plz help me out........coin sensors ??????????

[muralistarshine]

hi frends
i am doing my project of final semester,,,,,,,to collect money automatically for this i require coin sensors to differentiate 1 re and 5 re . my idea is to use weight sensor but can i get accurate result which is needed or else any idea suggest me................i am running out of my ideas too badly i was desperate to know this

 

[dougy83]

I have seen commercial coin slots that measure the time it takes for the coin to roll down a ramp. I would assume that the coin would enter the ramp vertically to reduce any affect the user has on the coin speed (e.g. it they push the coin in the slot quickly or slowly).

 

[haxan]

I have seen commercial coin slots that measure the time it takes for the coin to roll down a ramp. I would assume that the coin would enter the ramp vertically to reduce any affect the user has on the coin speed (e.g. it they push the coin in the slot quickly or slowly).

Doesn't everything fall down vertically at the same rate irrespective of its weight? (read it somewhere in science class 5th grade but its possible that laws change)

I have heard of something that revolves at a constant rate and you drop in coins into it and it separates everything according to its mass into several pockets. (some airports maybe use it to count coins and also separate original ones from fake)

 

[dougy83]

Doesn't everything fall down vertically at the same rate irrespective of its weight? (read it somewhere in science class 5th grade but its possible that laws change)

Oh, you're still in 5th-grade science class?

As for falling rate, that's not important. Once the coin has fallen onto the start of the ramp, it then starts rolling with a horizontal velocity component. Different size & weight coins will roll at different speeds; or so I've been led to believe. I will have a look for info.

 

[Brevor]

I used to work for a company that made coin acceptors. The coins would roll down a ramp past coils and the device would measure frequency shift, amplitude shift and permeability using 3 gated oscillators. Dougy83 is correct in that a double ramp is used to bring the coin to a dead stop before it enters the second ramp where the measurements are done. This eliminates speed variations. This is probably too complicated for a student to do. If the coins you want to measure are different diameters maybe you could use some led's and photosensors to measure the diameter.

 

[haxan]

Oh, you're still in 5th-grade science class?

dougy83 i was not trying to offend you or anything, just wanted to put an idea out there (in which i could be completely wrong) however because you said:

I would assume that the coin would enter the ramp vertically to reduce any affect the user has on the coin speed

Thats why i said that.
I have the most respect for anyone who is helping others on forums.

I think the scientist's name was gelilio.

 

[bryan1]

An easy make to make a coin sensor for different sized coins, make a slide that is just a bit wider than the coins. Put a slotted hole the size of the smallest coin then another slot to suit the bigger coin and so on. A simple photo transistor placed under each slot will pulse every time a coin goes thru.

A quick easy to do a final year project.

 

[Vizier87]

Are you using microcontrollers? Sensors alone ain't gonna make sense. Like the previous posts, try IR sensors.

 

[bryan1]

Are you using microcontrollers? Sensors alone ain't gonna make sense. Like the previous posts, try IR sensors.

Vizier,
Do you think I would give all the details for a final year project ???? I only give a snippet and a simple solution so the op can figure the rest out for himself. If he can't then he shouldn't bother asking in here again.


Cheers Bryan

 

[muralistarshine]

**broken link removed**
kindly check the above link and help me out
i need information coin sensors to be used regarding this project
so plz help me in respect to this project

 

[Vizier87]

Well, starshine, the link seems detailed enough. If you don't have a clue at all, start with the microcontroller basics first.
Better if you specify on what is it that you don't know.

Brian, a bit of detail doesn't hurt. We're all noobs once (I'm still one by status in this forum) so go easy.

 

[muralistarshine]

"we have to make coin box exactly same as used in pco coin box machine fixed on railway station or else whare. We have to make two coin size holes one for one rupee, and other for five rupee coin. You have to fixup coin sensors on these holes, one sensor should be fixed for five rupee coin and one sensor for one rupee coin." this was the more confusing part in the my project section.

so i need what kind of sensors do we use what opts most for this purpose?????????????plz check this out and help me yaar

 

[Oznog]

The coin sensor part is quite difficult to invent.
No, velocity cannot be used, because all objects fall at the same rate. This is true even when rolling down a ramp, one small exception being that wider or heavier wheels have rotational inertia which loads down the acceleration somewhat, but I doubt that's reliable.

I'm not sure how they make it work, but it works. I think you need to research coin detectors, maybe find one on a video game or whatever to take apart, and/or research on Google Patents. Are you plagiarizing someone else's work? Yeah, probably. But it'll have to be because reinventing a workable coin sensor with no idea about how they work is just not going to happen. Also, the mechanical work is far more significant than the electronics portion.

In fact buying a module, or recovering one from a scrapped machine, and putting it in your project is vastly more practical.

OK, looked at your schematic. Your project doesn't hinge around the design of a coin counter, the electronics are your contribution. SO... by all means, find a coin counter. If you're poor, try to talk to an engineer at one of the companies, and see if you can sweet-talk them out of a product sample or out of any old equipment they might have lying around.

 

[muralistarshine]

Well, starshine, the link seems detailed enough. If you don't have a clue at all, start with the microcontroller basics first.
Better if you specify on what is it that you don't know.

Brian, a bit of detail doesn't hurt. We're all noobs once (I'm still one by status in this forum) so go easy.

plz help me out reeeeeeeeeeeee

 

[muralistarshine]

plz help me out reeeeeeeeeeeee

can i use distance methodology to detct vehicles.....for large vehicles both sensors are interrupted and for small vehicles only one of themmmmmmmm

 

[MrNobody]

Hmm.. if there are 2 small vehicles back to back, both of the sensors will detect the vehicles and will think that it is a large vehicle.. right..?

 

[muralistarshine]

Hmm.. if there are 2 small vehicles back to back, both of the sensors will detect the vehicles and will think that it is a large vehicle.. right..?

but its a very ideal case re
as it is tolll gate no vehicle can enter zone while one is going

could it be possible using two ir sensors at a distance?????can it gie sense
help me out reeeeee

 

[MrNobody]

but its a very ideal case re
as it is tolll gate no vehicle can enter zone while one is going

could it be possible using two ir sensors at a distance?????can it gie sense
help me out reeeeee

If that is the case, then I don't see why not.. Where are you going to place the IR transmitter and the receiver? Do take note that black colour will not be able to reflect IR light.. Do also take note that reflected light (sunlight bouced off walls/objects) might result in false positives/negative..

 

[3v0]

Hayato and I worked the OP on chat the day he first posted this thread.

If I remember correctly the coins have a slightly different alloys that might be detected using a hall effect sensor on top the coin and a PM under it.

The composition of one of the coins has changed so one would be detecting 3 alloys.

I do not see where that has been mentioned here. But I only skimmed.

 

[muralistarshine]

Hayato and I worked the OP on chat the day he first posted this thread.

If I remember correctly the coins have a slightly different alloys that might be detected using a hall effect sensor on top the coin and a PM under it.

The composition of one of the coins has changed so one would be detecting 3 alloys.

I do not see where that has been mentioned here. But I only skimmed.

i also got some problem regarding my project so that is what i posted here!!!!!!!!!!!please do solve the problem if u have got my problem and say whether it is feasible or nottttttttt