can window comparator work here?

Discussion in 'General Electronics Chat' started by cheerzmiki, Aug 11, 2006.

  1. cheerzmiki

    Thread Starter New Member

    Aug 9, 2006
    Good day people.

    I've got some problem doing one of my project.

    And here goes,

    I am building a touch base input device for my project. And basically i came up with this idea of using a window comparator for the application.

    The list of component used:
    - touchpad (is basically a copper tracing which is a open circuit at first, refer to figure 1)
    - LM741 op-amp x 2pcs
    - 1kohm resistor x 2pcs
    - zener diode x 2pcs
    - 7408 AND GATE x 1pcs

    The result i wanted was that once i touch the touchpad, the output from the AND GATE must be a logic 1 and once i let go, it ouput must be a logic 0. (im comparing 6v and 1v respectively n' not 5v and 1v)

    And i tried quite a number of method to no avail.

    Am really quite stuck down by it.

    Any help would be grately appreciated

    figure 1: the touchpad
    figure 2: before implementing the touchpad to the window comparator
    figure 3: added in the touchpad to the comparator circuit




  2. thingmaker3

    Retired Moderator

    May 16, 2005