Abstract: A low-pass variable filter stage having a variable impedance circuit and may include an output buffer. The variable impedance circuit includes a transistor and a diode whose collector and anode respectively are connected to a current mirror and whose base and cathode respectively are connected to a voltage controlled current source. An external capacitor is connected across the diode to an external potential and the buffer is connected across the diode input.A first static voltage is applied producing a first static current in the transistor collector which is mirrored into the diode anode circuit as a second static current producing a second static voltage across the diode. The sum of the static currents form a control current flowing through the current source whose amplitude controls the small signal resistance of the diode. A small signal is superimposed upon the second static current. The diode resistance, the signal frequency, and the capacitor control which frequencies pass the filter.

Abstract: A voltage controller for use with a fluorescent-lighting system, the controller including a three-phase transformer having three auto-transformer windings each for developing two reduced voltages, three contactors for selectively coupling the full voltage and the reduced voltages to the lighting system, the contactors being switched in closed-transition fashion to avoid power interruptions, and another contactor for opening the winding-neutral connections during voltage switching to avoid shorting the transformer.

Abstract: A test fixture apparatus for testing drives of magnetic recording media; the apparatus being adapted to simulate magnetic media for insertion within a magnetic recording drive. The test fixture apparatus includes a structure formed with exterior dimensions approximating those of the magnetic media; one or more conductors positioned to be in close proximity to the gap or gaps of the magnetic recording head within the drive when the test fixture apparatus is inserted; signal detection and driver circuitry to drive the conductor or conductors in order to simulate readback flux reversals and to check write characteristics of the drive; and means to simulate index pulses for flexible disk applications. A magnetic data cartridge application is also included as an alternative embodiment.

Abstract: A heat transfer apparatus adapted for installation in a mobile liquid container such as a railroad tank car. The apparatus includes inlet and outlet ports at opposite ends of a continuous finned pipe. The continuous finned pipe extends within the container to provide a surface for conductive heat transfer from the heat transfer fluid flowing through the pipe to the contents of the container.The continuous finned pipe is provided with shock absorbers and flexible loop portions to prevent damage to the apparatus from inertial shocks to the container. A preferred embodiment is designed particularly for use in railroad tank cars adapted to carry molten sulfur. The apparatus is used to remelt the sulfur, which has solidified in transit, for unloading.

Abstract: A light reflector for specific use in combination with an elongate light source such as a fluorescent lamp. It has a plurality of reflecting surfaces disposed behind and symmetrically of the light source and includes opposed central tangent reflecting surfaces. The cumulative effect of the reflecting surfaces is to synthesize the light rays emitted upwards with those emitted downwards by the sourve towards the area to be lighted.

Abstract: A self-feeding feeder for use with printers having rotatably driven friction feed rollers. The feeder includes mounting plates conforming to the shape of the printer print station for removably mounting the feeder. A gear is attached to the friction feed rollers and supplies rotary motion to a pair of drive rollers via an intermediate drive train. A pair of spring loaded guides having integral sides formed therein urge individual cut sheets of media out of an input media support tray and into the printer. The drive mechanism includes a pin and key drive assembly to maintain media spacing. Deflector means and an output tray are provided which automatically collect and collate the sheets of media emerging from the printer.

Abstract: A visible spectrum radiation measuring apparatus achieving an absolute measurement utilizing a plurality of inversion layer silicon photodiodes in a configuration wherein light reflected from the surface of a photodiode impinges on another photodiode, and its respective reflected light impinges on another photodiode, such that each time the light impinges on a photodiode surface a portion is absorbed, and that ultimately most of the light of the beam being measured is absorbed.

Abstract: A method for monitoring the alignment of the read-write head of a magnetic media data storage device comprising the steps of: establishing an elasped time window during which the read-write head should pass through a predetermined position if the head alignment has not drifted; checking to determine if the actual time at which the read-write head passes through said position actually falls within said window; and providing a pair of signals for indication of alignment or misalignment.

Abstract: A standardized, calibrated drop-out disk is provided to test disk certification equipment. The disk is a previously certified high quality disk having one or more selected tracks thereon upon which data is recorded at a standard level over some portions of the track and at differing levels on other portions of the track known as drop-out portions. The magnitude and playback amplitude of the drop-out portions is selected to be less than that of the remaining portions of the track. Methods of creating the standardized drop-out disk utilizing either varying write currents delivered to the head for the different portions of the track and/or write heads of different width being utilized are also provided. The standardized drop-out disks are utilized to test the sensitivity and accuracy of disk certification equipment as it is used to test production of magnetic disks.

Abstract: An improved microwave multi-throw switch incorporating PIN diodes wherein the PIN diodes are mounted orthogonally to the conductive stripline.

Abstract: A solar heat exchanger having a mesh sandwiched between two thin films for transfer of radiant solar energy to a fluid drawn through the mesh by suction.

Abstract: A system for the metered pumping and dispensing of fluid includes a filter for the pumped fluid and a pump connected to the filter. The pump is of the displacement type which includes a tubular, longitudinally-contractable bellows to receive fluid for pumping, fluid-activated reciprocating means to expand and contract the bellows, and means to selectively introduce working fluid to the reciprocating means. A rigid fluid-tight chamber is formed to surround the bellows, and means are provided to selectively introduce working fluid into chamber, whereby the working fluid assists in contracting the bellows as well as in partially balancing the internal pressure on the bellows.

Abstract: A loadlock apparatus for a workpiece processing chamber such as those incorporated in vacuum processing systems. The apparatus includes an isolation chamber having evacuation apertures and workpiece transfer apertures with independently operable doors for closing and sealing the workpiece transfer apertures and an independent operable workpiece transfer mechanism. The doors and workpiece transfer mechanisms may be contained within the isolation chamber and the chamber may be closed and sealed while containing a workpiece. The door and workpiece transfer mechanisms may be adapted such that they are not positioned over the workpiece, thereby reducing the possibility of workpiece particulate contamination.The preferred embodiment of the workpiece transfer mechanism moves a workpiece through the isolation chamber along a path which is essentially a straight line.

Abstract: An automatic inflation system for use as an emergency locating system which is activated by the severance of an initiator wire which in turn begins the operation of a transmitter and a timer. Following a period of time as determined by the timer, a pair of electrically activated pyrotechnic thrusters are actuated and cause the rupture of seals on a pair of compressed gas storage cylinders which in turn results in the inflation of two sections of a twin mast, raising a radio antenna and radar reflective material. A radio transmitter is also activated at the start of the time delay with an emergency locating signal broadcast from the antenna, after the mast is raised. This system provides improved means of locating missing equipment when searched for by radio search, radar search, and/or visual search.

Abstract: An improved magnetic flexible disk for use in data storage is provided with a stabilized locating ring about the spindle aperture thereof. The stabilized locating ring is selected from an electrically conductive material having miniscule humidital expansion characteristics at normal use temperatures. The stabilized locating ring has an inside diameter precisely equal to the outside diameter of the drive spindle on the disk drive apparatus for which the disk is designed to be utilized. The locating ring is bonded onto an existing disk which has had its central aperture punched to be slightly oversized. The improved disk is characterized by its longer usable lifetime, substantially elimination of errors in registration and increased data capacity.

Abstract: A method for removing excess etchant from a work piece after the work piece exits an etching chamber. The steps include sensing the presence of the work piece as it exits the chamber and subjecting the work piece to a gas liquid spray to remove excess etchant, capture the excess etchant and recycle the captured excess etchant.

Abstract: A nitride etch bath having an inner vessel encapsulated within an outer housing with an electric heating element sandwiched therebetween. A condensing collar is heat sealed about the top of the inner vessel and supports a condensing lid hinged to the collar. The condensing lid includes an array of enclosed channels and canals in the top and bottom of the lid for transporting a condensing medium. As acid is boiled in the inner vessel, hot acid water vapors rise and impact the condenser lid which condenses the vapors to a liquid utilizing the condensing medium to cool the lid surface. The condenser lid and collar seal the inner vessel to prevent vapor leakage.

Abstract: A switching power supply in which the maximum power output is limited during various line voltages within a predetermined range on a cycle by cycle basis. The power supply comprises a transformer in which an alternating current voltage is applied across the primary winding thereof. Switching means are connected in series with the primary winding. The repetitive conduction and non-conduction of the switching means controls the flow of current in the secondary winding circuit of the transformer for producing a direct current output voltage in the secondary winding circuit. Output voltage is produced in the secondary winding circuit during the interval the switching means is not conducting. For limiting the maximum power output in the secondary winding circuit during various line voltages, a control circuit controls the maximum conduction time of the switching means in response to the rectified voltage appearing across the primary winding of the transformer.