AVR-Chat

Thanks again for more suggestions and ideas. I'm sorry
I can't be more specific on the application yet but I
don't really know how confidential the information is,
whether it is covered by patents or pending patents so
I'm trying to be generic in terms so I don't get into
any possible trouble. In a week or 2 I should be able
to know what I can say and what I can't.

The best analogy I can come up with is my kitchen oven.
Gas flame at the bottom, temp sensor at the top, food
in between and the oven door needs to be opened occasionally
because the oven lamp has been broken for a couple of years
an I haven't fixed because I "haven't got a round twit" :-[

In fact now that I think of it, all that my prospective client
needs is a kitchen oven temperature controller that goes up to
about 500 degrees celsius instead of the 280 that my oven goes
up to....but then I'll do myself out of a possible job :-)

 >Relative positioning is OK as long as you can map flame
 >temperature against step size (I'm assuming a well-regulated gas
 >pressure and sufficient oxygen). The "current flame" could probably
 >be used as a reference point against which to apply the delta.

That was my original idea. I may be able to get that info from the
client. It would need some possible trimming every few seconds
according to the readings of the temperature sensors.

 >Maybe add a pressure switch, ..........You may also want to alarm if 
there is a supply loss.

Already existing and handled by the main PLC.

 >What about a simple potentiometer?

That was one of my early option. Someone send me a link to a French
company that makes 360 degrees flat pots. The Absolute position sensors
with Gray code output seems a more elegant way of doing it but they seem
to be VERY expensive.

 >Hall effect rotary position sensors (also referred to in some circles as
 >Hall effect pots)

Extremely interesting, especially the sensor with integral activator and
spindle. Let's find out the price now...






Regards

John Samperi

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