Date:         Fri, 18 Mar 2011 14:38:39 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Reed Switch/water level sensor
Comments: To: Troy <colorworks@GCI.NET>
In-Reply-To:  <788B2B6EA92540F3A41AB83AACAD2BC5@troyb5bff49d63>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 01:34 PM 3/18/2011, Troy wrote:
>believe they are no longer available.  From my understanding, it's
>usually the reed switches in these that break.  I have determined
>that the lower, double pole double throw, switch is bad in mine,
>whereas the top one seems to still be working fine.  So, my question
>is does anyone know where I can buy the switches?  I see that eBay
>is filled with reed switches, I just don't know the specs.

It's a single pole, double throw miniature low-current switch.  Using
"reed switch spdt" on ebay this is the only candidate that would fit:
http://cgi.ebay.com/Miniature-Reed-Switch-SPCO-SPDT-Change-Over-pack-2-/270699072331?pt=UK_Trains_Railway_Models&hash=item3f06ec0b4b#shId

Digikey has these:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=374-1093-ND

This one might need too strong a magnet, although I *think* it would
fit physically:
  http://www.altex.com/Philmore-Open-Reed-Switch-SPDT-On-On-30-17154-P148426.aspx


>Here's a link to repairing the level sensor btw:
>
>http://www.brick-yard.co.uk/forum/westy-water-tank-level-sensor-repair_topic42742.html

That's a very good thread (of course I'd think so, I'm in it).  It
gives Radio Shack part numbers for the two reed switches.  Note my
deathless contribution on lead stress and keeping things
dry.  Unfortunately Radio Shack no longer sells reed switches, in
this country at least.


>Speaking of Reed switches, I do see that there are marine places
>that sell stainless steel reed sensor sender unit from a few inches
>to 100 inches.  What I don't know is how many switches there are
>inside of the things. Any boat owners on the list? The westy just
>has two, the lower one being a dual switch, so that it lights one of
>3 LEDs.  All in all, it's a pretty simple setup.

It isn't just the switches that matter, the resistors do as
well.  The Westy setup was made to duplicate the function of the
magic resistor pack in the earlier ones which may or may not be an
industry-wide standard.


>I also saw on eBay yesterday, a water level sensor that uses an 11
>lead wire.  One basically takes the total height of the tank,
>divides it by 10, and then strips the wire at regular intervals--one
>wire for each level.  This in turn sends a signal back to an
>indicator panel to show the various water levels.  Actually much
>more precise than the 3-level stock indicator.  The only drawback is
>the gauge is about 3" x 5", so kind of large. About $70. If I find
>anything more about the Marine reed switches sending units, I will
>pass along the info.  It would be nice to have a replacement option
>without having to do surgery on the old one.
>
>Here's a link to an alternative water level sensor gauge:
>http://cgi.ebay.com/Tank-Water-Level-Indicator-Meter-Monitor-Gauge-Sensor-/230587975521?pt=AU_B_I_Electrical_Test_Equipment&hash=item35b01d4761

This essentially goes back to the principle of the original ones
which have eletrodes in the tank side.  Clever-looking.  Not really
an elegant solution for the Westy...


>And finally the link to the reed switches, sender units sold by
>marine dealers:
>http://cgi.ebay.com/ebaymotors/MOELLER-19-INCH-WATER-SENSOR-SENDING-UNIT-boat-_W0QQcmdZViewItemQQhashZitem2eb2c00683QQitemZ200567424643QQptZBoatQ5fPartsQ5fAccessoriesQ5fGear

Back to the resistor question.

Yrs,
d