The **WJM-1A0-R** is a specific type of **Reed Relay** typically used in telecommunications, security systems, and automated test equipment. It is characterized by its compact SIP (Single In-line Package) design and high reliability. --- ### 1. Technical Specifications The following table outlines the core electronic characteristics of the WJM-1A0-R: | Parameter | Specification | | :--- | :--- | | **Contact Form** | 1 Form A (SPST-NO: Single Pole Single Throw, Normally Open) | | **Coil Voltage** | Typically 5V DC (Standard for WJM series) | | **Switching Voltage** | Max 100V DC / 125V AC | | **Switching Current** | Max 0.5A | | **Carry Current** | Max 1.0A | | **Contact Resistance** | Max 150mΩ | | **Package Style** | SIP (Single In-line Package) | --- ### 2. Key Internal Components A reed relay like the WJM-1A0-R operates based on magnetic principles rather than mechanical armatures found in standard relays. * **Reed Switch:** Two ferromagnetic blades (reeds) hermetically sealed in a glass tube with an inert gas. * **Electromagnetic Coil:** Wrapped around the glass tube. When energized, it creates a magnetic field that forces the reeds to touch, closing the circuit. * **Encapsulation:** The outer plastic shell protects the delicate glass tube from mechanical stress and moisture. * **Internal Diode (Optional/Model Dependent):** Some variations include a "flyback" diode connected across the coil to protect driving circuitry from voltage spikes. --- ### 3. Pin Configuration The WJM-1A0-R follows a standard SIP layout. Usually, the pins are arranged as follows (verify with specific datasheet as pinouts can vary by manufacturer): ```text Pin 1: Coil (+) Pin 2: Coil (-) Pin 3: Contact (Switch) Pin 4: Contact (Switch) ``` --- ### 4. Advantages & Use Cases * **High Speed:** Faster switching times (approx. 0.5ms) compared to electromechanical relays. * **Longevity:** Since the contacts are sealed in glass, they do not suffer from oxidation. * **Applications:** * Modems and Telecommunication line switching. * Signal routing in Oscilloscopes and Multimeters. * Low-power interface between microcontrollers and peripherals.