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a few questions about Digital Step-Km Counter circuit/help

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Newbie level 3
Sep 4, 2009
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digital step km counter

Hi friend
i have questions about below circuit & really need their answer soon

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_______10΅F 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]

1.the function of D1 with considering D2 function

2.why pin"14" of IC2 is grounded by C4?

3.if Q2 be in cutoff ,how is the function of D1?

4.function of Q1 in circuit dose D2 count(show) 50 & 100 meters (full function description )

6.IC1D with which logic state enable the circuit?

if its possible please describe the circuit and its elements briefly

Device purpose:

This circuit measures the distance covered during a walk. Hardware is located in a small box slipped in pants' pocket and the display is conceived in the following manner: the leftmost display D2 (the most significant digit) shows 0 to 9 Km. and its dot is always on to separate Km. from hm. The rightmost display D1 (the least significant digit) shows hundreds meters and its dot lights after every 50 meters of walking. A beeper (excludable), signals each count unit, which occurs every two steps. A normal step is calculated to span approx. 78 centimeters, thus the LED signaling 50 meters lights after 64 steps or 32 mercury switch's operations, the display indicates 100 meters after 128 steps and so on. For low battery consumption the display lights only on request, pushing P2. Accidental reset of the counters is avoided because to reset the circuit both pushbuttons must be operated together. Obviously this is not a precision meter, but its approximation's degree was found good for this kind of device. In any case, the most critical thing to do is placement and sloping degree of the mercury switch inside the box.

Circuit operation:

IC1A & IC1B form a monostable multivibrator providing some degree of freedom from excessive bouncing of the mercury switch. Therefore a clean square pulse enters IC2 that divide by 64. Q2 lights the dot of D1 every 32 pulses counted by IC2. IC3 & IC4 divide by 10 each and drive the displays. P1 resets the counters and P2 enables the displays. IC1C generates an audio frequency square wave that is enabled for a short time at each monostable count. Q1 drives the piezo sounder and SW2 let you disable the beep.


digital full counter circuit

i just know alittle about Electronics
would you tell where did you answer them?
or answer here too?

Added after 30 minutes:

please answer me i have no time :(

questions counters in digital

neverthought said:
i just know a little about Electronics
please answer me i have no time :(
It will take a couple of months for me to teach you some simple electronics but I have no time. Ask your teacher to teach you.

digital step / km counter

Audioguru said:
neverthought said:
i just know a little about Electronics
please answer me i have no time :(
It will take a couple of months for me to teach you some simple electronics but I have no time. Ask your teacher to teach you.

would you be my benevolent teacher?

kilometer cunter

neverthought said:
would you be my benevolent teacher?
I taught a few tricks to Noobs on these forums but some members here are actually real teachers. Maybe one will offer to teach electronics to you.

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