Grayhill 78B08 DIP Switch Equivalent & Substitute Parts

Part Overview

The Grayhill 78B08 is an 8-position DIP switch with SPST (Single Pole Single Throw) circuit configuration, rated for 150mA at 30VDC. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The 78B08 features a slide actuator with standard raised level, gold-plated copper alloy contacts, and through-hole PC pin termination suitable for PCB integration in industrial and commercial applications.

Key Parameters

Parameter	Value
Circuit Configuration	SPST (Single Pole Single Throw)
Number of Positions	8
Current Rating	150mA
Voltage Rating	30VDC
Actuator Type	Slide (Standard)
Mounting Type	Through Hole
Pitch	0.100" (2.54mm)
Operating Temperature Range	-40°C to 85°C
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution eligibility for the Grayhill 78B08 is determined by the following critical parameters: circuit configuration (SPST), number of positions (8), actuator type (slide standard), mounting method (through hole), pitch spacing (0.100"), and termination style (PC pin). Substitute parts must maintain compatibility across these mechanical and electrical interfaces.

The substitute parts are grouped into two categories based on electrical rating compatibility:

Category 1 - Direct Electrical Equivalent: Parts that maintain the same or higher current and voltage ratings, ensuring drop-in replacement capability without circuit redesign.

Category 2 - Reduced Rating Substitutes: Parts with lower current or voltage ratings that require circuit-level verification before implementation.

Parameter Comparison

Parameter	78B08 (Main)	78B08T	206-8	BD08
Manufacturer	Grayhill Inc.	Grayhill Inc.	CTS Electrocomponents	C&K
Product Status	Obsolete	Active	Active	Active
Circuit	SPST	SPST	SPST	SPST
Number of Positions	8	8	8	8
Current Rating (Amps)	150mA	150mA	50mA	100mA
Voltage Rating	30VDC	30VDC	24VDC	5VDC
Actuator Type	Slide (Standard)	Slide (Standard)	Slide (Standard)	Slide (Standard)
Actuator Level	Raised	Raised	Raised	Raised
Contact Finish	Gold	Gold	Gold	Gold
Height Above Board	0.315" (8.00mm)	0.315" (8.00mm)	0.334" (8.48mm)	0.297" (7.54mm)
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole
Termination Style	PC Pin	PC Pin	PC Pin	PC Pin
Pitch	0.100" (2.54mm)	0.100" (2.54mm)	0.100" (2.54mm)	0.100" (2.54mm)
Operating Temperature	-40°C to 85°C	-40°C to 85°C	-55°C to 85°C	-40°C to 85°C
Mechanical Life	2,000 Cycles	2,000 Cycles	Not Specified	10,000 Cycles
Electrical Life	2,000 Cycles	2,000 Cycles	10,000 Cycles	10,000 Cycles
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Packaging	Bulk	Tube	Tube	Tube

Engineering Selection Recommendations

Grayhill 78B08T is the primary recommended substitute for the obsolete 78B08. Both parts are manufactured by Grayhill Inc. and share identical electrical ratings (150mA, 30VDC), mechanical dimensions, and contact specifications. The 78B08T is currently in active production status with higher inventory availability (3409 units in stock versus 898 for the original 78B08). Both parts maintain ROHS3 compliance and identical operating temperature ranges. The only difference is packaging format (tube versus bulk), which does not affect functional performance. This substitute provides direct compatibility without circuit modification.

CTS Electrocomponents 206-8 is a secondary substitute suitable for applications where reduced current capacity is acceptable. The 206-8 operates at 50mA and 24VDC, representing a lower electrical rating than the 78B08. This part is appropriate only for circuits designed to operate within these reduced parameters. The 206-8 offers extended electrical life (10,000 cycles) and wider operating temperature range (-55°C to 85°C). Implementation requires verification that circuit current and voltage requirements do not exceed 50mA and 24VDC respectively.

C&K BD08 is a tertiary substitute limited to 5VDC applications with maximum 100mA current draw. The BD08 features superior mechanical life (10,000 cycles) and includes washable design capability. This part is suitable only for low-voltage digital logic circuits and embedded systems. The BD08 uses phosphor bronze contacts with glass-filled PBT body material, differing from the copper alloy contacts in the 78B08. Implementation is restricted to applications where voltage and current specifications align with the BD08 ratings.

All substitute parts maintain through-hole mounting with 0.100" pitch spacing, ensuring PCB footprint compatibility. All parts are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can the 78B08T directly replace the obsolete 78B08 without any circuit modifications?

A: Yes. The 78B08T is a direct equivalent with identical electrical ratings (150mA, 30VDC), mechanical dimensions, contact materials, and operating temperature range. The only difference is packaging format (tube versus bulk), which does not affect electrical or mechanical performance. No circuit redesign is required.

Q: What are the limitations of using the CTS 206-8 as a substitute?

A: The 206-8 has reduced electrical ratings: 50mA maximum current and 24VDC maximum voltage, compared to the 78B08's 150mA and 30VDC. This part is suitable only for circuits operating within these lower parameters. Circuit-level verification is required to confirm that actual operating current does not exceed 50mA and voltage does not exceed 24VDC. The 206-8 is not a drop-in replacement for all 78B08 applications.

Q: Is the C&K BD08 suitable for replacing the 78B08 in existing designs?

A: The BD08 is limited to 5VDC applications with maximum 100mA current. It is not suitable for circuits requiring 30VDC operation. The BD08 is appropriate only for new designs or redesigned circuits specifically intended for low-voltage digital logic applications. Contact material differs (phosphor bronze versus copper alloy), and body material is glass-filled PBT rather than thermoplastic.

Q: Do all substitute parts maintain the same PCB footprint as the 78B08?

A: All substitute parts share the same mounting type (through hole), pitch spacing (0.100"), and termination style (PC pin). Height above board varies slightly: 78B08/78B08T at 0.315", 206-8 at 0.334", and BD08 at 0.297". These minor height variations do not affect PCB footprint compatibility but may impact clearance in space-constrained applications.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. The 78B08T, 206-8, and BD08 are all ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements equivalent to the original 78B08.

Q: What is the difference in mechanical and electrical life between the 78B08 and its substitutes?

A: The 78B08 and 78B08T both specify 2,000 mechanical and electrical cycles. The 206-8 specifies 10,000 electrical cycles with mechanical life not specified. The BD08 specifies 10,000 cycles for both mechanical and electrical life. For applications requiring extended cycle life, the 206-8 and BD08 offer superior performance, provided their electrical ratings are compatible with circuit requirements.

Q: Can the 78B08T be used in applications requiring washable components?

A: No. The 78B08T is not washable. If washable capability is required, the C&K BD08 is the only substitute offering this feature, but only for 5VDC applications with maximum 100mA current.

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