ST-5-12 Equivalent & Substitute Parts Reference

Part Overview

The ST-5-12 is a laminated core power transformer manufactured by Signal Transformer, rated at 12VA with a 115V primary voltage and dual secondary windings capable of 6.3V parallel or 12.6V series output configurations. This through-hole mounted component is designed for applications requiring isolated AC power conversion with 2500Vrms isolation capability. The part is currently in active production status with 1102 units available in inventory. Substitute parts are identified to provide alternative sourcing options when the primary manufacturer part is unavailable or when supply chain optimization is required.

Substiute Parts

ST-5-12

Signal TransformerIn Stock: 1162ST-5-12 Datasheet

Current PartRFQ

3FS-512

TamuraIn Stock: 10063FS-512 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The ST-5-12 has one identified substitute: the 3FS-512 manufactured by Tamura. This substitution is valid based on the following matching electrical and mechanical parameters:

• Identical power rating: 12VA
• Identical primary voltage: 115V
• Identical secondary voltage outputs: 6.3V parallel and 12.6V series
• Identical output current ratings: 2A parallel and 1A series
• Identical core type: Laminated
• Identical mounting type: Through Hole
• Identical termination style: PC Pin
• Identical isolation voltage: 2500Vrms
• Identical secondary winding configuration: Dual windings with no center tap

Both parts meet the same electrical specifications and physical mounting requirements, making them functionally equivalent for applications designed around the ST-5-12 specification.

Parameter Comparison

Engineering Selection Recommendations

Both the ST-5-12 and 3FS-512 are active production components with full regulatory compliance. The ST-5-12 is available in box packaging with 1102 units in stock, while the 3FS-512 is supplied in tube packaging with 995 units available. Both parts carry RoHS compliance and EAR99 export classification. Selection between these parts should be based on packaging requirements, inventory availability, and supply chain logistics rather than electrical or mechanical performance, as all critical specifications are identical.

Frequently Asked Questions (FAQ)

Q: Can the 3FS-512 be used as a direct replacement for the ST-5-12?

A: Yes. The 3FS-512 meets all electrical and mechanical specifications of the ST-5-12, including power rating, voltage outputs, current ratings, core type, mounting configuration, and isolation voltage. Both parts are functionally equivalent.

Q: Are there any dimensional differences between these parts?

A: Minor dimensional variations exist. The ST-5-12 measures 47.80mm L × 39.60mm W × 36.90mm H (seated), while the 3FS-512 measures 48.50mm L × 41.52mm W × 38.00mm H (seated). These differences are within typical manufacturing tolerances for laminated core transformers and do not affect electrical performance or standard PCB mounting applications.

Q: What is the difference in packaging between these parts?

A: The ST-5-12 is supplied in box packaging, while the 3FS-512 is supplied in tube packaging. Packaging selection may affect handling, storage, and logistics considerations but does not impact component functionality.

Q: Are both parts RoHS compliant?

A: Yes. The ST-5-12 is ROHS3 compliant, and the 3FS-512 is RoHS compliant. Both parts meet regulatory requirements for hazardous substance restrictions.

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

A: Yes. Both the ST-5-12 and 3FS-512 feature dual secondary windings that allow flexible output configuration: parallel connection yields 6.3V at 2A maximum output current, while series connection yields 12.6V at 1A maximum output current.