Coin Mechanism

Thread Starter

Nicholas K. Heinrich

Joined Feb 25, 2012
102
I found a silver plated, steam lcomoitve shaped piggy bank. Its called a "Puff Puff" bank on the box, but it does not puff smoke. So Ive set out to make it do so. I have the smoke unit, light, restart timer, and power supply already worked out. The restart timer is triggered by a momentary pushbutton switch, once the switch is pushed, it turns on power to the smoke unit and light for one minute. I planned to replace the pushbutton switch with a photoresistor and a laser, so that when a coin was dropped in a laser would be blocked, causing the photresistor to become conductive and close the cicuit, acting just like the switch. This was great until I found out that photoresistors become conducticve when they are exposed to light, not when it is blocked. I need a way of causing a coin to momentarily complete a circuit, without using the coin as a conductor (hence the laser idea).
Please help, I am confused on how to accomplish this.:confused:
 
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Pencil

Joined Dec 8, 2009
271
I planned to replace the pushbutton switch with a photoresistor and a laser, so that when a coin was dropped in a laser would be blocked, causing the photresistor to become conductive and close the cicuit, acting just like the switch. I need a way of causing a coin to momentarily complete a circuit, without using the coin as a conductor (hence the laser idea).
Please help, I am confused on how to accomplish this.:confused:
I'm thinking instead of photoresistor you could accomplish this easily
with a phototransistor. The laser could also be replaced with an IR LED,
or maybe even another color of LED, depending on the specs of the
phototransistor. We'll need to know what components you have access
to, and specs on the various devices that will be driven in order to
work this out.
 

Thread Starter

Nicholas K. Heinrich

Joined Feb 25, 2012
102
I'm thinking instead of photoresistor you could accomplish this easily
with a phototransistor. The laser could also be replaced with an IR LED,
or maybe even another color of LED, depending on the specs of the
phototransistor. We'll need to know what components you have access
to, and specs on the various devices that will be driven in order to
work this out.
Thank You for your help, and I can get my hands on an IR led fairly easy. I will get the led and post its specs tomorrow, and hopefully you can guide me to a phototransistor based on that. Here is the link to the restart timer with the pusbutton switch to be replaced with the coin sensor: http://www.canakit.com/restart-timer-kit-ck197-uk197.html
 

Thread Starter

Nicholas K. Heinrich

Joined Feb 25, 2012
102
Also, this bank is going to cost me quite a bit of money, and is very special to me. My experience with things made in china is that they break, no offense, but I try to buy from my own continent.
 

Pencil

Joined Dec 8, 2009
271
The message from the Chinese supplier is spam.
Pay no attention to that. That post will most likely
disappear shortly as I have reported it.

I will get the led and post its specs tomorrow, and hopefully you can guide me to a phototransistor based on that.
I'd hold off on any components until more details are worked out.
The components need to be selected after the circuit is designed.

What will you you be using for power? Batteries? Wallwart (transformer
that plugs into the wall)? Other?

Do you have the restart timer in your possesion yet? It looks to be an adjustable
555 monostable from the description/photos. Probably going to have to do some
testing to verify the trigger pulse. All part of the process.

Where are you planning to get components from?
 
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#12

Joined Nov 30, 2010
18,076
Wallwart is such a well known term that I don't know the "real" name for these devices!
 

#12

Joined Nov 30, 2010
18,076
I am grateful that the only time this site gets a dogpile going it is directed at a spammer :)
 

Thread Starter

Nicholas K. Heinrich

Joined Feb 25, 2012
102
I do not have the restart timer in my posession yet, and I plan to get my components from radioshack/radioshack.com/or other internet site
 

Pencil

Joined Dec 8, 2009
271
Radio Shack has (or had) a phototransistor. I have
a couple here for testing if needed.

If you want, you may be able to make a circuit instead
of buying the restart timer. All the parts would be available
locally, although when all is said and done the cost savings
may not be that great (factoring in buying components at
greatly inflated prices from Radio Shack and a few missteps).
It depends on your comfort level, we'll try whatever you want.
There are other suppliers on line that are more reasonable on
price, but minimums and shipping may come into play.
 

Thread Starter

Nicholas K. Heinrich

Joined Feb 25, 2012
102
Thank You, I am all for trying to assemble my own circuit, although Ive never done one this complex, as it will allow me to better fit it into the odd space.
 

Pencil

Joined Dec 8, 2009
271
I am all for trying to assemble my own circuit, although Ive never done one this complex, as it will allow me to better fit it into the odd space.
To get started, look up "555 monostable". I believe this is the
type of operation you need. There are many sources on the web.
Here is a good one from one of our esteemed members right here
at AAC. 555 MONOSTABLE.

Here's another, 2/3 way down. Another 555 Monostable

Study a bit then get back. We can work this out.
 

Thread Starter

Nicholas K. Heinrich

Joined Feb 25, 2012
102
Ok, I will, thanks
I have reviewed the source you provided, and understood about half the words. I am not yet able to read cicuit schematics, so this is vey confusing. I am gathering that timing duration is based on the capacitors value?
 
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#12

Joined Nov 30, 2010
18,076
I'll bet that everyone with a hundred posts on this site can remember when they were going through exactly what you are doing.
 
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