Tony,

On Sat, 15 Apr 2006 13:56:08 +1000 (EST), Tony Smith wrote:

> I previously said:

>> Mount it vertically, then it won't matter if it spins...
> 
> But then you can only have one sensor...  well two, maybe.  For the pond
> you need two sensors, (high & low level) else you get chatter.

No, you'll find that reed switches have quite a sharp operating point when you're moving the magnet along the 
axis at a constant radial distance - much sharper than if you're moving it radially.  And there's quite high 
hysteresis in both cases, so I don't think you'd get chatter unless the water level is waving up and down half 
an inch or so.  Try a "dry" test on a piece of paper and plot the operating/release points, and I think you'll 
see what I mean.
 
> And I noticed my local electronic shop (Jaycar in Oz) has heatshrink with
> glue inside it, just what you need for a waterproof setup like this.  Only
> in black though.

I've only seen it in black (and it's darned expensive!).  You could put glue of your own at both ends of 
ordinary heat-shrink, but I'm not sure what type would stick to it.

Incidentally, I don't know how big your fountain is, or what size of sensor you're looking for, but these: 
http://www.rapidelectronics.co.uk/rkmain.asp?PAGEID=80010&CTL_CAT_CODE=&STK_PROD_CODE=M36677&XPAGENO=1  are 
pretty small, and cheap!  Only problem I can see is if the length of the mounting stem isn't long enough for 
your water depth.

Cheers,


Howard Winter
St.Albans, England


-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist