ZHT118F 5A/5mA Precision Miniature Current Transformer

ZHT118F 5A/5mA Precision Miniature Current Transformer is a high-accuracy sensing component designed for measuring and monitoring alternating current in precision electronic systems. This miniature device converts a high primary current into a proportional, low-level secondary current with exceptional linearity. Consequently, it allows microcontrollers and analog-to-digital converters to safely sample AC line currents without direct electrical contact with high-voltage rails. Utilizing a high-permeability nanocrystalline or permalloy core, the ZHT118F maintains minimal phase shift and high stability across a wide range of current levels. Therefore, you should integrate this current transformer into your power monitoring designs to achieve reliable, galvanic isolation and precise energy measurement.

Key Features:

• High Precision Sensing: The 1000:1 transformation ratio provides an accurate 5mA output for a 5A input, ensuring high-resolution data acquisition.
• Miniature PCB Mount Design: Its compact footprint allows for seamless integration into space-constrained circuit boards and power strips.
• Superior Galvanic Isolation: This transformer provides a high dielectric strength barrier, which effectively protects low-voltage control circuitry from high-voltage AC surges.
• Excellent Linearity: The advanced core material ensures that the output signal remains linear even during slight over-current conditions.
• Epoxy Encapsulated: The rugged, flame-retardant plastic casing filled with epoxy resin protects internal components from moisture, dust, and mechanical vibration.

Technical Specifications:

• Rated Input Current: 5 A (Continuous)
• Rated Output Current: 5 mA (at rated input)
• Turns Ratio: 1000:1
• Accuracy Class: ≤ 0.1 Class (Typical)
• Phase Error: ≤ 15′ (at 50/60 Hz)
• Isolation Voltage: ≥ 3000 V_RMS
• Load Resistance (Sampling Resistor): ≈ 10 Ω to 100 Ω
• Operating Frequency: 20 Hz to 20 kHz

Mechanical Specifications:

• Enclosure Material: PBT Flame Retardant Plastic (UL94-V0)
• Internal Core: High-permeability Permalloy or Nanocrystalline
• Mounting Type: PCB Through-Hole (THT)
• Potting: Epoxy Resin Encapsulation

Dimensions:

• Outer Width: ≈ 18.5 mm
• Outer Height: ≈ 20.0 mm
• Thickness: ≈ 11.5 mm
• Pin Length: ≈ 3.0 mm
• Pin Diameter: ≈ 0.8 mm

Pinout and Wiring:

• Primary (P1/P2): Pass the AC wire carrying the current through the center hole of the transformer (single turn).
• Secondary Pins (S1/S2): Connect these two pins to your measurement circuit; furthermore, you must connect a sampling resistor (burden resistor) across these pins to convert current to voltage.
• Wiring Note: Never leave the secondary circuit open while current flows through the primary; otherwise, high voltage may develop across the secondary terminals.

Datasheet Reference:

• Download ZHT118F Precision Current Transformer Datasheet

Commonly Used in:

• Smart Energy Meters: Providing the primary sensing element for calculating kilowatt-hour (kWh) consumption.
• Digital Power Monitors: Measuring real-time current draw in data center PDU units and industrial machinery.
• Overload Protection Devices: Detecting excessive current flow to trigger safety shut-off mechanisms.

Applications:

• AC Current Measurement: Converting mains-level currents into low-voltage signals for Arduino or STM32 ADC pins.
• Motor Load Monitoring: Tracking the health and efficiency of AC motors by observing current fluctuations.
• Smart Home Switches: Integrating current feedback into smart relays to provide energy usage statistics via mobile apps.

Equivalent Models:

• ZMCT103C: A popular alternative with a similar 5A/5mA ratio and comparable PCB mounting footprint.
• ZMCT118G: A slightly different variant within the same series offering alternative pin spacing or precision grades.
• DL-CT08CL5: A functionally equivalent precision current transformer however, users should verify the physical dimensions before replacement.

Package Includes:

• 1 x ZHT118F 5A/5mA Precision Miniature Current Transformer