## PJ-059B DC Power Jack Technical Overview The **PJ-059B** is a common Surface Mount Technology (SMT) DC power jack used primarily in consumer electronics for power input. It is designed to receive a barrel-type connector from an external AC/DC power adapter. --- ### 1. Physical and Mechanical Specifications The PJ-059B is characterized by its compact footprint and specific pin dimensions. | Feature | Specification | | :--- | :--- | | **Mounting Type** | Surface Mount (SMT) | | **Center Pin Diameter** | 2.0 mm (standard) | | **Outer Diameter Compatibility** | 5.5 mm | | **Housing Material** | Thermoplastic (High-temp UL94V-0) | | **Number of Terminals** | 3 (Center Pin, Outer Shield, and Shunt/Switch) | --- ### 2. Electrical Characteristics These parameters define the safe operating limits of the component. Exceeding these values can lead to overheating or component failure. * **Current Rating:** Typically **2.5A to 3.0A** (varies by manufacturer). * **Voltage Rating:** **16V to 24V DC**. * **Contact Resistance:** ≤ 30mΩ. * **Insulation Resistance:** ≥ 100MΩ at 500V DC. * **Dielectric Strength:** 500V AC for 1 minute. --- ### 3. Pin Configuration and Internal Switch The PJ-059B usually features three pins. Understanding the internal switch is crucial for battery-powered devices. 1. **Pin 1 (Center Pin):** Positive (+) terminal. Connects to the center of the barrel plug. 2. **Pin 2 (Outer Shield):** Negative/Ground (-) terminal. Connects to the outer sleeve of the plug. 3. **Pin 3 (Shunt/Switch):** This pin is normally closed (NC) to Pin 2 when no plug is inserted. When a plug is inserted, it breaks the connection. This is often used to disconnect an internal battery when an external power supply is plugged in. --- ### 4. Circuit Symbol Representation In a schematic, the PJ-059B is represented as a jack with a switch. ```text [Center Pin] --------(+) VCC / Plug < [Outer Shield] ----(-) GND \ ---[Shunt Pin] ----- Battery Negative (Optional) ``` --- ### 5. Common Applications * Laptops and Notebooks * Digital Cameras * Portable Medical Equipment * Wireless Routers and Network Hubs * Small DIY Electronics Projects