Seiko Epson Unveiling Non-Contact Power Transmission Device

September 18, 2008 by Jeff Shepard

Seiko Epson Corp. announced that it has started sampling its non-contact power transmission device, which can transmit power of up to 2.5W without metal-to-metal contact. The power transmission system is composed of the S4E96400 (primary) power supply module and the S4E96401 (secondary) power receiving module. The power supply and receiving modules are each composed of coil and control units. Using these units as a set, the system enables the power transmission.

The power receiving module has an output voltage of 5V and an output current of 500mA. The maximum power transmission efficiency of the system reaches 70%. The thickness of the coil unit of the receiving module is reduced to 0.8mm. The system is expected to be used to charge mobile devices, etc. It is targeted for use in water- and dust-proof devices as well as devices with an advanced design.

Like the company's existing product, the latest system employs the electromagnetic induction method. When the power supply and receiving modules are opposed to each other, the positional gap between the coils of both modules is 5mm in the horizontal direction and 3.8mm in the vertical direction. An electromagnetic shielding sheet is incorporated on the back side of the power transmission surface of each coil. The shield can reduce the effects on electronic parts in devices attached to the modules, according to the company.

The system has (1) a function to determine whether or not to transmit power to the object placed on the coil of the power supply module, (2) a function to detect foreign matters, such as metal pieces, trapped between the coils of the power supply and receiving modules and (3) a protection function to stop the operation when an overcurrent or an abnormal temperature is detected.

The coil unit of the power supply module measures 55 x 40 x 2.2mm, and the control unit of the supply module measures 40 x 30 x 5.3mm. The coil unit of the power receiving module measures 45 x 35 x 0.8mm, and the control unit of the receiving module measures 20 x 15 x 1.6mm.

Four components, the coil and control units of the supply module and the coil and control units of the receiving module are sold as a sample set. The set is priced at 5,000 yen (excluding tax, approx US$46).