Abstract: Boot firmware is manipulated within separately erasable/writable blocks of a flash EEPROM, and a non-volatile memory bit circuit is used to force manipulation of address space associated with the blocks to provide a powerfail durable flash upgrade for the EEPROM without the need for a separate ROM. During a firmware upgrade in the EEPROM, a block in the EEPROM is erased, other than the primary boot block, and is designated as an alternate boot block. The primary boot block firmware contents are then copied to the alternate boot block, and the non-volatile memory bit is set to cause the alternate boot block to appear in the address space of the primary boot block from a microprocessor's perspective. The primary boot block is then erased and written with new firmware information. The non-volatile memory bit is then reset back to allow the primary boot block to appear in its proper address space, and the alternate boot block is upgraded with its new firmware information.

Abstract: Powerfail durable non-volatile random access memory (NVRAM) testing is provided by using the available NVRAM itself to remember its own state of testing, by sequencing through the testing process, and by carefully placing memory image checksums within the NVRAM. The correctness of the NVRAM image is maintained while each memory word is tested for functional correctness without additional or specialized hardware. NVRAM is manipulated such that it can detect disrupted testing and restore the NVRAM image as it existed prior to the disruption. Specifically, test variables are kept in the NVRAM itself to retain and manipulate (1) a test-status signal indicative of a status of the memory testing process, (2) data from the memory location being tested, (3) an address for the memory location being tested, and (4) checksums for verifying the accuracy of the data after the memory is tested.

Abstract: A data memory system has a hierarchic disk array of multiple disks, a disk array controller for coordinating data transfer to and from the disks, and a RAID management system for mapping two different RAID areas onto the disks. The RAID management system stores data in one of the RAID areas according to mirror redundancy, and stores data in the other RAID area according to parity redundancy. The RAID management system then shifts or migrates data between the mirror and parity RAID areas on the disks in accordance with a predefined performance protocol, such as data access recency or access frequency. The data memory system also includes a memory map store embodied as a non-volatile RAM. The memory map store provides persistent storage of the virtual mapping information used by the RAID management system to map the first and second RAID areas onto the disks within the disk array.

Abstract: A hierarchic disk array data storage system has multiple storage disks that define a physical storage space and a RAID management system that maps the physical storage space into two virtual storage spaces. A RAID-level virtual storage space presents the physical storage space as mirror and parity RAID areas where the mirror RAID areas store data according to RAID Level 1 and the parity RAID areas store data according to RAID Level 5. An application-level virtual storage space presents the physical storage space as multiple virtual blocks. The RAID management system migrates data between the mirror and parity RAID areas to optimize performance and reliability. To facilitate migration, the RAID management system guarantees a minimum of unused storage space that can be used to empty a RAID area for the purpose of converting the RAID level or other storage attribute of the RAID area. The minimum unused storage space is preferably equivalent in size to at least one largest parity RAID area.

Abstract: A data storage system has a disk array having multiple storage disks and a disk array controller coupled to the disk array to coordinate data transfer to and from the storage disks. The disk array is configured into multiple stripes where each stripe extends across multiple ones of the storage disks. Additionally, each stripe consists of multiple segments of storage space where each segment is a portion of the stripe that resides on a single storage disk in the disk array. A memory manager is provided to manage memory allocation for storing user data redundantly according to parity redundancy techniques. The memory manager maintains a partial stripe pointer to reference individual stripes in the disk array and a segment fill pointer to references individual segments in the referenced stripe. These pointers are used to select a non-filled stripe and individual segments in that stripe.

Abstract: A mechanism for transferring torque from a motor to a gear train through a magnetic hysteresis slip clutch has a feature for disconnecting the motor from the gear train. A cup element of the clutch is carried on a shaft and can be shifted along the shaft's axis. The cup element has a magnetic member on its outer surface and an interior hysteresis layer. An electromagnet can magnetically apply force to the magnetic member to axially shift the cup element, and by so doing can shift a drive gear carried on the cup element into and out of mesh with a first gear of the gear train. In a preferred embodiment, the cup element shifts the drive gear into mesh with the gear train's first gear when the electromagnet is energized and magnetically applies force to the magnetic member, and allows magnetic force applied to the hysteresis layer by a permanent magnet element of the clutch to shift the drive gear into its unmeshed position when the electromagnet is deenergized and does not apply force to the magnetic member.

Abstract: A disk array has a plurality of disks, a disk array controller for coordinating data transfer to and from the disks, and a RAID management system for mapping two different RAID areas onto the disks. The RAID management system stores data in one of the RAID areas according to mirror redundancy, and stores data in the other RAID area according to parity redundancy. The RAID management system then shifts or migrates data between the mirror and parity RAID areas on the disks in accordance with a predefined performance protocol, such as data access recency or access frequency.

Abstract: The tendency of a motor-driven actuator driving against a dynamic (non-frictional) load to return upon reaching the limit switch sufficiently to again close the limit switch and create a persistent oscillation at the limit position can be prevented by placing a positive temperature coefficient thermistor across the limit switch involved. Such loads typically arise in actuators having spring-driven return capability, and can also arise when positioning air dampers and other loads where the actuator force is opposed by a spring or gravity.

Abstract: In variable air volume systems of buildings, a vortex valve is used for varying the volume of the air moving through the system.

Abstract: A control circuit for a fuel valve in a gas fired furnace controlled by an electronic thermostat is disclosed. The thermostat requires a load current to properly operate, and a pickup and hold circuit along with a time delay circuit are integrated to control a load current circuit to provide the correct load current for the thermostat.

Abstract: A thermostat having heat anticipation uses a temperature responsive bimetallic element for effecting a thermostat contact closure during a heating operation controlled by the thermostat with an electrical contact carried by terminal strip positioned adjacent to the bimetallic element and formed from a high resistance stainless steel material. The resistance of the terminal strip is enhanced by lengthening the current path into a convoluted path utilizing notched out areas of the terminal strip. The resistance heat generated in the terminal strip by the current flow therein during the heating operation provides the desired heat anticipation for the operation of the thermostat by the bimetallic element by increasing the temperature sensed by the element.

Abstract: An over-temperature control for a thermostat uses an electrical contact actuator of a memory metal having an ability to change its physical configuration at a transition temperature to a "memory" shape. The contact actuator is arranged to bear against a cantilevered leaf spring having electrical contacts at a free end of the spring while the other fixed end of the spring is connected to complete an electrical circuit through the spring. The spring is also actuated by a bi-metallic element to produce a normal temperature responsive operation of the thermostat. The memory material actuator is arranged to provide a flexing of the spring cantilever to move the free end contact between a first and a second electrical terminal when the memory material is exposed to a transition temperature allowing the actuator to assume its "memory" shape.

Abstract: A fluid pressure regulating valve having a two-stage high and low flow rate control capability combined with a natural-LP gas control pressure changeover uses a spring biased pressure regulating diaphragm controlling a fluid through an orifice defined by a valve seat. A solenoid valve armature is attached to a spring providing the spring bias for the diaphragm and is arranged to be actuated by a selectively energizable solenoid coil. An extension of the armature is captured by a step regulator assembly which is threaded into a valve body containing the regulating diaphragm. The high fire and low fire adjustments in the step regulator assembly are on non-moving threaded members attached to the regulator assembly and bearing on the extension of the armature to vary the energized and deenergized position of the solenoid armature.

Abstract: A gas valve assembly has a safety valve and two controlled valves connected in series. A first of the controlled valves is electromatic and a second is a conventional pressure controlled valve. A control knob provides for manual control of the safety valve and for locking the first electromagnetically controlled valve in an off position. The manual control knob, when in the off and pilot positions, causes a stop member to be moved against the movable core member of the electromagnetic operator to hold the electromagnetic controlled valve in an off position.

Abstract: A molded plastic housing mounts a coil adjacent to a conductor to act as a current responsive pickup means. The mounting arrangement for the pickup coil uses no magnetic circuit and is adapted to self-center the structure on conductors of varying sizes without the need to sever and reconnect the current carrying conductor. The pickup means provide a substantially linear output voltage from the pickup coil versus the current being carried in the monitored conductor.

Abstract: An energy saving thermostat having a selected offset temperature time period previously programmed with means to shift the time period ahead or backward.

Abstract: An electric thermostat having a knob and potentiometer means with a simple adjusting means to couple the two together. A single clip means made of a resilient material allows for connecting the knob to the potentiometer and allows for repositioning the knob at will during calibration of the thermostat.

Abstract: An adapter converts a conventional thermostat to effectively approximate a setback thermostat. A conventional thermostat includes a mercury switch which is actuated by a bi-metallic coil. The attachment is interposed between the thermostat and its standard base plate and operates to tilt the entire thermostat under control of the timing mechanism to thereby effectively change the setpoint of the thermostat.

Abstract: A capacitive humidity transducer having an electrically non-conductive dielectric base carrying a pair of electrically conductive coatings deposited directly on opposite respective sides of the non-conductive base to form parallel capacitor plates. The conductive coatings are each arranged in a configuration of a plurality of side-by-side forked legs with the legs of the electrically conductive elements being positioned in a facing relationship. One end of each of the electrically conductive coatings is provided with electrical connectors for attaching the transducer to respective electrically conductive circuits which may be on a printed circuit board. The dielectric base is arranged to be hygroscopic whereby atmospheric humidity provides a corresponding variation in the dielectric constant of the base to affect the capacitance of the transducer.

Abstract: An energy saving thermostat adapted to be connected to a remote temperature conditioning apparatus for controlling the temperature of air in a space maintains a first temperature during a first time period and a second energy saving temperature during other time periods of the day. The thermostat has a visual indicating means so that when a manually settable switch is pushed, a time interval counter means is energized for indicating and storing a series of pulses each indicative of an hour of setback time into a storage means. The thermostat also has a review button for reviewing the stored time by pulsing the visual indicating means for the number of hours of the time period energy saving temperature.