Abstract: A method and system for efficiently providing maintenance activity on a relational database that is utilized within a processing system is disclosed. The relational database includes a pool of threads and a plurality of resources. The pool of threads receive requests from a plurality of clients and control the plurality of resources. The method and system comprise determining that a maintenance activity is required and providing a first command that initiates a first process which terminates all threads in the pool of threads if the maintenance activity is required. The method and system further include providing a second command which initiates a second process after the maintenance activity has completed which causes the threads to be created and initiates the processing of requests.

Abstract: There is provided a humidifier control system including a water reservoir having a top opening. A pair of wicking pads extend into the reservoir and around a tube which extends over the top opening. An electrical heating element is received inside the tube. First and second spaced apart moisture sensor elements are attached to the tube and are in contact with the wicking pads. The sensor elements conduct electricity in the presence of moisture on the wicking pads and do not conduct electricity in the absence of moisture on the wicking pads. The sensor elements are attached to an electrical circuit which includes a switch and an alarm. When there is moisture on the wicking pads, the switch is on and normal current flows through the heating element and the switch. When there is not moisture on the wicking pads, the switch is turned off and the current through the heating element is reduced to a minimal level, and the alarm is turned on.

Abstract: The system, method, and program of this invention allows a two-phase commit protocol to work properly, even when the client acting as the coordinator does not have a log to record two-phase state information. In a preferred embodiment, the client in a client/server distributed transaction processing system is a personal computer. The client, without a recovery log, acts as a coordinator of a commit process. The coordinator migrates, i.e., passes, responsibility for resynchronization, and any associated logging requirement, to a server, e.g., to any of the connected relational database management system (RDBMS) servers, which is a participant in the transaction. The server uses its own recovery log for use in satisfying the logging requirement.

Abstract: A vehicle hand control device operable to control the brake pedal or accelerator pedal of a motor vehicle. The device includes an elongated support tube connectable to and along the steering column of the vehicle, a control arm tube pivotally connected at one end to, and extending from, the upper end of the support tube, and a slender, elongated control arm mounted for rotation only within the control arm tube. The control arm includes an elongated handle extending from one end of the control arm, the handle preferably having its longitudinal axis disposed from the longitudinal axis of the control arm. A control arm lever is connected at the other end of the control arm which also extends somewhat beyond the end of the control arm tube.

Abstract: Method and apparatus for selectively tensioning an endless, inextensible elastomeric belt entrained about a cooperating drive structure and idler structure having respective axes of rotation. A roller frame joined to a vehicular main frame supports the idler structure and constrains movement thereof to a longitudinal recoil path. The drive and idler structures are biasingly separated by a compression spring which exerts biasing force thereon in opposite longitudinal directions through a drive strut and an idler strut, respectively. The idler strut is connected to the idler structure longitudinally in front of the idler's axis. The length of one of the struts is adjustable to provide the desired tension in the spring and, thus, the entraining belt.

Abstract: The contacts of a conventional molded case residential circuit breaker are opened and closed in relay fashion by a remotely controllable operator module. The operator module, utilizing the compliance of the breaker operating mechanism in its ON condition, acts directly on the breaker movable contact arm to effect a separation of the movable contact from the stationary contact sufficient to switch rated current.

Abstract: A circuit breaker electronic trip unit is equipped with a plurality of current transformers for sensing overcurrent and ground fault conditions in a distribution circuit. A ground fault signal voltage is applied to a differential amplifier together with an adjusted voltage establishing a desired ground fault signal pick-up level. The differential amplifier controls a variable duty cycle switch to establish charging versus discharging rates for a timing capacitor in accordance with the ground fault signal amplitude. When the voltage across the capacitor exceeds a predetermined threshold, a thyristor is triggered to draw a safe level of energizing current through a trip coil. Secondary open circuited protection is provided for any of the current transformers disposed externally of the circuit breaker.

Abstract: A GFCI utilizes a single transformer in responding to ground faults on either of the line and neutral conductors of a distribution circuit. The transformer, a differential current transformer, has a secondary winding which is periodically strobed during a first sampling interval for the presence of a fault signal indicative of a line-ground fault. During a second sampling interval, a negative resistance network sets up a ringing oscillation in the transformer secondary circuit. If the neutral conductor is grounded through a low impedance ground fault, the oscillation is damped, and circuit interruption is initiated. Absent a low impedance ground fault on the neutral conductor, the oscillation amplitude increases to exceed a predetermined threshold level during the second sampling interval, and circuit interruption is not initiated.

Abstract: The secondary winding of the differential current transformer in a ground fault circuit interrupter is normally short circuited through an electronic switch. A relaxation oscillator, including a timing capacitor, acts to periodically open the switch and divert any secondary current through a burden resistor, developing thereacross a relatively high amplitude fault signal voltage indicative of a liine ground fault. The timing capacitor discharges through the primary winding of a second transformer coupled with the neutral conductor to develop, in the event of a desensitizing neutral ground fault, a fault signal voltage across the burden resistor.

Abstract: The secondary winding of a differential current transformer in a ground fault circuit interrupter is short circuited through an electronic switch. The switch is periodically opened to force any secondary current occasioned by the existence of a ground fault to flow through a burden resistor, thereby developing a relatively high amplitude signal voltage thereacross for processing by a signal processor pursuant to initiating circuit interruption.

Abstract: An electronic module for ground fault circuit interrupters (GFCI) in both circuit breaker and receptacle configurations includes a signal processor having a plurality of fault signal threshold stages for differentially charging an integrating capacitor in accordance with the magnitude of the fault signal as amplified by a high gain differential amplifier. The accumulated charge on the integrating capacitor controls the generation of a trip signal. The processor also includes a highly stable grounded neutral excitation oscillator and a noise rejection network to combat nuisance tripping.

Abstract: An electronic module for use in ground fault circuit interrupting devices comprises an improved shell design structurally adapted for ease of assembly therein of the electronics and magnetics. The electronics, carried on a printed circuit board, is positionally mounted and retained in one shell compartment by integrally formed latching means. The magnetics are positionally mounted in other shell compartments and locked in place by the insertion therethrough of single-turn transformer winding elements. Potting of the electronics and magnetics thus becomes unnecessary.