SCR triggering-Theory vs Practical

Discussion in 'General Electronics Chat' started by textu123, Feb 7, 2012.

  1. textu123

    Thread Starter New Member

    Jan 10, 2012
    This is about my electoric hobby.Thyristor may be old-fashioned device,and I can't find good articles about it on the web of my country.
    Refer to the figure of 'Phase-shifted signal triggers SCR into conduction.' from vol_3/chpt_7/5.html

    In the figure I mentioned,I attempted to adjust firing angles(infomation:single phase,half-wave rectification:AC Power eff 20V,60Hz,Load 50 ohms,SCR SF30F13). So,approximated Anode to Kathode as an infinite resistance and as(Gate to Kathode resistance)>>(variable ressistance ) . I also presumed that the angle of voltage E is always 0degrees.
    This estimation caused great gap between expressions and practical.

    I thought out 'Harmonics' 'remain voltage in C' 'firing distorts sine-wave' 'added harmonics on Voltage E' 'extended on-time to msec order unusually'

    Please tell me Major causes of this difference.