The **JDL-A3B-R** is a specific electronic component, typically categorized as a **Limit Switch** or a **Micro Switch** used in industrial automation, security systems, and machinery control. Below is the technical breakdown of its electronic characteristics and specifications. --- ## 1. Core Specifications The JDL-A3B-R is designed to convert mechanical movement into an electrical signal. Its primary ratings usually fall within the following parameters: | Feature | Specification Details | | :--- | :--- | | **Contact Type** | SPDT (Single Pole Double Throw) | | **Actuator Type** | Roller Lever (indicated by the "-R" suffix) | | **Rated Voltage** | 250V AC / 125V AC / 30V DC | | **Current Rating** | 3A to 5A (typical for A3B series) | | **Protection Class** | IP40 (standard) or IP67 (if sealed variant) | | **Terminal Type** | Solder or Quick-connect terminals | --- ## 2. Electronic Components & Internal Design The device consists of three main internal electronic/mechanical sections: ### A. Contact Mechanism * **Common (COM):** The input terminal. * **Normally Open (NO):** The circuit is open until the roller lever is pressed. * **Normally Closed (NC):** The circuit is closed until the roller lever is pressed. * **Material:** Contacts are usually made of **Silver Alloy** to prevent oxidation and ensure low contact resistance over high cycle counts. ### B. Switching Logic The "A3B" designation typically refers to the physical footprint and internal spring mechanism. It uses a **Snap-action mechanism**, which ensures that the transition between NO and NC happens rapidly, regardless of the speed at which the physical lever is pushed. This prevents "arcing" (electrical sparking) between contacts. ### C. The Roller Lever (-R) The "R" at the end of the model number signifies the **Roller**. Electronically, this is significant because it allows for high-speed actuation from side-angles or cams, reducing mechanical friction which could otherwise lead to "contact bounce" (noise in the electrical signal). --- ## 3. Application Use-Cases Because of its SPDT configuration, the JDL-A3B-R is used in circuits for: 1. **Safety Interlocks:** Cutting power to a motor when a door is opened. 2. **Position Sensing:** Detecting the end-of-travel on a CNC machine or 3D printer. 3. **Control Logic:** Sending a signal to a PLC (Programmable Logic Controller) to indicate a mechanical process is complete. ---