Equivalent & Substitute Parts for 3FS-412 Laminated Power Transformer

Part Overview

The 3FS-412 is a laminated core power transformer manufactured by Tamura, rated at 6VA with a 115V primary voltage and dual secondary windings providing parallel 6.3V/1A or series 12.6V/500mA output. This through-hole mounted transformer is designed for applications requiring low-voltage AC power conversion with Class 2/3 isolation characteristics. The part is currently active in production and RoHS compliant, making it suitable for modern electronic equipment requiring regulated secondary voltage supplies.

Equivalent and substitute parts are identified when component availability is limited, lead times are extended, or design flexibility permits alternative sourcing from qualified manufacturers meeting identical electrical and mechanical specifications.

Substiute Parts

3FS-412

TamuraIn Stock: 12813FS-412 Datasheet

Current PartRFQ

ST-4-12

Signal TransformerIn Stock: 2713ST-4-12 Datasheet

DirectRFQ

F12-500

Triad MagneticsIn Stock: 1100F12-500 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 3FS-412 are classified based on strict electrical and mechanical parameter matching. Substitution is valid when the following criteria are met:

Electrical Parameters (Must Match Exactly):

• Primary voltage: 115V
• Secondary voltage configuration: Parallel 6.3V and Series 12.6V
• Output current ratings: Parallel 1A, Series 500mA
• Power rating: 6VA
• Isolation voltage: 2500Vrms
• Core type: Laminated
• Winding configuration: Single primary, dual secondary, no center tap

Mechanical Parameters (Must Match Exactly):

• Mounting type: Through hole
• Termination style: PC pin
• Physical dimensions: Compatible with 41.30mm–41.50mm length and 33.30mm–34.83mm width envelopes
• Height seated: 33.30mm–34.55mm maximum

Compliance Parameters:

• RoHS compliance status (RoHS Compliant or ROHS3 Compliant acceptable)
• Product status: Active

The 3FS-412 has two identified substitutes: ST-4-12 (Signal Transformer) and F12-500 (Triad Magnetics). Both parts meet all electrical and mechanical requirements and maintain active product status with current RoHS compliance.

Parameter Comparison

Engineering Selection Recommendations

All three transformers—3FS-412, ST-4-12, and F12-500—are functionally equivalent for applications requiring 6VA laminated core power transformation with 115V primary input and dual secondary windings. Selection among these parts is based on availability, lead time, and packaging preference rather than electrical performance differences.

3FS-412 (Tamura): Currently maintains 1,178 units in stock. Packaged in tube format. RoHS compliant. Suitable for immediate procurement when Tamura sourcing is preferred or when tube packaging is required for assembly operations.

ST-4-12 (Signal Transformer): Currently maintains 2,607 units in stock. Packaged in box format. ROHS3 compliant. Highest inventory availability among the three options. Dimensions are slightly smaller (41.30mm L × 33.30mm W × 33.30mm H), which may provide marginal PCB layout advantages in space-constrained designs.

F12-500 (Triad Magnetics): Currently maintains 1,001 units in stock. Packaged in box format. ROHS3 compliant. Designated as Split Pack™ series with Class 2/3 rating. Dimensions are comparable to ST-4-12 (41.28mm L × 33.32mm W × 33.32mm H). Suitable for applications where Triad Magnetics qualification is required or when Split Pack™ series compatibility is specified.

All parts carry identical ECCN (EAR99) and HTSUS (8504.31.4035) classifications, confirming regulatory equivalence for export and tariff purposes.

Frequently Asked Questions (FAQ)

Q: Can ST-4-12 be used as a direct replacement for 3FS-412 in existing designs?

A: Yes. The ST-4-12 meets all electrical specifications (6VA, 115V primary, 6.3V/12.6V secondary, 1A/500mA output, 2500Vrms isolation) and mechanical requirements (through-hole mounting, PC pin termination, compatible dimensions). The slight dimensional reduction (1.2mm shorter length, 1.53mm narrower width) does not affect functionality and may provide layout benefits.

Q: What is the difference between RoHS Compliant and ROHS3 Compliant status?

A: Both designations indicate compliance with RoHS (Restriction of Hazardous Substances) regulations. RoHS Compliant refers to the original 2002/95/EC directive, while ROHS3 Compliant refers to the recast 2011/65/EU directive with updated substance restrictions. Both are acceptable for modern applications; ROHS3 represents the current regulatory standard.

Q: Are there packaging differences between the three parts?

A: Yes. The 3FS-412 is supplied in tube packaging, while both ST-4-12 and F12-500 are supplied in box packaging. Tube packaging is typically used for automated assembly processes, while box packaging is standard for manual assembly or kit distribution. Selection depends on assembly methodology and inventory management requirements.

Q: Do all three transformers have identical isolation voltage ratings?

A: Yes. All three parts are rated at 2500Vrms isolation voltage, confirming equivalent safety performance for Class 2/3 applications requiring galvanic isolation between primary and secondary circuits.

Q: Which part has the highest current inventory?

A: ST-4-12 (Signal Transformer) has the highest inventory at 2,607 units in stock, followed by F12-500 (Triad Magnetics) at 1,001 units and 3FS-412 (Tamura) at 1,178 units. Inventory levels should be verified at time of procurement as stock quantities change.

Q: Are the physical dimensions of ST-4-12 and F12-500 interchangeable with 3FS-412?

A: The dimensions are compatible within typical PCB layout tolerances. The 3FS-412 is slightly larger (41.50mm L × 34.83mm W × 34.55mm H) compared to ST-4-12 (41.30mm L × 33.30mm W × 33.30mm H) and F12-500 (41.28mm L × 33.32mm W × 33.32mm H). Designs with tight spatial constraints may benefit from the smaller ST-4-12 or F12-500 footprint, but all three fit within standard through-hole transformer mounting envelopes.

Q: Can these transformers be used interchangeably in series or parallel secondary configurations?

A: Yes. All three transformers provide identical dual secondary winding configurations supporting both parallel (6.3V/1A) and series (12.6V/500mA) output modes. The winding configuration and current ratings are identical across all three parts.