Abstract:
An electrical protection system which uses a ground fault interrupter (GFI) to protect a circuit from (A) ground faults and (B) overcurrents and/or overvoltages. For overcurrent protection, a control element may be coupled in series with the line or return input to the GFI, and a bypass element may be coupled in parallel with the control element and the GFI. In case of an overcurrent, the control element causes current to be diverted through the bypass element, thereby creating a current imbalance in the GFI circuitry causing the GFI to open the circuit. For overvoltage protection, a bypass element (e.g. a varistor) may be coupled between, e.g., the line sense input of the GFI and the return sense input of the GFI. In case of an overvoltage, the bypass element conducts current, thereby creating a current imbalance in the GFI circuitry causing the GFI to open the circuit.
Abstract:
A conventional ground fault circuit interrupter (GFCI) is modified to provide frequency-selective current protection. A control element is connected in series with the line path (or return path) of the GFCI, and a bypass element is connected in parallel with the combination of the control element and the line path (or return path) of the GFCI. Under normal conditions, little or no current flows through the bypass element. However, frequency response characteristics of the control and/or bypass elements are such that a frequency-selective component of the current (i.e. high-pass, low-pass or band-pass) is diverted through the bypass element. When the magnitude of the frequency-selective component reaches a predetermined value, the bypass current flow causes sensing of a resulting current imbalance and tripping of the GFCI.
Abstract:
An overcurrent protection system which will give a rapid response to overcurrents which cause a reduction in the voltage across the load, e.g. a partial or complete short across the load, and is particularly suitable for protecting circuits against relatively small overcurrents, comprising: a circuit interruption element which, in the operating circuit, is connected in series between the electrical power supply and the electrical load, and which has (1) a closed state which permits the flow of a normal current, I.sub.NORMAL, through the circuit interruption element, and (2) an open state which permits the flow of at most a reduced current, substantially less than I.sub.NORMAL, through the circuit interruption element; a control element which, in the operating circuit, is connected in parallel with the load, and which has (1)(i) an on state, when the voltage across the control element is a normal voltage, V.sub.NORMAL, and (ii) is converted to an off state, when the voltage across the control element falls to a value V.sub.FAULT, or less, and (2) is functionally linked to the circuit interruption element so that when the control element is in the on state, the circuit interruption element is in the closed state, and when the control element is in the off state, the circuit interruption element is in the open state; and a bypass element which (1) is connected in parallel with the circuit interruption element, and (2) has (i) a start-up state such that, if the circuit interruption element is in the fault state and a current I.sub.NORMAL is passed through the bypass element, the voltage across the control element is greater than V.sub.FAULT, and (ii) a stopped state such that if the circuit interruption element is in the fault state as a result of the voltage across the control element having fallen to a value V.sub.FAULT or less, the current through the bypass element is such that the voltage across the control element remains at a value of V.sub.FAULT or less.
Abstract:
An overcurrent protection system which will give a rapid response to relatively small overcurrents. The system, which can be connected between an electrical power supply and an electrical load to form an operating circuit, and which when so connected protects the circuit from overcurrents, has a normal operating condition and a fault condition, and comprises: a circuit interruption element having, (1) a normal state which permits the flow of a normal current, I.sub.NORMAL, when the system is in the normal operating condition, and (2) a fault state which permits the flow of at most a reduced current, substantially less than I.sub.NORMAL, when the system is in the fault condition; and a control element, connected in series with the circuit interruption element, the control element having a variable resistance which (1) is low when the current in the system does not exceed the normal current, I.sub.NORMAL, by a predetermined current amount, and (2) increases by at least a predetermined resistance amount when the current in the system exceeds the normal current, I.sub.NORMAL, by the predetermined current amount; the circuit interruption element changing from its normal state to its fault state, thereby causing the system to change from its normal operating condition to its fault condition, when the resistance of the control element has increased by the predetermined resistance amount.
Abstract:
Various embodiments of optical fiber designs and fabrication processes for ultra small core fibers (USCF) are disclosed. In some embodiments, the USCF includes a core that is at least partially surrounded by a region comprising first features. The USCF further includes a second region at least partially surrounding the first region. The second region includes second features. In an embodiment, the first features are smaller than the second features, and the second features have a filling fraction greater than about 90 percent. The first features and/or the second features may include air holes. Embodiments of the USCF may provide dispersion tailoring. Embodiments of the USCF may be used with nonlinear optical devices configured to provide, for example, a frequency comb or a supercontinuum.
Abstract:
This invention provides methods and processes to attach or bond hydrogels to suitable surfaces using irradiation techniques and also provides methods and processes to create crosslinked regions in hydrogel articles using these irradiation techniques. Specifically, lasers at wavelengths tuned to the irradiation absorption bands of hydroxyl groups, carboxylic acid groups or water may be used to attach or bond hydrogels to surfaces such as soft tissue and hydrogel surfaces or to crosslink regions in hydrogel articles.
Abstract:
The present invention provides a hydrogel article having a multi-layered structure and exhibiting a gradient in polymer molecular weight. The invention also provides a method of forming a hydrogel article having a multi-layered structure and exhibiting a gradient in polymer molecular weight.
Abstract:
A synthetic polymer based adhesive formulation that has properties substantially simulating selected properties of fibrin glue, and methods of making and using the same. The adhesive formulation includes a discrete acid solution and discrete base solution that when combined form a synthetic polymer based adhesive that substantially simulates selected properties of fibrin glue. The discrete acid solution includes a polymer and a cross-linking agent precursor. The discrete base solution includes a polymer and a base.
Abstract:
The method and system of the present invention provides an improved technique for replacing, implementing and managing computer-related assets. A technician accesses the World Wide Web through a user's computer. The information resident on the computer, including information regarding the computer and the user's preferences, are downloaded to a remote storage medium through the World Wide Web. Once downloaded, all information may be removed from the user's computer. Subsequently, the technician accesses another computer such as, for example, a new computer that has been assigned to the same user. The technician accesses the World Wide Web through the new computer and downloads the information previously stored on the remote storage medium. This information can then be used to install the user's prior applications, settings and preferences on the new computer.
Abstract:
An image receiving element is a composite of two or more extruded layers on a support including, in order, an extruded compliant layer, an extruded antistatic tie layer, and an image receiving layer that may also be extruded. The extruded compliant layer is non-voided and comprises from about 10 to about 40 weight % of at least one elastomeric polymer. This image receiving element can be disposed on a support to form a thermal dye transfer receiver element, an electrophotographic image receiver element, or a thermal wax receiver element. Two or more extruded layers can be co-extruded.