Irrigation Controller Technologies
Ambient’s is experienced in the design and development of battery free, energy efficient, solar powered control system technologies that have been incorporated into a number of successful commercial products for applications in irrigation control. Trade marked as Light Energized Irrigation Technology (LEITtm), this technology provided the necessary long term energy source required to operate the LEIT series of solar powered, battery-free irrigation controllers. With successfully national and international deployments currently spanning 16 years, these controllers activate and deactivate irrigation control valves using either time based or soil moisture based control.
The LEIT controller system was developed and refined over a 12 year period at a cost of $20M IR&D. A series of patents were filed on the technology, the most notable being Patent Number 5,229,649 titled “Light-Energized Electronics Energy Management System” and Patent Number 5,661,349 titled “Graceful Energization and Degradation of an Electronic Device Micro powered by a Source of Energy in its Environment”. Utilizing a mid-door amorphous silicon photovoltaic module, energy is collected from dim room light through one sun light levels and stored in an array of low leakage supercapacitors. This energy is used to power an embedded micro-controller that performs all of the system’s software and hardware control functions. Totally self contained, the LEIT controller provides the optimum level of irrigation control based on timed watering cycles and/or optimum soil moisture levels. Water valve control is enabled through magnetically latched actuators that are current loop controlled from the LEIT. Ground moisture and rain levels are measured by the LEIT with switch type sensors over the same current loop. First introduced in 1992, well over 100,000 valve actuating devices have been installed in over 800 municipalities worldwide giving this technology a level of time proven maturity. Under an exclusive licensing agreement, Ambient sold a technology license to the DIG Corporation in 2001 for $1.4M. This license granted DIG the exclusive use of the above mentioned patents only in the field of irrigation, leaving Ambient free to exploit these patents in all other technology areas.