Grayhill 78RB04S DIP Switch Equivalent & Substitute Parts

Part Overview

The Grayhill 78RB04S is a slide-actuated DIP switch featuring SPST (Single Pole Single Throw) circuit configuration with 4-position through-hole mounting. This component is rated for 150mA at 30VDC and is designed for applications requiring reliable switching in compact form factors. The 78RB04S carries an obsolete product status, making identification of functionally equivalent alternatives essential for ongoing design support, maintenance, and production continuity.

Substiute Parts

78RB04S

Grayhill Inc.In Stock: 98278RB04S Datasheet

Current PartRFQ

78RB04ST

Grayhill Inc.In Stock: 631378RB04ST Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the Grayhill 78RB04S is determined by strict equivalence across the following critical parameters:

Electrical Parameters: Circuit type (SPST), number of positions (4), current rating (150mA), and voltage rating (30VDC) must be identical.

Mechanical Parameters: Actuator type (Slide Standard), mounting method (Through Hole), pitch spacing (0.100"), and height above board (0.265") must match exactly.

Environmental Parameters: Operating temperature range (-40°C to 85°C), mechanical life (2,000 cycles), and electrical life (2,000 cycles) establish minimum performance thresholds.

Material Specifications: Contact material (Copper Alloy) and contact finish (Gold) ensure electrical performance and reliability consistency.

The 78RB04ST qualifies as a direct substitute based on complete alignment with all specified parameters. The primary distinction is product status and compliance certification, not functional or physical characteristics.

Parameter Comparison

Engineering Selection Recommendations

The 78RB04ST serves as the direct functional equivalent to the obsolete 78RB04S. All electrical, mechanical, and environmental specifications are identical, ensuring drop-in compatibility in circuit designs and PCB layouts.

Product Status Consideration: The 78RB04S is classified as obsolete, while the 78RB04ST maintains active product status. For new designs, ongoing production, and long-term supply chain stability, the 78RB04ST is the appropriate selection.

Compliance Advantage: The 78RB04ST achieves ROHS3 compliance, whereas the 78RB04S is RoHS non-compliant. Applications subject to RoHS directives or customer compliance requirements must utilize the 78RB04ST.

Packaging Difference: The 78RB04ST is supplied in tube packaging, compared to bulk packaging for the 78RB04S. Packaging selection should align with procurement volume and handling requirements.

Inventory and Availability: The 78RB04ST maintains significantly higher inventory levels (6,268 pieces) relative to the 78RB04S (963 pieces), supporting consistent supply for production and maintenance applications.

Frequently Asked Questions (FAQ)

Q: Can the 78RB04ST replace the 78RB04S in existing circuit designs?

A: Yes. The 78RB04ST is electrically and mechanically identical to the 78RB04S. All electrical parameters (150mA, 30VDC, SPST), mechanical dimensions (0.265" height, 0.100" pitch), and performance characteristics (2,000 cycle life) are equivalent. No circuit modifications are required.

Q: What is the primary reason to transition from 78RB04S to 78RB04ST?

A: The 78RB04S is obsolete, while the 78RB04ST is an active product. The 78RB04ST also achieves ROHS3 compliance, addressing regulatory requirements and ensuring long-term component availability.

Q: Are there physical differences between these parts that affect PCB layout?

A: No. Both parts share identical mounting specifications: through-hole termination, 0.100" pitch, 0.265" height above board, and flush/recessed actuator level. PCB footprints and assembly procedures remain unchanged.

Q: Does packaging affect component performance or compatibility?

A: No. Packaging (tube versus bulk) affects logistics and handling only. The electrical and mechanical performance of the component itself is independent of packaging format.

Q: What compliance certifications apply to each part?

A: The 78RB04S is RoHS non-compliant. The 78RB04ST is ROHS3 compliant. Both parts are REACH unaffected and classified under ECCN EAR99. Applications requiring RoHS compliance must use the 78RB04ST.

Q: Are there any electrical performance differences between the 78RB04S and 78RB04ST?

A: No. Both parts are rated for 150mA at 30VDC, feature identical contact materials (copper alloy with gold finish), and deliver equivalent mechanical and electrical life (2,000 cycles each). Operating temperature range is identical (-40°C to 85°C).