AVR-Chat

Thank you for all your replies so far. I guess I will need to explain
a little more.

I'm trying to come up with some ideas for a prospective client.

 From what I understand so far the valve controls gas to a burner
which needs to keep a temperature of about 450 degrees celsius
(flaming hot!!) perhaps +- 30 degrees. A Mega16 (possibly) will
be monitoring the thermocouples and will adjust the opening of the
valve to maintain the temperature. So, yes I have some feedback
on what's happening with the valve perhaps 1 or several seconds later.

The valve will be moving a maximum of 1/2 turn, so no high speed
sensors are needed. An Absolute Position sensor would be nice
to have to find if the valve has moved or if the valve motor
has moved in the right direction or not moved at all i.e. faulty
motor, broken wire, jammed/locked valve etc. as a safety precaution.

As far as having the valve going to 0 (perhaps a limit switch) it
may be possible at power up but not during operation as it will
extinguish the burner. Also in case of a WDT reset it would
be good to know where the valve is located without having to zero
it's position.

This is a bit of additional equipment that has to work with an
existing PLC which control a lot of other stuff.

Keep on coming with ideas/suggestion PLEASE!! :-) I know many of you
have already gone down this road and have lots of experience on
the subject.....and I hope flattery will get me somewhere :-)

p.s. The stepper motor the client has is a 1.8 degrees step angle.

Regards

John Samperi

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                Email: samperi@ampertronics.com.au
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