Try giving them 120v for a few minutes (in series with a 100n cap to
limit the current if they decide to go short).
They may be a type of thermo-pneumatic actuator


-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU] On Behalf Of Martin McCormick
Sent: Monday, March 01, 2004 8:29 PM
To: PICLIST@MITVMA.MIT.EDU
Subject: [OT]: Strange Part Salvaged from Maytag Dish Washer

        Before sending our old dish washer to the recycler, I pulled
the solenoid water valve off of it and a couple of parts that I
thought were solenoids which do not behave like a solenoid should.

        The two parts in question are actuators of some type.  One
used to trip the latch on the soap dispenser and the other did
something similar to a "pre-rinse" dispenser.

        Both objects look like solenoids in that they have rectangular
bodies about the size of two nine-volt batteries end to end.  Two
blade terminals come out the side of each device and there is a metal
shaft protruding from one end making the whole thing also look kind of
like a switch except that I can't pull or push the rod in or out.

        Each part has the word Ltech stamped on it and a part number.

        If I read across the terminals with an Ohm-meter, they show
megohms.  They also do exactly nothing when I feed up to 120-volts AC
from a variac.

        Both parts snapped in to clips that held them firmly next to
the mechanical lever they were supposed to move.  My impression is
that the rod extended and pushed a spring-loaded lever which popped
the lid on the soap box, etc.

        It is remotely possible that both are solenoids that have
burned out as the release on the soap dish stopped working weeks ago,
but I find it unlikely that they both failed the same way.

        This particular machine had no electronics as far as I know,
just an electromechanical timer and mains voltage to all the
electrical parts.  When I fed the 120-volt AC to them, they drew no
measurable current at all.

        What could these strange things be?


Martin McCormick WB5AGZ  Stillwater, OK
OSU Information Technology Division Network Operations Group

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