Abstract: An apparatus for controllably generating sparks is provided. The apparatus includes a spark generating device; at least two output stages connected to the spark generating device; means for charging energy storage devices in the output stages and at least partially isolating each of the energy storage devices from the energy storage devices of the other output stages; and, a logic circuit for selectively triggering the output stages to generate a spark. Each of the output stages preferably includes: (1) an energy storage device to store the energy; (2) a controlled switch for selectively discharging the energy storage device; and (3) a network for transferring the energy discharged by the energy storage device to the spark generating device.

Abstract: A power supply is described that comprises two or more flyback-type, DC-to-DC converters having substantially the same periods for their respective charge-discharge cycles; inputs from a common power source; outputs that are connected to a common output node and circuitry for controlling the charge-discharge cycles of the two or more converters so that the cycles of one converter is out of phase with respect to the charge-discharge cycles of at least one of the other converters.

Abstract: A variable function calculator utilizes a fixed program memory array such as a programmed read only memory in which a number of programs are stored depending upon the desired functions of the calculator. The calculator also includes a program counter, an instruction register, control decoders, jump-condition circuits, a clock generator, a timing generator, digit and FLAG mask decoders, key input logic, a register and FLAG data storage array, a decimal and FLAG arithmetic logic unit, an output decoder, and a digit scanner which scans both the keyboard and display outputs. Aside from providing basic desk top calculator functions, the read only memory may be programmed so that the system provides metering functions, arithmetic teaching functions, control functions, etc.. A preferred embodiment of the invention is capable of being fabricated as a monolithic integrated semiconductor system utilizing contemporary metal-insulator-semiconductor techniques.

Abstract: A power supply is described that comprises two or more flyback-type, DC-to-DC converters having substantially the same periods for their respective charge-discharge cycles; inputs from a common power source; outputs that are connected to a common output node and circuitry for controlling the charge-discharge cycles of the two or more converters so that the cycles of one converter is out of phase with respect to the charge-discharge cycles of at least one of the other converters.

Abstract: An apparatus is described for generating a sustained arc at a spark-generating device. A power converter charges an energy storage device to a voltage that will ionize an air gap of a spark device such as an igniter plug. After the voltage is applied to the spark device, the air gap is ionized and the energy from the energy storage device has been exhausted, energy continues to be supplied to the gap by the converter for a predetermined time period.

Abstract: An apparatus for controllably generating sparks is provided. The apparatus includes a spark generating device; at least two output stages connected to the spark generating device; means for charging energy storage devices in the output stages and at least partially isolating each of the energy storage devices from the energy storage devices of the other output stages; and, a logic circuit for selectively triggering the output stages to generate a spark. Each of the output stages preferably includes: (1) an energy storage device to store the energy; (2) a controlled switch for selectively discharging the energy storage device; and (3) a network for transferring the energy discharged by the energy storage device to the spark generating device.

Abstract: An apparatus for controllably generating sparks is provided. The apparatus includes a spark generating device; at least two output stages connected to the spark generating device; means for charging energy storage devices in the output stages and at least partially isolating each of the energy storage devices from the energy storage devices of the other output stages; and, a logic circuit for selectively triggering the output stages to generate a spark. Each of the output stages preferably includes: (1) an energy storage device to store the energy; (2) a controlled switch for selectively discharging the energy storage device; and (3) a network for transferring the energy discharged by the energy storage device to the spark generating device.

Abstract: A dive computer for use by a user of a self-contained underwater breathing apparatus that calculates and displays the user's breathing parameter, which is indicative of the rate at which air pressure in the user's compressed-air tank is decreasing normalized with respect to the user's depth.

Abstract: An apparatus and method are disclosed for reducing peaks of operating power drawn from a power source by a multi-channel system. Each channel of the system drives a load and demands operating power from the power source in an intermittent manner. Power is supplied to the multi-channel system from the power source. Operating power from the power source is drawn in an intermittent manner into each of two or more channels of the multi-channel system. The drawing of the operating power is by the two or more channels so that occurrences of peak operating power launched in a first channel do not fully overlap the occurrences of peak operating power in a second channel.

Abstract: An apparatus for controllably generating sparks is provided. The apparatus includes a spark generating device; at least two output stages connected to the spark generating device; means for charging energy storage devices in the output stages and at least partially isolating each of the energy storage devices from the energy storage devices of the other output stages; and, a logic circuit for selectively triggering the output stages to generate a spark. Each of the output stages preferably includes: (1) an energy storage device to store the energy; (2) a controlled switch for selectively discharging the energy storage device; and (3) a network for transferring the energy discharged by the energy storage device to the spark generating device.

Abstract: A re-breather that includes an inhalant counterlung (18) and an exhalant counterlung (20), with a mouthpiece (30) disposed therebetween. Gas flows from the counterlung (18) to the mouthpiece (30) for use by the diver, with exhalant from the diver directed to the counterlung (20). Gas forced out of the counterlung (20) is input to a canister/scrubber (10) for processing through a scrubbing material in an interior canister (14). The CO.sub.2 -depleted gas is passed back to the counterlung (18). The counterlung (18) has disposed therein a PPO.sub.2 sensor (68) which is directed toward a control system (66) for controlling a valve (46) to adjust the rate of flow of oxygen from a bottle (40) into the CO.sub.2 -depleted gas exiting the canister/scrubber 10 prior to input to the counterlung (18). The rate is varied to maintain the PPO.sub.2 level at a substantially constant level.

Abstract: A wrist unit is provided for allowing the diver to view the breathing parameters that are determined. The breathing parameters are determined by a tank processor via sensors that are disposed on the breathing tank of the diver. These are transmitted to the display unit on the wrist of the diver via a wireless communication link. An inertia switch is provided in the wrist unit, the wrist unit having a watertight housing. The inertia switch is responsive to impacts in the form of tapping on the housing or of rotation of the wrist. When the wrist is rotated, the inertia switch will generate impulses that can be counted and, after a predetermined number, generate a control signal. The control signal controls the on/off function of the wrist unit and also allows switching between alternate displays.

Abstract: A multi-gas blending system for a diving profile is provided with three separate tanks, each having a different gas mix contained therein. The first tank, the primary tank, has a mix that is designed to be O.sub.2 rich for descending from the surface to a predetermined diving depth. At the predetermined diving depth, a switch is made by the diver and the system detects this switch. Prior to the switch, breathing parameters are calculated based upon the gas mix in the primary tank. Once the switch is detected, the calculation is performed on the mix in the second tank. This calculation continues until a predetermined amount of time has elapsed while the diver is on the secondary tank and the diver has begun an ascent and has passed a predefined depth. Once these two conditions occur, this is defined as a switch to a third gas mix, at which time the dive computer begins calculating the breathing parameters based upon a gas mix in a third tank. This is a decompression mixture.

Abstract: An apparatus for controllably generating sparks is provided. The apparatus includes a spark generating device; at least two output stages connected to the spark generating device; means for charging energy storage devices in the output stages and at least partially isolating each of the energy storage devices from the energy storage devices of the other output stages; and, a logic circuit for selectively triggering the output stages to generate a spark. Each of the output stages preferably includes: (1) an energy storage device to store the energy; (2) a controlled switch for selectively discharging the energy storage device; and (3) a network for transferring the energy discharged by the energy storage device to the spark generating device.

Abstract: A personal data unit (PDU) is operable to collect video information via a camera (12) and audio information via a microphone (14). The PDU (10) utilizes a cellular link for transmission of the collected information to a central station (27). Position/time information is received from a GPS satellite network (22) via an antenna (24). This allows the system to be packaged such that it can be attached to an individual and carried with that individual.

Abstract: A dive computer for use by a user of a self-contained underwater breathing apparatus that calculates and displays the user's breathing parameter, which is indicative of the rate at which air pressure in the user's compressed-air tank is decreasing normalized with respect to the user's depth. The dive computer measures the salinity of the water and bases the depth calculation on whether the diver is in fresh or sea water. The dive computer can be actuated by tapping.

Abstract: An advanced dive computer for use by a user of a self-contained underwater breathing apparatus that can communicate with a conventional personal computer through a digital computer interface to allow the user to customize the dive computer. The dive computer also calculates and stores a variety of dive parameters that the user can access with a conventional personal computer. Moreover, the dive computer automatically calibrates its depth calculations in accordance with the salinity of the water into which it is submerged and is sealed in a secure watertight case with as few case-penetrations a possible.

Abstract: A dialysis machine has control circuit which detects changes in input water temperature and compensates the water heater. The control circuit detects changes in the conductivity of the dialysate concentrate and compensates the concentrate pump. Changes in supply voltage are detected and the outputs of the several sensors and the inputs to the pumps and heater comensated. The control circuit periodically calibrates the blood leak detector. In each of the feedback loops which service the heater and each of the pumps, the control circuit varies both the loop response time and the loop gain to compensate for changes in the dialysate flow rate. The resolution of the D/A converters which drive the pumps are enhanced by the control circuit by time modulating the LSB of the respective digital drive value. If any of the several sensed operating conditions varies significantly from the expected value, the control circuit terminates dialysis.

Abstract: A dialysis machine has control circuit which detects changes in input water temperature and compensates the water heater. The control circuit detects changes in the conductivity of the dialysate concentrate and compensates the concentrate pump. Changes in supply voltage are detected and the outputs of the several sensors and the inputs to the pumps and heater comensated. The control circuit periodically calibrates the blood leak detector. In each of the feedback loops which service the heater and each of the pumps, the control circuit varies both the loop response time and the loop gain to compensate for changes in the dialysate flow rate. The resolution of the D/A converters which drive the pumps are enhanced by the control circuit by time modulating the LSB of the respective digital drive value. If any of the several sensed operating conditions varies significantly from the expected value, the control circuit terminates dialysis.

Abstract: A variable function calculator utilizes a fixed program memory array such as a programmed read only memory in which a number of programs are stored depending upon the desired functions of the calculator. The calculator also includes a program counter, an instruction register, control decoders, jump-condition circuits, a clock generator, a timing generator, digit and FLAG mask decoders, key input logic, a register and FLAG data storage array, a decimal and FLAG arithmetic logic unit, an output decoder, and a digit scanner which scans both the keyboard and display outputs. Aside from providing basic desk top calculator functions, the read only memory may be programmed so that the system provides metering functions, arithmetic teaching functions, control functions, etc.. A preferred embodiment of the invention is capable of being fabricated as a monolithic integrated semiconductor system utilizing contemporary metal-insulator-semiconductor techniques.