[Hai-users] Sun sensor

[Dan Barclay]

That would do it, but when the pump is running the temps may get pretty
close.  If so, it may cycle the pump on and off if you try to recover heat
when solar heating is low (but still available).  It will certainly work
well when it's putting out a lot of heat.  It may cycle when it's recovering
real heat, but not a lot.

By comparing with something outside the control loop you can avoid the
cycling.

Dan


> -----Original Message-----
> From: hai-users-bounces at tssi.com [mailto:hai-users-bounces at tssi.com] On
> Behalf Of Ray Manning
> Sent: Monday, May 09, 2005 5:52 PM
> To: Dan Barclay; 'Justin Matlock'; hai-users at tssi.com
> Subject: RE: [Hai-users] Sun sensor
> 
> 
> Why not use the water temperatures themselves? Measure the pool water
> temperature against the water temperature in the collector. Make
> adjustments
> based on the delta and minimum pump on time to gain the efficiency you're
> after. You could implement that with two HAI water temperature sensors
> relatively easily.
> 
> - Ray
> 
> -----Original Message-----
> From: hai-users-bounces at tssi.com [mailto:hai-users-bounces at tssi.com]On
> Behalf Of Dan Barclay
> Sent: Monday, May 09, 2005 3:25 PM
> To: 'Justin Matlock'; hai-users at tssi.com
> Subject: RE: [Hai-users] Sun sensor
> 
> 
> Justin,
> 
> You may want to consider triggering off temperature differential instead.
> 
> If you measure temperature of something near the collectors that has about
> the same absorption, you should be able to tell when you have a positive
> energy flow by comparing that temp with ambient temp.  If you're getting a
> temperature rise on the target, compared with ambient, you'll be getting
> heat from the collectors.  A small section of collector should be good for
> this.
> 
> No, I haven't done it.  Just suggesting it as an engineer.
> 
> Dan
> 
> 
> > -----Original Message-----
> > From: hai-users-bounces at tssi.com [mailto:hai-users-bounces at tssi.com] On
> > Behalf Of Justin Matlock
> > Sent: Monday, May 09, 2005 4:15 PM
> > To: hai-users at tssi.com
> > Subject: [Hai-users] Sun sensor
> >
> > Anyone out there have a recommended source or part for a sun sensor?
> >
> > I need something that will activate when the sun is actually shining,
> and
> > deactivate when it's not.  I have solar collectors on my roof for
> heating
> > my
> > pool, and the only time I want them to have water flowing is when the
> sun
> > is
> > actually shining -- otherwise, the collectors end up cooling the pool
> > down.
> >
> > I already control the pump system using a standard 220v X10 controller,
> > and
> > want to use the OP2 to control the valves (12v) that divert water to the
> > collectors.  Simple enough.
> >
> > I was thinking I could get a small electric solar cell and connect it
> (in
> > some way) to a relay that will only throw when a certain voltage is
> > produced
> > by the solar chip.. But I have no idea how to go about wiring that up.
> >
> > Thanks;
> > Justin
> >
> >
> > _______________________________________________
> > HAI-users mailing list
> > HAI-users at tssi.com
> > http://romaine.tssi.com/mailman/listinfo/hai-users
> 
> _______________________________________________
> HAI-users mailing list
> HAI-users at tssi.com
> http://romaine.tssi.com/mailman/listinfo/hai-users
> 
> _______________________________________________
> HAI-users mailing list
> HAI-users at tssi.com
> http://romaine.tssi.com/mailman/listinfo/hai-users