COTA – OSSIA Wireless Charging / Power Transfer

Design HMI is working on developing applications for wireless charging that go beyond the standard transmitter to receiver applications that are commonly being marketed for cell phone charging. We are looking to develop applications that are based on in-direct coupling like those offered by Power-By-Proxi and other upcoming technology providers.

The COTA – OSSIA illuminated monolithic cylinder charges devices wirelessly. Peer write up in Digital Trends the technology behind it is anything but simple, however. The Cota’s filled with hundreds of omnidirectional antennas that beam radio (RF) waves over 2.8GHz at 100 Hz, well beyond the interference range of Bluetooth and Wi-Fi.

Once a device needs to be charged Cota proprietary transceiver design sends a packet of information to the Cota that includes its current power level. The Cota then directs the needed power to the transceiver’s relative location, or to multiple transceivers’ locations. You can charge multiple devices simultaneously.

After a transceiver requests power, the Cota sends an initial RF pulse that’s attenuated by walls, furniture, people, and any other RF-absorbing objects in its path. When part of the signal reaches a transceiver (or transceivers), it’s reflected back to the Cota, establishing an invisible path along which power is sent continuously. The successive, current-carrying RF signals are then converted at the individual transceivers.

The RF waves reach a maximum of 30 feet. And any object that crosses in front of the established path, like the cloth of a pants pocket, immediately stops the transmission. Cota relies on transceivers to initiate power transfer — and if the transceiver’s RF waves don’t penetrate an object in the Cota’s line of sight, power deliver won’t begin.

Few points to consider:

• Base station requires between 300 and 500 watts, it distributes as little as one watt of that stored energy over the course of a day.
• To meet FCC limits for human exposure, the Cota transmits power at only one-fifth to one-third the charging speed provided by USB.

Up to 5W Power – Up to 10M Range. Unlike radio waves that pass through a human body, Ossie’s Cota technology considers our bodies to be obstructions and therefore power signals avoid them.

Here is how it provides seamless delivery to simultaneous multiple devices

RF Efficiency: Cota Multipath vs. Beam Forming

SAFETY:

Ossia has spend considerable time and effort in testing the safety of Cota

Multiple testing for SAR exposure and Field Strength have shown that Cota does not exceed the recommended health and safety limits defined by the FCC and FDA

Cota systems 100 times reaction to changing environment ensures that the system does not expose people in highly dynamic situations

FCC Regulations & Testing:

Ossia has been working with the FCC since June 2013

Ossia is establishing the required guidelines for approved FCC certification of devices

FCC specific testing of Cota prototypes has been made with different configurations and approaches, with Cota meeting important milestones for regulatory compliance

Handheld devices are tested using SAR (Specific Absorption Rate) measurement the RF energy captured by human flesh

Mobile devices are tested at a distance of 20cm for field strength measurements and/or power density