Discussion in 'The Projects Forum' started by Edmunds, Aug 27, 2014.

  1. Edmunds

    Thread Starter Active Member

    Sep 27, 2010
    Dear all,

    Attached is a problem I'm struggling with. A and B are infrared signals that are to be routed to 4 different IR LEDs. One of the signals should be "always on" on all four LEDs (signal "B"). The user should be able to select (by means of switches S1 through S4), which of the LEDs if any will carry signal "A" along with signal "B".

    My understanding is that switching any of the switches on, will channel signal "A" to all 4 IR LEDs because of the permanent connection to "B".

    Can this be rectified with signal diodes like 1N4148 between signal "B" and each connection to 1 through 4 so that signal "A" would not "travel back" to signal "B" and thus would not connect to all other IR LEDs?

    Thank you for your time,

  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
    I'm confused about the statement of the problem. Are you wanting to switch IR signals that exist in some medium like air or a light pipe, or are you simply switching a DC current to power said IR LEDs?
  3. shteii01

    AAC Fanatic!

    Feb 19, 2010
    If B is "always on" on all four LED, then there is no place for A because all four LED are already ON. So we don't really care what A does, we don't care that A is OFF, we don't care that A is ON. A side note, when A and B are both ON, you might have too much current going to LED, which might burn LED out.