Abstract: A gas manifold that provides an uninterrupted supply of gas and automatically switches between at least two gas sources. This gas manifold couples to a on-line gas source and a reserve gas source. A pressure transducer at the inlet to the manifold reads the pressure of the gas source. A downstream pressure regulator of each pressure transducer regulates the pressure of gas supplied to a control valve directed by a control circuit. This control circuit monitors the pressure read by the pressure transducers to determine which gas source will be placed on service depending on user preferences, and directs the operation of the control valve to effect those choices.

Abstract: A gas manifold that provides an uninterrupted supply of gas and automatically switches between at least two gas sources. This gas manifold couples to a on-line gas source and a reserve gas source. A pressure transducer at the inlet to the manifold reads the pressure of the gas source. A downstream pressure regulator of each pressure transducer regulates the pressure of gas supplied to a control valve directed by a control circuit. This control circuit monitors the pressure read by the pressure transducers to determine which gas source will be placed on service depending on user preferences, and directs the operation of the control valve to effect those choices.

Abstract: An integrated circuit with three independently programmable "time bomb" functions. The integrated circuit can be set to disable itself after a certain number of power-up cycles, or after a certain total duration of operation, or after a certain absolute time and date. This is particularly advantageous for authorization functions, where the manufacturer may want to enable the user to "test drive" a demonstration or rental item of hardware or software.

Abstract: A surgical sleeve includes a housing and inner and outer sleeves coupled to the housing. A modular expandable hinge member is coupled to the outer sleeve and defines a radially expandable member to prevent inadvertent withdrawal of the surgical sleeve from a body cavity. A trigger is carried by the housing to cause relative movement between the inner and outer sleeves and radial expansion of the expandable member. The housing is further provided with a transversely slidable reducer assembly having three outer diameter seals for sealing against the exterior of surgical instruments having a variety of outer diameters. A trocar is provided for use with the surgical sleeve that is modular in construction and includes a shaft member and a modular, tubular, metallic cutting portion. The cutting portion forms only a portion of the trocar spike and the length of the shaft member governs the overall length of the trocar.

Abstract: An integrated circuit which includes not only a real time clock, but also an elapsed time counter, and a third counter. The elapsed time counter measures the total number of seconds during which a system has been powered up. The third counter is a "cycle counter," which measures the number of times a power cycle (power-up and power-down) has occurred. Thus, by reading the cycle counter and the elapsed time indicator, the general power history of a system can readily be determined, even if the system itself has totally failed. This integrated circuit is battery backed, and is advantageously combined with a system for which power history must be maintained.

Abstract: A battery management chip which controls charging and discharging currents of a rechargeable battery. A further novel teaching set forth in the present application is an integrated circuit which includes a crystal-controlled oscillator for precise time measurement. Crystal-controlled oscillators are normally fairly power-hungry circuits, and such circuits would not normally be used in the low-power part unless needed. However, according to this innovative teaching, the precise time integration provided by the crystal oscillator is significantly advantageous, since it permits accurate time integration to derive the present state of the battery after multiple charge and discharge cycles. In addition, in the presently preferred embodiment, a low-power crystal-controlled oscillator is used.

Abstract: A battery management chip which controls charging and discharging currents of a rechargeable battery. The chip includes a differential temperature-sensing circuit, for connection to two separate temperature-sensing devices. Thus, one thermistor can be placed in close thermal contact with the casing of the battery, while the other thermistor is exposed to ambient temperature. This permits a temperature rise in the battery to be sensed. This is very useful in controlling charging characteristics. Otherwise, the rate of charging current may be excessive under a low ambient temperature and lower than necessary under high ambient temperature.