ST3-12B5 Equivalent & Substitute Parts

Part Overview

The ST3-12B5 is a laminated core power transformer manufactured by Pulse Electronics, rated at 2.4VA with a 115V primary voltage and dual secondary windings capable of 6.3V parallel or 12.6V series output. The part is classified as obsolete, necessitating identification of active equivalent alternatives for ongoing procurement and design continuity. Substitute parts must maintain identical electrical specifications and mechanical compatibility to ensure direct replacement capability.

Substiute Parts

ST3-12B5

Pulse ElectronicsIn Stock: 1165ST3-12B5 Datasheet

Current PartRFQ

6013R-012

API Delevan Inc.In Stock: 9636013R-012 Datasheet

DirectRFQ

ST-3-12

Signal TransformerIn Stock: 1476ST-3-12 Datasheet

DirectRFQ

3FS-312

TamuraIn Stock: 23143FS-312 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts are classified based on electrical parameter equivalence and product status:

Direct Equivalents (6013R-012, ST-3-12): These parts maintain all critical electrical specifications identical to the ST3-12B5, including primary voltage, secondary voltage configurations, output current ratings, power rating, isolation voltage, and core type. Both are active products with current manufacturing status, providing immediate procurement alternatives.

Similar Equivalent (3FS-312): This part matches all electrical specifications and core characteristics but exhibits minor dimensional variations in length (35.56mm vs. 35.05mm), width (31.00mm vs. 28.70mm), and height (32.10mm vs. 30.23mm). The similar classification reflects these mechanical differences while confirming electrical interchangeability.

Substitution eligibility is determined by:

• Identical primary and secondary voltage specifications
• Matching output current ratings (parallel and series configurations)
• Equivalent power rating (2.4VA)
• Identical core type (laminated)
• Compatible mounting and termination methods
• Equivalent isolation voltage rating

Parameter Comparison

Engineering Selection Recommendations

6013R-012 (API Delevan Inc.) is the preferred direct substitute. This part maintains dimensional compatibility within 0.12mm length tolerance and 0.12mm width tolerance relative to the ST3-12B5. The part carries active product status with ROHS3 compliance, ensuring current manufacturing support and regulatory alignment.

ST-3-12 (Signal Transformer) serves as an alternative direct equivalent with active product status and ROHS3 compliance. Dimensional variation in height (30.80mm vs. 30.23mm) represents a 0.57mm increase, which may require verification in space-constrained applications.

3FS-312 (Tamura) provides electrical equivalence with active product status and RoHS compliance. Dimensional differences are more pronounced: length increases by 0.51mm, width increases by 2.30mm, and height increases by 1.87mm. This part is suitable for applications where mechanical envelope constraints are not restrictive.

Selection should prioritize dimensional compatibility with existing printed circuit board layouts and mechanical enclosures. All three substitute parts satisfy electrical and regulatory requirements for direct replacement.

Frequently Asked Questions (FAQ)

Q: Can the 6013R-012 replace the ST3-12B5 in existing designs? A: Yes. The 6013R-012 maintains identical electrical specifications and operates within equivalent dimensional tolerances. Verification of PCB footprint compatibility is recommended prior to implementation.

Q: What are the key differences between the three substitute options? A: All three substitutes provide identical electrical performance. Differences are limited to dimensional variations and packaging formats. The 6013R-012 and ST-3-12 exhibit minimal dimensional deviation, while the 3FS-312 shows greater variation in width and height.

Q: Are there compliance differences between the substitutes? A: The 6013R-012 and ST-3-12 carry ROHS3 certification, while the ST3-12B5 and 3FS-312 carry RoHS compliance. All parts maintain REACH Unaffected status. ROHS3 represents an updated compliance standard and does not preclude use of RoHS-compliant alternatives in equivalent applications.

Q: Does the 3FS-312 dimensional variation affect compatibility? A: The 3FS-312 exhibits dimensional increases of up to 2.30mm in width. Compatibility depends on specific mechanical constraints within the target application. PCB layout and enclosure clearance verification is necessary.

Q: What packaging formats are available? A: The ST3-12B5 is supplied in standard packaging. The 6013R-012 is supplied in standard format, the ST-3-12 is supplied in box packaging, and the 3FS-312 is supplied in tube packaging. Packaging format does not affect electrical or mechanical performance.

Q: Can multiple substitutes be used interchangeably in production? A: Yes, provided that dimensional verification confirms compatibility with the specific PCB layout and mechanical enclosure. All three substitutes meet identical electrical specifications and regulatory requirements.