Abstract: A system for detecting wetness in diapers for the propose of calling the attention of a caretaker. The system is based on the nonlinear interaction of an implanted device inside the diaper with a low distortion background electromagnetic field. The background field is generated by a transmitter external to the diaper. The device is a combination of an antenna, a nonlinear element and two electrodes. Upon a wet condition the resistance between the two electrodes decrease, resulting in an increase in coupling between the antenna and the nonlinear element. The ensuing nonlinear interaction between the antenna and the background field gives rise to harmonics of the field which are detected by a receiver. The receiver which is also external to the diaper triggers a suitable alarm.

Abstract: A tool for depositing seed uniformly along a prepared furrow. The tool uses the rolling motion of a ground engaging wheel to drive a seed pickup and delivery mechanism. A pickup wheel which is coupled to the ground engaging wheel contacts the seeds via a slot in the seed container. A suction force created by an oscillating bellow is channeled to a pickup aperture in the circumference of the pickup wheel. Picked seed is carried by the pickup wheel to a guiding duct to be released and delivered to the soil. The tool also includes an electronic monitor that produces a short audible beep for every deposited seed.

Abstract: An add-on apparatus for feeding container plants. The apparatus contains a battery-powered pump which is designed to pump feeding solution out of a user-supplied container. The apparatus also contains a moisture sensor which is embedded by the user in the growth medium of the plant. This sensor controls the operation of the pump. On the condition of low moisture level, indicative of the need to feed, the pump operates for a controlled duration thus delivering a controlled amount of feeding solution to the plant.

Abstract: A high voltage power driven circuit for producing variable power pulses is responsive to a fixed low amplitude voltage input pulse train for determining the timing of the variable pulses, and to a variable control voltage power source for determining the power level of the pulse. In one embodiment the circuit is used in conjunction with associated circuits for transmitting an apodized and focussed beam of coherent ultrasound from an ultrasonic transducer array.