## Overview of the PJ-059AH The **PJ-059AH** is a specific model of a **DC Power Jack**, widely used in electronic devices to provide a connection point for external power adapters. It is a surface-mount (SMT) or through-hole component depending on the specific variant, designed to handle low to medium voltage DC inputs. --- ### Technical Specifications The following table outlines the typical electrical and mechanical characteristics of the PJ-059AH: | Parameter | Specification | | :--- | :--- | | **Connector Type** | DC Power Jack | | **Center Pin Diameter** | 2.0 mm | | **Internal Diameter** | 5.5 mm (Compatible with 5.5x2.0mm plugs) | | **Current Rating** | 2.5 A to 3.0 A | | **Voltage Rating** | 16 VDC to 24 VDC | | **Contact Resistance** | 30 mΩ Max | | **Insulation Resistance** | 100 MΩ Min at 500 VDC | | **Mounting Type** | Through-hole (Right Angle) | | **Number of Pins** | 3 Pins (Positive, Negative, and Shunt/Switch) | --- ### Key Electronic Components & Design The PJ-059AH consists of several critical parts that ensure reliable power delivery: 1. **Center Pin:** This represents the positive (+) terminal in most standard configurations. It is made of a conductive copper alloy, often nickel or gold-plated to prevent oxidation. 2. **Shunt Spring/Terminal:** This is a flexible metal contact. When no plug is inserted, it usually touches the outer contact. When a plug is inserted, it breaks the connection, which can be used by the circuit to detect if an external power supply is present. 3. **Housing:** Made of high-temperature thermoplastic (e.g., PBT or Polyamide). This ensures the jack can withstand the heat of soldering (reflow or wave) and provides electrical insulation. 4. **Terminals:** The solder pins that connect to the PCB. * **Pin 1:** Center Pin (Power). * **Pin 2:** Outer Sleeve (Ground). * **Pin 3:** Shunt/Switch (Used for battery bypass circuits). --- ### Typical Circuit Application In many designs, the 3rd pin (shunt) is used to disconnect an internal battery when the external DC adapter is plugged in. ```c // Logical Representation of the Switch If (Plug_Inserted == TRUE) { Internal_Battery = DISCONNECTED; External_Power = CONNECTED; } else { Internal_Battery = CONNECTED; } ``` --- ### Comparison with Similar Models | Model | Pin Size | Mounting | Current Limit | | :--- | :--- | :--- | :--- | | **PJ-059AH** | 2.0 mm | Through-hole | 2.5A | | **PJ-059BH** | 2.5 mm | Through-hole | 2.5A | | **PJ-002A** | 2.1 mm | Through-hole | 2.0A |