Showing papers on "Electrical network published in 1975"

Stability and entropy production in electrical circuits

Abstract: A number of the theorems expounded by Prigogine, Glansdorff and their collaborators are translated into electrical circuit terminology and their validity and significance discussed. The simultaneous occurrence of inductors and capacitors represents a situation not envisioned in the chemically oriented discussions and imposes some limitations. The electrical terminology also leads to “dual” theorems, in which voltage sources are replaced by current sources. The validity of the theorems in situations in which fluctuations are critical to the relaxation behavior is analyzed. The “excess entropy production” theorem is only valid if the circuit relaxation can be described by single-valued macroscopic variables, but not if it must be described by distribution functions. We stress that no purely local characterization, which examines a multistable system only in the neighborhoods where it occurs with high probability, can predict or characterize the steady state.

Detachable chuck for electro-surgical instrument

Abstract: A generally flat insulator chuck is arranged to retain surgical electrodes so that the working area of the electrodes extends externally on one end and an electrical circuit accomodating prong is contained within a recessed chamber at the other end. The recessed chamber is dimensioned so as to effect continuous contouring relative to a receiving control handle apparatus in such a manner that the physical stress is translated between the insulator sidewalls of the chuck and the insulator of an extended plug on the handle. The electrical connection extension prong within the recess slidingly engages an electrical connector embedded within the handle extension so as to provide electrical contact free of physical stress from usage. Locking and guiding arrangements cooperate between the handle and the chuck to further insure firm attachment.

Multi-area generation system reliability calculations

Abstract: This paper presents the results of an investigation of a technique for the evaluation of the reliability of supplying power in a system with a number of interconnected load-generation areas. There is no restriction as to how the areas may be interconnected. Most previous techniques using analytical methods (as opposed to Monte Carlo simulations) have been limited to systems with a maximum of three interconnected areas. Systems with more areas have been analyzed assuming that the interconnecting electrical network did not contain any loops. The application of straightforward enumerative methods to systems with more complex interconnections than these can result in an improbably large number of computations. The method of analysis described in this paper is based upon the use of a linear flow network to model the transmission interconnections and makes use of an efficient graph theory algorithm to segregate the failure states by finding critical minimal cuts in the network. The probabilities of failure to supply the various loads are computed by evaluating the various combined event probabilities associated with these critical minimal cuts. For the cases tested, the technique reduces the number of probability evaluations required by about one to two orders of magnitude in comparison with complete state enumeration methods. The tested method provides reliability measures (i.e., the probability of failure to meet the load) for each individual area and the total system, and also allows the computation of the probability that each "link" (transmission line or source) is a member of a critical minimal cut. The latter will facilitate the application of the method to the design of systems and specifically to the problem of evaluating the reliability benefits of increased transmission capacity versus added generation.

Apparatus for detecting changes in the electrical characteristics of sensor devices

Abstract: The invention relates to electrical apparatus for detecting a change in the electrical characteristics of a sensor device, such as a device for sensing fire, the apparatus comprising a plurality of electrical circuits arranged in parallel and connected to an output circuit which can activate or initiate operation of a device which is required to be operated when the electrical characteristics of the sensor device change, each parallel circuit being provided with means for automatically indicating that the circuit is functioning correctly, any fault in the circuit being automatically indicated and the circuit preventing the output circuit from activating or initiating operation of said device due to a fault.

Charger with multiple attachable cellholder modules

Abstract: A charging system for alternatively charging cells having different physical sizes and/or electrical characteristics comprising a charge current source, a plurality of cellholder modules and interconnection means on said charger and said modules for selective alternative connection of each of said modules to the charger. Each module has an electrical circuit including a discharge prevention means for preventing inadvertent discharge of cells disposed in the module.

Broadband electroacoustic converter

Abstract: A broadband electroacoustic converter incorporating a two-layer acoustic coupler is disclosed for efficiently converting between electrical signals carried on an electrical network having a specified electrical impedance and acoustic signals carried in a load medium having a specified acoustic impedance.

Vehicular electrical safety apparatus

Abstract: This disclosure pertains to apparatus mounted to the frame of a vehicle, sensitive to impacts exceeding a predetermined level. The impact device disables a main control relay which feeds all of the electrical circuitry of the vehicle. Turning the ignition switch to the "off" position also de-energizes the main control relay in the same fashion as the impact device further insuring that all electrical circuits in the vehicle are fully disabled.

Temperature control device

Abstract: The temperature control device described is humidity-compensated and comprises a temperature-sensitive element which changes its shape in response to changes in temperature, and a humidity-sensitive element which changes its shape in response to changes in humidity, each of the elements carrying an electrical contact, the two contacts being so disposed so as to be engageable with each other to close an electrical circuit under predetermined temperature and humidity conditions as sensed by the two elements

Electrical protection means and method

Abstract: An electrical protection unit having a plurality of main leads for respectively interconnecting a plurality of lines of an electrical power source to at least one electrically operated unit. At least one main lead has a device therein for opening the respective lead when the device is activated. The one main lead has one side of an electrical circuit interconnected thereto with the other side of the circuit being adapted to be interconnected to ground, the circuit having means for activating the device when the circuit is operatively interconnected to ground. Control means are provided for operatively interconnecting the circuit to ground.

The regularization of nonlinear electrical circuits

Abstract: Recently Smale [1] proposed the question 'under what conditions can an electrical circuit be regularized?' This note gives a solution to the problem.

Current limiting device for an electrical network

Abstract: A current limiting device for a network which comprises a magnetically shielded superconductor coupled to the network with the shielding means having controllable magnetizing coils by which they can be transversely magnetized up to saturation.

Thermal writing power

Abstract: A thermal nib is provided, which is heated by being directly inserted into an electrical circuit, and which enables writing on thermal paper

Electric heating system circuit for sequentially energizing a plurality of heating elements

Abstract: An electrical circuit for a heating system has a plurality of electrical resistance heating elements and a blower all controlled by a plurality of electro-thermally actuated relays. The circuit is arranged so that the heating elements are sequentially energized and de-energized and so that the blower is maintained in operation at all times that any one of the heating elements is energized. A thermostat controls the operation of the relays, the second and the last of which each having switches connected in series circuits with the actuator of the first relay and in parallel with the thermostat so as to maintain blower operation, which is controlled by the first relay, when the thermostat opens.

Simulation of traffic flow using electrical network parameters

Abstract: The efficacy of simulation of deterministic traffic flow with electrical network parameters is examined. First the car-following model is described and then compared to both lumped and distributed parameter electrical networks. New models are then introduced for use in simulating steady-state and transient-flow conditions. The strengths and weaknesses of the results of a simple PCAP computer run performed on illustrative problem situations are described.

High frequency electrical network with frequency dependent characteristics having a constant input resistance

Abstract: A constant resistance network which exhibits frequency dependent characteristics consists of a cavity resonator having two coupling loops mounted transverse to the natural direction of propagation of resonant waves within the cavity. The network is less bulky and cheaper to produce than hitherto known equivelent networks.

The Application of Linear Programming to the Determination of Transmission Fees in an Electrical Power Network

Abstract: This article demonstrates how the transportation method of linear programming was used to solve a practical accounting problem in the electrical power industry of Norway, namely, the determination of transmission costs as a function of the product of megawatts times the distance in kilometers for each subscriber in the electrical network. It a subscriber has several points where power is fed into the system or taken out of the system, contract requirements specify that he shall pay for a transmission configuration which gives the lowest sum of the transmission quantities. The transportation algorithm is used to solve this minimization problem.

Electrical circuit fused link assembly - has tubular insulator containing fuse held by bayonet fitting and two end terminals

Abstract: The fuse link assembly for electrical circuits consists of a hollow cylindrical housing (22) of insulating material into which is inserted a closure cap (24), and within which is the fuse (20) One lead has a button-shaped terminal (26) in contact with a tip of the fuse and is held on the wire (8) by a small grub screw (28) affixed through a small access hole (30) in the end cap Pressure is maintained by a bayonet fitting in the insulator The other end of the fuse has a side cap (50) with a side screw fitting (14) incorporating a shoulder (12) onto which fits a terminal lug (16) for the main line wire The large screw joint also provides a mechanical anchor point for the whole fuse assembly

Automatic control for machines with variable power supply - has device connected to machine housing mounted on buffers

Abstract: The device connected to the machine housing (2) is constructed in such a way that when the machine housing is partly displaced or turned in a predetermined direction a lever (4) for operating an additional power supply is shifted. The lever can also be used to activate an auxiliary feeding system (5) for fuel. The lever can also actuate a switch (6) which is connected to an electrical circuit, a magnetic circuit or a combination of both kinds of circuit. When applied to motor vehicles, the device permits more efficient utilisation of fuel and the avoidance of fuel losses, as the power required is automatically supplemented.

Computer Programs for Prediction of Lightning Induced Voltages in Aircraft Electrical Circuits

Abstract: : The report describes a computerized program to define the induced circuit voltage within an aircraft electrical system due to a lightning strike on the aircraft. One routine of the program (DIFFUSION) calculates the effect of magnetic fields caused by current on the aircraft skin. The other routine (APERTURE) calculates the magnetic field that enters the aircraft because of an opening. The induced voltages are then calculated for any given electrical circuit. The program has defined geometrical configurations for a fuselage, rectangular wing, and empennage sections. A subroutine calculates the current distribution on the skin of the section being analyzed. The program input current and output voltage are in the time domain.

Heat meter for central heating systems - uses heat to current transducer and circuit integrating current with respect to time

Abstract: The meter measures heat consumption by determining the difference between the flow and return temperatures of the heating medium. The temperature difference is converted into an electric current which is measured in a current/time integrator as an indication of heat consumption. The integrator may be a coulometer or a microcoulometer, using a gold/silver cell nad pref. with a linear scale. The electrical circuit may contain a voltage source and an electronic control circuit, although thermocouples may be used instead of the voltage source and the temperature difference measuring device. Manipulation of the meter to falsify the reading is almost impossible.