Equivalent & Substitute Parts for F7-28 Laminated Power Transformer

Part Overview

The F7-28 is a laminated core power transformer manufactured by Triad Magnetics, rated at 56VA with a single primary winding (115V) and single secondary winding (28V) featuring a center tap. This chassis mount transformer is designed for applications requiring step-down voltage conversion with isolation. The part is actively produced and stocked, with ROHS3 compliance and 2500VAC isolation rating. 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

F7-28

Triad MagneticsIn Stock: 1046F7-28 Datasheet

Current PartRFQ

241-7-28

Signal TransformerIn Stock: 1291241-7-28 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The F7-28 transformer is substitutable with the Signal Transformer model 241-7-28 based on strict electrical and mechanical parameter equivalence. Substitution is valid when the following criteria are met:

Electrical Parameters (Must Match Exactly):

• Primary voltage: 115V
• Secondary voltage: 28V
• Power rating: 56VA
• Output current capacity: 2A
• Center tap configuration: Present
• Isolation voltage: 2500VAC minimum
• Winding configuration: Single primary, single secondary

Mechanical Parameters (Must Match Exactly):

• Mounting type: Chassis Mount
• Termination style: Solder and Quick Connect compatible
• Core type: Laminated

Compliance Parameters (Must Match Exactly):

• RoHS3 Compliant
• REACH Unaffected status

The 241-7-28 meets all specified criteria and is classified as a direct equivalent substitute.

Parameter Comparison

Engineering Selection Recommendations

Both the F7-28 (Triad Magnetics) and 241-7-28 (Signal Transformer) are active production parts with full ROHS3 compliance and REACH unaffected status. Selection between these parts should be based on:

Availability and Lead Time: The 241-7-28 currently maintains higher inventory (1216 pcs) compared to the F7-28 (1035 pcs), which may influence procurement decisions for high-volume applications.

Dimensional Considerations: While both parts are functionally equivalent, minor dimensional variations exist. The F7-28 measures 93.65mm L x 46.02mm W x 57.15mm H (seated), while the 241-7-28 measures 93.70mm L x 49.20mm W x 57.80mm H (seated). These differences are within typical manufacturing tolerances for chassis mount transformers and do not affect electrical performance or standard mounting applications.

Series Designation: The F7-28 belongs to the Quick Pack series, while the 241-7-28 belongs to the Two-4-One™ series. Both series maintain equivalent electrical and mechanical specifications for this power rating.

Compliance Certification: Both parts carry identical compliance certifications (ROHS3, REACH Unaffected, ECCN EAR99, HTSUS 8504.31.4065), ensuring regulatory equivalence for all applications.

Frequently Asked Questions (FAQ)

Q: Can the 241-7-28 be used as a direct replacement for the F7-28 in existing designs?

A: Yes. The 241-7-28 is electrically and mechanically equivalent to the F7-28. All electrical parameters (voltage, current, power rating, isolation) are identical. Minor dimensional variations (approximately 3mm in width and height) fall within standard manufacturing tolerances and do not affect standard chassis mount applications.

Q: Are there any compliance or certification differences between these parts?

A: No. Both the F7-28 and 241-7-28 carry identical compliance certifications: ROHS3 Compliant, REACH Unaffected, ECCN EAR99, and HTSUS code 8504.31.4065. They are fully equivalent for regulatory purposes.

Q: What are the key electrical parameters that define substitutability for this transformer?

A: Substitutability is determined by: primary voltage (115V), secondary voltage (28V), power rating (56VA), maximum output current (2A), center tap presence, isolation voltage (2500VAC), and winding configuration (single primary, single secondary). Both parts match all these parameters exactly.

Q: Do the termination styles differ between these parts?

A: Both parts feature Solder and Quick Connect termination styles. The F7-28 specifies 0.187" (4.7mm) quick connect terminals. The 241-7-28 specifies Quick Connect without dimensional detail, but this represents standard industry practice for this transformer class and is compatible with the F7-28 termination specification.

Q: What is the significance of the center tap in these transformers?

A: The center tap allows the secondary winding to be used in three configurations: full 28V output, or split ±14V output from center tap to either end. Both the F7-28 and 241-7-28 include this center tap, maintaining functional equivalence for all application topologies.

Q: Are there any inventory or lead time considerations for selecting between these parts?

A: The 241-7-28 currently maintains higher stock levels (1216 pcs) versus the F7-28 (1035 pcs). For time-sensitive procurement, the 241-7-28 may offer faster availability. Both parts are listed as active production items.

Q: How do the physical dimensions affect mounting compatibility?

A: Both parts are chassis mount transformers with nearly identical footprints. The F7-28 is 93.65mm L x 46.02mm W, while the 241-7-28 is 93.70mm L x 49.20mm W. The 3.18mm width difference is negligible for standard chassis mounting applications and does not require design modifications.