Chapter 1 electro mecha device part 2

514 views

Published on

Published in: Education, Business, Technology
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
514
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
13
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

Chapter 1 electro mecha device part 2

  1. 1. Type of timer…cont 3) Solid state timer -time delay provided by solid state electronic device. -design as plug in module. -not suitable for outside environmental usage since it is encapsulate in epoxy resin for more protection. -since it is encapsulate, impossible to repair.
  2. 2. Type of timer…cont <ul><li>4) Programmable timer </li></ul><ul><li>- is a timer (timing function) </li></ul><ul><li>included in electrical </li></ul><ul><li>devices such PLCs </li></ul><ul><li>- Retentive timer -maintain </li></ul><ul><li>its current accumulated </li></ul><ul><li>time when its control input </li></ul><ul><li>is interrupted. </li></ul><ul><li>- Non retentive timer -Do not </li></ul><ul><li>maintain its current accumulated </li></ul><ul><li>time value when its control </li></ul><ul><li>input signal is interrupted. </li></ul>
  3. 3. Timing Function <ul><li>There is several timing function is available </li></ul><ul><li>inside the timers. </li></ul><ul><li>1) On Delay </li></ul><ul><li>2) Off Delay </li></ul><ul><li>3) One shot </li></ul>
  4. 4. On Delay (delay on operate) timer <ul><li>-Has a preset time period </li></ul><ul><li>that must been passed </li></ul><ul><li>after the timer has been </li></ul><ul><li>energized before any </li></ul><ul><li>action occur. </li></ul><ul><li>-On delay timer contact do </li></ul><ul><li>not change position until </li></ul><ul><li>the set time period passes </li></ul><ul><li>after the timer receive power. </li></ul><ul><li>-Once activated, it maybe </li></ul><ul><li>ON or OFF the load. </li></ul>
  5. 5. Example application of On Delay <ul><li>-maybe use to monitor patient </li></ul><ul><li>breathing </li></ul><ul><li>-timer use to sound alarm if patient </li></ul><ul><li>not take a breath within 10 sec. </li></ul><ul><li>-The circuit includes a low pressure </li></ul><ul><li>actuated switch build into patient </li></ul><ul><li>monitoring system. </li></ul><ul><li>-Low Pressure switch will activate if </li></ul><ul><li>the pressure less than 1 psi </li></ul><ul><li>(6kPA),means the patient start not </li></ul><ul><li>breathing. </li></ul><ul><li>-Means, the timer start timing and </li></ul><ul><li>continues until patient takes a breath </li></ul><ul><li>(which reset the timer). </li></ul>

×