Digital step-KM counter

SOUL

SOUL

@soul-VYdXn7 • Oct 26, 2024
Guys, I've got a circuit for this device from "<a href="https://www.redcircuits.com/Page9.htm" target="_blank" rel="nofollow noopener noreferrer">Digital Step-Km Counter - RED - Page9</a>" , but there is problem... i.e., there's a buzzer which is to be sound when mercury switch is 'ON',(through walking)... BUT it beeps constantly...😡

Can anyone provide me the right schematic...? 😔
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  • Kaustubh Katdare

    Kaustubh Katdare

    @thebigk • Nov 7, 2009

    Inserting the circuit diagram below -

    [​IMG]

    R1,R3____22K 1/4W Resistor
    R2________2M2 1/4W Resistor
    R4________1M 1/4W Resistor
    R5,R7,R8__4K7 1/4W Resistor
    R6_______47R 1/4W Resistor
    R9________1K 1/4W Resistor

    C1_______47nF 63V Polyester Capacitor
    C2______100nF 63V Polyester Capacitor
    C3_______10nF 63V Polyester Capacitor
    C4_______10µF 25V Electrolytic Capacitor

    D1_______Common-cathode 7-segment LED mini-display (Hundreds meters)
    D2_______Common-cathode 7-segment LED mini-display (Kilometers)

    IC1______4093 Quad 2 input Schmitt NAND Gate IC
    IC2______4024 7 stage ripple counter IC
    IC3,IC4__4026 Decade counter with decoded 7-segment display outputs IC

    Q1,Q2___BC327 45V 800mA PNP Transistors

    P1_______SPST Pushbutton (Reset)
    P2_______SPST Pushbutton (Display)

    SW1______SPST Mercury Switch, called also Tilt Switch
    SW2______SPST Slider Switch (Sound on-off)
    SW3______SPST Slider Switch (Power on-off)

    BZ_______Piezo sounder

    B1_______3V Battery (2 AA 1.5V Cells in series)
  • adinickluv

    adinickluv

    @adinickluv-L3bAsE • Nov 7, 2009

    Is it a some kind of digital distance meter?
    Can somebody explain its working??
  • reachrkata

    reachrkata

    @reachrkata-FOcqhH • Nov 11, 2009

    Hmm !!!
    It is a bit tedious to explain this circuit, because there is a reason for each and every value of R & C used.

    Best is to use a simulation to check only the IC1A,B,C part with the transistors. That may give a clue to why your buzzer is always buzzing !!!

    -Karthik