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This article was posted to the Usenet group alt.hackers in 1995; any technical information is probably outdated.

Like son, like father ?

Article: 8394 of alt.hackers
From: (Alex Wiebe)
Newsgroups: alt.hackers
Subject: Like son, like father ?
Date: 3 Aug 1995 17:52:36 GMT
Organization: Continental Healthcare Systems Canada, Inc.
Lines: 78
Approved: oh, why not...
Distribution: world
Message-ID: 3vr2d4$
Keywords: pump, float-switch, etc.
Status: RO


A few years ago, when I lived in the basement of my parents house, I came up
with a this one:

In the basement it around here it gets *very* damp in summer. (Read any paper
on the floor gets water damaged in about 2-3 days.) So I had a de-humidifier
running in my room. Only problem was that a) I'm a forgetful / lazy SOB and b)
the tray that catches the water was filling up (about 8l - ~2 gallons for you
Yanks ;-) every 2-3 days. The nearest drain hole (for the weeping tiles that
drain away ground moisture) was on the other side of the basement, which meant
that carrying a wide flat vessel full of water was quite the challenge. So, I
decided to create my own little sump pump to pump out the water. At the time I
worked at a car dealership (lot-rat) and managed to aquire a pump used for
the windshield washer and rigged a momentary lever switch to a float to
the pump. I then needed to pump the water someplace (duh!). Well, not
having any
tubing kicking around I went and grabbed some 5 conductor cable (used for
TV antenas - aiming or something like that). Pulled the conductors and
and presto
I had a tube to pump the water through. Ran the tube out the window and into my
moms garden, powered it up and forgot about it - BAD! Turns out those little
windshield washer pumps are meant to run for only a few seconds at a time - not
a couple of minutes as it pumps a tank empty. After about 2 days it stopped
working. Took a look at the pump - I had melted the entire top to the point of
complete distruction. Oh, well.


Related to the above, my dad just had central air installed. Same problem, the
a/c produces a *LOT* of water (at least for the first few days), and there is
no convenient place to drain it. (Smashing random holes in the floor looking
for a weeping tile? Running a tube across my mom's laundry floor? Trying to
remember to empty a tub that collects the water?) So my dad bolted an ice-cream
pail to the furnace and dropped in a small (12v 2A) bilge pump (the kind used
in small ornamental water fountains - no burnout problem here). Directing the
water is about 10m (30') of 1cm (3/8") tube, which follows the a/c
to the great outdoors. For a switch he used.... the old thermistat! Rigged as

|	 ________	  |			   ______  <- Shut
off washer
|	/	 \ <-Murcury switch			||
|	\_****___/	  |			     ||
|	 /		  |			     LL
|	/  _____	  |=============____________[__]
|      /  / __	\	  |  ^			__== ||
|      | |    \ |	  |  L Extra rod    __==     ||
|      |  \ || ||	  |  hinged to	__==	     ||     <- Control
|	\  \||/ /	  |  assist __==	     ||
|	 \__||_/	  |	__==		     ||
|	    ||		  | __==		     ||
|	    ||		__==  <- Rod 'hinged' to   __LL__   <-
Start washer
|	    ||	    __==  |	 controll arm of     ||
|	    ||	__==	  |	 the thermistat      ||
|	    ()==	  |			     ||
|  Hotter ---->	     |				||
|_________________________|			     ||
					      ______/  \______
					      |		      |
					      |  Float	      |
Basic idea being, when the water in the pail reaches a certain point the
'cranks the temperature on the thermistat' which starts the pump. When
the water
has dropped to an appropriate level the thermistat is pushed the other
way shutting
the pump off. The only real challenge is ensuring that the washers are
far enough
apart that when the water drains out of the tube (back into the pail) that it
doesn't re-start the pump.

I'm sure there are simpler ways to accomplish this, but hey this looks cool.
"...  the computational demand of a frisbee is relatively light
and workstations cannot usually stay airborne long enough to replace
frisbees despite their superior processing power." - Alt.hackers
Alex Wiebe <alex@{chs,asylum.magic}> CHSCI ph: (204) 942-2992

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