Grayhill 78C04SRAT DIP Switch Equivalent & Substitute Parts

Part Overview

The Grayhill 78C04SRAT is a 4-position DIP switch featuring SPST (Single Pole Single Throw) circuit configuration with slide actuator, rated for 25mA at 24VDC. This component is classified as obsolete product status. Identifying equivalent and substitute parts is necessary to support ongoing system maintenance, design updates, and procurement continuity where the original part is no longer in active production.

Substiute Parts

78C04SRAT

Grayhill Inc.In Stock: 93278C04SRAT Datasheet

Current PartRFQ

78B04SRAT

Grayhill Inc.In Stock: 99478B04SRAT Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 78C04SRAT is determined by the following critical parameters:

Electrical Compatibility Parameters:

• Circuit configuration (SPST maintained)
• Number of positions (4 positions maintained)
• Current rating (must equal or exceed 25mA)
• Voltage rating (must equal or exceed 24VDC)

Mechanical Compatibility Parameters:

• Actuator type (Slide Standard maintained)
• Mounting type (Through Hole, Right Angle maintained)
• Pitch spacing (0.100" / 2.54mm maintained)
• Termination style (PC Pin maintained)

Environmental & Compliance Parameters:

• Operating temperature range (must encompass or exceed -20°C ~ 70°C)
• RoHS compliance status
• Moisture sensitivity level

The 78B04SRAT qualifies as a direct substitute because it maintains identical mechanical form factor, mounting configuration, and circuit topology while providing enhanced electrical ratings (150mA at 30VDC) and extended operating temperature range (-40°C ~ 85°C). The substitute part operates within all electrical and thermal parameters required by applications designed for the 78C04SRAT.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement Applications:

The 78B04SRAT is the appropriate substitute for the obsolete 78C04SRAT in new designs and system updates. The substitute part maintains identical mechanical footprint and electrical circuit topology while providing superior performance characteristics. The 78B04SRAT carries active product status from Grayhill Inc., ensuring long-term availability and supply chain continuity.

Compliance Considerations:

Both parts maintain RoHS compliance status. The 78B04SRAT achieves ROHS3 compliance, representing current regulatory alignment. Both components are REACH Unaffected and classified under ECCN EAR99, maintaining identical export control status.

Performance Enhancement:

The 78B04SRAT provides increased electrical ratings (150mA versus 25mA; 30VDC versus 24VDC) and extended operating temperature range (-40°C ~ 85°C versus -20°C ~ 70°C). These enhanced specifications support applications requiring greater thermal tolerance and electrical headroom without requiring PCB redesign or mechanical modification.

Electrical Life Advantage:

The substitute part offers 10,000 electrical life cycles compared to 2,000 cycles in the original part, providing extended operational durability in switching applications.

Frequently Asked Questions (FAQ)

Q: Can the 78B04SRAT be used as a direct drop-in replacement for the 78C04SRAT?

A: Yes. The 78B04SRAT maintains identical mechanical dimensions, mounting configuration, pitch spacing, and circuit topology. No PCB modifications or mechanical redesign is required for substitution.

Q: What are the key electrical differences between these parts?

A: The 78B04SRAT provides higher current rating (150mA versus 25mA) and higher voltage rating (30VDC versus 24VDC). Applications designed for 25mA at 24VDC operate within the electrical envelope of the substitute part.

Q: Does the height difference affect PCB assembly?

A: The height difference is minimal (0.380" versus 0.390", a 0.010" reduction). This variation is within standard PCB assembly tolerances and does not affect component placement or clearance requirements.

Q: Why is the 78C04SRAT classified as obsolete?

A: The 78C04SRAT has been discontinued by Grayhill Inc. The 78B04SRAT from the active 78 series represents the current production equivalent.

Q: Are there packaging differences between these parts?

A: The 78C04SRAT is supplied in standard packaging. The 78B04SRAT is supplied in Tube packaging. Both maintain identical component specifications and performance characteristics.

Q: What is the contact material difference and does it affect performance?

A: The 78C04SRAT uses Phosphor Bronze contacts; the 78B04SRAT uses Copper Alloy contacts. Both feature gold finish and maintain equivalent electrical performance and reliability for the specified current and voltage ratings.

Q: Does the extended operating temperature range of the 78B04SRAT affect compatibility?

A: No. The extended range (-40°C ~ 85°C) encompasses the original operating range (-20°C ~ 70°C). Applications designed for the narrower temperature range operate within the substitute part's specifications.

Q: Are both parts RoHS compliant?

A: Yes. The 78C04SRAT is RoHS Compliant. The 78B04SRAT is ROHS3 Compliant, representing current regulatory standards. Both meet RoHS requirements.