture and mechanical stress. 4. **Terminations:** Lead-free (Sn) plating over a Nickel (Ni) barrier to prevent leaching during soldering. --- ## 3. Physical Dimensions (Typical 1206/0805 Size) While "25W" refers to the power, these resistors usually adhere to standard SMT footprints. | Dimension | Description | | :--- | :--- | | **L (Length)** | ~3.10 mm | | **W (Width)** | ~1.55 mm | | **H (Thickness)** | ~0.55 mm | --- ## 4. Key Applications Because these resistors are **Flame-Proof**, they are often used in safety-critical power circuits: * **Power Supplies:** Used as bleed-off resistors or current limiters. * **Consumer Electronics:** Found in TVs, adapters, and chargers. * **Automotive:** Used in non-critical control modules. * **Industrial Controls:** Integrated into PLC boards and sensor interfaces. --- ## 5. Typical Circuit Symbol In a schematic, this part is represented by the standard resistor symbol: ```text R1 ----/\/\/\---- 0.25W, 1% ```