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

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ssrssd

New Member
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]
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Questions
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

5.how 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.

thanks
 

audioguru

Well-Known Member
Most Helpful Member
Your questions are much too simple:
1) Why does it have D1 to display how many hundreds of meters and have D2 to display how many thousands of meters????
2) C4 is a capacitor that does not ground anything. It is the supply bypass capacitor that keeps the battery voltage fairly stable so it doesn't bounce all over the place.
3) What does Q1 drive and why?????
 

ssrssd

New Member
its not a homework but i must explain this circuit and i do not know electronics much
 

ssrssd

New Member
Your questions are much too simple:
1) Why does it have D1 to display how many hundreds of meters and have D2 to display how many thousands of meters????
2) C4 is a capacitor that does not ground anything. It is the supply bypass capacitor that keeps the battery voltage fairly stable so it doesn't bounce all over the place.
3) What does Q1 drive and why?????
ok i found you
d1 display up to 900 m and D2 up to 9 Km

Q1 drive Piezo sounder
you just answered one of this easy questions

but others remain ....
 
Last edited:

ssrssd

New Member
i have a limit time
i want to use others Knowledge but no one share
 
Last edited:

ssrssd

New Member
Isn't homework to demonstrate your knowledge and ability to study? Why didn't you study the coursework?
ok let see
they have just Taught us one electronic book.i am not a designer & did not design this circuit .nowhere i studied about this issues.
my teacher emailed me and asked this questions i had 5 or 6 hours to answer and clearly correct answer so i thought asking is one one of ways of learning but its seems you do not think so.
i knew somethings about them but i did not sure .
it was out of plan to ask this questions
 
Last edited:

audioguru

Well-Known Member
Most Helpful Member
I think teachers do not teach anything in some countries.
This teacher just e-mailed questions to the students and let the students find other teachers to teach them.
 

blueroomelectronics

Well-Known Member
What would happen if someone replied with all wrong answers.

Was the OPs plan just to post and wait?

Just a sidenote it looks like an old Graff / Sheets design or perhaps something from Radio Electronics.
 

blueroomelectronics

Well-Known Member
I think teachers do not teach anything in some countries.
This teacher just e-mailed questions to the students and let the students find other teachers to teach them.
sounds like a pretty cushy job.

Here's my effortless guess at the answers
1. Bunny
2. Happy
3. Monkey
4. Red
5. Red
6. Banana

These answers have a 99.9999% chance of being wrong.
 

ssrssd

New Member
Ok at least make an effort. Post what you think the answers are.
1.the function of D1 with considering D2 function?
Decade counter with decoded 7-segment display outputs drive D1 and after 9 digit pin"5" give out 1 and D2 show 1 Km

2.why pin"14" of IC2 is grounded by C4?C4 provide needed voltage for IC

3.if Q2 be in cutoff ,how is the function of D1?i do not know

4.function of Q1 in circuit?driving pizo sounder

5.how dose D2 count(show) 50 & 100 meters (full function description )?i just know 100m but not 50 m

6.IC1D with which logic state enable the circuit?it enable by low to high transition
 

audioguru

Well-Known Member
Most Helpful Member
This same person posted this same assignment on two other websites.
 
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