• Home
  • Download PDF
  • Order CD-ROM
  • Order in Print
Example 1 - h1016v2_64
Example 2 - h1016v2_66

Engineering Symbology Prints and Drawings Volume 2 of 2
Page Navigation
  39    40    41    42    43  44  45    46    47    48    49  
Logic Diagrams DOE-HDBK-1016/2-93 TRUTH TABLES AND EXERCISES Rev. 0 Page 15 PR-05 1. Identify by number the following logic symbols:               a.   AND               b. OR               c.   Time delay               d.   Retentive-Memory 2. How long must the safety signal be present before the time delay (1) will pass an output (on) signal to Gate 2? 3. Under what conditions will Gate 2 turn on? 4. Under what conditions will the low flow alarm (5) sound? 5. Since  the  control  switch  is  always  in  the  AUTO  position  (due  to  the  spring  return feature), what logic gate keeps the continuous on signal that is generated by the control switch being in the AUTO position from starting the fan?  What signal must also be present to allow the AUTO signal to start the fan? 6. If  12  minutes after first receiving a safety signal, with the fan control switch in the AUTO position, the safety signal is removed (off), what will happen to the fan?  Why? 7. How many ways can the fan be started?  How many ways can the fan be stopped?







Western Governors University

Privacy Statement
Press Release
Contact

© Copyright Integrated Publishing, Inc.. All Rights Reserved. Design by Strategico.