Despite the temptation, size alone is not the right descriptor for ac "microdrives"—those ultracompact variable-frequency drives (VFDs) that sprouted during the first-half of the 1990s. For quite a while, it seemed, each new model would be even more miniature than the one announced just a month or so earlier.
Avon, Mass.—Custom engineered for severe service application, V-LOG trim provides staged pressure reductions through a series of discrete flow channels combining 90° turns with intermediate expansions and contractions within the flow passage. Energy levels are efficiently managed and dissipated during the pressure reduction process, eliminating valve problems.
Boeing Explores Development of ‘Smart’ Transducer Bus Lee Eccles of Boeing Commercial Airplane Co. began his presentation in the ‘Use of Automation to Enhance Productivity in the Aerospace Industry’ by asking the question ‘why bother?’ In structural sensing and testing of airplane wings and fuselages at Boeing, a lot of effort goes into simply setting up the test. Structures for destructive testing of a wing or testing flight-control actuators require huge setup times.
KEY WORDSMotors, drives, & motion controlAC variable-speed drivesAC induction motorsAdaptive controlControversial right from their name, "sensorless" ac drives actually use current and voltage sensors to achieve motor control. Even beyond terminology, it's not obvious what sensorless ac drives can or can't do, and where they fit into the big picture.
KEY WORDS Process control and instrumentation Process sensing Pressure sensing One of the most-used sensors, pressure instrumentation is found nearly everywhere now. The old process standby is still there—chemical change-of-state monitoring still requires tracking such mundane variables as pressure and temperature—but it now can be found, however tiny, in manufactured goods from au...