摘要 |
<p>Wireless sensors configured to sense, record and transmit data are provided herein. In one aspect, the wireless sensor has a power harvesting unit; a transducing A-to-D converter unit, a microcontroller unit, and a transmitting coil. The power harvesting unit is configured to receive an external energizing magnetic field generated by an external interrogator and store the energy generated thereby. The transducing A-to-D converter unit has a passive electrical transducer configured to respond to variations in a physical property and a converter configured to measure a characteristic value of the passive electrical transducer and provide a digital signal that is indicative of the measured characteristic value. The microcontroller unit is electrically coupled to the power harvesting unit and the transducing A-to-D converter unit and is configured to receive the digital signal from the transducing A-to-D converter unit. The transmitting coil is configured to receive the digital signal and to transmit the digital signal to the external interrogator. Upon receiving a start signal, the transducing A-to-D converter unit charges a current through the passive electrical transducer until a reference voltage is reached and, upon reaching the reference voltage, the microcontroller unit receives the digital signal.</p> |