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Ternary Punchcard Reader 
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Joined: 08 Jan 2003 23:22
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In April-May 2005 I got idea to build "ternary" punchcard reader that will use regular business cards as a "media" for ternary data (I have a lot of my old business cards ;) and 1-hole manual puncher to make holes in it:

Image

As you can see we may have 10 lines with 6 places for holes - lets recognize every 2 places as 1 ternary value - no holes for O (0), left hole for N (-1), right hole for P (+1) and two holes are invalid and must not be used:

Image

To build actual reader I purchased three 1-to-5 phone cable outlets in 1-dollar store to take "pins" from it ;)

Image

Scheme is really easy one - left hole will be connected to -5V and right hole will be connected to +5V. In 2007 actual reader board was finished and now I need to build whole device:

Image


31 Aug 2008 17:24
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Joined: 17 Sep 2012 13:36
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Interesting project.

I think it should be possible to achieve greater data density and human readability by using two hole dimensions (big holes for P, small holes for 0, and no holes for N). This might cause greater error frequency though, since the holes need greater precision, and the likelihood of misreadings and short circuits should increase somewhat.


01 Sep 2008 03:56
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eudoxie wrote:
Interesting project.

I think it should be possible to achieve greater data density and human readability by using two hole dimensions (big holes for P, small holes for 0, and no holes for N). This might cause greater error frequency though, since the holes need greater precision, and the likelihood of misreadings and short circuits should increase somewhat.


I thought about something like this but decided that 2-hole approach is simpler and more reliable because it allows using of regular 1-hole puncher (that can be bought in almost any store) and manual not so precision force :)


01 Sep 2008 05:21
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Hi,

Just one query:
Do we have any device which can convert AC signal to -1,0 and 1, instead of DC.


01 Sep 2008 05:51
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hemuman wrote:
Hi,

Just one query:
Do we have any device which can convert AC signal to -1,0 and 1, instead of DC.


Do you mean ADC or just -5V/+5V power supply?


01 Sep 2008 06:22
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I mean -5v/+5v to -1,0,+1


01 Sep 2008 06:54
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hemuman wrote:
I mean -5v/+5v to -1,0,+1


Hm, at least all my ternary hardware is doing this - converting analog signal (weak and distorted ternary signal that becomes noisy analog in relatively long cables) to -1,0,+1 in form -5V,0V,+5V :)

Probably you mean ADC (Analog-to-Digital Converter) so look at this.


01 Sep 2008 07:23
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Yes. I was looking for the same.

Thanks,


01 Sep 2008 07:35
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hemuman wrote:
Yes. I was looking for the same.

Thanks,


If you are talking about 1-trit ADC then it's probably just a buffer (ternary buffer):

Simple ternary buffer by Ronin (Apr 2005):

Image

Ternary buffer by Shaos (Dec 2004) with additional outputs:

Image


01 Sep 2008 13:36
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I was actually looking for below:

Image


02 Sep 2008 00:05
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hemuman wrote:
I was actually looking for below:

Image


Yes, it's a buffer - second one (2 comparators and 2 diodes) will work exactly the same way (output BUF) and you can even choose thresholds by changing resistors' values:

Image


02 Sep 2008 06:26
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I am not good at electronics, but I will try to understand.

how about the imaginary device

Thanks,


02 Sep 2008 07:32
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hemuman wrote:
I am not good at electronics, but I will try to understand.

how about the imaginary device

Thanks,


Your imaginary device is a ternary buffer, no?

Code:
if(Uin > +2.5) Uout=+5.0;
if(-2.5 >= Uin && Uin <= +2.5) Uout=0.0;
if(Uin < -2.5) Uout=-5.0;


02 Sep 2008 17:53
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Yes,
i wanted to behave it like that.

Thanks,


03 Sep 2008 00:22
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hemuman wrote:
Yes,
i wanted to behave it like that.

Thanks,


OK, so my ternary buffer actually is what you want


03 Sep 2008 19:46
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