Subject:
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Re: Voltage problem
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Fri, 1 Aug 1997 16:57:29 GMT
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Original-From:
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Owen Wessling <owesslin@us.oracle.(IHateSpam)com>
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Viewed:
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1279 times
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Well, further experimentation revealed that the chips are working, but with a quirk:
If the the input of the '232 (pin 10) is tied to ground (pin 15), then the output (pin 7 of the
'232, or pin 3 of J9) goes to the expected value of ~+10 volts.
If, however, the input is tied to the -10 supply, then the output is only about 0 volts. I'm
not sure if this is 'normal', but since the input on the TTL/CMOS pins shouldn't wander too
far from 0-5V, I'm not worried about it.
Incidentally, when I was looking through the data sheets for the ADM232LJN, they
mentioned that the ADM2xxL series chips were designed to use 1.0 uF caps, whereas the
handyboard uses 10uF. Is this a legacy from an older style 232, or is there some deeper
purpose here?
Quest Life,
Owen
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Owen Wessling |
Developer - Companion Products | "He who dies
Visual Development Tools | with the most toys
415.506.4841 | is, nonetheless, still dead."
owesslin@us.oracle.com |
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