Abstract: A device for measuring the voltage of a voltage source includes a number of temperature responsive displays and a circuit including a number of heating circuits, each heating circuit for heating one of the temperature responsive displays when a threshold voltage of the heating circuit is exceeded, and a printed resistor, each heating circuit being connected to a length of the printed resistor such that the voltage of the voltage source at which each heating circuit heats a temperature responsive display is a function of the ratio of the lengths of the printed resistor to which the heating circuits are connected.

Abstract: A movement actuator includes an elongate filament made of a flexible material, and a strip of shape memory alloy disposed on the surface of one side of the filament. The shape memory alloy is responsive to actuation signals, heat or electrical signals, for changing its shape and when its shape changes, it causes the filament to move, i.e., bend, to accommodate the change in shape of the alloy. Also included is a signal supply device for selectively applying heat signals or electrical current to the strip of shape memory alloy to cause the alloy to change its shape and cause the filament to bend. Other patterns for the shape memory alloy could be disposed on the filament to cause other kinds of movements. For example, a helical pattern of the shape memory alloy about the filament would cause the filament to twist when the helical pattern were caused to shorten or lengthen.

Abstract: A system for determining the sag of an overhead power transmission line to prevent flashover to adjacent objects on earth. A small replica of the transmission line conductor is provided and located in proximity to the transmission line. The temperature of the replica is measured along with the ambient temperature. By appropriate calculations, the ampacity determination is made to determine the maximum permitted current through the transmission line under the particular weather conditions.

Abstract: A system for determining the sag of an overhead power transmission line to prevent flashover to adjacent objects on earth. Power line tension is measured as well as ambient temperature at two different times. From these measurements the Ruling Span of a power line can be calculated from which a determination can be made of the maximum safe current to avoid unsafe line sag.

Abstract: A movement actuator includes an elongate filament made of a flexible material, and a strip of shape memory alloy disposed on the surface of one side of the filament. The shape memory alloy is responsive to actuation signals, heat or electrical signals, for changing its shape and when its shape changes, it causes the filament to move, i.e., bend, to accommodate the change in shape of the alloy. Also included is a signal supply device for selectively applying heat signals or electrical current to the strip of shape memory alloy to cause the alloy to change its shape and cause the filament to bend. Other patterns for the shape memory alloy could be disposed on the filament to cause other kinds of movements. For example, a helical pattern of the shape memory alloy about the filament would cause the filament to twist when the helical pattern were caused to shorten or lengthen.

Abstract: A device for measuring the electrical characteristics of a ferromagnetic erial as a function of temperature, such as its dielectric constant verses temperature characteristics. The device having a quick mount fixture that utilizes a gravity feed and thermal grease to insure a quick reliable thermal connection between the temperature controller and the device under test (DUT). In addition, the device can be remotely controlled by a computer to automate the measuring procedure, thus reducing measuring time and alleviating the intensive manual procedure of making such measurements. Moreover, the device is easily mountable in a humidity-free or desiccation chamber to insure the measurements are reliable and accurate.

Abstract: An apparatus is disclosed which accurately measures, over a wide ambient temperature range, the average power derived from an electrical signal. Furthermore, embodiments of the present invention can be fabricated with inexpensive, off-the-shelf components and can have excellent circuit characteristics at RF frequencies. These results are obtained in an illustrative embodiment of the present invention that comprises a first thermal detector, a second thermal detector, an error amplifier and a summer. The first thermal detector provides a reference signal, which varies with the ambient temperature, to the error amplifier. The summer receives the signal to be measured and the signal output from the error amplifier, and outputs to the second thermal detector a composite signal, which is indicative of the sum of the power derived from input signal and the output signal from the error amplifier.

Abstract: A monolithic integrated circuit power sensor provides a monolithic integrated circuit substrate a conversion element formed either on or in the substrate for converting microwave energy into heat, an electrically insulating dielectric layer affixed to the conversion element, and an integrated circuit, heat sensitive element formed in sufficiently close proximity to the conversion element to be thermally coupled thereto through the dielectric layer for sensing temperature changes in the conversion element.

Abstract: A system for determining the current carrying capability of one or more overhead power transmission lines monitors one or more spans of each line on real-time basis and identifies the span having the lowest current carrying capacity which in turn establishes the maximum capacity of the entire line. The thermal state of each monitored line span is determined by measuring the conductor temperature, line current, solar radiation, ambient temperature, and in some cases wind speed and wind direction. These parameters are montiored by a sensor-transmitter unit that may be removably clamped on the line conductor which may range in size from one to several inches in diameter, and includes a radio transmitter for transmitting sensed data to a receiving substation.

Abstract: A monolithic integrated circuit power sensor provides a monolithic integrated circuit substrate, a conversion element formed either on or in the substrate for converting microwave energy into heat, and a thermally sensitive diode junction formed in sufficiently close proximity to the conversion element to be thermally coupled thereto.

Abstract: A thermal power sensor for providing an output signal that is linearly related to the amount of power derived from a power source over a first range and that is square law related to the amount of power derived from a power source over a second range which may overlap the first range. The apparatus comprises a pair of matched transistors connected in a common emitter configuration. Each of the matched transistors is thermally coupled to a matched resistor so that heat generated in the resistor is transmitted to its respective transistor to cause temperature variations therein. The current through each transistor is a function of the temperature of the transistor. The matched transistors are connected in series with a pair of cascode transistors. The cascode transistors are connected to a first differential amplifier which senses and amplifies the differential voltage which results from any difference in current flow through the matched transistors.

Abstract: A thermo-responsive device for testing dc voltage sources, particularly small, low voltage dry cells, employs a very thin resistive heater film deposited onto a thin flexible dielectric substrate. During testing the ends of the resistive film engage the pole terminals of the battery. Current from the battery flows through the resistive film and uniformly heats the substrate by resistance heating, causing a series of thermo-responsive elements mounted on the substrate to undergo visual "temperature events" at progressively higher temperatures. The resistive film is uniform in thickness and uniform in sheet resistivity. The current density and resistive heating of the film is therefore uniform throughout the substrate and the thermo-responsive elements. The uniform heating permits the thermo-responsive elements to be mounted anywhere on the substrate. The length of the resistive heater may be varied to vary the heating current and the heating temperature.

Abstract: A circuit for measuring the R.M.S. voltage of a high frequency signal (e.g. 100MHz) comprises two series-connected ntc thermistors (TH1, TH2) in a bridge circuit which is energized by a current source (1). The unknown signal is applied across one (TH1) of the thermistors and the resulting change in the resistance causes a D.C. output voltage to appear across the balanced terminals (T3, T4) of the bridge. This output voltage is proportional to the square of the R.M.S. voltage of the A.C. signal. In another embodiment, two ptc thermistors are connected in parallel in a bridge circuit which is energized by a voltage source, and are used to measure R.M.S. current. In each case, the thermistors are preferably operated in a negative slope resistance portion of their voltage-current characteristic.

Abstract: A system for determining the current carrying capability of one or more overhead power transmission lines monitors one or more spans of each line on real-time basis and identifies the span having the lowest current carrying capacity which in turn establishes the maximum capacity of the entire line. The thermal state of each monitored line span is determined by measuring the conductor temperature, line current, solar radiation, ambient temperature, and in some cases wind speed and wind direction. These parameters are monitored by a sensor-transmitter unit that may be removably clamped on the line conductor which may range in size from one to several inches in diameter, and includes a radio transmitter for transmitting sensed data to a receiving substation.

Abstract: A DC voltage tester having a plurality of resistive elements in thermal contact with a thermochromic material wherein the resistive elements are connected in a parallel configuration.

Abstract: A thermo-optical current sensor includes a resistive or semiconducting sensing element that has an optical property that varies as a function of temperature. Current to be measured flows through the sensing element thereby causing heating that is detected by a change in the optical property. The sensing element may be either a resistive or semiconducting material having a temperature dependent optical property or a resistive or semiconducting material that is in thermal contact with an optical temperature sensor. The thermo-optical current sensor may be used as a field meter to measure the intensity of an electromagnetic field or as a current meter to measure the current flowing through a power line.

Abstract: A microwave calorimeter is disclosed for substantially measuring the total icrowave energy in an applied microwave pulse. The microwave calorimeter includes: a housing having a highly reflective interior surface, a microwave absorbing device disposed in the housing for substantially absorbing microwave energy transmitted into the housing and for producing a thermal response proportional to the amount of microwave energy being absorbed, and a measurement device responsive to the thermal response for determining the amount of microwave energy being absorbed by the microwave absorbing device.

Abstract: The present invention relates to devices utilized for measurement of high frequency and microwave power. More specifically, the present invention relates to apparatus and technique for measurement of power including the construction and configuration of a power-sensing probe for detection of the power level of a high frequency or microwave signal.

Abstract: In an arrangement for measuring the energy of a microwave pulse a container (2) is placed on the end of a waveguide (1). In container (2) there is an absorption liquid (3) with a given heat content, which absorbs the energy of the irradiated microwave pulse. The increase of the heat content thus caused which corresponds to the energy of the microwave pulse is determined by the volume expansion of the absorption liquid (3). For this purpose container (2) is connected to a capillary (4). Preferably container (2) is covered with a reflection layer (12). Further, it is additionally connected to a balancing volume (5) and is cooled with a cooling coil (14).

Abstract: A microwave oven wattage detector having a visually and microwave transparent container holding a thermally homogeneous fluid having a wattage-indicating strip contained in the fluid with a plurality of different temperature-sensitive areas on the strip with indicia associated with each of the areas to indicate power levels when such container is heated within a microwave oven for a set time and one of such temperature-sensitive areas changes color to denote the indicia indicating the power level of the microwave oven.

Abstract: A method and apparatus for the comparision of AC signals by electrothermal means in which both signals are applied to an electrothermal converter, such as a thermocouple converter or a thermoresistive converter, and the temperature produced by the signals is converted to a difference signal. The DC component of the difference signal is used to maintain the electrothermal converter at a stable operating temperature. The AC component of the difference signal is used to indicate the difference between two signals when used as a comparator, to control the amplitude of a reference standard's output when used as a voltmeter or calibration standard, and also to control the amplitude of an oscillator when used as a calibration standard.

Abstract: A bimetallic indicator includes a bimetal being deformed by heat generated by an electric current supplied to a heat coil wound around the bimetal, a pointer moved in relation to the deformation of the bimetal and indicating a measured value in accordance with an amount of electric current supplied to the heating coil, and a driving gear, which is rotated by the deformation of said bimetal. The driving gear includes two first pitch portions each having a plurality of teeth with a regular pitch and a second pitch portion provided between the first pitch portions and having a pitch smaller than that of the first pitch portion. A driven gear to which the pointer is mounted is engaged with the driving gear and rotated together with the pointer by the rotation of the driving gear. The rotation of the driving gear is transmitted to the driven gear only when the first pitch portion of the driving gear is in engagement with the driven gear.

Abstract: In a power sensor for RF power measurments, comprising a thin-film absorbing resistor formed on the top surface of a support member and a thermocouple which is electrically isolated from the circuit of said absorbing resistor, the absorbing resistor is formed on an insulating film of a silicon support member so as to increase the sensitivity and to facilitate manufacture thereof, the silicon support member including an island formed beneath the absorbing resistor, a thermally conducting portion formed in spaced relationship thereto with a narrow bridge portion provided inbetween, and said thermocouple being constituted by the bridge portion and by mutually spaced contact zones formed thereon.

Abstract: A true RMS instrument using a multijunction thermal converter with two beaters automatically determines and displays the RMS value of an unknown voltage using two steps or modes. In an AC mode, the unknown voltage is attenuated and balanced in the thermal converter with a DC voltage. DC voltage is stored in digital form in a first latch. In the DC mode, the unknown attenuated voltage is replaced by a chopped DC voltage which is then balanced with the DC voltage obtained in the AC mode. The unknown voltage is determined by decoding the contents of a second lath which controls the chopped DC voltage.

Abstract: A microwave power sensor utilizing a semiconductor power absorption element which is mounted on a fin-line structure within a waveguide channel. In order to check calibration of the sensor, a coaxial line is used to feed a relatively low frequency reference signal to the power sensor. The power element is positioned between the input port of the waveguide and a coaxial line input port at which the reference signal is applied. The use of a precise and accurate reference signal enables the power sensor to be used for microwave measurements.

Abstract: A thermal transfer device for use in the measurement of alternating current comprising an evacuated enclosure containing a first electrical conductor heated by the alternating current being measured and a thermal sensor to provide an electrical signal representative of the temperature of the conductor, wherein the first electrical conductor is formed of a low temperature coefficient of resistivity material, and the thermal sensor is a second electrical conductor of a relatively high temperature coefficient of resistivity material thermally coupled with and encompassing most of the first electrical conductor.

Abstract: An antenna comprising orthogonal arrays of resistive thermocouple dipoles interconnected by transversely extending conductive elements of discrete length. The components are designed to create an additional response by a traveling wave effect on the dipoles along the Poynting vector to offset the fall-off in dipole sensitivity experienced as frequency rises.

Abstract: A differential thermal wattmeter of the type disclosed in U.S. Pat. No. 4,045,734 is modified to remove undesirable in-phase a.c. ripple at the fundamental frequency in the feedback path. This result is achieved by a closed loop system in which the in-phase signal in the feedback path is detected and driven to zero by injecting sufficient signal in opposite polarity into the feedback path to cancel the ripple. The advantages are reduction of error and the ability to use standard, low cost components.

Abstract: An improved meter for measuring RF power. The RF power is applied to thermocouple means which transforms the RF power into a low level d.c. signal which then passes through a chopper stage that is driven by a clamped sinusoidal input. The output of the chopper stage includes periodic pulses with a prescribed pulse spacing: pulse duration ratio, the pulses being passed through a band-pass filter at a harmonic of the chopper drive signal. The filtered signal, which is also amplified, undergoes synchronous detection with a tri-level square-wave signal which is centered in phase relative to the amplified, filtered signal when the two signals are in phase. The power meter measurements adjusted for zero drift and calibration drift by a microprocessor; based on zero measurements and calibration measurements made before and after an RF measurement is made. Measurements are stored and processed digitally to enhance accuracy.

Abstract: An electromagnetic field detector adapted to display potential hazard to humans and other animals arising from illuminating electromagnetic energy over the frequency range determined to be hazardous by the American National Standards Institute; the detector being designed with various sensing means to create a sensitivity vs. frequency response that is the inverse of the A.N.S.I. protection guides.

Abstract: Passage of current through a power transmission line causes infrared radiation therefrom. The construction of a high-tension (HT) line with counterwound helical conductors for current around a supporting core minimizes the surrounding magnetic field, reducing the skin resistance of the line per unit length as compared to its bulk resistance per unit length. Infrared radiation from the I.sup.2 R losses in the line is thus linearized, and the current in the line can be indirectly measured by sensing the infrared radiation from the line itself using infrared detectors.

Abstract: An overhead conductor monitoring device includes a simulation conductor designed to have thermal characteristics similar to those of the overhead conductor. The simulation conductor is placed in the same ambient atmosphere as the overhead conductor and is selectively heated by a coil embedded within the simulation conductor. The power supply to the coil is computed by a microcomputer to be the same as the power of the overhead conductor. Temperature sensors are placed in or on the simulation conductor to monitor the temperature thereof. As the temperature of the simulation conductor increases, the power of the overhead conductor is recomputed to reflect changes in the characteristics of the overhead conductor. An alarm signal is generated if the temperature of the simulation conductor exceeds a predetermined temperature and theoretical values of overhead conductor power can be supplied microprocessor to determine the effects on the temperature of the overhead conductor.

Abstract: A self-balancing DC-substitution measuring system includes a temperature dependant resistor (TDR) which is placed in one leg of a Wheatstone Bridge circuit, diagonally opposed first and second nodes of the bridge being driven respectively by the outputs of two operational amplifiers such that the potential at each of these first and second nodes, when measured with respect to a common reference point is equal in magnitude and opposite in polarity to the other. Each of the amplifiers has a pair of differential inputs and each of these inputs are connected to either of the remaining third and fourth nodes of the bridge circuit or to the common reference point, no two inputs from the same amplifier being connected to the same point and each of the third and fourth nodes and the common reference point having at least one amplifier input connected to it.

Abstract: A radiation detector utilizing thin film thermocouples serially connected in an array and substantially disposed within a plane, said thermocouples being selectively mounted for non-perturbing introduction into the near-field region of an electric field.This application is a continuation of copending application Ser. No. 678,901 filed Apr. 21, 1976, now abandoned, which prior application was a continuation of previously copending application Ser. No. 423,754 filed Dec. 11, 1973, now abandoned, which latter application was a divisional of copending application Ser. No. 200,536, filed Nov. 19, 1971, now U.S. Pat. No. 3,794,914, which latter application was a continuation-in-part of copending application Ser. No. 848,620 filed Aug. 8, 1969, now U.S. Pat. No. 3,641,439.

Abstract: To record significant discharges of a surge arrester, the energy dissipated in a separate varistor element equivalent to the varistor elements in the arrester and connected in the arrester discharge path is monitored. When an arrester discharge results in a temperature increase above a predetermined minimum in the separate varistor element, heat sensing means thermally coupled therewith triggers a counter to record the event.

Abstract: A liquid crystal film pack for detecting leakage from a microwave oven by passing the moist film pack adjacent the joints and seams of the oven to produce a color change in the liquid crystal material in response to a microwave radiation leak.

Abstract: A radio wave power measuring apparatus is disclosed, which includes a thel load confined in a reference temperature housing, a wave absorber disposed in the load for absorbing radio waves supplied thereto, a heater for heating the load, a thermoelectric cooler element provided between the housing and the load for the load, a temperature difference detector having a thermoelectric sensor element provided between the housing and the load for detecting the difference in temperature between the housing and the load, a heater controller for feeding to the heater the power corresponding to the temperature difference detected by the detector so as to maintain the load and the housing at the same temperature, and a measuring member for measuring the power fed to the heater.

Abstract: An indicator includes a dial having a translucent section supported on a housing, a light beam directed along a path through the housing such that light is not normally received at the translucent section, a measuring element movable within the housing in accordance with a condition to be sensed and a reflector carried by the measuring element and movable therewith to intersect the light beam path to reflect the light beam to the translucent section when a predetermined condition is sensed.

Abstract: A progressively shorted tapered resistance device including a body of material which undergoes an irreversible resistance decrease when heated beyond a threshold temperature in operative association with a tapered electrical resistance element which develops a non-uniform temperature profile when electrically energized. Upon sufficient energization, the tapered resistor element will cause portions of the heat sensitive material to be heated beyond its threshold temperature resulting in a shorting out of a portion of the tapered resistance element. The amount of the tapered resistance element shorted out is measured at low currents to provide an indication of the energizing current.

Abstract: An improved analog meter is provided having no moving parts. This meter comprises a tapered resistor device having a tapered, electrically resistive element which develops a non-uniform temperature profile on electrical energization and a heat sensitive element operatively associated with the tapered resistive element. The heat sensitive medium employed is a reversible medium which either undergoes a change in color or contrast when heated to an appropriate temperature and when viewed under appropriate illumination. A method of metering employing this device is also disclosed.

Abstract: A tapered resistor heating element is provided which sequentially heats and actuates in a controlled fashion heat sensitive media. In one embodiment a tapered resistor heating element sequentially heats in a controlled fashion heat sensitive switches. Heat sensitive resistors and heat sensitive threshold switches may also be employed in this configuration. This system may be utilized as a meter relay or as described in another embodiment as a scanner. Novel exclusive OR gates are also disclosed which are employed in one embodiment of the scanner of the instant invention.BACKGROUND OF THE INVENTIONThis invention relates generally to scanning devices and more specifically to monolithic electronic scanning devices.It is known that a major problem with matrix addressed displays and the like is the requirement for numerous connections in their implementation between the matrix elements and the ancillary addressing and driving devices. For instance, a display panel with 10.sup.6 matrix elements requires about 2.

Abstract: Liquid crystals having color play centered at different temperatures are arranged in a similar pattern on metal coated and non-metal coated disks which are used to monitor electromagnetic radiation. An embodiment which measures radiation in the range of 1 to 15 mW/cm.sup.2 at 2.45 GHz is described. The monitor uses the temperature-dependent light scattering properties of liquid crystals as the measuring and indicating mechanism. While both disks will respond equally to changes in ambient temperature, the metal coated disk also responds to induced temperature changes caused by incident radiation. Thus the difference between the temperature indications of the two disks is a measure of the radiation present.

Abstract: The differential thermal wattmeter for the ac/dc transfer of power includes a differential thermal converter as a "sum and difference" multiplier, with both ac and dc voltage and current signals simultaneously applied to both heaters. DC feedback to the current input speeds up the response and maintains thermal balance between the heaters, so that the output meter becomes a null indicator. This reduces and can eliminate the need for quadratic response. The requirement for exact matching of the thermal converters is also eliminated by effective interchange of the heaters.

Abstract: A measuring arrangement for measuring the effective value of an a.c. signal. Said a.c. signal is applied to a first thermal convertor, while a d.c. output signal is applied to a second thermal convertor. The two thermal convertors differentially drive a differential amplifier, which at its outputs delivers the d.c. output signal. For values of the d.c. output signal which are smaller than a threshold value, a negative feedback signal which linearly depends on said d.c. output signal is applied via an additional negative-feedback network to at least one of the inputs of the differential amplifier. This facilitates zero-point adjustment, and also allows the measuring speed to be increased.

Abstract: A self-balancing D.C.-substitution R.F. power measuring system includes ft and second high gain differential operational amplifiers, a bolometer element, and a reference resistor element. The amplifiers and the two elements are connected in a current loop with one of the elements connected between the output terminals from the differential amplifiers and the other of the elements connected between center points of isolated dual power supplies associated with each of the amplifiers. The inputs to one amplifier are connected from an adjacent end of one of the elements and the far end of the other element, while the inputs to the second amplifier are connected to the far end of the one element and the adjacent end of the other element. Current flows out of one amplifier and into the other.

Abstract: An indicating device in the form of a thin metallic foil such as manganin on which a temperature indicating material such as Tempilaq is sprayed the foil being tapered to provide a temperature gradient whereby the passage of current through the tapered wedge causes a melt line to occur indicating the amount of current flow.

Abstract: A detection device for electromagnetic radiation uses strips of thin resistive films connected in electrically conductive paths with the area of spacing between adjacent ones of the strips being greater than the area of the strips to achieve an impedance which is largely resistive over a broad band of radio frequencies. The strips are mounted in dielectric material and exposed to free space radiation. A radiation hazard meter is produced with thermally sinked thermocouple elements forming the resistive strips.