Micropelt has launched compact thermogenerator package (TGP) devices that makes thermal energy harvesting ready for mass production. The devices enable automatic assembly of autonomous DC power supplies for ultra low power wireless sensors and actuators. Battery maintenance, a stumbling block in the deployment of wireless sensor networks, can be eliminated by TGP autonomous DC power modules whenever a temperature difference of 5 °C or more is available.
Output power ranges from 100 microwatts to over 10 milliwatts, sufficient to replace most batteries. Micropelt's standardised TGP package comes in two interchangeable versions: TGP-651 and TGP-751. This allows output power and cost to be matched to target applications and markets without any changes to the PCB design.
The TGP devices are designed for mounting in a sandwich configuration with a heat sink on one side and a PCB on the other side. The circular aluminium heat source interface passes through a 10 mm hole in the host PCB. The rectangular cold face carries the electrical contacts for reflow soldering and connects to the heat sink on its outer side. The device's vertical dimensions ensure sufficient clearance for electronic components mounted next to it below the heat sink.
At relatively low thermal gradients (between 10 and 40 °C), both devices produce very similar power levels, so the TGP-651 with a 6 mm2 TEG is more cost-effective. The TGP-751, with a footprint of 12 mm², is preferable for situations with very low gradient or high power demand.