[SOLVED] Can someone help me build visitor counter only using analog circuit??

[aii]

I have a project to build analog circuit and my idea is to build visitor counter....but everytime i search for the schematic it is always using IC or arduino. But my class is analog so yeah can someone help me

 

[D.A.(Tony)Stewart]

Do you mean like an analog clock counter. Describe how it works.

 

[BradtheRad]

A) Make up a way to add a tiny amount of charge on a capacitor each time a pulse arrives. This is known as a charge bucket. Then build circuitry that reads the charge voltage on a meter.

B) A key element in counters is the clock-divide-by-2 circuit. This is not easy to build from analog components. Cascade several of these to serve as bits counting in a binary pattern. Read each bit with an led.

 

[Easy peasy]

infra red links across door ways are commonplace to buy - count the interruptions, divide by two to account for every one who enters also leaves ( the same way we assume ) this can be done on a cheap PLC.

 

[FvM]

In usual terminology, a counter is a digital circuit, no matter if it's comprised of IC or discrete transistors. A one-bit counter (T-flip-flop) can be made of two transistors and various passive components. The flips-flops can be cascaded to a ripple-carry binary counter. How many bits do you want to count?

Alternatively you could think of a real analog visitor monitor, an integrator with its output voltage getting increased by some amount for each event.

 

[aii]

Do you mean like an analog clock counter. Describe how it works.

So it supposed to be a visitor counter placed near the lift door, when certain amount of maximum person on the lift is hit the door will be close.
Sorry for my bad english but did you get it?

 

[aii]

A) Make up a way to add a tiny amount of charge on a capacitor each time a pulse arrives. This is known as a charge bucket. Then build circuitry that reads the charge voltage on a meter.

B) A key element in counters is the clock-divide-by-2 circuit. This is not easy to build from analog components. Cascade several of these to serve as bits counting in a binary pattern. Read each bit with an led.

Yeah i plan to replace the counter like on didgital clock with LED because it is an analog

 

[aii]

So it supposed to be a visitor counter placed near the lift door, when certain amount of maximum person on the lift is hit the door will be close
Sorry for my bad english but did you get it?

In usual terminology, a counter is a digital circuit, no matter if it's comprised of IC or discrete transistors. A one-bit counter (T-flip-flop) can be made of two transistors and various passive components. The flips-flops can be cascaded to a ripple-carry binary counter. How many bits do you want to count?

Alternatively you could think of a real analog visitor monitor, an integrator with its output voltage getting increased by some amount for each event.

I think about changing the digital counter to LED but the limit will only be at three so i am not using lots of it....but to achieve the same result can i change the IC to transistor? Or maybe there are something else to make it analog?

 

[betwixt]

I detect a misunderstanding now we know the application. You don't need a number count of visitors, only an indication of when a certain number of people are present.

You can do it entirely in analog circuitry. You need a sensor to measure either weight of the lift or pressure on its floor then measure it and use the result to operate the display and the door. If you use something like strain gauge or pressure mat to detect the people it will produce an analog voltage. You can display the voltage as a bar graph rather than a number using analog components and you can use a comparator to detect when maximum capacity is reached to operate the door.

It is an interesting problem that most of us would do digitally but if you are constrained to using analog there are still solutions.

Please be aware that in a real life situation you have to be able to detect people of different weight and you have to provide safety features and delays. For example you wouldn't want the doors to close instantly and crush someone!

Brian.

 

[KlausST]

Hi,

technically I´d say "analog" and "counter" contradicts itself.

Klaus

 

[danadakk]

Tricky design, not all people weigh the same, not all legs cross a threshold in series, one at
a time.

Have each person entering press a button - very accurate

Use image scan and algorithms to count heads....pretty accurate

Use processor to count feet patterns on x-y touch matt- fairly accurate

Hire a kid at elevator entrance to count, ADD kids excluded, fairly accurate

Funnel people thru a narrow entrance, one at a time - pretty accurate

Lift users have to have implaneted chips - Very accurate

Problem areas - different mass/person, dwarfs and midgets, babies, bats
flying around.....

To name a few.

 

[D.A.(Tony)Stewart]

ok try again to state your assignment. Using a google translator if possible. Correct the assumptions to define what is a MUST BE , or MAY BE

Whenever you are given an assignment, always be clear on assumptions from your "customer" in this case, your Prof. If not clear, ask others or your Prof.

I think your goal is to learn about analog weight sensors waiting for a count of 3 to close a door ?
The reference is some shift in weight above % Max and the counter is a key to trigger Close Door?

--- Updated Apr 28, 2025 ---

Hi,

technically I´d say "analog" and "counter" contradicts itself.

Klaus

Yes it looks like an oxymoron. An analog counter could refer to a device that counts analog events, like a Geiger counter, which detects continuous radiation events but tallies them discretely or fluid pressure gauge with a continuous level that integrates the input.

He must focus on how it should work and not work (non-events) and define better "design specifications".

 

[dick_freebird]

There's "analog" and there's "analog" but maybe the
course is really about designing with discrete devices.

A charge-gate and bucket would certainly be analog-ish.
But there are secondary concerns affecting initial accuracy
and over time.

Are there actual performance requirements beyond the
"behavior" (like, if the bucket leaks and you deliver 1.27V
when you had 128 entries, is that a pass or a fail or an
irrelevancy in context?)? Do you need to reset, ever?
How long does the "right answer" have to hang around?
Like that.

 

[aii]

I can't reply one by one but thank you everyone for helping me, may you all have a nice day

 

[betwixt]

I had in mind something like an LM3914 with one output connected to the door operating mechanism. Alternatively, as it only has to 'count' to three, use a quad comparator to sense the weight.

Brian.