PSPICE for an alarm design

Discussion in 'Homework Help' started by DancingDevil, Nov 25, 2012.

  1. DancingDevil

    Thread Starter New Member

    Nov 25, 2012
    Hi all! :)

    I have been asked to create a PSPICE simulation for an alarm that I designed as part of a project. There are two parts to this project. The first project required that we create an alarm system composed out of the given list:

    1000 1Ω Resistors
    12 Rechargeable AAA Batteries (1.5V)
    A 2900 Hz piezoelectric buzzer that draws 15 mA at 6V
    100Ω Wire

    The goal was to design a circuit with no switches that set off the buzzer if the window around which it was placed was breached.

    My design (A diagram attached) was made so that I used all 12 AAA batteries. Based on the diagram, The current that ran through my circuit was 0.0321 A, the power it consumed was 0.289W and the time between recharges was 3 days and 3 hours.

    As I am unable to attach the design, I will outline the system. There was the buzzer's resistance in parallel with the resistance of the wire. These two in turn were in parallel with the 200 Ω resistors.

    The second design is a spinoff on this one. All components used in part I are used again, in addition to a capacitor with a value of our choice.

    I found my capacitance using the formula tau = RC, where tau = 6 seconds and R is 280Ω. This gave me a capacitance of 0.021 F.

    We are supposed to calculate the maximum time that the system can monitor the window as well as a PSPICE simulation. We need to display the DC voltages and currents for the monitoring and buzzing stage by plotting the buzzer voltage against time before and after.

    This is the part that I am stuck on.

    Doing this will help me boost my grade, which is quite poor in this class. :(

    Thank you to all who take the time to read this and help :)