Abstract: A two-dimensional bar code is used to identify a traveler's luggage, permitting the luggage to be tracked and, if desired, to be delivered to the traveler's ultimate destination (e.g., a hotel). If the traveler is traveling on an airline, a corresponding two-dimensional bar code is applied to the traveler's boarding pass. A two-dimensional bar code reader is used to read the boarding-pass bar code of each enplaning passenger; comparison of these bar codes with luggage bar-code data permits an alarm to be raised if each item of checked luggage is not matched by an enplaned passenger. The boarding-pass bar code may take the form of an integrated passenger identification code for use by, e.g., rental car companies, hotels, and the like.

Abstract: An automatic safety switch provides an automotive battery with protection against accidental discharge due to operator neglect. Such operator neglect includes inadvertent use of electrical circuits such as headlights, parking lights, or interior lights subsequently to turning the ignition off. This invention is connected in series with at least one of the power cables connecting the battery to the fuse box of a vehicle. The choice of power cable is made based on where the circuits to be protected are connected inside the fuse box itself. The automatic safety switch is connected as close to the fuse box as possible, since all necessary connection points are available in the immediate vicinity of the fuse box. The automatic safety switch comprises circuitry that impedes a current flow to its protected output loads when the battery voltage has diminished to a minimum voltage that can safely start a vehicle. The automatic safety switch remains in its current impeded state until reset by the ignition switch.

Abstract: A power converter has a resonant circuit composed of a serially connected inductor and capacitor. The resonant circuit is selectively connected to a DC voltage source, thereby establishing a charge cycle. The DC voltage source is normally derived from an AC voltage source by means of a rectifier and a filter capacitor. A second capacitor is selectively connected to the resonant circuit, thereby establishing a discharge cycle. The second capacitor is never connected with the resonant circuit simultaneously with the DC voltage source. The second capacitor serves as an output capacitor which maintains a substantially constant voltage. The second capacitor is connected to an external load. A control circuit synchronizes the charge transfers to the resonant frequency of the resonant circuit. The control circuit further measures the output voltage to determine if the second capacitor should be engaged in a discharge cycle in order to maintain its constant voltage.