Wireless Power Supply for Wearables

Würth Elektronik eiSos GmbH & Co. KG, manufacturer of electronic and electromechanical components, now offers wireless power coils for wearables. Since de­vices such as fitness sensors and smart watches are gen­erally encapsulated to protect them from the effects of the en­vironment, but due to the variety of integrated sen­sory components (GPS, radio) have to be recharged fre­quent­ly, the contactless transfer of energy without a charging plug is the call of the day.

By expanding its portfolio of proven wireless power-trans­fer products, Würth Elektronik eiSos is taking a leading position in the trend, and now offers two new transmitter and three receiver coils that are optimally suited for solu­tions for charging wearables and mobile devices. The coils are adapted to the already existing standard chip sets for the WPC Qi standard, making it easy to use al­ready available designs simply by exchanging the coils for wearables.

Slim receiver coils

The striking feature of the WE-WPCC 760308102212 and WE-WPCC 760308102213 receiver coils is their extreme thinness of just 0.64 mm, making them the component of choice for use in wearables with space for relatively large coil areas (29 x 29 mm), but with strong limitations re­garding their height. In addition, the broad ferrite projec­tion of the WE-WPCC 760308102212 unit offers excellent shielding properties – an important aspect in applications that are sensitive to electromagnetic interference.

Dual standard

The selection of the inductance value used in the WE-WPCC 760308102213 product makes it a dual-standard receiver. Fitted with the corresponding receiver chip, the coil is capable of responding to transmitters that are com­patible with either the WPC Qi standard or the PMA standard.

The third receiver coil, the WE-WPCC 760308101214 product, is slightly thicker at 0.8mm, a feature that is offset somewhat by having a diameter of just 19 mm.

Thanks to its compact design, this product is ideally suited for wireless power transfer in devices with only limited space. Used in conjunction with the new WE-WPCC 760308101104 and WE-WPCC 760308101105 transmit­ter coils, it is capable of achieving excellent power-trans­fer results.

Charging stations

To make charging stations that are ideally compatible with these receiver coils, Würth Elektronik eiSos also offers two new wireless power-charging transmitter coils, the WE-WPCC 760308101104 and WE-WPCC 760308101105 products. Both coils have an external diameter of just 21 mm, and use high-quality ferrite for shielding and stranded wire to keep the R_DC to a mini­mum. The two coils differ in their inductance values.
“Smart watches like the Motorola 360 and Apple Watch are leading the way, with fitness trackers and other wear­ables as well as smart phones already in the pipeline. Especially for devices that must be protected against moisture, contact-free recharging has the advan­tage that the cable socket can be dispensed with”, says Oliver Konz, CEO of Würth Elektronik eiSos. Thomas Schrott, also a CEO at Würth Elektronik eiSos, adds: “We’ve been involved in the Wireless Power Consortium for many years now, actively contributing our competence to drive standardization further. With our high-quality wire­less power products we’re supporting a trend that will in all probability one day enable us to recharge all our mo­bile devices using one and the same wireless charging unit.”