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How is the switching circuit in the power section of an AC output module operated to switch power ON and OFF in PLC?

How is the switching circuit in the power section of an AC output module operated to switch power ON and OFF in PLC? Correct Answer <span style="">Either by using a TRIAC or SCR</span>

Advantages of TRIAC or SCR as switching circuit in power section:

  • Triacs are electronic components that are widely used in AC power control applications.
  • They are able to switch high voltages and high levels of current, and over both parts of an AC waveform.
  • This makes triac circuits ideal for use in PLC modules where power switching is needed.
  • The fact that the triac switching action occurs on both halves of an AC waveform means that for AC electronic switching applications, the complete cycle can be used.
  • Due to the wide variety of advantages, like ability to turn ON from OFF state in response to a low gate current and also able to switch high voltages, makes the SCR or thyristor to be used in a variety of applications including switching, rectification, regulation, protection, etc.
  • The SCRs are capable to control the power transmitted to the load.
  • It is often required to vary the power delivered to the load depending on the load requirements such as motor speed control and light dimmers.

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