F28-700 Laminated Power Transformer Equivalent & Substitute Parts

Part Overview

The F28-700 is a 20VA laminated core power transformer manufactured by Triad Magnetics, designed for through-hole mounting applications. This transformer features dual secondary windings with configurable parallel (14V, 1.4A) or series (28V, 700mA) output modes, powered by a single 115V primary winding. The product maintains active status with 1062 units in current inventory stock.

Identification of equivalent and substitute parts becomes necessary when primary part availability is limited, when procurement lead times require alternative sourcing, or when design flexibility permits component interchange within specified electrical and mechanical parameters.

Substiute Parts

F28-700

Triad MagneticsIn Stock: 1079F28-700 Datasheet

Current PartRFQ

164H28

Hammond ManufacturingIn Stock: 817164H28 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the F28-700 is determined by strict equivalence across the following critical parameters:

Electrical Parameters (Non-Negotiable):

• Power rating: 20VA
• Primary voltage: 115V
• Secondary voltage configuration: Parallel 14V / Series 28V
• Output current capacity: Parallel 1.4A / Series 700mA
• Isolation voltage: 2500Vrms
• Winding configuration: Single primary, dual secondary, no center tap

Mechanical Parameters (Non-Negotiable):

• Core type: Laminated
• Mounting type: Through hole
• Termination style: PC pin
• Physical dimensions: 57.15mm L × 47.63mm W
• Height seated (maximum): 36.50mm ±0.02mm tolerance

Compliance Parameters:

• RoHS3 compliance required
• REACH unaffected status
• ECCN classification: EAR99
• HTSUS code: 8504.31.4035

Only components meeting all specified electrical, mechanical, and compliance criteria qualify as direct substitutes.

Parameter Comparison

Engineering Selection Recommendations

The Hammond Manufacturing 164H28 transformer qualifies as a direct electrical and mechanical equivalent to the Triad Magnetics F28-700 based on complete parameter alignment across all critical specifications.

Substitution Basis:

Both transformers maintain identical electrical performance characteristics: 20VA power capacity, 115V primary input, dual secondary windings with 14V parallel and 28V series output configurations, and 2500Vrms isolation voltage. Output current ratings of 1.4A (parallel) and 700mA (series) are matched across both components.

Mechanical compatibility is confirmed through equivalent through-hole mounting, PC pin termination, laminated core construction, and physical dimensions of 57.15mm × 47.63mm with maximum seated heights of 36.50mm (F28-700) and 36.52mm (164H28), representing a negligible 0.02mm variance within standard manufacturing tolerances.

Both components maintain active product status with current inventory availability. Compliance certifications are equivalent: ROHS3 compliance, REACH unaffected status, EAR99 ECCN classification, and matching HTSUS code 8504.31.4035.

The 164H28 is suitable for direct substitution in applications where the F28-700 is specified, provided that circuit design does not impose constraints on packaging format (Hammond supplies in bulk packaging versus Triad's box packaging).

Frequently Asked Questions (FAQ)

Q: Can the Hammond 164H28 be used as a direct replacement for the F28-700 in existing circuit designs?

A: Yes. The 164H28 meets all electrical and mechanical specifications of the F28-700. Both transformers deliver identical voltage and current outputs, support the same mounting configuration, and maintain equivalent isolation ratings. Direct substitution is permissible without circuit modification.

Q: Are there dimensional differences that would affect PCB layout?

A: Dimensional compatibility is confirmed. Both transformers measure 57.15mm length × 47.63mm width. The seated height difference of 0.02mm (F28-700 at 36.50mm maximum, 164H28 at 36.52mm maximum) falls within standard manufacturing tolerances and does not affect PCB clearance or assembly procedures.

Q: What is the difference between the packaging formats?

A: The F28-700 is supplied in box packaging, while the 164H28 is supplied in bulk packaging. This distinction affects only procurement and handling procedures; it does not impact component performance or compatibility.

Q: Do both transformers meet the same compliance standards?

A: Yes. Both the F28-700 and 164H28 are ROHS3 compliant, REACH unaffected, classified as EAR99, and share the identical HTSUS code 8504.31.4035. Compliance requirements are fully satisfied by either component.

Q: Can I use the 164H28 in applications requiring the F28-700's specific series designation?

A: The series designation (Split Pack™, Class 2/3, F for Triad; 164 for Hammond) identifies the manufacturer's product line but does not affect electrical or mechanical compatibility. The 164H28 performs identically to the F28-700 in all functional parameters.

Q: What should I verify before implementing the 164H28 as a substitute?

A: Confirm that your application circuit accepts the specified electrical parameters: 115V primary input, 14V/1.4A parallel or 28V/700mA series secondary output, and 2500Vrms isolation. Verify that through-hole mounting and PC pin termination are compatible with your PCB design. No additional testing or verification is required for parameter compatibility.