Terminal Blocks - Headers, Plugs and Sockets

Part Number	Description / PDF	Quantity
EM257518VC PowerStor (Eaton)	TERM BLOCK HDR 18POS VERT 5.08MM	0
EM257512VC-BK PowerStor (Eaton)	TERM BLOCK HDR 12POS VERT 5.08MM	0
EM353306 PowerStor (Eaton)	TERM BLOCK PLUG 6POS STR 3.5MM	0
EM253512HC PowerStor (Eaton)	TERM BLOCK HDR 12POS 90DEG 5MM	0
EM252509-KIT PowerStor (Eaton)	TERM BLOCK HDR 9POS 5MM	0
EM257502HC PowerStor (Eaton)	TERM BLOCK HDR 2POS 90DEG 5.08MM	400
EM256508HL1 PowerStor (Eaton)	TERM BLOCK PLUG 8POS STR 5.08MM	0
EM256510VR PowerStor (Eaton)	TERM BLOCK PLUG 10POS 5.08MM	0
EM221803H PowerStor (Eaton)	TERM BLOCK HDR 3POS 90DEG 5.08MM	0
EM221804V PowerStor (Eaton)	TERM BLOCK HDR 4POS VERT 5.08MM	0
EM252506 PowerStor (Eaton)	EURO (110106) KEEP	0
EM257506VC-BK PowerStor (Eaton)	TERM BLOCK HDR 6POS VERT 5.08MM	0
EM256507H-BK PowerStor (Eaton)	TERM BLOCK PLUG 7POS STR 5.08MM	0
EM221806V PowerStor (Eaton)	TERM BLOCK HDR 6POS VERT 5.08MM	0
EM257511HC PowerStor (Eaton)	TERM BLOCK HDR 11POS 5.08MM	0
EM222102V PowerStor (Eaton)	EUROMAG 2221XXV SERIES 2 POLE	0
EM221808H PowerStor (Eaton)	TERM BLOCK HDR 8POS 90DEG 5.08MM	0
EM253509VO PowerStor (Eaton)	TERM BLOCK HDR 9POS VERT 5MM	0
EM256503H PowerStor (Eaton)	TERM BLOCK PLUG 3POS STR 5.08MM	0
EM256504H PowerStor (Eaton)	TERM BLOCK PLUG 4POS STR 5.08MM	0

Terminal Blocks - Headers, Plugs and Sockets

1. Overview

Terminal blocks, headers, plugs, and sockets are essential components in electrical and electronic systems for establishing reliable connections between circuits. These devices enable signal transmission, power distribution, and system modularity. Their standardized designs ensure interoperability, scalability, and ease of maintenance in complex systems.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Terminal Blocks	Screw/clamp-based connections for high current/ voltage	Industrial control panels, power distribution units
PCB Headers	Pin/grid arrays for board-to-board connections	Embedded systems, Arduino shields
RJ Connectors	Modular jacks for data/telecom signals	Ethernet networks (RJ45), telephone systems (RJ11)
D-Sub Connectors	Multi-pin trapezoidal shells for analog/digital signals	Legacy serial interfaces, industrial sensors
USB Connectors	Hot-pluggable interfaces for power/data	Consumer electronics, peripheral devices

3. Structure and Components

Typical structures include:

Insulating housing (PA66, PBT, or LCP plastics)
Contact elements (phosphor bronze, beryllium copper)
Plating materials (gold, tin, nickel for corrosion resistance)
Actuation mechanisms (screws, spring clamps, or friction fits)
EMI shielding layers (for high-frequency applications)

4. Key Technical Specifications

Parameter	Importance
Current Rating (A)	Determines power handling capacity
Voltage Rating (V)	Defines dielectric strength requirements
Contact Resistance (m )	Impacts signal integrity and power loss
Insertion Loss (dB)	Critical for high-speed data transmission
Mating Cycles	Indicates mechanical durability
Operating Temperature (- C to + C)	Defines environmental tolerance

5. Application Fields

Primary industries include:

Industrial automation (PLCs, HMIs)
Telecommunications (5G base stations, routers)
Consumer electronics (smartphones, wearables)
Medical equipment (imaging devices, patient monitors)
Automotive (EV charging systems, ADAS)

6. Leading Manufacturers and Products

Manufacturer	Representative Product
Phoenix Contact	COMBICON series terminal blocks
TE Connectivity	MICRO MATCH connectors
Molex	SL Series headers
Amphenol	D-Subminiature connectors
Samtec	QTE high-speed socket systems

7. Selection Guidelines

Key considerations:

Electrical requirements (current/voltage levels)
Mechanical constraints (space, vibration)
Environmental factors (temperature, humidity)
Signal integrity needs (frequency, noise rejection)
Cost vs. reliability trade-offs
Compliance with standards (IPC, IEC, UL)

8. Industry Trends

Emerging developments include:

Miniaturization for wearable devices
High-speed connectors for 5G/6G ( 25 Gbps)
Hybrid connectors integrating power/data
Eco-friendly materials (halogen-free, RoHS compliant)
Smart connectors with built-in sensors
Automotive-grade connectors for EVs