VAC presents sensor solutions with newly-developed highly integrated circuits at electronica 2014



Munich’s exhibition center, Messe München, will open its doors from 11 to 14 November 2014 for the 26th electronica. The leading international trade fair for electronic components, systems and applications has the heading “Welcome to Planet e”. VACUUMSCHMELZE will again be present, exhibiting new products and proven solutions from its wide portfolio of current sensors in Hall B5, Stand 119.

VAC’s current sensors now feature advanced integration of electronic components thanks to the development of a new highly integrated circuit. The Hanau-based company will present the first products from a new generation of current sensors. Over the medium term, these advanced sensors will replace many of the present models with supply voltages of +/- 12 … +/- 15 V or +/- 24 V and current output. The new 4648-xxx family of sensors will be fully compatible with their corresponding predecessors.

Further improvements to the performance and reliability parameters of MTBF and FIT will be achieved by significantly reducing the number of internal components compared to previous models. In some models, thermal reliability will be additionally enhanced by improving cooling conditions for internal components. The circuitry protecting against undefined operating states, such as temporary failure or drop in supply voltage during operation, has been optimized. More and more models from previous VAC product series will become available using the new technology in the near future.

VAC's series of current sensors for PCB assembly with integrated electronics have achieved outstanding market success in recent years. VAC invented the principle of a closed-loop sensor with magnetic probe as the zero field detector which is distinguished by extremely high-precision current detection. The new VAC current sensors concentrate practically all their electronics in a custom-designed signal-conditioning IC produced in partnership with a leading semiconductor manufacturer. The sensors offer outstandingly accurate measurements together with low temperature dependence and low long-term drift of the output variable. All sensors feature compact dimensions and measure high maximum and continuous current. Models available include sensors for unipolar or bipolar power supply and models with voltage or current output.

VAC’s existing and well-established range of current sensors for PCB assembly, with model numbers of 4646-X7xx, is largely identical to VAC's successful ultra-compact 4646-X6xx range, but offers additional advantages. The extended clearance and creepage distances of the sensors enable them to be used for higher system and operating voltages (600 V / 1020 V as per EN61800). They also have four current bars instead of three, reducing current density and allowing users more options for parallel and series connection, to tailor measurement ranges to their specific application.

As present trends continue to move towards increasingly high-power applications such as wind turbines, central inverters for solar energy and large-scale drive systems, demand for devices capable of detecting higher current levels is growing. In response to this need, VAC has advanced the superior functional principle of its current sensor and developed high-current sensors for currents of 1000 Arms and higher, with a measurement range of up to 2500 A. Compared to existing devices, VAC's solution offers the hallmark advantages of VAC sensors, such as high measurement precision and stability, broad measurement range and outstanding dynamic properties, as well as low sensor power consumption thanks to a PWM driver for the compensation current. The wide opening enhances flexibility for the user when connecting the primary conductor.
AC-DC-sensitive differential current sensors, or DI- sensors, form the core of residual current monitoring units (RCMUs) tailored for use in transformerless solar inverters compliant with the EN 62109 standard. The DI- sensors render the installation of expensive DC-sensitive residual current devices type B superfluous.

The operating current conductors (L1, L2, L3 and N) and – where applicable – external test current are routed through the sensor, which measures only the current difference between the conductors, i.e. the residual current, to an accuracy of 1.5% of the allowable residual current of 300 mA. Output is a voltage proportional to the differential current. VAC’s DI-sensors offer a range of additional functions including sensor core demagnetization, which can be triggered by the supply voltage or as required. The new 4646-X976 sensor model has integrated primary conductors for three-phase systems plus a test current conductor. It complements the family of DI sensors with primary conductors for single-phase systems and push-through openings.