Search

Il brevetto descrive un procedimento ed un apparato per la valutazione della durezza e per la selezione di prodotti orto-frutticoli

This chapter introduced power management circuits and energy storage unit designs for sub‐1 mW low power energy harvesting technologies, including indoor light energy harvesting, thermoelectric energy harvesting and vibration energy harvesting. The solutions address several of the problems associated with energy harvesting, power management and storage issues including low voltage operation, self‐start, efficiency (conversion efficiency as well as impact of power consumption of the power management circuit itself), energy density and leakage current levels. Additionally, efforts to miniaturize and integrate magnetic parts as well as integrate discrete circuits onto silicon are outlined to offer improvements in cost, size and efficiency. Finally initial results from efforts to improve energy density of storage devices using nanomaterials are introduced.

This thesis presents a new approach for the design and fabrication of bond wire magnetics for power converter applications by using standard IC gold bonding wires and micro-machined magnetic cores. It shows a systematic design and characterization study for bond wire transformers with toroidal and race-track cores for both PCB and silicon substrates. Measurement results show that the use of ferrite cores increases the secondary self-inductance up to 315 µH with a Q-factor up to 24.5 at 100 kHz. Measurement results on LTCC core report an enhancement of the secondary self-inductance up to 23 µH with a Q-factor up to 10.5 at 1.4 MHz. A resonant DC-DC converter is designed in 0.32 µm BCD6s technology at STMicroelectronics with a depletion nmosfet and a bond wire micro-transformer for EH applications. Measures report that the circuit begins to oscillate from a TEG voltage of 280 mV while starts to convert from an input down to 330 mV to a rectified output of 0.8 V at an input of 400 mV. Bond wire magnetics is a cost-effective approach that enables a flexible design of inductors and transformers with high inductance and high turns ratio. Additionally, it supports the development of magnetics on top of the IC active circuitry for package and wafer level integrations, thus enabling the design of high density power components. This makes possible the evolution of PwrSiP and PwrSoC with reliable highly efficient magnetics.

Method for measuring the hardness of agricultural products comprising the operations of: - implementing a test program suitable for identifying and selecting one or more indices (S3, S4) which can be measured with a non-destructive test on a respective product/fruit, correlated with the hardness (Du) of the same product/fruit, measured by a respective penetration test; - calculating the coefficients that define the straight line representative of the linear correlation between said indices and the hardness for the respective product. The method is implemented with the operations of: - applying on the product a dynamic force, preferably of impulsive type; - detecting the mechanical reaction through at least a piezoelectric transducer capable of generating an electric signal based on the application or transmission of said dynamic force through the respective kiwi fruit; - analyzing said electric signal relative to the fruit, and measuring the crossing time of said dynamic force through the same kiwi fruit; - calculating the value of the index S4 of said dynamic force through the fruit. It was found that the S4 index has a very significant correlation with the hardness of the respective kiwi fruit, and that the coefficients of the relative correlation straight line are respectively a = -1.5084, and b = 0.0072.

Method for measuring the hardness of agricultural products comprising the operations of: - implementing a test program suitable for identifying and selecting one or more indices (S3, S4) which can be measured with a non-destructive test on a respective product/fruit, correlated with the hardness (Du) of the same product/fruit, measured by a respective penetration test; - calculating the coefficients that define the straight line representative of the linear correlation between said indices and the hardness for the respective product. The method is implemented with the operations of: - applying on the product a dynamic force, preferably of impulsive type; - detecting the mechanical reaction through at least a piezoelectric transducer capable of generating an electric signal based on the application or transmission of said dynamic force through the respective kiwi fruit; - analyzing said electric signal relative to the fruit, and measuring the crossing time of said dynamic force through the same kiwi fruit; - calculating the value of the index S4 of said dynamic force through the fruit. It was found that the S4 index has a very significant correlation with the hardness of the respective kiwi fruit, and that the coefficients of the relative correlation straight line are respectively a = -1.5084, and b = 0.0072.

This paper presents a novel method for battery-less circuit start-up from ultra-low voltage energy harvesting sources. The approach proposes for the first time the use of a Piezoelectric Transformer (PT) as the key component of a step-up oscillator. The proposed oscillator circuit is first modelled from a theoretical point of view and then validated experimentally with a commercial PT. The minimum achieved start-up voltage is about 69 mV, with no need for any external magnetic component. Hence, the presented system is compatible with the typical output voltages of thermoelectric generators (TEGs). Oscillation is achieved through a positive feedback coupling the PT with an inverter stage made up of JFETs. All the used components are in perspective compatible with microelectronic and MEMS technologies. In addition, in case the use of a ∼40 μH inductor is acceptable, the minimum start-up voltage becomes as low as about 32 mV.