Coil Bobbin: Inner Diameter 5-30 mm, Outer Diameter 10-50 mm

Component Specifications

Definition

A coil bobbin is a critical component in industrial electromagnetic relay coil assemblies, designed to hold and organize copper or aluminum wire windings. It provides mechanical stability, thermal management, and electrical insulation between the coil windings and the relay's magnetic core. Typically made from high-temperature resistant polymers or ceramics, it features flanges at both ends to prevent wire slippage and maintain winding integrity under operational stresses.

Working Principle

The coil bobbin functions by providing a rigid, insulated form around which conductive wire is wound to create an electromagnetic coil. When current flows through the wire, it generates a magnetic field, and the bobbin ensures consistent coil geometry for reliable magnetic flux generation. It isolates the windings from the core and other components, preventing short circuits and maintaining electrical efficiency.

Materials

Typically made from high-temperature thermoplastics (e.g., PBT, PET, PPS), thermosetting plastics (e.g., phenolic resins), or ceramics. Materials must have high dielectric strength, thermal stability (up to 155°C or higher), and resistance to moisture and chemicals.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Height	15-60 mm
Inner Diameter	5-30 mm
Outer Diameter	10-50 mm
Flange Diameter	15-70 mm
Temperature Rating	-40°C to 155°C
Dielectric Strength	>10 kV/mm
Insulation Resistance	>10^12 Ω

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards

ISO 9001, IEC 61810, UL 94

Parent Products

This component is used in the following industrial products

Industrial Electromagnetic Relay Coil Assembly

This industrial electromagnetic relay coil assembly is a precision component designed for use in industrial control relays.

View Product Details

Solenoid Coil & Plunger

An electromagnetic actuator assembly consisting of a wire-wound coil and a movable ferromagnetic plunger, used to convert electrical energy into linear mechanical motion.

View Product Details

Engineering Analysis

Risks & Mitigation

Electrical insulation failure due to material degradation
Mechanical deformation under thermal stress
Inconsistent winding leading to relay malfunction

FMEA Triads

Trigger: Material thermal degradation
Failure: Reduced dielectric strength causing short circuits
Mitigation: Use materials with higher temperature ratings and implement thermal management in design

Trigger: Improper winding tension
Failure: Coil deformation or wire breakage
Mitigation: Automate winding processes with tension control and quality checks

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

±0.1 mm on critical dimensions

Test Method

Dielectric withstand test per IEC 60243, thermal cycling per IEC 60068

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

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Manufacturers of Coil Bobbin

Manufacturer profiles associated with Coil Bobbin.

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Frequently Asked Questions

What is the primary function of a coil bobbin in a relay?

The primary function is to provide structural support and electrical insulation for the coil windings, ensuring consistent magnetic field generation and preventing short circuits.

What materials are commonly used for coil bobbins?

Common materials include high-temperature thermoplastics like PBT and PPS, thermosetting plastics such as phenolic resins, and ceramics, chosen for their dielectric strength and thermal stability.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Coil Bobbin