Designing for Control Reliability in Safety-Critical Machine Controls

摘要

This is the third and concluding segment of a three-part series. Parts one and two appeared in the July and August 1996 issues. Electro-mechanical control systems, using relays as logic elements, were the first electrical control technology of any sophistication used on industrial machinery. A relay is a device that uses an electro-magnetic coil to open or close one or more electrical contacts, which can be used to switch electricity.