We Continue the Work of Those
Who Were the First.

  • Electrotechnics
  • Electrical Engineering
  • Light & Lighting
  • Power Engineering
  • Transportation
  • Automation
  • Communication
  • Smart Buildings
  • Industry
  • Innovation

Current issue

ELEKTRO 7/2020 was released on June 24th 2020. Its digital version will be available on July 24th 2020.

Topic: Cables, conductors and cable engineering

Main Article
New traction power supply technology 25 kV/50 Hz (part 2)

SVĚTLO (Light) 3/2020 was released on June 8th 2020. Its digital version will be available on July 8th 2020.

Professional organizations activities
Announcement: LUMEN V4 2020 is cancelled
What is new in CIE, April 2020

Accessories of lighting installations
Foxtrot as a “Master Control” in Hotel Breukelen
Lighting regulators – control of lighting on the constant level

First battery-free cellphone

10. 7. 2017 | University of Washington | www.washington.edu

University of Washington researchers have invented a cellphone that requires no batteries — a major leap forward in moving beyond chargers, cords and dying phones. Instead, the phone harvests the few microwatts of power it requires from either ambient radio signals or light.

The team also made Skype calls using its battery-free phone, demonstrating that the prototype made of commercial, off-the-shelf components can receive and transmit speech and communicate with a base station.

First battery-free cellphone

The team of UW computer scientists and electrical engineers eliminated a power-hungry step in most modern cellular transmissions — converting analog signals that convey sound into digital data that a phone can understand. This process consumes so much energy that it’s been impossible to design a phone that can rely on ambient power sources. Instead, the battery-free cellphone takes advantage of tiny vibrations in a phone’s microphone or speaker that occur when a person is talking into a phone or listening to a call.

An antenna connected to those components converts that motion into changes in standard analog radio signal emitted by a cellular base station. This process essentially encodes speech patterns in reflected radio signals in a way that uses almost no power.

Read more at University of Washington

Image Credit: Mark Stone/University of Washington

-jk-