Hioki Launches 500 A AC/DC Current Sensor CT6904

Hioki is pleased to announce the launch of the AC/DC Current Sensor CT6904 (rated for 500 A). The device delivers world-class measurement band (4 MHz, or 40 times the previous design) and accuracy, making it ideally suited to applications such as the evaluation of inverters, where high-current, high-frequency designs are increasingly the norm.

The switching frequencies used in power conversion circuitry in the inverters and power conditioners found in environmentally friendly vehicles (EVs, PHVs, PHEVs, and HVs) have been increasing as those devices move toward higher-efficiency, more compact designs. This trend has proven problematic since the performance of existing current sensors is insufficient for measuring devices such as inverters that operate at increasingly high frequencies. Hioki developed the CT6904 to resolve these issues.

By using a newly developed opposed split coil, the CT6904 is able to offer a measurement band of 4 MHz, 40 times that of the previous design (9709: 100 kHz). Measurement accuracy has also been dramatically improved from the previous model, to ±0.02% rdg. (9709: ±0.05% rdg.). These improvements allow the CT6904 to meet demand for the ability to measure devices that operate with increasing large currents and at increasingly high frequencies.

Thanks to machined aluminum solid shield developed by Hioki to completely cover the sensor’s magnetic core and winding, the CT6904 delivers high noise resistance, with a common-mode rejection ratio (CMRR) of 120 dB or greater at 100 kHz. This level of performance makes possible accurate measurement that is free of the effects of nearby voltages.