Abstract: There is provided a receptacle system for detecting at least one metallic object entering therein and alerting a user in response to the detection. The system of the preferred embodiment comprises a receptacle body forming an interior cavity. Moreover, a cover may be engaged to the receptacle body, in which the cover may define an opening for providing access to the interior cavity. A metal detector may be attached to the cover to detect the at least one metallic object entering through the opening of the cover. Thereafter, the metal detector may alert the user in response to the detection of the at least one metallic object.

Abstract: There is provided a receptacle system for detecting at least one metallic object entering therein and alerting a user in response to the detection. The system of the preferred embodiment comprises a receptacle body forming an interior cavity. Moreover, a cover may be engaged to the receptacle body, in which the cover may define an opening for providing access to the interior cavity. A metal detector may be attached to the cover to detect the at least one metallic object entering through the opening of the cover. Thereafter, the metal detector may alert the user in response to the detection of the at least one metallic object.

Abstract: A water conductivity monitor that is controlled by a microcontroller which provides a pair of probe driving signals that are 180° out of phase. The monitor is connected to a feed water probe that is located within the unfiltered water of a water purification system and a filter water probe that is located within the filtered water of the system. The driving signals are provided to the probes to create a probe test signal. The filtered water test signal is a ratio of the voltage across the feed water probe and the voltage across the filter water probe. The driving signals are also provided to a resistor circuit which provides a threshold test signal. The test signals are integrated by an integrator circuit which is controlled by the microcontroller. The integrated test signals are compared by a comparator. The comparator provides an output signal to the microcontroller if the voltage level of the probe test signal is below the threshold test signal.