RL on sinusoidal inverter

Discussion in 'General Electronics Chat' started by franticAAC, Apr 15, 2015.

  1. franticAAC

    Thread Starter New Member

    Jun 25, 2012
    28
    1
    Hi,
    i've found an old inverter schematic with an inductor and resistor on high mosfets' drain as figure below
    hbridgerl.jpg
    I try to reproduce it without RL circuit and mosfets become hot (80° over ambient) for conduction and switching losses as in my calculations.

    Then i tried to mount the RL circuit and temperature rise on mosfets was very low (30° over ambient).

    I did not understand how this circuit (RL red circle in figure) acts and how you can calculate component values.

    Could you help me? I don't found anything (tutorial or application note on this subject).

    This RL also allow me to increase switching frequency...

    Parameters:
    Fswitching=50Khz
    Pout=150Wrms
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,135
    1,786
    First question: What is the impedance of the inductor at the fundamental of the switching frequency, and at the first ten harmonics?
    Second question: What is the parallel combination of the 100 Ω resistor and the inductor at the fundamental and each of the harmonics?

    Is the light bulb starting to glow?
     
  3. franticAAC

    Thread Starter New Member

    Jun 25, 2012
    28
    1
    this is the link for 10u inductor (it is the first of the table)

    http://www.coilcraft.com/pdfs/MSS1210.pdf

    I don't know how to respond to your question... I just noticed that it acts up to 200KHz switching frequency.

    Could you explain me better? Thanks
     
  4. KLillie

    Member

    May 31, 2014
    126
    14
    Did you look up inductance? They kinda like you to do a little legwork on this site. I try not to ask a question on a circuit that's to far out of my league or I end up studying for days.
     
Loading...