Hello,

I'm looking for a counter that will count up, only one count each time a hand goes into a box and touches a meteorite exhibit at a science center.

A counter is needed that will keep its count information even if power has been taken away, yes non-volatile memory. I want to keep track how many times a meteorite has been touch by the public, there is 1.2 million vistors each year. Maybe only 200,000 per year will trigger the counter or more.

If you don't know where I can get something like this. I hope someone will know who will, I really want to make this happen

Please help me in this matter.


Sincerely,
Tim

A 99¢ solar powered calculator fed by a long life battery instead of relying on its solar cells will keep the counting alive for very, very long time.

Introducing the value 1 (one) on memory, if the hand-in-the-box sensing circuit triggers the calculator M+ key, you have a digital counter.

Miguel

Originally Posted by Rolf

The $1.00 calculators I have found lately have NO solar cell, just a picture of one!
But they do have a battery; aren't those Chinese SOB's clever.

A guy at work bought a portable USB charger (to charge USB devices from a battery anywere) that had a few unwired coils and relay things inside to make it look complicated and a piece of rusted metal to add weight.

Originally Posted by Willbe

So you need a non-volatile memory.

How accurately do you need to read the count? Better than 1%? 5%?

What accuracy do you expect adding 1 + 1 in a calculator?

A calculator is not an estimator.

Originally Posted by Willbe

So you need a non-volatile memory.

How accurately do you need to read the count? Better than 1%? 5%?

It does not need to be perfect, it would be a cool idea after 300,000 people have touched this counter display be seen by those who come to touch it.

A big read out, digital display for all to see. Maybe a big sign that says you are the 300,000 person to touch this, next person, you are the 300,001 person to touch this

Originally Posted by Willbe

OK.
Non-volatile memory.
Six or seven digit display.
Each digit resolvable (no rounding)
Photocell sensing.

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This runs off the wall outlet or batteries?
Indoor environment?
High ambient lighting?
Any adverse environmental stuff - moisture, vibration, etc.?

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It needs to run on 110vac wired to a junction box with a battery back-up.

This counter would work http://www.electronickits.com:80/kit...lec/ck1612.htm with 12vdc but I need a photocell circuit to trigger counting or a touch alarm circuit.

I can do a 12vdc 7 AH lead acid battery with a battery charger to keep battery charged, they use these in home alarms.

That lead acid battery and charger combo I think would work well to power it. Unit will be used in an Indoor environment, not a brightly lighted room, no moisture or vibration.

Maybe I can use this 12vdc touch alarm circuit to trigger counting http://www.uoguelph.ca/~antoon/circ/alarm2.htm

The idea here is when you finger touches the hole where the Mars Meteorite is (around that hole is a small metal ring that triggers a count) it counts up one


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These chinese are something ! Adding scrap metal, useless parts, faking a solar cell...

Seen 11 inch x 8 inch very large digits display/large buttons calculators at the 99 cent store too, perhaps with some luck you can find those ; or ordering on the net.

Like this----> http://www.amazon.com/Digit-Display-.../dp/B000WSL87E

Miguel

Hi easytim,

did you notice that the counter you mentioned has only four digits for display? To count up to 999,999 six digits are required.

I suggest making an own design cascading six CD40110 decimal counters. To clock the counter you might use an IR-barrier arranged the way that only hands touching the metorite can trigger the counter.

For display you might use Kingbright 7-segment LEDs of 100mm height. (package height 122mm)

Hans

Originally Posted by Boncuk

Hi easytim,

did you notice that the counter you mentioned has only four digits for display? To count up to 999,999 six digits are required.

I suggest making an own design cascading six CD40110 decimal counters. To clock the counter you might use an IR-barrier arranged the way that only hands touching the metorite can trigger the counter.

For display you might use Kingbright 7-segment LEDs of 100mm height. (package height 122mm)

Hans

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Please read more, you can use two, then it will give it 8 digits. Thats some great ideas you have given me THANKS






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Hi easytim,

I've already designed a schematic and layout for the six-digit-counter. Is the 4-digit-counter built the way that two of them fit together to make them look like one display?

I also have a circuit and PCB-layout for an IR-barrier to be used for object recognition in a can crusher.

This is what the 100mm display looks like. Power supply connector and RESET-button are on the right hand side. The counter & decoder ICs are underneath the display.

Regards

Hans