<br>Binary logic is, well, binary - either 1 or 0 and no in between. <br>The chips are often designed to prevent any ambiguous voltages (like 2.5).<br><br>What exactly are you trying to do?<br>There may be a simple analog way to do it <br>(like making a D/A converter with some <br>resistors to give you voltages in between 0 and 5V). <br><br>No switches closed = 2.5V, one switch closed = ?<br><br> - Chris <br> www.noisemantra.com<br><br><br><br><br>
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<table class="readtext" border="0" cellpadding="1" cellspacing="7"><tbody><tr><td bgcolor="#789be0"><div style="width: 1px;"> </div></td><td>-------Original Message-------<br>
From: Alison Lewis <lewischicken@gmail.com><br>
Subject: Re: [dorkbotnyc-blabber] Looking for the right off-the shelf component<br>
Sent: 19 Dec '08 20:48<br>
<br>
Lee:<br><br>Can I ask you something about these NOR gate ICs - I have one now (74HCT4002) and its pretty easy. But what if you have three states and only one output? I've tried a number of options, but it seems to me that I can only get either HI or LOW outputs from this IC. I'd like to have HI, LOW, and Middle (2.5V). I am thinking that a multiplexer is the right way to go, but I wanted to ask you first since you seem to know pretty well.<br>
<br>All my best,<br>Alison<br><br><br><div class="gmail_quote">On Mon, Nov 24, 2008 at 11:22 AM, Lee von Kraus <span dir="ltr"><<a href="mailto:leevonk@gmail.com" target="_blank" mce_href="mailto:leevonk@gmail.com">leevonk@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
use 'nor gate' ICs like the IC 7402<br><br>description:<br><a href="http://hyperphysics.phy-astr.gsu.edu/Hbase/Electronic/nor.html" mce_href="http://hyperphysics.phy-astr.gsu.edu/Hbase/Electronic/nor.html" target="_blank">http://hyperphysics.phy-astr.gsu.edu/Hbase/Electronic/nor.html</a><br>
<br>where to buy:<br>
<a href="http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=DM7402N-ND" mce_href="http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=DM7402N-ND" target="_blank">http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=DM7402N-ND</a><br><br>-Lee<br><br><br><br><div class="gmail_quote">
<div><div></div><div class="Wj3C7c">On Mon, Nov 24, 2008 at 11:07 AM, Alison Lewis <span dir="ltr"><<a href="mailto:lewischicken@gmail.com" mce_href="mailto:lewischicken@gmail.com" target="_blank">lewischicken@gmail.com</a>></span> wrote:<br>
</div></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div><div></div><div class="Wj3C7c">Hi all:<br><br>I've been asked to hack into a sensor that has four contacts (it acts somewhat like a hand built joystick to control a moving image). Basically, I am looking for a simple circuit that can do logic to know if any of the four contacts are closed. If they are all open, then it should send out 2.5 Volts. I can program a PIC to do this, but I was hoping there was an off the shelf solution out there somewhere. I was also thinking a timer could do the trick, but I am open to other suggestions if you have any. <br>
<br>Thank You,<br><font color="#888888">Alison<br><br>
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