I like the idea but doesn't it still need a uController to process the=20
1-wire information?

--------------------------------
Long ago when men cursed and beat the
ground with sticks,  it was called witchcraft..

Today, it's called golf.

On 7/14/2013 10:30 AM, Steve Smith wrote:
> Well my first thought was a pair of dallas one wire thermometers they nee=
d a
> resistor to support them and a single fet / relay from a 4.5v battery... =
I
> think its probably the lowest parts count.
>
> Steve
>
> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf =
Of
> Phil Keller
> Sent: 14 July 2013 15:52
> To: PICLIST Post
> Subject: [EE] Looking for a more eligant solution
>
> A friend of mine was wondering if I could build a simple device for him. =
 He
> is looking for something that senses the outside and inside air
> temperatures.  If the outside temperature is greater than ~70 and if the
> inside temperature is 5 degrees greater than the outside temperature it
> would enable an exhaust fan.  (We would probably need some hysteresis on =
the
> temperatures to keep the fan from oscillating ON-OFF.)
>
> I can see how this could be done easily with a small PIC, a couple of
> thermistors, a FET & relay and a 5v power supply.
> I could also do it with a few comparators, logic gates, FET & Relay,
> thermistors and a power supply.
>
> Both of these solutions seem overly complex for the problem.  Does anyone
> have a more simplistically elegant solution?
>
>     Thanks
> -Phil-
> --
> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/cha=
nge
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