The **JR-55-R** is a specific model of a **DC Power Jack** (also known as a barrel connector) commonly used in electronic devices for power input. It is designed to be mounted onto a Printed Circuit Board (PCB). Below is a detailed breakdown of its electronic specifications and physical characteristics. --- ### 1. Technical Specifications The JR-55-R is categorized as a 2.1mm DC Power Jack. Its primary function is to provide a secure interface between an external power adapter and an internal circuit. | Parameter | Specification | | :--- | :--- | | **Pin Diameter** | 2.1 mm | | **Bushing Diameter** | 5.5 mm | | **Current Rating** | 2A to 5A (depending on manufacturer) | | **Voltage Rating** | 12V to 24V DC | | **Contact Resistance** | ≤ 30mΩ | | **Insulation Resistance** | ≥ 100MΩ (500V DC) | | **Withstand Voltage** | 500V AC for 1 minute | --- ### 2. Physical Construction & Pinout The "R" in the model name typically indicates a **Right-Angle** PCB mount configuration. It usually features three terminals: 1. **Center Pin (Tip):** Usually connected to the Positive (+) terminal. 2. **Outer Sleeve (Barrel):** Usually connected to the Negative/Ground (-) terminal. 3. **Shunt/Switch Pin:** A third pin that acts as a physical switch. When no plug is inserted, it connects to the sleeve pin. When a plug is inserted, the connection is broken. This is often used to disconnect an internal battery when an external power supply is plugged in. --- ### 3. Materials The longevity of the part depends on the materials used in its construction: * **Housing:** High-temperature PBT or Nylon (PA66) for wave soldering compatibility. * **Center Pin:** Brass (Nickel or Tin plated). * **Contacts:** Phosphor Bronze or Copper Alloy. --- ### 4. Common Applications * **Arduino/Microcontroller Boards:** Often used as the primary power input. * **Consumer Electronics:** Routers, LED strip controllers, and external hard drive enclosures. * **DIY Projects:** Providing a standard 12V DC input interface. ---