Abstract: A Complementary Metal Oxide Semiconductor (CMOS) power switching circuit and a method for operating a CMOS power switching circuit are described. In one embodiment, a CMOS power switching circuit includes a voltage selection circuit configured to output the highest output voltage between an output voltage of a primary power supply and an output voltage of a backup power supply and a control circuit configured to connect a load circuit to either the primary power supply or the backup power supply by comparing the output voltage of the primary power supply with a power supply switchover level that is set as a function of the highest output voltage. The backup power supply serves as a voltage reference to set the power supply switchover level only when the output voltage of the primary power supply is lower than the output voltage of the backup power supply. Other embodiments are also described.

Abstract: An electronic timekeeping circuit and a method for operating an electronic timekeeping circuit are described. In one embodiment, an electronic timekeeping circuit includes power supplies and timekeeping circuit components that are grouped into power supply domains. Power is supplied to each of the power supply domains by a corresponding one of the power supplies. Timekeeping registers are duplicated for each of the power supply domains. The timekeeping registers are synchronized between the power supply domains if one of the timekeeping registers is modified or if one of the power supplies is turned off and subsequently turned back on. Other embodiments are also described.

Abstract: A Complementary Metal Oxide Semiconductor (CMOS) power switching circuit and a method for operating a CMOS power switching circuit are described. In one embodiment, a CMOS power switching circuit includes a voltage selection circuit configured to output the highest output voltage between an output voltage of a primary power supply and an output voltage of a backup power supply and a control circuit configured to connect a load circuit to either the primary power supply or the backup power supply by comparing the output voltage of the primary power supply with a power supply switchover level that is set as a function of the highest output voltage. The backup power supply serves as a voltage reference to set the power supply switchover level only when the output voltage of the primary power supply is lower than the output voltage of the backup power supply. Other embodiments are also described.

Abstract: An electronic timekeeping circuit and a method for operating an electronic timekeeping circuit are described. In one embodiment, an electronic timekeeping circuit includes power supplies and timekeeping circuit components that are grouped into power supply domains. Power is supplied to each of the power supply domains by a corresponding one of the power supplies. Timekeeping registers are duplicated for each of the power supply domains. The timekeeping registers are synchronized between the power supply domains if one of the timekeeping registers is modified or if one of the power supplies is turned off and subsequently turned back on. Other embodiments are also described.

Abstract: A color wheel has one or a plurality of color filter segments made from a first material, typically glass, having a coefficient of thermal expansion that is substantially different from a carrier, which is made from a second material, typically aluminum. An intermediate washer or coating is disposed in between the segment(s) and the carrier, and has a coefficient of thermal expansion either equal to the segment(s) or in between that of the segment(s) and the carrier. The segment(s) is/are adhered to the washer or coating via a rigid or strong adhesive capable to withstand the strong centrifugal forces associated with rotating the color wheel and the filter segments at high speed.

Abstract: A color wheel has one or a plurality of color filter segments made from a first material, typically glass, having a coefficient of thermal expansion that is substantially different from a carrier, which is made from a second material, typically aluminum. An intermediate washer or coating is disposed in between the segment(s) and the carrier, and has a coefficient of thermal expansion either equal to the segment(s) or in between that of the segment(s) and the carrier. The segment(s) is/are adhered to the washer or coating via a rigid or strong adhesive capable to withstand the strong centrifugal forces associated with rotating the color wheel and the filter segments at high speed.

Abstract: An inline backwash, flushing filter assembly comprising a header assembly, a rotatable valve assembly, and a filter element assembly disposed within a filter housing assembly. In operation, the controller moves the turn knob of the rotatable valve assembly a one-quarter turn which results in the reversal of fluid flow through the assembly to periodically back flush the filter utilizing fluid from the system inlet. Debris removed from the filter element during the backwash process are immediately discharged from the system through a drain port. Simultaneously, the hydraulic shearing mechanism of the backwash process dislodges and drains debris which may have accumulated on the screen and at the bottom of the lower filter assembly during normal filter operations. The controller then returns the filter assembly to filtration operation by a reverse one-quarter turn of the turn knob of the rotatable valve assembly.

Abstract: The invention is a headset for holding electrodes on the head of a person for measuring the electrical activity of the person's brain. In detail, the invention includes a pair of fittings for attachment about the ears of a person. A first flexible front strap is adapted to fit about the forehead of the person is connected to each fitting. A second flexible strap adapted to fit about the rear of the head of the person is also connected to each fitting. A plurality of sets of flexible members is connected to each fitting and which are adapted to fit over the top portion of the head of the person between the first and second straps. A plurality of electrode mounts are movably mounted to each of the plurality of sets of guide members. The head set's ear fittings also provides a means for holding the lead wires of electrodes placed on a person's face for monitoring such parameters as eye movement and facial muscle activity during routine sleep testing.