Grayhill 78B03S DIP Switch Equivalent & Substitute Parts

Part Overview

The Grayhill 78B03S is a single-pole single-throw (SPST) slide DIP switch designed for through-hole mounting applications requiring 150mA at 30VDC switching capability. This component features a 3-position configuration with gold-plated copper alloy contacts and operates across the industrial temperature range of -40°C to 85°C.

The 78B03S carries an obsolete product status. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or repair requirements for legacy systems utilizing this component.

Substiute Parts

78B03S

Grayhill Inc.In Stock: 115278B03S Datasheet

Current PartRFQ

78B03ST

Grayhill Inc.In Stock: 477778B03ST Datasheet

DirectRFQ

206-3ST

CTS ElectrocomponentsIn Stock: 13568206-3ST Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 78B03S is determined by the following critical parameters:

Primary Compatibility Criteria:

• Circuit configuration (SPST)
• Number of positions (3)
• Mounting type (Through Hole)
• Pitch spacing (0.100" / 2.54mm)
• Actuator type (Slide Standard)
• Termination style (PC Pin)

Electrical Performance Criteria:

• Current rating must equal or exceed 150mA
• Voltage rating must equal or exceed 30VDC
• Operating temperature range must encompass or exceed -40°C to 85°C

Mechanical Compatibility Criteria:

• Height above board and overall dimensions must be compatible with existing PCB layouts
• Contact material and finish must support equivalent switching performance

Two substitute parts meet the core mechanical and electrical interface requirements:

78B03ST (Grayhill Inc.): Direct manufacturer equivalent with identical electrical ratings, mechanical dimensions, and circuit configuration. Product status is Active. Primary difference is RoHS3 compliance versus non-compliance of the original part.

206-3ST (CTS Electrocomponents): Cross-manufacturer substitute with compatible mechanical interface and circuit configuration. Electrical ratings differ: 50mA current and 24VDC voltage versus the original 150mA and 30VDC specifications. This part operates within a wider temperature range (-55°C to 85°C) and provides extended electrical life (10,000 cycles).

Parameter Comparison

Engineering Selection Recommendations

78B03ST Selection Criteria:

The 78B03ST is the primary substitute for the obsolete 78B03S. This part maintains identical electrical specifications (150mA, 30VDC), mechanical dimensions, and circuit configuration. The 78B03ST is manufactured by the same supplier (Grayhill Inc.) and carries Active product status, ensuring ongoing availability and supply chain stability.

The 78B03ST achieves ROHS3 compliance, whereas the original 78B03S is non-compliant. This compliance upgrade is advantageous for new designs and manufacturing environments subject to RoHS regulations. Both parts share equivalent moisture sensitivity levels and REACH status.

Selection of the 78B03ST is appropriate for direct replacement in existing designs without PCB layout modifications or electrical circuit redesign.

206-3ST Selection Criteria:

The 206-3ST is a cross-manufacturer substitute manufactured by CTS Electrocomponents. This part is suitable only for applications where the electrical load requirements are lower than the original specification. The 206-3ST is rated for 50mA at 24VDC, representing a reduction in both current and voltage capacity compared to the 78B03S (150mA at 30VDC).

The 206-3ST provides extended electrical life (10,000 cycles versus 2,000 cycles) and operates across a wider temperature range (-55°C to 85°C). The height above board is marginally increased (0.334" versus 0.315"), which may require verification against PCB clearance constraints.

Selection of the 206-3ST is appropriate only when circuit requirements do not exceed 50mA at 24VDC and when the extended electrical life and temperature range provide design advantages.

Compliance and Regulatory Considerations:

Both substitute parts maintain EAR99 export classification and REACH Unaffected status, consistent with the original part. Both substitutes achieve ROHS3 compliance, supporting modern manufacturing and environmental standards.

Frequently Asked Questions (FAQ)

Q: Can the 78B03ST be used as a direct replacement for the 78B03S without PCB modifications?

A: Yes. The 78B03ST maintains identical electrical ratings (150mA, 30VDC), mechanical dimensions, pitch spacing (0.100"), and through-hole mounting configuration. No PCB layout changes are required. The primary difference is product status (Active versus Obsolete) and RoHS3 compliance.

Q: What are the limitations of using the 206-3ST as a substitute?

A: The 206-3ST has reduced electrical capacity: 50mA at 24VDC versus the original 150mA at 30VDC. This part is suitable only for applications with lower switching loads. The height above board is 0.334" compared to 0.315" for the original part; verify PCB clearance compatibility. Contact material specifications are not provided for the 206-3ST.

Q: Are there packaging differences between the 78B03S and 78B03ST?

A: The 78B03S is supplied in standard packaging (dash notation), while the 78B03ST is supplied in Tube packaging. Both parts use identical PC Pin termination and pitch specifications. Verify packaging requirements for your procurement and assembly processes.

Q: Does the 78B03ST meet modern regulatory requirements?

A: Yes. The 78B03ST is ROHS3 compliant and REACH Unaffected, meeting current environmental and regulatory standards. The original 78B03S is RoHS non-compliant. The 78B03ST is recommended for new designs and manufacturing environments subject to RoHS regulations.

Q: What is the mechanical life specification for the 206-3ST?

A: The mechanical life specification for the 206-3ST is not provided in the available technical data. The electrical life is specified as 10,000 cycles, compared to 2,000 cycles for both the 78B03S and 78B03ST. Contact the manufacturer for complete mechanical life specifications if this parameter is critical to your application.

Q: Can the 78B03S be used in applications requiring operation below -40°C?

A: No. The 78B03S operating temperature range is -40°C to 85°C. The 206-3ST extends the lower temperature limit to -55°C. If operation below -40°C is required, the 206-3ST is the only substitute option among those listed, provided the electrical load requirements do not exceed 50mA at 24VDC.

Q: What is the moisture sensitivity level (MSL) for the 206-3ST?

A: The 206-3ST has a moisture sensitivity level designation of Not Applicable. Both the 78B03S and 78B03ST are rated MSL 1 (Unlimited), indicating no moisture sensitivity constraints. The 206-3ST's Not Applicable designation indicates different handling requirements; verify storage and handling procedures with the manufacturer.