Equivalent & Substitute Parts for Grayhill 78C03RAT DIP Switch

Part Overview

The Grayhill 78C03RAT is a single-pole single-throw (SPST) slide DIP switch with 3 positions, rated for 25mA at 24VDC. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The 78C03RAT features through-hole, right-angle mounting with gold-plated phosphor bronze contacts and operates across a temperature range of -20°C to 70°C. Identifying compatible alternatives ensures design continuity and supply chain reliability for applications requiring SPST DIP switch functionality.

Substiute Parts

78C03RAT

Grayhill Inc.In Stock: 107378C03RAT Datasheet

Current PartRFQ

78B03RAT

Grayhill Inc.In Stock: 95978B03RAT Datasheet

DirectRFQ

KAS2103E

E-SwitchIn Stock: 1051KAS2103E Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 78C03RAT are identified based on strict electrical and mechanical compatibility criteria. The primary substitution logic follows these parameters:

Direct Electrical Compatibility: Substitute parts must support SPST circuit configuration with 3 positions and through-hole, right-angle mounting with 0.100" pitch. The 78C03RAT operates at 25mA and 24VDC; substitutes must support these ratings or higher without exceeding application limits.

Mechanical Compatibility: All substitutes must feature slide-type actuators with raised actuator levels, PC pin termination, and gold-plated contacts. Physical dimensions, particularly height above board and length, must accommodate existing PCB layouts.

Compliance and Status: Substitutes are prioritized by active product status and current RoHS/REACH compliance certifications, ensuring long-term availability and regulatory alignment.

Two substitute parts meet these criteria:

1. 78B03RAT (Grayhill Inc.): Direct manufacturer alternative with enhanced electrical ratings (150mA, 30VDC) and extended operating temperature range (-40°C to 85°C). Copper alloy contacts with improved electrical life (10,000 cycles). Active product status ensures continued availability.

2. KAS2103E (E-Switch): Cross-manufacturer equivalent with identical electrical ratings (25mA, 24VDC) and contact material (phosphor bronze). Extended operating temperature range (-40°C to 85°C) and active product status. Polybutylene terephthalate (PBT) glass-filled body material.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Identical Electrical Performance):

The KAS2103E from E-Switch provides the closest functional equivalent to the 78C03RAT. Both components share identical electrical ratings (25mA, 24VDC), SPST configuration, 3-position design, and phosphor bronze contact material. The KAS2103E maintains mechanical compatibility with through-hole, right-angle mounting and 0.100" pitch. Extended operating temperature range (-40°C to 85°C) and active product status with ROHS3 compliance support long-term design continuity.

For Enhanced Performance Applications:

The 78B03RAT from Grayhill Inc. offers higher electrical ratings (150mA, 30VDC) and extended electrical life (10,000 cycles versus 2,000 cycles). This substitute is suitable for applications requiring greater current capacity or longer operational cycles. Copper alloy contacts provide alternative contact material characteristics. Active product status and ROHS3 compliance ensure regulatory alignment. Height above board is marginally reduced (0.380" versus 0.390"), which may require PCB layout verification in space-constrained designs.

Compliance Considerations:

Both substitute parts carry ROHS3 compliance and REACH unaffected status, meeting current regulatory requirements. The obsolete status of the 78C03RAT necessitates transition to either active substitute for new designs or ongoing production.

Frequently Asked Questions (FAQ)

Q: Can the 78B03RAT replace the 78C03RAT in all applications?

A: The 78B03RAT is electrically compatible with the 78C03RAT for applications operating at 25mA and 24VDC. The higher ratings (150mA, 30VDC) do not prevent substitution in lower-demand circuits. However, the reduced height above board (0.380" versus 0.390") requires verification that PCB clearances and component spacing remain adequate. Both parts share identical mechanical pitch (0.100") and mounting type.

Q: What is the difference between the 78B03RAT and KAS2103E?

A: The 78B03RAT and KAS2103E differ in manufacturer (Grayhill versus E-Switch), contact material (copper alloy versus phosphor bronze), and body material (plastic versus PBT glass-filled). Electrically, both support 25mA at 24VDC. The 78B03RAT offers higher current capacity (150mA) and extended electrical life (10,000 cycles). The KAS2103E provides identical electrical ratings to the original 78C03RAT with extended temperature range.

Q: Are there packaging differences between these substitutes?

A: The 78C03RAT original specification does not list packaging detail. Both substitutes (78B03RAT and KAS2103E) are supplied in tube packaging. Tube packaging is standard for DIP switches and does not affect functional compatibility or PCB mounting.

Q: Does the extended operating temperature range of the substitutes affect compatibility?

A: No. The 78C03RAT operates from -20°C to 70°C. Both substitutes extend this range to -40°C to 85°C, which is a superset of the original specification. Extended temperature capability does not reduce compatibility; it provides additional operational margin for applications in wider temperature environments.

Q: What is the significance of electrical life ratings?

A: The 78C03RAT and KAS2103E both specify 2,000 electrical life cycles. The 78B03RAT specifies 10,000 cycles. Electrical life indicates the number of switching operations before contact degradation occurs. For applications with frequent switching, the 78B03RAT provides extended service life. For static or infrequent switching applications, all three parts are equivalent.

Q: Are all three parts RoHS compliant?

A: Yes. The 78C03RAT carries RoHS compliance. Both substitutes carry ROHS3 compliance, which represents the current regulatory standard. ROHS3 compliance is a superset of earlier RoHS standards and ensures regulatory alignment for new designs and ongoing production.