The **WJPA-1C2-R** is a specific high-performance **Electromagnetic Relay** typically manufactured by components specialists like *Wanji*. It is widely used in automotive electronics, industrial control systems, and power management modules due to its compact size and high switching capability. --- ### 1. Key Technical Specifications The part number follows a specific nomenclature that defines its electrical characteristics: | Parameter | Specification | | :--- | :--- | | **Contact Form** | 1C (SPDT - Single Pole Double Throw) | | **Coil Voltage** | Typically 12V DC (Standard for automotive/industrial) | | **Contact Rating** | 20A to 30A (Depending on the specific load type) | | **Mounting Type** | PCB (Through-hole) | | **Terminal Material** | Silver Alloy (AgSnO2 or similar for arc resistance) | | **Enclosure** | Sealed/Flux-proof (R suffix often denotes ROHS compliance or specific sealing) | --- ### 2. Functional Components The WJPA-1C2-R consists of several critical electronic and mechanical parts internally: * **Electromagnetic Coil:** When energized, it creates a magnetic field that pulls the armature. * **Armature & Spring:** The mechanical linkage that moves the contacts. The spring ensures the contacts return to their "Normal" state when power is removed. * **Contacts (Common, NO, NC):** * **NO (Normally Open):** Connects when the relay is energized. * **NC (Normally Closed):** Disconnects when the relay is energized. * **COM (Common):** The moving terminal that switches between NO and NC. * **Yoke and Core:** High-permeability metal parts that concentrate the magnetic flux to increase efficiency. --- ### 3. Application Use-Cases Because of its "1C" (Changeover) configuration and high current handling, it is found in: 1. **Automotive Power Windows:** Reversing motor polarity to move glass up or down. 2. **Central Locking Systems:** Actuating door locks. 3. **Lighting Control:** Switching high-intensity headlamps or auxiliary LEDs. 4. **HVAC Systems:** Controlling fans or small compressors. --- ### 4. Circuit Implementation Example When integrating this part into a circuit, a **Flyback Diode** is essential to protect the driving transistor from voltage spikes. ```python # Conceptual connection for WJPA-1C2-R # Coil Pins: Connected to VCC and a Switching NPN Transistor # Contact Pins: Switching a High-Current 12V Load [VCC] --- [Coil Pin 1] --- [Coil Pin 2] --- [Collector of Transistor] | | +---|<|---------+ (Flyback Diode 1N4007) ``` ---