Showing papers on "Electric power published in 1969"

Electro-mechanical transducer for secondary oil recovery

Abstract: An electromechanical transducer for use in secondary recovery in oil wells which, in effect, produces a dipole-type radiation field of increased magnitude which extends along a single axis perpendicular to the axis of the oil well. This allows the surrounding casing to vibrate in a displacement mode rather than in a circumferential expansion mode, to enable energy coupling to the surrounding oil-producing formation. In specific form of the invention, the transducer includes two resonant beams forced to vibrate at an audio or sonic frequency by piezoelectric element stacks driven by an external electrical power source and transferring energy through additive shear waves to an external body.

Motor-generator combination

Abstract: A compact unit for supplying an aircraft with both DC and AC electric power under normal running conditions and to provide also electric starting facilities, and which can be attached to a single engine pad of an aircraft turbine, is obtained by energizing the rotor field windings of an alternator with DC power via a rectifier system participating in its rotation from the armature windings of a coaxially arranged starter motor, which for the purpose has a second multiturn field winding, the starter motor having also automatic brush-lifting gear; the DC power output is obtained from a second stator winding of the alternator via a built-in rectifier set.

System for blending dynamic and regenerative braking

Abstract: A method and a system wherein the electric power generated by a motor in the braking mode is distributed between a dynamic brake resistor and the motor supply lines in a ratio that varies as a function of the degree of power receptivity of the motor supply lines. Power receptivity is the capability of the supply lines to accept the power generated by the motor in the braking mode at a given time.

Electric system of a device for deicing the surface of thin-walled structures

Abstract: A system is disclosed for deicing the skin surface of aircraft and comprises a power supply unit to which are connected an electrical power accumulator and a program switch. Low inertia converters such as magnetostrictive vibrators are provided in close proximity to the skin surface and are fed from the power supply unit via key switches each having one input connected to the electrical power accumulator while its second input is connected to the program selector switch such that the switch will produce successive single or bundles of electrical pulses separated by pauses at the converters.

Portable electric automobile jack

Abstract: A portable electric automobile jack that raises and lowers the bumper of a vehicle in a smooth, continuous motion using electric power produced by the automobile but the structure of which is otherwise independent from the body of the automobile, thereby enabling the jack to be disassembled, transported to other vehicles when needed and stored in the trunk of the automobile.

Method of and power supply for electric arc welding

Abstract: Electric power supply for arc welding of the drop transfer type with a small diameter electrode which changes its dynamic characteristics when the drop short circuits the electrode to the weld pool. The supply is a DC power source having a short circuit current rate of rise greater than 100,000 amperes per second in series with an inductive choke which substantially reduces the rate of rise. Two circuits, each including a generally low resistance and/or low inductance and each including an appropriately polarized diode, are each in electrical parallel with the inductive choke. One circuit functions to increase the short circuit current rate of rise when the drop contacts the weld pool and the current starts to rise. The other absorbs the inductive energy in the choke when the short is broken and the current starts to decrease.

Reluctance motor power circuit

Abstract: Conventional SCRs and diodes are used to apply DC electric power from a storage battery to a winding of a reluctance-type motor. The circuit provides full and partial motoring and regenerative braking, freewheels the winding current at low speeds to improve motor torque, and returns winding current to the storage battery at the end of the motoring cycle to improve efficiency. Electrically powered automotive vehicles use the circuit to great advantage and the circuit also can be used in stationary industrial applications.

Floor and ground cleaner

Abstract: A NOVEL AND VERSATILE CLEANER IS COMPOSED OF A CLEANER BODY MOVABLY SUPPORTED ON WHEELS, A ROTATING BRUSH ENCLOSED IN A HOUSING AT THE LOWER PORTION OF THE CLEANER BODY AND ALLOWED TO CONTACT WITH THE FLOOR SURFACE AT LEAST WHILE THE CLEANER IS OPERATED, A DUST BOX DETACHABLY MOUNTED IN THE CLEANER BODY FOR RECEIVING DUST STIRRED UP FROM THE FLOOR BY THE BRUSH OPERATION, AN AIR PASSAGE EXTENDING FROM THE BRUSH PORTION OR THE DUST BOX TO THE OUTSIDE OF THE CLEANER BODY, AN ELECTRIC PRECIPITATOR, OR, AN ELECTROSTATIC DUST COLLECTING UNIT, DETACHABLY MOUNTED IN THE AIR PASSAGE, AN AIR BLOWER TO INTRODUCE AIR THROUGH SAID AIR PASSAGE, AN ELECTRIC MOTOR FOR DRIVING THE ROTATING BRUSH AND THE BLOWER, A HIGH VOLTAGE POWER SOURCE FOR SUPPLYING A HIGH VOLTAGE TO THE ELECTRIC PRECIPITATOR, AND AN ELECTRIC POWER SOURCE FOR SUPPLYING POWER TO THE HIGH VOLTAGE SOURCE AND TO THE ELECTRIC MOTOR.

Power-driven rear view mirror

Abstract: A remotely operable power-driven rear view mirror for vehicles of simple and reliable construction having a drive mechanism protectively contained entirely within the mirror casing and including a reversible electric power motor. The motor housing is secured to the inside of the mirror casing, while its motor armature is joined to a fixed shaft. The motor, when energized, carries the motor housing and the mirror to rotate about the armature and the shaft. A slip clutch is utilized to couple the armature and shaft and provides free manual adjustability and protection for the motor.

Tobacco pipe dryer

Abstract: THE INVENTION RELATES TO A TOBACCO PIPE DRYER COMPRISING A ONE-PIECE STAND HAVING A CYLINDRICAL HEATING DEVICE MOUNTED THEREIN, ONE END PORTION OF THE HEATING DEVICE PROJECTING ABOVE A DISHED UPPER SURFACE OF THE STAND FOR RECEPTION OF A PIPE BOWL AND THE OTHER END PORTION BEING DISPOSED IN A RECESS IN THE STAND WITH MEANS FOR CONNECTING IT TO A SOURCE OF ELECTRIC POWER

Power semiconductor device with negative thermal feedback

Abstract: A composite power semiconductor is disclosed which is adapted to avoid second breakdown and therefore provide stable operation. The composite semiconductor consists of an array of parallel-connected integrated circuits constructed in a single chip, each circuit comprising an output power device, for connection between an electric power source and a load, and one or more associated low-level control amplifiers. The effect of the thermal instability called second breakdown in such an array is to channel a disproportionate amount of electric current through the output device undergoing second breakdown, thereby increasing the temperature of the affected output device, thereby increasing the current, etc. until failure occurs. In the power semiconductor disclosed, the output power device and associated low-level amplifier are thermally closely coupled so that each is at all times substantially at the temperature of the other or bears a predetermined temperature relationship therewith, and the two are interconnected in a fashion that will produce high electrical gain. There is negative thermal feedback so that a change in power dissipation with resulting temperature change in the output device causes the low-level amplifier to alter the electric current carried by the output device. For example, an increase in temperature which will tend to cause the output device to conduct a larger amount of electric current and which will also tend to cause the low-level amplifier to conduct a larger amount of current, can have the result, because of the close thermal coupling and interconnection, of maintaining the output current substantially constant.

System for blending dynamic and regenerative braking

Abstract: A method and a system wherein the electric power generated by a motor in the braking mode is distributed between a dynamic brake resistor and the motor supply lines in a ratio that varies as a function of the degree of power receptivity of the motor supply lines. Power receptivity is the capability of the supply lines to accept the power generated by the motor in the braking mode at a given time.

Solid state de-energizer having current sensing loops

Abstract: Overload and other excessive current conditions as regards an electric motor are sensed by current sensing loops which form the primary winding of respective transformers. The voltage developed across the secondary windings are rectified and supplied to a deenergizing circuit which additionally includes a holding circuit and a timing circuit. In the event of an overload condition, the current supply to the electric motor is interrupted and also a time delay is effected before reset occurs assuming that electric power is again available.

Temperature Modification and Costs of Electric Power Generation

Abstract: The electric power industry has long been known to be sensitive to weather events. In particular, daily temperatures in distribution areas are known to affect electric power consumption. In this paper the relationship between power consumption and daily temperatures is estimated using simple regression techniques. The resulting relationships permit an investigation of the consequences of temperature modification for 14 midwestern electric power production companies. Comparisons between power production costs for observed and modified historical and experimentally generated temperature series suggest that changes of 3–5F in average daily temperature can reduce costs substantially. Exact differentials in production cost which can be attributed to temperature modification are presented so as to be useful in firm, industry and public policy decisions.

Tower Designs for AEP 765-KV Project

Abstract: The highlights of the 765-kv tower designs used by the American Electric Power Company are summarized. The weather loading conditions and line design criteria used in developing structure configuration and designs are described. Tower designers and engineers responsible for developing design specifications are alerted to the pitfalls of designing towers without considering all practical combinations of loads (within a loading combination), i.e., combination of some minimum with maximum loads and unequal leg extension combinations in rough terrain. The AEP Computer Program for analyzing towers as three-dimensional elastic structures is highlighted. Comparisons are made to hand (statics) methods used to analyze towers. Alternate types of foundations employed are described, insofar as anchor movement affects structure capabilities.

Pan-Africanism—Land and Power

Abstract: (1969). Pan-Africanism-Land and Power. The Black Scholar: Vol. 1, The Culture of Revolution, pp. 36-43.

An analysis of the possibility of reduction of sonic boom by electro-aerodynamic devices,

Abstract: : The purpose of the paper is to investigate the physics of electro-aerodynamic techniques for reducing the sonic boom and to draw conclusions as to the usefulness of the proposed techniques. An analysis of the interaction of ions and electrons of an electric discharge with neutral particles in moving air according to a one-dimensional model is described and analyzed. A simple expression for the change of total stream thrust by the electric wind mechanism is given. The electric power required for maintaining the discharge is calculated. With these basic results, the specific power requirement of the electro-aerodynamic devices proposed for deflecting the oncoming air of the supersonic transport is evaluated to be of the order of 1 watt/dyne (1/2 megawatt/pound force). For 10% change of boom intensity by electro-aerodynamic deflection of the oncoming stream thrust, a commercial supersonic transport requires of the order of thousands of megawatts of electric power. At the specific weight of 1 pound per kilowatt, clearly the electric equipment is beyond payload capability. (Author)

Computer Simulation of Satellite Electric Power Systems

Abstract: A computer program concept is described for performing an electrical analysis and a transient thermal analysis of a satellite electric power subsystem consisting of a solar array, battery, and power controls. The program "flies" the power subsystem and certain thermally sensitive portions of the spacecraft through one or more complete orbits, and plots curves of voltages, currents, temperatures, and energy balance in critical parts of the power and thermal subsystems.

Timepiece driven by nuclear energy

Abstract: A timepiece driven by nuclear energy, wherein the radiation of a radioactive source serves at the same time for producing the electric power for energizing a counting circuit and for control of a counting frequency or recombination frequency determining the advance of the timepiece.

Method of making electric power cable

Abstract: D R A W I N G UNDULATORY DRAIN WIRES ARE EMBEDDED IN A CABLE JACKET BY PAYING THEM INTO AN EXTRUDER DIE DURING THE EXTRUSION OPERATION.

Power comsumption rate monitored electric water-heating system

Abstract: A power consumption rate-monitored electric water-heating system featuring provision, in functional combination; a water storage tank; an electric immersion heater device shrouded and extending into the lower portion of the tank; the heater shroud being open at its inner end and in communication at its outer end with the intake of a pump which is arranged to discharge through a distributor conduit into the uppermost level of the tank; a heated water takeoff connection located at the top of the tank; a cold water inlet connection located at the bottom of the tank; a waterflow-rate-regulating valve in the line between the shroud and the distributor conduit; and an electric power supply monitoring mechanism operative to limit the power consumption rate during normal periods to a prescribed maximum which is much less than the total power which may be consumed by the heating device so as to limit the total power consumption of ''''offpeak'''' periods when the power price rate is lowest. The waterflowregulating valve is arranged to be automatically responsive to temperature changes.

Synthesis of an Electrical Power System for a Manned Lunar Base

Abstract: Current program planning in the area of lunar surface explorationenvisions missions of increasing energy requirements and duration.During the mid 1970's it has been estimated that the electrical powerrequirements for a 3-man mission of one year duration might be in theorder of 33 000 kWh. Load profiles to support regeneration of fuelcell reactants for lunar roving vehicles and base nighttime operationsindicate potential power levels of from 30 to 100 kW. An electricalpower system using a state-of-the-art photovoltaic energy conversionsource was postulated on the assumption that nuclear power systemtechnology would not be flight ready by this time period.The process of synthesizing an overall electrical power system isdiscussed. Included are analyses and system design rationale. A rangefrom 50 to 500 volts dc is considered and the effect on weight andefficiency determined. Additional system criteria such as thermalcontrol, reliability, and emergency operation are discussed. A shred-out oftotal system weight as a function of voltage and regulation is presentedfor a 36 kWload. The impact ofload level, conditioning efficiency,transmission length, and temperature on system weight is discussed. Sensitivityivity curves depicting the effect of variations in these parameters areprovided.It is concluded that an efficiency of 80 percent or greater can beattained by matching the load profile with distribution voltage.

Power control circuit

Abstract: A power control system incorporating a silicon-controlled rectifier for selectively applying electrical power to an electroluminescent device so as to cause illumination thereof The silicon-controlled rectifier is selectively switched between its nonconducting and conducting state by a controlled bilevel signal applied to the cathode and by selectively controlling the bias values, the silicon-controlled rectifier will have a 360* conduction angle thereby applying maximum power to the electroluminescent device

Thermal control for fuel cell module

Abstract: An assembly of fuel cells or like source of electrical power having mounted on an outer surface of the fuel cell module interleaved sets of high and low thermal emissivity surfaces, with one set of surfaces being stationary and the other set of surfaces being movable. Means are provided for sensing the thermal condition of the fuel cell module and for moving one set of surfaces relative to the other set of surfaces to vary the thermal radiation from the fuel cell module and thus to control the temperature of the fuel cell module.

Underwater electrical power source and sonic beacon

Abstract: The specification discloses an underwater sonic beacon for marking the location of metallic structures such as underwater wellheads. The sonic beacon is powered by a galvanic cell formed by the water as the electrolyte, the metallic structure as one electrode, and a galvanic anode spaced from the metallic structure as the other electrode. An electronic oscillator circuit and electroacoustic transducer are connected as the load on the galvanic cell. The sonic beacon is provided extended lifetime by sequentially activated anodes which produce continuous electrical power.