Archival room control

Discussion in 'The Projects Forum' started by Eplanet, Oct 28, 2007.

  1. Eplanet

    Thread Starter Active Member

    Oct 25, 2007
    hello dears
    I want to make an Archival room control device that see how many persons entering to archival room with counter above it.
    keep in mind that a person that enter to this room i am sure that coming out in moment time but when person coming out don't should counting.
    look at this picture.
    do you have any circuit for this issue?
    thanks Eplanet
  2. Ron H

    AAC Fanatic!

    Apr 14, 2005
    Is the PIR adequate for this purpose? If you can be certain that every person who approaches the door enters, and that only one person at a time is in the field of the PIR, you can simply divide the output of the PIR by two before counting, i.e., when a person enters, increment the counter. When they leave, don't increment the counter. If two persons are in the room at the same time, the count will be temporarily wrong, but it will eventually get corrected.
    However... What if a person approaches the door, but then turns around and leaves? What if two (or more) people approach the door and enter at the same time?
    It seems like two beam-breaking sensors would be better. Then you can determine direction, and you can ignore cases where a person breaks one beam but not the other.
    I can imagine scenarios where the count could still be wrong, such as when two people break the beams going in opposite directions. Maybe that's why turnstiles were invented.:)
  3. Eplanet

    Thread Starter Active Member

    Oct 25, 2007
    i want this device have reset counter that i reset in every morning and i want to know how many people in one day enter to archival room and two people can't enter to room at same time and this room not in the end of corridor.
    if accidentlly two people enter to room in the same time we can install this device within the room or not in the out of door.
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    Possibly you could use a pair of light beams - one inside and the other outside the door. With a bit of separation between the beams, the passage of a body into as opposed to out of the room could be distinguished. That would let you keep an absolute count, and run another counter with count up and down functions used. If it shows zero at the end of the day, then all bodies are accounted for.