Equivalent & Substitute Parts: PF24-34 Semi-Toroidal Power Transformer

Part Overview

The PF24-34 is a 24VA semi-toroidal power transformer manufactured by Tamura, designed for through-hole mounting applications. It features dual primary and secondary windings with selectable voltage configurations (115V or 230V primary input; 17V parallel or 34V series secondary output). The product is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and component procurement.

Substiute Parts

PF24-34

TamuraIn Stock: 1077PF24-34 Datasheet

Current PartRFQ

LP-34-700

Signal TransformerIn Stock: 1272LP-34-700 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the PF24-34 is determined by strict equivalence across the following critical parameters:

Mandatory Matching Criteria:

• Power rating: 24VA
• Transformer type: Semi-toroidal
• Primary voltage options: 115V and 230V selectable
• Secondary voltage outputs: 17V (parallel) and 34V (series) configurations
• Winding configuration: Dual primary and dual secondary
• Mounting interface: Through-hole with PC pin termination
• Isolation voltage: 1500Vrms minimum
• Physical envelope: Compatible dimensions and height

The LP-34-700 manufactured by Signal Transformer satisfies all mandatory matching criteria. While the LP-34-700 exhibits higher secondary current capacity in parallel configuration (1.4A versus 850mA), this represents a performance enhancement rather than a deviation, as the series configuration current (700mA) remains within acceptable tolerance of the original specification (430mA). The substitute maintains identical primary voltage selectivity, secondary voltage outputs, winding topology, mounting method, and isolation rating.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: LP-34-700 (Signal Transformer)

The LP-34-700 is the qualified equivalent for PF24-34 replacement applications. Selection rationale is based on the following engineering factors:

Functional Equivalence: The LP-34-700 maintains complete electrical and mechanical compatibility with the PF24-34 across all critical parameters. Voltage transformation ratios, winding configurations, isolation ratings, and mounting interfaces are identical.

Product Status Advantage: The LP-34-700 carries active product status, ensuring ongoing availability and manufacturing support. The PF24-34 is classified as obsolete, creating supply chain risk for new designs or system repairs.

Regulatory Compliance: The LP-34-700 is certified ROHS3 compliant, meeting current environmental and hazardous substance restrictions. This certification supports compliance with modern procurement standards and regulatory requirements.

Performance Enhancement: The LP-34-700 provides higher secondary current capacity in both parallel (1.4A) and series (700mA) configurations compared to the original specification. This enhancement does not introduce incompatibility; rather, it provides additional design margin for applications operating at or near the original current limits.

Physical Compatibility: Dimensional variance between the two transformers (0.9mm length difference, 0.8mm width difference) remains within standard PCB layout tolerances for through-hole mounted components. Height remains identical at 31.80mm seated maximum.

Frequently Asked Questions (FAQ)

Q: Can the LP-34-700 be used as a direct replacement for the PF24-34 in existing designs?

A: Yes. The LP-34-700 is electrically and mechanically equivalent to the PF24-34. Both transformers provide identical primary voltage selectivity (115V/230V), secondary voltage outputs (17V parallel, 34V series), winding topology, isolation rating, and through-hole PC pin termination. PCB layouts designed for the PF24-34 will accommodate the LP-34-700 without modification.

Q: What is the significance of the higher current ratings on the LP-34-700?

A: The LP-34-700 secondary current specifications (1.4A parallel, 700mA series) exceed the PF24-34 ratings (850mA parallel, 430mA series). This represents a performance enhancement that increases design margin. Applications drawing current within the original PF24-34 limits will operate identically on the LP-34-700. Applications requiring higher current capacity can utilize the additional capacity of the substitute.

Q: Are there dimensional concerns when substituting the LP-34-700 for the PF24-34?

A: Dimensional differences are minimal and within standard PCB layout tolerances. The LP-34-700 is 0.9mm longer and 0.8mm narrower than the PF24-34, with identical seated height (31.80mm). These variations do not affect through-hole mounting compatibility or standard PCB spacing requirements.

Q: Why is the PF24-34 classified as obsolete?

A: Obsolete status indicates that the manufacturer (Tamura) has discontinued production and support for this model. The LP-34-700 provides an active, supported alternative with equivalent functionality and enhanced performance characteristics.

Q: Does the LP-34-700 meet current regulatory requirements?

A: Yes. The LP-34-700 is ROHS3 compliant, meeting current environmental and hazardous substance restrictions. The PF24-34 regulatory status is not specified in available documentation. For applications subject to modern procurement standards or regulatory compliance requirements, the LP-34-700 is the appropriate selection.

Q: Are there any electrical performance differences between the two transformers?

A: No electrical performance differences exist within the specified operating parameters. Both transformers provide identical voltage transformation ratios, isolation voltage (1500Vrms), and winding configurations. The LP-34-700 provides higher current capacity, which represents an enhancement rather than a deviation.

Q: What packaging options are available for the LP-34-700?

A: The LP-34-700 is supplied in bulk packaging. The PF24-34 packaging specification is not provided in available documentation. Confirm packaging requirements with your procurement department when transitioning from PF24-34 to LP-34-700.