ST-6-56 Power Transformer Equivalent & Substitute Parts

Part Overview

The ST-6-56 is a 20VA laminated core power transformer manufactured by Signal Transformer, designed for through-hole mounting applications. This transformer features dual secondary windings capable of parallel (28V, 700mA) or series (56V, 350mA) configuration, with a single 115V primary winding. The part maintains Active product status with full RoHS3 compliance and 2500Vrms isolation rating. Substitute parts are identified when equivalent electrical specifications, mechanical dimensions, and compliance certifications align with the original design requirements.

Substiute Parts

ST-6-56

Signal TransformerIn Stock: 906ST-6-56 Datasheet

Current PartRFQ

F56-350

Triad MagneticsIn Stock: 734F56-350 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The F56-350 manufactured by Triad Magnetics qualifies as a direct substitute for the ST-6-56 based on the following alignment of critical parameters:

Electrical Equivalence: Both transformers deliver identical power capacity (20VA), primary voltage (115V), secondary voltage configurations (parallel 28V/series 56V), and output current ratings (parallel 700mA/series 350mA). Isolation voltage specification matches at 2500Vrms.

Mechanical Compatibility: Both parts feature identical mounting type (through hole) and termination style (PC pin). Physical dimensions are equivalent: ST-6-56 measures 57.20mm L × 47.60mm W × 36.90mm H; F56-350 measures 57.15mm L × 47.63mm W × 36.50mm H. These dimensional tolerances fall within acceptable mechanical fit parameters for PCB mounting.

Compliance Alignment: Both transformers maintain RoHS3 compliance, REACH unaffected status, and identical ECCN/HTSUS classifications (EAR99/8504.31.4035).

Core Architecture: Both employ laminated core construction with single primary and dual secondary windings, with no center tap configuration.

Parameter Comparison

Engineering Selection Recommendations

Both the ST-6-56 and F56-350 maintain Active product status, ensuring continued availability and manufacturer support. Selection between these parts should be based on supply chain requirements and packaging preferences. The ST-6-56 is supplied in bulk packaging with 856 units in stock, while the F56-350 is supplied in box packaging with 691 units in stock. Both transformers carry identical compliance certifications (RoHS3, REACH unaffected, EAR99), making either suitable for applications requiring regulatory compliance. The dimensional equivalence and electrical parameter matching ensure direct PCB-level substitution without circuit redesign.

Frequently Asked Questions (FAQ)

Q: Can the F56-350 replace the ST-6-56 in existing designs? A: Yes. Both transformers meet identical electrical specifications (20VA, 115V primary, 28V/56V secondary, 700mA/350mA output), employ the same core type (laminated), feature identical winding configurations (single primary, dual secondary), and share equivalent mechanical dimensions and mounting characteristics (through-hole, PC pin termination).

Q: Are there dimensional differences between these parts? A: Dimensional variations are minimal. The ST-6-56 measures 57.20mm L × 47.60mm W × 36.90mm H, while the F56-350 measures 57.15mm L × 47.63mm W × 36.50mm H. These differences fall within acceptable mechanical tolerances for through-hole PCB mounting and do not affect circuit board layout compatibility.

Q: Do both transformers meet the same compliance standards? A: Yes. Both the ST-6-56 and F56-350 are RoHS3 compliant, REACH unaffected, and classified under identical ECCN (EAR99) and HTSUS (8504.31.4035) codes.

Q: What is the difference in packaging between these parts? A: The ST-6-56 is supplied in bulk packaging, while the F56-350 is supplied in box packaging. This distinction affects only storage and handling procedures, not electrical or mechanical performance.

Q: Are the isolation voltage ratings equivalent? A: Yes. Both transformers provide 2500Vrms isolation voltage, meeting identical safety and performance requirements.