+ Post New Thread
Page 2 of 2 FirstFirst 1 2
Results 21 to 22 of 22
  1. #21
    Full Member level 4
    Points: 1,473, Level: 8

    Join Date
    Sep 2016
    Posts
    227
    Helped
    1 / 1
    Points
    1,473
    Level
    8

    Re: Driving Induction motor using TRIAC

    Quote Originally Posted by venkates2218 View Post
    For clarification i'm asking,in the document which you provided about snubber,in many circuits they used the RC across the TRIAC,but here we are taking an tap after RESISTOR.
    What's the difference between RC across TRIAC and taking TAPPING after RESISTOR..?
    If we replacing the TRIAC by relay to control motor means also need snubber..?



    •   AltAdvertisment

        
       

  2. #22
    Super Moderator
    Points: 250,835, Level: 100
    Awards:
    1st Helpful Member

    Join Date
    Jan 2008
    Location
    Bochum, Germany
    Posts
    43,673
    Helped
    13283 / 13283
    Points
    250,835
    Level
    100

    Re: Driving Induction motor using TRIAC

    The X2 Capacitors cost 3 to 4 USD. Why not simply use 40A type snubberless TRIAC ?
    47n or 100 nF/275 VAC X2 capacitors from major manufacturers are starting below 50 cent, single quantity at catalog distributors.

    Snubbering the triac is one point and never wrong with inductive loads, although not necessarily required.

    What's the difference between RC across TRIAC and taking TAPPING after RESISTOR..?
    Opto triac dV/dt sensitivity is the other point, and usually more critical. That's why a suggested a modified snubber/filter circuit in post #11. It's discussed in detail in the linked Onsemi application note. With a 220 ohm series resistor, it's absorbing transients across the triac to some extent and to a greater degree filtering the opto triac input voltage. The circuit proved useful for me, but it's surely not the only way.



--[[ ]]--