FS28-85 Equivalent & Substitute Parts Reference

Part Overview

The FS28-85 is a laminated core power transformer manufactured by Triad Magnetics, rated at 2.4VA with dual primary and secondary windings. This through-hole mounted component operates at 115V or 230V primary input with configurable secondary output of 14V parallel or 28V series. The part is actively produced and ROHS3 compliant, making it suitable for industrial and commercial power supply applications requiring galvanic isolation at 2500Vrms.

Equivalent and substitute parts are identified when component availability changes, supply chain disruptions occur, or design flexibility is required across manufacturing batches while maintaining electrical and mechanical compatibility.

Substiute Parts

FS28-85

Triad MagneticsIn Stock: 1054FS28-85 Datasheet

Current PartRFQ

FS28-85-B

Triad MagneticsIn Stock: 1105FS28-85-B Datasheet

DirectRFQ

3FD-328

TamuraIn Stock: 23443FD-328 Datasheet

DirectRFQ

162E28

Hammond ManufacturingIn Stock: 713162E28 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the FS28-85 is determined by strict equivalence across the following critical parameters:

Electrical Equivalence Requirements: All substitute parts must provide identical primary voltage selection (115V, 230V), secondary voltage configuration (Parallel 14V, Series 28V), maximum output current (Parallel 170mA, Series 85mA), power rating (2.4VA), and isolation voltage (2500Vrms).

Mechanical Equivalence Requirements: Substitute parts must feature through-hole mounting with PC pin termination, dual primary and dual secondary windings, and laminated core construction without center tap.

Compliance Requirements: All parts must maintain EAR99 classification and ROHS compliance status (ROHS3 or equivalent RoHS Compliant designation).

Substitution Categories:

Direct Equivalents maintain identical electrical and mechanical specifications with only packaging differences (FS28-85-B from Triad Magnetics).

Cross-Manufacturer Equivalents meet all electrical and mechanical parameters from alternative manufacturers (3FD-328 from Tamura, 162E28 from Hammond Manufacturing) with allowable dimensional tolerances within the through-hole footprint.

Parameter Comparison

Engineering Selection Recommendations

FS28-85-B (Triad Magnetics): Direct equivalent with identical electrical and mechanical specifications. Differs only in packaging format (bulk versus box). Both parts maintain ROHS3 compliance and active product status. Selection between FS28-85 and FS28-85-B depends on procurement quantity requirements and packaging logistics.

3FD-328 (Tamura): Cross-manufacturer equivalent meeting all electrical specifications. Dimensional variations exist: length increases 0.63mm, width increases 2.44mm, height increases 1.95mm. These dimensional differences remain within through-hole PCB footprint tolerances for standard 0.1-inch grid spacing. RoHS compliance confirmed. Suitable for applications where Tamura supply chain availability is preferred.

162E28 (Hammond Manufacturing): Cross-manufacturer equivalent with electrical specifications identical to FS28-85. Dimensional profile nearly matches original part (length 34.93mm, width 28.58mm, height 30.15mm). ROHS3 compliance maintained. Suitable for direct substitution with minimal PCB layout modification.

All substitute parts maintain active product status and EAR99 export classification consistent with the original FS28-85.

Frequently Asked Questions (FAQ)

Q: Can FS28-85-B replace FS28-85 in existing designs?

A: Yes. FS28-85-B is a direct electrical and mechanical equivalent. The only difference is packaging format (bulk versus box). No circuit design or PCB layout changes are required.

Q: What are the dimensional constraints when substituting 3FD-328 for FS28-85?

A: The 3FD-328 is 0.63mm longer, 2.44mm wider, and 1.95mm taller than the FS28-85. These differences remain compatible with standard through-hole PCB designs using 0.1-inch grid spacing. Verify clearance in confined mounting areas before implementation.

Q: Are all substitute parts ROHS compliant?

A: Yes. FS28-85-B and 162E28 are ROHS3 compliant. 3FD-328 is RoHS compliant. All parts meet regulatory requirements for restricted substance elimination.

Q: Do substitute parts maintain the same isolation voltage rating?

A: Yes. All substitute parts (FS28-85-B, 3FD-328, 162E28) provide 2500Vrms isolation voltage identical to the original FS28-85.

Q: Can I use 3FD-328 or 162E28 if FS28-85 is unavailable?

A: Yes. Both parts are cross-manufacturer equivalents with identical electrical specifications and compatible mechanical mounting. Verify PCB layout clearances for 3FD-328 due to dimensional variations. 162E28 requires minimal or no layout modification.

Q: What is the difference between parallel and series secondary output configuration?

A: The dual secondary windings allow two operating modes. Parallel configuration provides 14V at 170mA maximum output current. Series configuration provides 28V at 85mA maximum output current. Circuit design determines which configuration is required.

Q: Are all substitute parts available in the same packaging options?

A: No. FS28-85 is supplied in box packaging. FS28-85-B is supplied in bulk packaging. 3FD-328 is supplied in tube packaging. 162E28 is supplied in bulk packaging. Packaging selection affects procurement quantity minimums and logistics.