Grayhill 78K01 DIP Switch DPDT Equivalent & Substitute Parts

Part Overview

The Grayhill 78K01 is a slide-actuated DIP switch with DPDT (Double Pole Double Throw) configuration, rated for 150mA at 30VDC. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing production support and design continuity. The 78K01 features a standard slide actuator with gold-plated copper alloy contacts, through-hole mounting, and a compact 0.100" pitch footprint suitable for PC board integration.

Substiute Parts

78K01

Grayhill Inc.In Stock: 98078K01 Datasheet

Current PartRFQ

78K01T

Grayhill Inc.In Stock: 618778K01T Datasheet

DirectRFQ

3-435470-1

TE Connectivity ALCOSWITCH SwitchesIn Stock: 7973-435470-1 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 78K01 is determined by strict equivalence across the following critical parameters:

Direct Equivalent Criteria:

• Circuit configuration (DPDT)
• Number of positions (1)
• Current rating (150mA minimum)
• Voltage rating (30VDC minimum)
• Mounting type (Through Hole)
• Pitch specification (0.100" / 2.54mm)
• Termination style (PC Pin)

Acceptable Variation Parameters:

• Actuator type (slide vs. toggle) — affects user interface but not electrical function
• Mechanical and electrical life cycles — acceptable if equal to or exceeding original specification
• Operating temperature range — acceptable if encompassing or exceeding original range
• RoHS and REACH compliance status — determines regulatory suitability for new designs

Non-Substitutable Parameters:

• Circuit configuration must remain DPDT
• Current and voltage ratings cannot be reduced below specified values
• Mounting type must remain through-hole with matching pitch

The 78K01T (Grayhill) qualifies as a direct equivalent with identical electrical and mechanical specifications but improved product status (Active) and RoHS3 compliance. The 3-435470-1 (TE Connectivity) is classified as a similar part due to differences in actuator type, current rating, and voltage rating, making it suitable only for applications with reduced current and voltage requirements.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Recommended Primary Choice):

The 78K01T is the recommended substitute for the obsolete 78K01. Both parts share identical electrical specifications (150mA, 30VDC, DPDT), mechanical dimensions (0.315" height, 0.100" pitch), and actuator type (slide). The 78K01T offers the additional advantage of Active product status with RoHS3 compliance, making it suitable for new designs and long-term supply chain continuity. Inventory availability (6,131 pcs) supports production requirements.

For Current and Voltage-Reduced Applications:

The 3-435470-1 (TE Connectivity ALCOSWITCH) may be considered only for applications where current requirements do not exceed 25mA and voltage does not exceed 24VDC. This part features an extended operating temperature range (-55°C to 105°C) and superior mechanical/electrical life (7,000 cycles). However, the toggle actuator differs from the slide actuator of the 78K01, and the increased height (0.460" vs. 0.315") may present PCB layout constraints. This part is obsolete and should not be selected for new designs.

Compliance Considerations:

For applications requiring RoHS3 compliance, the 78K01T is the only suitable option among the provided alternatives. The original 78K01 and 3-435470-1 are both RoHS non-compliant.

Frequently Asked Questions (FAQ)

Q: Can the 78K01T be used as a direct drop-in replacement for the 78K01?

A: Yes. The 78K01T is electrically and mechanically identical to the 78K01 across all critical parameters: DPDT circuit, 150mA current rating, 30VDC voltage rating, slide actuator, 0.100" pitch, and through-hole mounting. The 78K01T is the recommended substitute.

Q: What is the primary difference between the 78K01 and 78K01T?

A: The 78K01T has Active product status (vs. Obsolete for 78K01) and is RoHS3 compliant (vs. RoHS non-compliant for 78K01). Electrical and mechanical specifications are identical.

Q: Can the 3-435470-1 replace the 78K01 in existing designs?

A: The 3-435470-1 is not a direct replacement. It has reduced current (25mA vs. 150mA) and voltage (24VDC vs. 30VDC) ratings, a different actuator type (toggle vs. slide), and greater height (0.460" vs. 0.315"). It is suitable only for applications with lower current and voltage requirements and where the toggle actuator is acceptable. This part is obsolete.

Q: What does "DPDT" mean in the context of these DIP switches?

A: DPDT (Double Pole Double Throw) indicates the switch has two independent poles, each capable of switching between two positions. This configuration allows simultaneous control of two separate circuits with a single actuator.

Q: Are there packaging differences between the 78K01 and 78K01T?

A: The 78K01 is supplied in standard packaging (not specified), while the 78K01T is supplied in Tube packaging. Both are through-hole components with identical pitch and mounting specifications.

Q: What is the mechanical life specification, and why does it matter?

A: Mechanical life (2,000 cycles for 78K01/78K01T) indicates the number of actuator cycles the switch can withstand before mechanical degradation. The 3-435470-1 offers 7,000 cycles, providing extended durability for high-cycle applications.

Q: Is the 78K01 still available for purchase?

A: The 78K01 is classified as Obsolete. However, 871 pcs are reported in stock. The 78K01T (Active status, 6,131 pcs in stock) is the recommended alternative for ongoing supply.

Q: What operating temperature range should I consider for my application?

A: The 78K01 and 78K01T operate from -40°C to 85°C. The 3-435470-1 operates from -55°C to 105°C, providing a wider range suitable for extreme temperature environments. Verify your application requirements against the specified range.

Q: Does the pitch specification affect substitution?

A: Yes. All three parts share a 0.100" (2.54mm) pitch, which is a standard DIP switch spacing. This ensures PCB footprint compatibility. Any substitute must maintain this pitch specification.