HMI, OI
ISA TECH/97 Highlights From Anaheim, Calif., Day Two
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.
Ground Loops and Their Cures
The National Electrical Code (NEC) defines a ground as 'a conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth, or to some conducting body that serves in place of the earth.' A ground loop can be defined as any objectionable current flowing in a circuit's ground or return path. Here is a short guide that will help identify possible sources of ground loops in your electrical systems and how to solve them. The simplest ground loop involves connection between two different earth grounds as shown in the top figure. With earth ground #1 at one potential, and earth ground #2 at a different potential, a ground loop current will flow in the loop as indicated.
Buyer’s Guide Information
Control Engineering Buyer's Guide 2000-01FREQUENTLY ASKED QUESTIONS... Q. How do I update my free listings?A.