Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Cuk Converter

  1. Oct 7, 2014 #1
    Hi,

    I'm currently studying the topology of the cuk converter and I'm wondering why do you hhave to add that first inductor to the topology? Can't you just charge the capacitor straight through the voltage source?

    Thank you.
     
  2. jcsd
  3. Oct 7, 2014 #2

    analogdesign

    User Avatar
    Science Advisor

    If you didn't have the input inductor and connected the voltage source directly to the capacitor you would have a very large current spike. The first inductor acts like a current source so it kind of smooths the current going into the capacitor. This reduces loss.

    So, to summarize, if you connected the voltage source straight to the capacitor it would still work, but it wouldn't work very well.

    A useful exercise would be to simulate it in LT Spice or something similar. It's a simple circuit. Make sure you put a small output resistance for the voltage source (some fraction of an ohm). You'll see there is much more variation in the current without the inductor than with.
     
  4. Oct 7, 2014 #3
    Mhh... I get it! So the large current spike would dissipate in the resistance and you would lose a lot of energy right? Cool.
     
  5. Oct 7, 2014 #4
    Just imagine what would happen to the transistor if it is turned on and put directly across the voltage source...

    6power_014.gif

    Edit: circuit drawing :)
     
    Last edited: Oct 7, 2014
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Cuk Converter
  1. Boost converter (Replies: 2)

  2. Boost converter (Replies: 5)

  3. Buck converter (Replies: 5)

  4. Converter transformer (Replies: 3)

Loading...