Help required

Discussion in 'General Electronics Chat' started by xyz9915, Oct 7, 2008.

  1. xyz9915

    Thread Starter Member

    Feb 24, 2008
    Hi, the attachment is a schematic of SMPS built using IC TL494. The problem is that the capacitors C4,C5 get to much hot under full load. please guide what to do?
  2. scubasteve_911

    Senior Member

    Dec 27, 2007
    This is because your ripple current is joule heating the capacitors.

    Ensure your capacitors are meant for use in switching converters. They should specify the maximum allowable ripple current. For a quick fix, you can add in a couple more parallel caps. Did you have a bill of materials for this schematic?, or did you sub in many of your own parts?