EnOcean taps heat as energy source for energy harvesting modules

This marks another important step in the continuing development of the company’s energy harvesting technology for building and industrial automation.. In addition to motion and light, this is the third energy source exploited by EnOcean for its service-free wireless modules. The ECT 310 works as an interface between thermoelectric converters and EnOcean modules – the all-purpose, bidirectional STM 300 sensor and the new plug&play STM 312. EnOcean is presenting the ECT 310 at electronica 2010 in Munich (November 9-12, booth A4.266).

Using heat to produce power opens doors to many new applications for energy harvesting wireless technology, in building and industrial automation as well as in medicine. For example, it enables the use of heating cost allocators and temperature sensors, control engineering or sensors for preventive diagnostics wherever heat is available.
Energized interface

The ECT 310 is an ultra-low-voltage DC/DC converter, which converts low input voltage upwards of 20 mV into conventional used electronic output voltage of 3 to 4 V. The energy obtained in this way powers EnOcean wireless modules. To achieve maximum system efficiency, the output voltage of the ECT 310 is crudely regulated. With its plug&play capability, the ECT 310 can be combined with a thermoelectric converter and the STM 300 or STM 312 energy harvesting wireless modules for simple implementation of batteryless sensors or actuators powered solely by heat.
Combination variety

The bidirectional STM 300 is part of EnOcean's Dolphin platform and is able to both transmit and receive wireless signals. The module possesses an all-purpose energy harvesting interface and can be fitted with a short term energy storage mechanism or optional long term energy storage. Such flexibility of energy storage means that a whole variety of heat-powered, batteryless wireless sensors and actuators can be implemented together with the new ECT 310 converter to deliver solutions that will also work reliably in surroundings where temperatures fluctuate. If enough heat is available, a small energy storage mechanism suffices to power a module. The larger storage will bridge occasional periods where there are minor differences in temperature. Storage is controlled automatically on a digital output of the STM 300 module. This combination is especially suitable for temperature-powered, bidirectional sensors and actuators – for example, sensors in industrial plants that require data feedback, or control parameters from a control center, or actuators to manage heat distribution.

In contrast to the STM 300, the STM 312 wireless sensor module comes with two ready integrated energy storage mechanisms, an antenna and a port for connecting a sensor element. Product manufacturers can solder the ECT 310 and the thermo element straight to the STM 312, resulting in an especially compact design with a minimum of development effort. That makes this combination highly suitable for sensors installed to operate in low-light areas – as in suspended ceilings or under floor compartments. Both STM modules are available in 868 MHz and 315 MHz versions, allowing worldwide application.
Heat for the taking

EnOcean is offering the ECT 310 as part of the EDK 312 developer kit, an advanced version of EDK 300. Together with the accompanying STM 300 and STM 312 wireless modules, a thermoelectric converter and comprehensive documentation, product manufacturers can embark on developing their own heat-powered, energy harvesting solutions for building and industrial automation, or other areas of application.

You find differences of temperature in diverse environments: in manufacturing, in heated or air-conditioned premises, through solar radiation, on motors and engines or even on humans themselves. That makes heat an ideal extra energy source for our self-powered wireless modules, says Armin Anders, VP product management and co-founder of EnOcean. Supported by the ECT 310 you can implement our wireless solutions wherever there's a temperature difference, at least in part, of 2 degrees or more. So we're anticipating an even faster pace in the development of applications for energy-efficient automation and energy harvesting wireless sensor technology.