Thermo-powered, self-sufficient wireless sensor node evaluation unit.
Exploration of thermoharvester-driven wireless technology and location specific power budget exploration.
This device represents Micropelt’s third generation of thermoharvesting evaluation units. We designed the TE-Power NODE to provide our customers with an easy-to-handle plug and play wireless sensor system which lets you explore and understand thermal harvesting and its major influencing factors. Sensor data provided include hot and cold side temperatures of the thermogenerator (TEG) and output voltage of the power source.
A datasheet of the » TE-Power NODE is available as a pdf document (829 KB).
Thermoharvesters are much limited in power output. Therefore we use the latest ultra-low-power microcontrollers and radios. Sleep power consumption in particular needs be minimized as much as possible, while optimized resource management in active mode must be supported by the active components. TE-Power NODE features a pluggable sensor/wireless module which integrates a TI (Texas Instruments) MSP430 microcontroller with a TI CC2500 radio.
This device is intended for evaluation and laboratory use.
– Harvesting Target Attach
Attachment of a thermoharvester to its target heat source is probably the most critical factor of any implementation. TE-Power NODE allows to explore the influences of mounting pressure, surface flatness and roughness, and the impact of thermal interface materials applied to mechanical interfaces and learn how these factors influence the harvesting result. The TE-Power NODE comes with an aluminum base plate which let’s you explore these criteria.
– Heat Sink Design
The TE-Power NODE comes with a 15 × 15 mm² aluminum heat sink base with M1 threaded holes for easy attach of any type of heat sink. This way both input and output of the thermal path can be explored and the most efficient heat sink can be identified for each considered application and operating condition.
– Power Conditioning
Our plug-on DC-DC step-up converter provides constant 2.4 Volts of output voltage as long as the thermal energy flowing through the device exceeds the required minimum level. We have allocated space for energy storage components such as capacitors, super caps, thin film batteries and rechargeable button cells. This will allow you to optimize the energy supply such that both peak power and drop-out capacity are matched.
– Sensor Signal Processing
Per default we use three signals and provide an additional I2C digital sensor interface to connect any compatible sensor. Power restrictions to that sensor may apply dependent on available thermopower.
– Wireless Interface TE-Power Scope
A TI CC2500 radio connects the TE-Power NODE to a PC, transmitting condition monitoring data to a TI USB receiver via our simplified custom protocol. This radio is optimized for ultra low power applications and hence not IEEE 802.15.4 compliant. However, compliant radios are pin compatible and may be selected optionally. Power consumption will likely increase significantly, demanding sufficient thermopower or extended sleep periods.
– Harvesting Explorer Interface (TE-Power SCOPE)
The user interface displays the data transmitted by the TE-Power NODE on a once-per-second basis. This includes temperatures of both hot and cold sides of the thermogenerator chip and the current voltage level of the DC-DC converter. Further values help better understand the power budget generated by the respective setup:
If you type in the power and duty cycle specifications of your target system TE-Power SCOPE will show you if you can run that system right off the thermoharvester.
If you have to bridge major drop-out phases a rechargeable battery may be supplied. Type in the capacity and average current draw of your system – and see how much life extension is provided by the thermoharvester.
At the heart of the TE-Power NODE: the Micropelt » MPG-D751 thermogenerator chip.