Abstract: A package heat exchange system using an expanded surface gas-fired burner to supply heat via a heat exchange coil in a dome above the extended surface heat exchanger which heats domestic hot water and supplies heat via the dome to a radiator for heating a living area of a home. A control system provides for utilizing steam from the extended surface heat exchanger to heat the coil in the dome and maintains a first pressure for supplying the domestic hot water and a higher pressure when radiator heat is called for. The heat for domestic hot water may be further heat transferred in a fourth heat exchanger which adjusts the temperature of the domestic hot water. The heat supplied to the radiator may be self-pumping by utilizing steam and the heat to the radiator may be cut off by supplying a control to the return pipe of the radiator which allows the radiator to fill with condensate from the steam.

Abstract: A package heat exchange system using an expanded surface gas-fired burner to supply heat via a heat exchange coil in a dome above the extended surface heat exchanger which heats domestic hot water and supplies heat via the dome to a radiator for heating a living area of a home. A control system provides for utilizing steam from the extended surface heat exchanger to heat the coil in the dome and maintains a first pressure for supplying the domestic hot water and a higher pressure when radiator heat is called for. The heat for domestic hot water may be further heat transferred in a fourth heat exchanger which adjusts the temperature of the domestic hot water. The heat supplied to the radiator may be self-pumping by utilizing steam and the heat to the radiator may be cut off by supplying a control to the return pipe of the radiator which allows the radiator to fill with condensate from the steam.

Abstract: A surface acoustic wave low loss filter device having input and output transducers located along opposed sides of a rectangular propagation path with frequency selective reflective gratings at each of the four corners of the rectangle. Two traveling surface waves traverse the device along opposed paths encountering frequency filtering at the gratings. The two waves arrive at the output transducer additively in phase eliminating the bidirectionality loss normally associated with surface acoustic wave devices. At frequencies for which the gratings are reflective there can be nearly lossless transmission from input to output. At all other frequencies, transmission between input and output transducers is negligible. The device has high sidelobe rejection, adjustable passband skirt slopes, and an adjustable bandwidth.

Abstract: In a switched multipath filter network, the passband is varied by varying the duty cycle of the switches which commutate the constituent filters. When no filter is operative, the output connection of the filters is interrupted to prevent the unfiltered signal passing through, but the network output is smoothed to provide sample and hold action.

Abstract: A package heat exchange system using an expanded surface gas-fired burner to supply heat via a heat exchange coil in a dome above the extended surface heat exchanger which heats domestic hot water and supplies heat via the dome to a radiator for heating a living area of a home. A control system provides for utilizing steam from the extended surface heat exchanger to heat the coil in the dome and maintains a first pressure for supplying the domestic hot water and a higher pressure when radiator heat is called for. The heat for domestic hot water may be further heat transferred in a fourth heat exchanger which adjusts the temperature of the domestic hot water. The heat supplied to the radiator may be self-pumping by utilizing steam and the heat to the radiator may be cut off by supplying a control to the return pipe of the radiator which allows the radiator to fill with condensate from the steam.

Abstract: A microwave oven control system in which the average microwave power may be selected by selecting different duty cycles of a cyclically closing semiconductor switch controlling the AC power supplied to a microwave magnetron anode power supply which has a saturable high voltage transformer with input current surges to said power supply being minimized by turning on said switch in the region a voltage peak of said AC power and with the cycle time of said switch being greater than the AC power cycle time but being substantially less than the thermal response time of a food body being cooked by microwave energy so that changing the duty cycle can change the power applied to the food body rapidly in the event that undesired results such as boiling over or burning of the food body are observed.

Abstract: A performance monitor for use with marine radars which produces a visual indication upon the radar display screen only when the radar transmitter power, and the radar receiver sensitivity and tuning are within predetermined limits. An RF sample of the radar transmitted signal is mixed with a local oscillator signal and the resulting IF signal is coupled to an AFC loop which controls the frequency of the local oscillator. If the amplitude of the radar transmitted signal is above a threshold level, a single frequency response signal of fixed power is generated by the performance monitor and transmitted back to the radar antenna. A distinctive test pattern is produced upon the radar display if the radar receiver tuning is accurate and its sensitivity is sufficiently high.

Abstract: A semiconductor device with active junction area determined by the surface of the floor of a hole etched into a body of semiconductor material. A body of highly doped semiconductor material is overlayed with two layers of semiconductor material of the same conductivity type. The layer in contact with the highly doped body is moderately doped while the upper layer is very lightly doped. A hole is etched through the top layer extending slightly into the moderately doped layer. A Schottky barrier contact is plated throughout the etched region. The total parasitic capacitance of such devices is much lower than that of prior art devices and the reverse breakdown characteristics are improved.

Abstract: A method is disclosed for dicing individual or groups of diode mesas fabricated upon a single metal heat sink. The undiced device is placed diode mesas down upon a transparent glass plate with the mesas protected in wax. A first mask is positioned upon the opposite side of the plate by alignment with the diode mesas as seen through the plate. Portions of the first mask extend on the plate beyond the edges of the wax and heat sink. A second etching mask is then fabricated upon the bottom of the heat sink by exposing a layer of photoresist through a mask having the same grid pattern as the first mask and which is aligned with the portions of the first mask seen through the glass plate beyond the edge of the heat sink. The diode mesas are etched apart by spraying an appropriate etchant through apertures in the etching mask.

Abstract: A microwave oven having a magnetron wave energy supply energized by high voltage pulses at a superaudible frequency wherein the voltage pulses are produced by a decreasing portion of a magnetic flux cycle of said frequency in a transformer added to a voltage on a capacitance whose charge is replenished during a portion of said cycle during which a semiconductor switch connects a winding of the transformer to a source of unidirectional voltage to increase the flux in the transformer thereby energizing the magnetron with voltage pulses from a supply having a substantially constant current characteristic and permitting variation of the constant current level by variation of the average flux density in the transformer.

Abstract: A four frequency laser gyroscope system having a rugged and compact output structure for producing output signals representing the frequency differences between counter-circulating wave pairs circulating as two beams within the gyroscope cavity. A partially transmitting dielectric mirror forms both one of the cavity reflectors and the means for extracting a small portion of each beam. The two extracted beams are combined on a beam splitter. Both the transmitted and reflected beams from the output of the beam splitter, each containing waves of all four frequencies, are utilized. Each resultant beam is then polarization discriminated to extract the desired signal content. The entire structure is adapted for rigid mechanical coupling and may be constructed to have a small size.

Abstract: The process and apparatus for extracting the products of kerogen in situ from an oil shale body by supplying energy selectively to the kerogen by high frequency electric fields in the frequency range between 100 kilohertz and 1000 megahertz at an intensity which heats the kerogen to a temperature range between 250.degree. C. and 500.degree. C. to allow pyrolysis of the kerogen prior to substantial heat transfer to the surrounding mineral portions of the oil shale.

Abstract: A microwave oven having a door with a peripheral microwave seal structure which is fabricated from one or more die formed aluminum parts and solid dielectric inserts to form a resonant transmission line structure with peripheral oven wall portions, with transmission of microwave energy in the seal around the periphery of the door prevented by impedance discontinuities, and leakage of microwave energy through the seal is prevented by impedance mismatch or resonant choke action of the seal structure, and the size of a notch in a solid dielectric insert in a quarter wavelength shorted branch line of the seal is selected for different production runs of the oven to compensate for dimensional changes in different die stamped metal parts or assembled door structures due to assembly jig changes, stamping die wear or assembly procedures.

Abstract: A heat exchange system is provided having first and second heat exchangers connected to one another. A burner supplies products of combustion to the first heat exchanger. Fluid heated in the first heat exchanger is pumped to the second heat exchanger. A blower forces air over the second heat exchanger to heat the air. An electric heater is provided in heat exchange relationship with the first heat exchanger. The electric heater maintains the temperature of the fluid in the first heat exchanger above the effective dew point of the flue gas in the heat exchanger.

Abstract: A method and apparatus for fracturing and/or heating subsurface formations wherein an alternating current electric field is produced in the frequency range between 100 kilohertz and 100 meghertz between electrodes spaced apart in the formation and a radio frequency generator supplying a voltage between said lines with suitable loading structures tuned to the frequency of the generator to resonate the electrodes as a parallel wire transmission line which is terminated in an open circuit and produces a standing wave having a voltage node at the end of the line.

Abstract: Surface acoustic wave devices are disclosed which have enhanced reflectivity gratings with conductive stripes between grooves in the substrate or conductive stripes within the grooves. For lithium niobate substrates, aluminum stripes coupled together and positioned between grooves or unconnected and positioned within the grooves are preferred. For quartz substrates, gold stripes within the grooves are used. Methods for fabricating such structures are also disclosed.

Abstract: A platinum film resistor device and method for making the same. A layer of quartz, deposited upon an insulative substrate preferably silicon, is sputter etched at high power levels to produce etch pits in the surface thereof. A layer of platinum is then deposited over the quartz layer by first sputtering platinum at high power for a relatively short period of time and then completing the layer by continuing to sputter deposit platinum at a lower power. A second layer of quartz is deposited over the layer of platinum and the second layer of quartz masked and chemically etched away in the regions where portions of the platinum layer are to be removed. The exposed platinum and a portion of the second quartz layer are then sputter etched away leaving the platinum in a predetermined configuration. The platinum is then annealed, the second quartz layer removed above the lead bonding pads, and external leads attached. The device is particularly useful in temperature measuring application.

Abstract: A microwave oven control circuit in which the filament of a magnetron supplying microwave energy to the oven is heated to its electron emitting temperature around 1500.degree. C where it emits red spectrum radiation which is sensed by a photoconductive element through the magnetron microwave output structure to produce a control signal actuating the magnetron high voltage supply.

Abstract: A variable range marker processing device for use with a PPI radar with digitized video displayed in non-real time. The position of the range marker is initially operator determined by rotation of a knob mechanically linked to an optically encoded disc. Optical sensors produce a digital output indicative of the disc rotation angle and range mark position as a distance from the center of the radar display screen. A counter is preset with the digital output at the start of each sweep and decremented once each range cell until a count of zero is reached at which time an unblanking pulse is produced. A numeric display of range is produced by dividing the number of range cells to the range mark by the range setting, scaling according to chosen units of measure, and displaying the result with a LED display, the computations being performed by a processor controlled by a permanently programmed memory. The range mark stays on target as the range scale is changed.

Abstract: A compact heating and cooling system in which air ducts are connected to a heat exchanger system through which a coolant fluid from a condensing unit or a heating fluid from a compact water heater is selectively directed by a control circuit so that the system may be mounted outside a building to be heated and/or cooled.