Re: Gap Question

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: robert & june heidlebaugh <rheidlebaugh-at-desertgate-dot-com> 

A POSITIVE THERMISTOR has a non linier resistance dependant on the power
disipation without a negative charicteristic
      Robert   H
-- 


 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > Date: Thu, 26 Feb 2004 23:15:43 -0700
 > To: tesla-at-pupman-dot-com
 > Subject: RE: Gap Question
 > Resent-From: tesla-at-pupman-dot-com
 > Resent-Date: Thu, 26 Feb 2004 23:20:12 -0700
 >
 > Original poster: "Luke" <Bluu-at-cox-dot-net>
 >
 > Can anyone point me to a device that does not have a linear resistance
 > but yet does not display a negative resistance?
 > Is there such an animal?
 >
 > Thanx
 >
 > Luke Galyan
 > Bluu-at-cox-dot-net
 > http://members.cox-dot-net/bluu
 >
 > -----Original Message-----
 > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > Sent: Thursday, February 26, 2004 5:34 PM
 > To: tesla-at-pupman-dot-com
 > Subject: RE: Gap Question
 >
 > Original poster: "Luke" <Bluu-at-cox-dot-net>
 >
 > Ok I see what you are saying.
 > Thanx
 > This is starting to click a bit.
 >
 > This has been a very enlightening topic for me!!
 >
 > I was used to thinking of resistance as something the hinders the flow
 > of electricity.  I know that is what it normally means.  But I was not
 > used to the term being made to refer to the V I properties and not
 > thought of as actual resistance per say.
 >
 > And yup I see what you mean in the lower graph the resistance decreases
 > but the slope does not go negative.
 >
 > So as well as learning some other stuff here I finally came to grips
 > with the word resistance in the term negative resistance is not
 > referring to actual resistance even though the V I can be used to
 > calculate a resistance.
 >
 > Thanx.
 >
 > Luke Galyan
 > Bluu-at-cox-dot-net
 > http://members.cox-dot-net/bluu
 >
 > -----Original Message-----
 > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > Sent: Thursday, February 26, 2004 7:19 AM
 > To: tesla-at-pupman-dot-com
 > Subject: Re: Gap Question
 >
 > Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br>
 >
 > Tesla list wrote:
 >
 >> Is it safe to say that a device that displays negative resistance,
 >> refers to a components ohmic value decreasing when there is an
 > increase
 >> of voltage or current?  And yes I realize that this would only occur
 > at
 >> certain areas on the V I curve.
 >
 > Use a fixed-width font to see the pictures.
 > Negative resistance occurs when the voltage decreases and the current
 > increases, or when the slope of the i x v curve is negative.
 >
 > |i         /      |i                /
 > |         /       |                /
 > |        /        |               /
 > |        \        |              /
 > |         \ here  |      here   /
 > |          \      |    /\      /
 > |        __/      |   /  \    /
 > |     __/         |  /    \  /
 > |  __/            | /      \/
 > |_/          v    |/                  v
 > +-------------    +--------------------
 >
 > It's not safe to define as Ohmic value i/v. In the negative resistance
 > region of the curves above it decreases as the voltage decreases, but
 > it does the same in the curve below, that doesn't have a negative
 > resistance area:
 >
 > |i              /
 > |              /
 > |             /
 > |    ________/
 > |   /
 > |  /
 > | /
 > |/                v
 > +------------------
 >
 > So, reserve the term "resistance" for linear resistors, or to measure
 > the slope of the i x v curve.
 >
 > Antonio Carlos M. de Queiroz
 >
 >