TRANSMITTER
100W RF generator supplies up to 100W of wire-free power to charge or power multiple devices simultaneously. The wire loop is flexible to accommodate being embedded around the edge of various surfaces, and is optimized for a 2x4 foot desktop.

RECEIVERS
The kit includes 8 round shaped receivers, representing a variety of sizes and power specifications. The bigger the receiver, the more power it can intake. For receiver specifications, click here.

LED LIGHTS
The kit also includes 2 different colored magnetic field indicator LEDs. Use these to visualize/map the power zone.

ETI Technology uses magnetic resonance to wirelessly transfer power to multiple receivers within a space called the “power zone.”

The concept of wireless power goes back to Nikola Tesla in the late 1800s. Tesla showed that resonance allows efficient energy transfer between systems tuned to the same frequency. As a result, the electrical amplitudes are much stronger than if the systems were non-resonant. ETI builds on this idea, using resonant transmitters and receivers coupled through magnetic induction. We focus on magnetic fields because they interact only weakly with the human body.

Our system generates magnetic fields oscillating at 6.78 MHz — a frequency low enough that most energy stays near the transmitter in the 3D region we call the “power zone”. Receivers within the power zone capture this energy. Any unused magnetic energy returns to the transmitter, where a portion is lost as heat and the rest helps power the next cycle. The system becomes more efficient as more receivers are added.

ETI's power generator draws a minimum power of 10-15 Watts to maintain the magnetic field of a tabletop-sized system. As the loading is increased, the power generator draws more DC power, up to a maximum of 100 Watts.

The system efficiency increases as the load is increased. Under laboratory conditions, we measured a maximum DC-to-DC efficiency of 69% (44.3 Watts of DC output with 64.0 Watts of DC input).

This result is in the latest paper that we submitted to the 2025 WPTCE, and it will be published in IEEE in a few months. This may be compared to Qi charging, for which typical efficiency ranges from 60% to 75%, or MagSafe, for which typical efficiency ranges from 70% to 80%.

This kit is for evaluation purposes only. It is not for commercial use or resale.

RF SAFETY
ETI’s magnetic resonance wireless power systems generate magnetic fields which oscillate at 6.78MHz. Electromagnetic fields at the frequency of 6.78MHz are categorized as non-ionizing electromagnetic radiation. Human exposure limits for non-ionizing radiation are regulated by the Electronic Code of Federal Regulations §1.1310, which stipulates thermal limits which are quantified by the Specific Absorption Rate (SAR) of Watts of heat generated per kilogram of tissue. ETI's first product, Airbrite, has been certified by UL to be compliant with the SAR limits, and ETI is currently in the process of testing our Eval Kit for compliance with the SAR limits.

SURFACE TEMPERATURE
Following consumer product safety guidelines, we designed our system to produce no more than 47C degree of product surface temperature. In our lab (room temperature at 23C degree), the product surface temperature reaches a maximum of 45C degree.

INTERFERENCE
If your transmitter light is blinking, you likely have interference that is causing the power zone to shut off.

The presence of any large metallic surfaces in the power zone imposes extra constraints. With careful design, transmitter loops can be made to operate in proximity to metal. However, performance may be reduced in comparison to a metal-free environment.

Power output may be reduced if Exclusion Zones of two receivers overlap. Presence of metallic surfaces or magnetic materials in Exclusion Zone may also reduce power output. Non-conductive and non-magnetic materials in the Exclusion Zone are acceptable, as are small metallic objects like small, non-magnetic screws.

AVOID METAL
For best performance, avoid large, flat metal surfaces or large, closed loops of conductor parallel to the surface of the receiver within the Exclusion zone.

RECEIVER ORIENTATION
Inside the power zone, the receivers will be powered regardless of their position. However, the receiver will not be powered if it’s in perpendicular position to the transmitter surface.

MULTIPLE DEVICES POWERED
On the number of devices can be powered, it depends on the total power requirements (the Eval Kit transmitter can provide up to 100W). One ETI transmitter can power many ETI receivers. The most we have tried was 1 transmitter powered 141 receivers (we ran out of the receivers)!

For engineering support for your DIY projects, please join our Community Forum.

For commercial initiatives, ETI can assist with integrating wireless power into your environments and products. To inquire about ETI design and engineering consulting services, as well as licensing opportunities, please Contact Us.