Re: [Paddlewise] electric pump switch

From: Ulli Hoeger <uhoeger_at_dal.ca>
Date: Sun, 17 Aug 2003 16:15:14 -0300
Hi folks,

I use electric bilge pumps (Rule 500 or Attwood 500) in my boats.  
Power is supplied by 8 AA alkaline batteries (last for almost an hour 
of pumping, i.e a full season).
Vulnerable parts are the battery holder (even condensation in the 
waterproof box causes it to corrode away), and the switch.  Tried a 
lot of ways to solve the switch problem.  One version was to glue a 
switch into the lid of the battery container (Nalgene bottle) and 
seal it with silicone. Pushing the switch through the silicone works.

Now I found a different solution.  On a german website 
http://www.faltboot.net/DIY/Lenzpumpe/lenzpumpe.html Rainer describes 
a switch made up from a REED relay and a second relay. The REED relay 
is closed by a magnet, the resulting current pulse switches the 2nd 
relay into its on position and pump runs. Another magnetic/current 
pulse on the REED relay turns the 2nd relay/pump off.

I didn't bother with the second relay.  I bought at Lee Valley a rare 
earth magnet (2 CAD) and a matching cup socket.  Plan is to install 
the REED relay switch under the deck and the magnet cup on the 
outside on top of the relay's sweet spot.  To close the switch, i.e. 
start the pump, the magnet (size of a quarter secured to the 
decklines with a bungee) goes into the cup.  When the pump job is 
done, the magnet is pulled away from the cup and the pump stops.

Works on the bench, and will go into the kayak sometime next week.  I 
will post the results....

Ulli






--
Ulli Hoeger
Dept. Physiology and Biophysics
Dalhousie University 
Halifax, B3H 4H7
Nova Scotia, Canada
 
Phone: INT 902 494 2673
Fax:  INT 902 494 1685
Phone 2: 902 488 1646

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Received on Sun Aug 17 2003 - 12:15:20 PDT

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