SCR Load Placement

Discussion in 'General Electronics Chat' started by DC_Kid, Mar 3, 2008.

  1. DC_Kid

    Thread Starter Distinguished Member

    Feb 25, 2008
    can the load be placed on cathode side of a SCR? i am using bi-color LED's that have common cathode (ground) and i need to be able to latch on one side of the LED. with common cathode LED i have to control the anode side.

    let me clarify (will this work).
    Code ( (Unknown Language)):
    3.                                      gate
    4.                                        |
    5.                                        |
    6. +V----voltage drop resistor-----anode/SCR/cathode----anode/LED/cathode-----ground
    7.                             |
    8.                             |
    9.                             |
    10.                             ------- NO switch ----ground
  2. Ron H

    AAC Fanatic!

    Apr 14, 2005
    That should work, but your gate drive voltage will have to overcome the LED drop plus the gate-to-cathode drop of the SCR. If you are triggering from a 5V source through a current-limiting resistor, it should work.
    You could also trigger through a transformer with the secondary connected gate to cathode with an antiparallel diode, or you could use an optocoupler.