NK Technologies introduces ATPR “E-Out” Series AC current transducers. ATPR current transducers combine a current transformer with a true RMS signal conditioner in a single package. This enables the ATPR series to produce a 0-5 or 0-10 VDC RMS output on distorted waveforms located in the output of variable-frequency drives, phase angle fired heating controls, and on linear loads in “noisy” power environments. 

“The ATPR series provides true RMS sensing, meaning output is proportional to the current flowing in the circuit even with high distortion or harmonic loads,” says Philip Gregory, NK Technologies president. “Field selectable ranges minimize inventory requirements and easily accommodate changes in load conditions, and a split core housing simplifies installation — users simply release the latch and snap it over the conductor. And the unit’s DC voltage output is ideal for data acquisition systems, panel meters or controllers with only voltage inputs available.” 

The ATPR series monitors the output of variable-frequency driven loads, even when in bypass mode. They can also be used to measure phase angle fired heating controls and other SCR controlled loads. These current transducers respond quickly to element failure by monitoring current instead of temperature, and accurately measure power supply and ballast input power. 

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“Many building energy management controllers provide 0-5 VDC inputs, and many data loggers utilize 0-10 VDC inputs. ATPR series current transducers can be used in applications where the current wave is distorted or where it is sinusoidal with equal accuracy,” explains Gregory. “Even when the amount of distortion is not known users can be certain the measurement will be accurate. With this sensor the installer can use the industry standard for monitoring AC current, without having to use an external resistor that can add a degree of inaccuracy to the system.” 

Engineers designing switched mode power supplies work to improve pulse width modulation so the controlled load will have the cleanest power applied, reducing harmonics to reduce overheating of transformers and motors in addition to reducing zero-crossing noise. The methods for doing this are expensive, so distortion in these types of power supplies will continue for the foreseeable future. Variable-speed drives, electronic ballasts, uninterruptible power supplies and other devices that use switched mode power supplies are sources of current sine wave distortion and require frequent monitoring. ATPR series current transducers are a simple and cost effective solution for monitoring distorted AC current. 

About NK Technologies
Founded in 1982, NK Technologies designed the first the low-cost solid-state current sensing technology. The company provides sensing, ground fault detection and power monitoring products to the industrial and factory automation markets, with a product portfolio that includes more than 1,300 models to satisfy a wide range of specific application needs. As the needs of these markets change, NK Technologies is well-positioned to respond with sophisticated new product designs and improved product functionality necessary to meet those applications. 

For more information, visit www.nktechnologies.com.


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