The **SV-5WC-R** is a specific model of a **Miniature Relay**, typically manufactured by companies like **Fujitsu** (formerly Takamisawa). It is widely used in telecommunications, audio equipment, and low-signal switching applications. --- ## 1. Technical Specifications The part number can be broken down to understand its core electronic characteristics: | Parameter | Specification | | :--- | :--- | | **Coil Voltage** | 5V DC | | **Contact Form** | 1 Form C (SPDT - Single Pole Double Throw) | | **Contact Rating** | 1A at 30VDC / 0.5A at 125VAC | | **Power Consumption** | Approx. 150mW (High sensitivity) | | **Mounting Type** | Through-Hole (PCB Mount) | | **Terminal Pitch** | 2.54mm (Standard DIP layout) | --- ## 2. Key Internal Components The SV-5WC-R consists of several critical electronic and mechanical parts: ### A. The Coil (Electromagnet) * **Material:** Fine copper wire wound around a core. * **Function:** When 5V DC is applied, it creates a magnetic field that pulls the armature. * **Sensitivity:** The "W" in the part number often denotes a high-sensitivity coil, meaning it requires very little current to trigger. ### B. Contacts (The Switch) * **Material:** Usually **Gold-overlay silver-palladium**. * **Why Gold?** Gold prevents oxidation, ensuring a reliable connection for "dry circuits" (very low current signals) where a standard power relay might fail. ### C. The Armature and Spring * **Function:** A mechanical lever that moves between the Normally Closed (NC) and Normally Open (NO) positions. * **Bifurcated Contacts:** This model often uses "bifurcated" (split) contacts to increase reliability through redundancy. --- ## 3. Terminal Configuration The device usually follows a standard DIP-6 or DIP-8 footprint. | Pin Type | Description | | :--- | :--- | | **Coil Pins** | Where the 5V input is applied. | | **Common (COM)** | The moving part of the switch. | | **Normally Closed (NC)** | Connected to COM when no power is applied. | | **Normally Open (NO)** | Connects to COM only when 5V is applied to the coil. | --- ## 4. Typical Applications * **Telecommunications:** Switching telephone lines or signal routing. * **Audio Equipment:** Input switching in high-fidelity pre-amplifiers. * **Industrial Controls:** Interfacing low-power microcontrollers (like an Arduino or ESP32) to switch small external loads. * **Measurement Instruments:** Signal path selection in multimeters or oscilloscopes.