The **WJM-1AA-R** is a specific model of a **Miniature Low-Profile Power Relay**. These components are widely used in industrial automation, smart home devices, and automotive electronics to control high-power circuits using low-power signals. Below is a detailed breakdown of its electronic specifications and characteristics. --- ### 1. Technical Specifications The WJM-1AA-R is typically characterized by its compact footprint and high switching capacity. | Feature | Specification Details | | :--- | :--- | | **Contact Form** | 1 Form A (Normally Open - SPST-NO) | | **Contact Material** | AgSnO2 (Silver Tin Oxide) for arc resistance | | **Rated Load (Resistive)** | Typically 5A to 10A @ 250VAC / 30VDC | | **Coil Voltage (DC)** | Options usually include 5V, 12V, or 24V DC | | **Coil Power Consumption** | Approx. 200mW (Sensitive type) | | **Dielectric Strength** | 4,000VAC (between coil and contacts) | | **Mounting Type** | Through-hole PCB Mount | --- ### 2. Key Components & Construction The "electronic parts" within the relay assembly consist of three main functional blocks: #### A. The Coil (Input Side) * **Copper Winding:** A fine wire coil that creates a magnetic field when energized. * **Core:** A soft iron piece that concentrates the magnetic flux. * **R-Suffix (Resistance/RoHS):** In many naming conventions, the "R" indicates **RoHS Compliance** (lead-free) or a specific **Sensitive Coil** resistance version. #### B. The Contact System (Output Side) * **Stationary & Movable Contacts:** These are the "switch" parts. The use of AgSnO2 ensures the contacts don't weld together during high-current inrush. * **Armature:** A moving metal lever that is pulled by the coil's magnetism to close the circuit. #### C. The Housing * **Sealed Protection:** Usually features a "Wash Tight" or "Flux Proof" plastic casing to protect internal parts from dust and solder flux. --- ### 3. Pinout Configuration While exact dimensions depend on the manufacturer (often associated with brands like *Wanjia* or similar regional suppliers), the 1 Form A configuration usually follows this logic: 1. **Pins 1 & 2:** Coil Terminals (Non-polarized unless a diode is built-in). 2. **Pin 3:** Common (COM) contact. 3. **Pin 4:** Normally Open (NO) contact. --- ### 4. Typical Applications * **Home Appliances:** Control of fans, heaters, or microwave motors. * **PLC Outputs:** Interface between microcontrollers and heavy industrial loads. * **Lighting Control:** Switching LED drivers or ballast circuits.