FunctionsA current transducer converts the measured current into standard output signals for subsequent measurement, control and display. Its main functions are as follows.Signal conversion: It converts the measured current into industrial standard signals such as 4‑20mA and 0‑10V to adapt to the back‑end measurement, control and display units. It can also convert AC current into standard DC output signals.Electrical isolation: It provides electrical isolation between the measurement circuit and control circuit to improve system safety and reliability.Signal amplification: It amplifies weak input current signals to facilitate further signal acquisition and control.Signal filtering: It filters input current signals to eliminate noise interference and improve measurement accuracy.
Display and recording compatibility: It can be matched with display instruments and recording equipment to realize real‑time display and recording of current signals.
Working PrincipleA current transducer adopts current sensing elements to convert the measured current signal into a voltage signal. Through subsequent amplification, filtering, conversion and isolation processes, standard industrial signals are finally output. The specific working links are as follows.Current sensor: As the core component of the current transducer, it converts the measured current signal into a voltage signal. Common types include Hall sensors, shunts and current transformers.Signal amplification: The weak voltage signal output by the current sensor is amplified to meet the processing requirements of subsequent circuits.Signal filtering: Low‑pass filters, band‑pass filters and other filtering circuits are used to process the amplified voltage signal, eliminate noise interference and improve measurement precision.Signal conversion: The filtered voltage signal is converted into standard output signals such as 4‑20mA and 0‑10V through D/A converters and V/I converters.Signal isolation: Optocoupler isolation, magnetic isolation and other isolation technologies are applied to separate the measurement circuit from the control circuit, effectively improving the safety and stability of the whole system.
Signal output and display: Cooperate with display and recording instruments to realize real‑time monitoring, display and data recording of current signals.
ClassificationAccording to the working principle and application fields, current transducers are divided into the following types.DC current transducer: Suitable for measuring DC current signals and outputting standard DC signals such as 4‑20mA and 0‑10V.AC current transducer: Suitable for measuring AC current signals and outputting standard DC signals such as 4‑20mA and 0‑10V.AC‑DC universal current transducer: Capable of measuring both AC and DC current signals and outputting standard DC signals.Hall‑effect current transducer: Adopts Hall sensor as the core sensing component, featuring fast response speed, high measurement accuracy and strong anti‑interference ability.Shunt‑based current transducer: Takes the shunt as the sensing element, with wide measurement range, good stability and low cost.
Current transformer type current transducer: Uses a current transformer for sampling, applicable to large current measurement with wide range and high safety.
Selection GuidelinesThe following factors need to be considered when selecting a current transducer.Measuring range: Select a suitable measuring range according to the magnitude of the measured current signal.Output signal: Choose a reasonable output signal type such as 4‑20mA or 0‑10V according to the requirements of rear‑end equipment.Accuracy class: Select the appropriate accuracy grade based on actual measurement precision requirements.Stability: Choose products with corresponding stability performance according to the service environment and measurement standards.Anti‑interference ability: Select current transducers with matching anti‑interference performance according to the electromagnetic interference condition of the application site.
