Popular Articles (March 2015)Includes the top 50 most frequently downloaded documents for this publication according to the most recent monthly usage statistics.
This 9-Gc system used a microwave signal reflected from the surface of a rotating roll of paper or plastic film to detect irregularities in the outer layers of the rolled material. The microwave package comprised a klystron oscillator, silicon dector crystal, and flared wave-guide horn antenna. A standard laboratory oscilloscope was used as the ``receiver'' and display system. Examples of materials tested were: kraft paper, cellophane, polypropylene and polyethylene film. The cellulosic materials absorbed more energy and gave weaker reflections than the polyolefins. The minimum detectable surface ``ripples'' were 0.010 inch high. A simple radar of this sort is useful for the noncontacting monitoring of moving surfaces. It has been used to detect surface motion through heavy protective windows. View full abstract»
Cited by: Patents (1)
During the past ten years much effort has been expended on the development of fiber optic devices. Some of the more basic devices are used simply for transmitting light to remote areas. These are generally referred to as "light pipes." Other fiber optic devices are capable of transmitting complete coherent images through rigid or flexible fiber bundles from one area to another. View full abstract»
As a high-speed incrementer, the printed circuit motor, while less accurate than a detented incrementer, provides unusual flexibility and reliability with relatively simple input controls. This paper presents an analysis of printed circuit motor response to a unit step of input voltage for incrementing purely inertial and dissipative loads. Incrementing is stable and quite accurate if sufficient friction damping is provided. Input power requirements can be accurately predicted in terms of motor and load parameters, increment displacement, and increment time. Average power during an increment varies approximately as J2, Â¿2, and (1/T)4. Armature heating dictates maximum input power and incrementing rate. With external cooling and 120 watts average input power, a combined load of 0.009 oz-in-sec2 moment of inertia, 10.8 oz-in/100 rpm eddy current damping, and 20 oz-in friction damping was incremented at a continuous rate of 150 steps/sec for 5Â° increments with Â±6 per cent accuracy. View full abstract»