What is a DC Power Jack?
A DC Power Jack is an electronic connector specifically designed to receive DC power from an external power adapter. It is typically soldered or mounted onto the printed circuit board (PCB) of an electronic device and is commonly found in equipment such as laptop computers, routers, and surveillance cameras. Its primary function is to deliver DC power from the power adapter to the device’s mainboard and battery in a stable manner.
Main Functions and Features
- Power Input Interface
Safely and reliably delivers low-voltage DC power converted by an external power adapter, such as 5V, 12V, or 24V, to the device’s internal circuitry. - Mechanical and Electrical Stability
The internal structure typically includes spring contacts to ensure a secure connection with the DC Power Plug, helping prevent looseness, poor contact, and sparking. - Common Applications
Widely used in routers, monitors, compact audio systems, network cameras, measuring instruments, small household appliances, and various embedded control modules.
Structure and Working Principle
- Physical Structure
A typical DC Power Jack consists of a central metal pin, usually the positive terminal; an outer metal sleeve or spring contact, usually the negative terminal; and an insulating layer between them. - Working Principle
When the plug is inserted, the spring contact flexes to maintain close contact with the plug, forming a low-resistance electrical path. When the plug is removed, the spring contact returns to its original position and disconnects the circuit. - Polarity Requirements
DC Power Jacks have specific polarity requirements. The most common configuration is center-positive and outer-negative. Reversing the polarity may cause immediate damage to the device.
Common Specifications and Classifications
- Common Sizes
5.5 mm × 2.1 mm and 5.5 mm × 2.5 mm are the two most common sizes. Although they share the same outer diameter, their inner diameters differ, so they are not interchangeable. - Other Sizes
Other specifications include 3.5 mm × 1.35 mm, commonly used in small devices such as routers, and 4.0 mm × 1.7 mm, used in audio equipment, among others. - Mounting and Soldering Types
- DIP (Dual In-line Package / Through-Hole Mounting)
Soldered to the PCB through holes, providing high mechanical strength. - SMT (Surface-Mount Technology)
Soldered directly onto the surface of the circuit board, making it suitable for compact, lightweight devices. - Special Designs
For certain high-current or industrial applications, a locking DC Jack with a twist-lock mechanism may be used to prevent accidental disconnection when the cable is pulled.
- DIP (Dual In-line Package / Through-Hole Mounting)
Where to Buy DC Power Jacks
DC Power Jacks are a long-established product category. Taiwanese manufacturers Chun Chi Industrial Co., Ltd. and Anytronic Corporation Limited have been producing DC Power Jacks since 1988. Products are available in LCP and PBT materials, with a wide range of configurations, specifications, and colors.
DC Power Jacks are widely used in laptop computers, routers, surveillance equipment, industrial control equipment, and various other electronic devices.
Introduction to DC Power Jack Specifications and Component Names
