The **FCR-22-R** is an electronic component primarily classified as a **Film Resistor** (typically a Flame Coating Carbon Film Resistor). These are widely used in power supplies, consumer electronics, and industrial circuits due to their stability and safety features. --- ## 1. Technical Specifications The "FCR" series generally follows a standard naming convention for electronic resistors. Below are the typical electronic characteristics for a part numbered **FCR-22-R**: | Parameter | Characteristic | Details | | :--- | :--- | :--- | | **Type** | Carbon Film Resistor | Offers high stability and reliability. | | **Power Rating** | 0.25W (1/4 Watt) | "22" often denotes the size/power class. | | **Resistance Value** | Variable | Depends on the color bands or specific suffix. | | **Coating** | Flame Retardant | "FCR" stands for Flame-proof Carbon Resistor. | | **Tolerance** | ±5% (Standard) | Common for R-series carbon films. | | **Mounting Type** | Through-hole | Axial leaded design. | --- ## 2. Key Electronic Components & Materials ### A. Resistive Element The core consists of a **ceramic rod** (usually high-grade alumina). A thin film of carbon is deposited onto this rod. The resistance value is determined by cutting a helical groove into the carbon layer (spiraling), which increases the path for electricity. ### B. Termination (Leads) * **Material:** Solder-plated copper or copper-clad steel. * **Connection:** The leads are welded to end caps that press onto the ceramic rod, ensuring a low-resistance physical connection. ### C. Protective Coating The "Flame-proof" aspect is critical. The resistor is coated with a non-flammable silicone or lacquer. In the event of an electronic failure (overload), the resistor will open the circuit without catching fire or emitting significant smoke. --- ## 3. Identification: The "R" Suffix In electronic part numbering, the **-R** suffix usually carries one of two meanings depending on the manufacturer: 1. **RoHS Compliant:** Indicates the part is lead-free and meets environmental safety standards. 2. **Packaging:** Often indicates "Tape and Reel" (Ammo pack) for automated insertion machines. --- ## 4. Typical Application Circuit FCR resistors are general-purpose components. You will find them in: * **Current Limiting:** Protecting LEDs or transistors. * **Voltage Dividers:** Establishing reference voltages. * **Pull-up/Pull-down:** Ensuring stable logic levels in digital circuits. ```cpp // Example: Using FCR-22-R in a simple Arduino-style circuit void setup() { pinMode(7, INPUT); // Digital pin 7 } /* The FCR-22-R acts as a 10k Ohm pull-up resistor here to prevent a floating signal on the input pin. */ ```