Terminal Blocks - Headers, Plugs and Sockets

Part Number	Description / PDF	Quantity
EM257505HC PowerStor (Eaton)	TERM BLOCK HDR 5POS 90DEG 5.08MM	0
EM501502 PowerStor (Eaton)	TERM BLOCK PLUG 2POS 90DEG 5MM	144
EM211802H PowerStor (Eaton)	TERM BLOCK PLUG 2POS STR 5.08MM	188
EM252513 PowerStor (Eaton)	TERM BLOCK PLUG 13POS STR 5MM	0
EM253502HC PowerStor (Eaton)	TERM BLOCK HDR 2POS 90DEG 5MM	0
EM358307 PowerStor (Eaton)	TERM BLOCK PLUG 7POS 3.81MM	0
EM359303VC PowerStor (Eaton)	TERM BLOCK HDR 3POS VERT 3.81MM	0
EM359302HC PowerStor (Eaton)	TERM BLOCK HDR 2POS 90DEG 3.81MM	0
EM256503H-BK PowerStor (Eaton)	TERM BLOCK PLUG 3POS STR 5.08MM	0
EM252508 PowerStor (Eaton)	TERM BLOCK PLUG 8POS STR 5MM	0
EM256503VR PowerStor (Eaton)	TERM BLOCK PLUG 3POS 5.08MM	0
EM256505H PowerStor (Eaton)	TERM BLOCK PLUG 5POS STR 5.08MM	0
EM256508VL PowerStor (Eaton)	TERM BLOCK PLUG 8POS 5.08MM	800
EM355306 PowerStor (Eaton)	TERM BLOCK PLUG 6POS STR 3.81MM	0
EM211506VR PowerStor (Eaton)	TERM BLOCK PLUG 6POS 270DEG 5MM	0
EM221508V PowerStor (Eaton)	TERM BLOCK HDR 8POS VERT 5MM	0
EM256506H PowerStor (Eaton)	TERM BLOCK PLUG 6POS STR 5.08MM	0
EM257514HC PowerStor (Eaton)	TERM BLOCK HDR 14POS 5.08MM	0
EM211816H PowerStor (Eaton)	TERM BLOCK PLUG 16POS STR 5.08MM	0
EM359310HC PowerStor (Eaton)	TERM BLOCK HDR 10POS 3.81MM	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