PE-51687 Current Sense Transformer Equivalent & Substitute Parts

Part Overview

The PE-51687 is a 20 A current sense transformer designed for non-invasive measurement applications operating in the 20 kHz to 200 kHz frequency range. This through-hole mounted component features a 100:1 current ratio and 20 mH inductance, making it suitable for power monitoring and control circuits requiring galvanic isolation.

The PE-51687 is classified as obsolete. Locating equivalent or substitute components is necessary to support ongoing production, maintenance, and design updates where this part is specified in existing schematics or bill of materials.

Substiute Parts

PE-51687

Pulse ElectronicsIn Stock: 1061PE-51687 Datasheet

Current PartRFQ

PE-51687NL

Pulse ElectronicsIn Stock: 2004PE-51687NL Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the PE-51687 is determined by the following critical parameters:

• Current Rating: 20 A (exact match required)
• Frequency Range: 20 kHz – 200 kHz (exact match required)
• Current Ratio: 100:1 (exact match required)
• Inductance: 20 mH (exact match required)
• Mounting Type: Through Hole (exact match required)
• Termination Style: PC Pin (exact match required)

The PE-51687NL meets all substitution criteria. While it differs in measurement approach (invasive vs. non-invasive), packaging format (tray vs. bulk), and compliance status, it maintains electrical equivalence across all core performance parameters. The PE-51687NL is an active product from the same manufacturer, ensuring continued availability and support.

Parameter Comparison

Engineering Selection Recommendations

The PE-51687NL is the direct substitute for the PE-51687. Both components share identical electrical specifications across current rating, frequency range, current ratio, and inductance—the parameters that determine functional equivalence in current sensing applications.

Selection of PE-51687NL is supported by:

• Active product status ensuring long-term availability and supply chain stability
• RoHS compliance, meeting modern environmental and regulatory requirements
• Identical through-hole mounting and PC pin termination, enabling direct PCB layout compatibility
• Smaller physical footprint (0.670" × 0.390" vs. 0.900" × 0.700"), providing layout optimization benefits
• Specified DC resistance values (100 Ω primary, 1.4 Ω secondary) enabling precise circuit analysis

The measurement approach difference (invasive vs. non-invasive) reflects design evolution within the product line. Both approaches deliver the same 100:1 current ratio and 20 mH inductance required for circuit function.

Frequently Asked Questions (FAQ)

Q: Can PE-51687NL replace PE-51687 in existing designs?

A: Yes. Both components maintain identical current rating (20 A), frequency range (20 kHz – 200 kHz), current ratio (100:1), and inductance (20 mH). Through-hole mounting and PC pin termination are identical, supporting direct PCB substitution.

Q: What is the difference between non-invasive and invasive current sense transformers?

A: Non-invasive (solid core) transformers measure current without breaking the circuit path. Invasive transformers require the primary conductor to pass through the core. Both deliver equivalent electrical performance when current ratio and inductance specifications match.

Q: Does the smaller size of PE-51687NL affect performance?

A: No. Physical dimensions do not alter electrical performance. The PE-51687NL's reduced footprint (0.670" × 0.390" vs. 0.900" × 0.700") provides layout flexibility without compromising current sensing accuracy or frequency response.

Q: Is RoHS compliance required for my application?

A: RoHS compliance is mandatory for products sold into regulated markets (EU, China, Japan). PE-51687NL meets RoHS requirements; PE-51687 does not. For new designs or products subject to environmental regulations, PE-51687NL is the appropriate selection.

Q: Are the DC resistance values important for circuit design?

A: Yes. PE-51687NL specifies 100 Ω primary and 1.4 Ω secondary resistance. These values affect circuit impedance and signal conditioning requirements. PE-51687 does not provide DC resistance specifications, making PE-51687NL preferable for precise circuit analysis and design validation.

Q: What packaging formats are available?

A: PE-51687 is supplied in bulk packaging. PE-51687NL is supplied in tray packaging, which is standard for automated assembly and inventory management in modern manufacturing environments.