Re: [ST] RE: Speaking of Heated Grips...

[Tom Emberson <ate_st@xxxxxxxxxx>]

On Fri, 7 Jun 2002, Bil Swartz wrote:

> On Fri, 7 Jun 2002, Keith Tynan wrote:
> 
> > OK so this is a factor, but this won't change the fact that the resistance
> > in the left grip (9.0 Ohm) is greater than that in the right (7.7 Ohm) and
> > hence the right will produce more heat.
> 
> I'm no EE but I always thought that resistance = heat, so doesn't more
> resistance = more heat?  Or is that just my stereotypical american way of
> thinking?!?  Har!

For a given current yes, V=IR or E=IR depending on if you are an EE op a
physisist, can't remember which right now.

Power = IE = IIR = I^2 * R, and that is where you are getting your heat.

With a constant voltage (12V), and the resistance goes up, then the
current goes down.

Lets look at the typical situation, where you are talking about a wire
supplying a load.  So on the one extreen, if the wire has zero
resistance it will consume no power, no matter what the current is. As
the resistance in the wire goes up, the the over all reistance of the
loop (including a load, say light buld) goes up, but since the load is
still drawing the bulk of the current then the wire will heat up since
the resistance of the load is constant (okay so a light bulb is not the
best example here).

At the other extreeme, the heated grips, the wire is the load,
increasing the resistance will decrease the current, thus power
consumption of the grip will also decrease.

As well, measuring the resistance of the wire at room temperature is not
going to get you too far, since most write will increase its resistance
as the temperature goes up. In fact, if they are using nichrome wire,
resistance goes up significantly.

Call it self regulating.

Does that make sence?

Tom.


/*************************************************************
 Thomas Emberson
 '01 BRG Sprint ST (last count 14 months old, 21,400 miles)
 '00 Yamaha WR400F
 sold: '98 ZX6e, '99 ZX9r, '95 EX500
*************************************************************/


     *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *
      The ST/RS Mailing list is sponsored by Jack Lilley Ltd.
          http://www.TriumphNet.com/st/lilley for more info
   http://www.TriumphNet.com/st for ST, RS and Mailing List info

=-=-=-= Next Message =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=