Grayhill 78M08S DIP Switch SPST 8-Position Equivalent & Substitute Parts

Part Overview

The Grayhill 78M08S is an 8-position DIP switch with SPST (Single Pole Single Throw) circuit configuration, rated for 150mA at 30VDC. This component features a slide actuator with standard raised level, gold-plated copper alloy contacts, and through-hole PC pin termination. The 78M08S is classified as obsolete product status, necessitating identification of active equivalent alternatives to ensure continued design support and procurement availability for new production builds and field replacements.

Substiute Parts

78M08S

Grayhill Inc.In Stock: 611278M08S Datasheet

Current PartRFQ

78B08ST

Grayhill Inc.In Stock: 253978B08ST Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the Grayhill 78M08S is determined by strict equivalence across the following critical parameters:

Electrical Parameters: Circuit type (SPST), number of positions (8), 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 (0.315") must match exactly.

Material & Environmental Parameters: Contact material (copper alloy), contact finish (gold), operating temperature range (-40°C to 85°C), mechanical life (2,000 cycles), and electrical life (2,000 cycles) must be equivalent.

Compliance & Status: While product status may differ (obsolete versus active), RoHS compliance and REACH status are documented for engineering decision-making but do not disqualify functional equivalence.

The Grayhill 78B08ST meets all substitution criteria as a direct functional equivalent with identical electrical and mechanical specifications.

Parameter Comparison

Engineering Selection Recommendations

The Grayhill 78B08ST is a direct functional substitute for the obsolete 78M08S. All electrical and mechanical parameters are identical, ensuring pin-for-pin and form-factor compatibility in existing PCB designs.

Product Status Consideration: The 78M08S is classified as obsolete, while the 78B08ST is active product. Selection of the 78B08ST ensures access to current manufacturing, quality assurance, and long-term supply chain stability.

Compliance Upgrade: The 78B08ST achieves ROHS3 compliance, whereas the 78M08S is RoHS non-compliant. For applications subject to RoHS regulatory requirements, the 78B08ST provides compliance alignment.

Packaging Difference: The 78B08ST is supplied in tube packaging, compared to standard packaging for the 78M08S. Packaging format does not affect electrical or mechanical performance and is a procurement consideration only.

Direct Substitution: No design modifications, PCB layout changes, or firmware adjustments are required when transitioning from 78M08S to 78B08ST.

Frequently Asked Questions (FAQ)

Q: Can the 78B08ST be used as a direct replacement for the 78M08S in existing designs?

A: Yes. The 78B08ST is electrically and mechanically identical to the 78M08S. All electrical parameters (150mA, 30VDC, SPST 8-position), mechanical dimensions (0.315" height, 0.100" pitch, through-hole mounting), and contact specifications (gold-plated copper alloy) are equivalent. No design changes are required.

Q: What is the difference between the 78M08S and 78B08ST?

A: The primary differences are product status and compliance. The 78M08S is obsolete and RoHS non-compliant. The 78B08ST is active product with ROHS3 compliance. Packaging differs (tube for 78B08ST versus standard for 78M08S). Functional performance is identical.

Q: Why is the 78M08S listed as obsolete?

A: Obsolete status indicates the manufacturer has discontinued active production and support. The 78B08ST is the active equivalent, ensuring continued availability and manufacturing support.

Q: Does the tube packaging of the 78B08ST affect performance?

A: No. Packaging format is a logistics and handling consideration only. Tube packaging does not alter electrical performance, mechanical specifications, or reliability characteristics.

Q: Are there any environmental or temperature differences between these parts?

A: No. Both parts operate across the identical temperature range of -40°C to 85°C with identical mechanical and electrical life ratings of 2,000 cycles.

Q: Is the 78B08ST suitable for RoHS-regulated applications?

A: Yes. The 78B08ST is ROHS3 compliant, making it suitable for applications subject to RoHS directives. The 78M08S is not RoHS compliant.

Q: Can I mix 78M08S and 78B08ST components in the same production batch?

A: Yes, from a functional standpoint. Both parts are electrically and mechanically identical. However, procurement and quality documentation should reflect the specific part numbers used in each batch for traceability and compliance purposes.