Hi,
I am contemplating running a light wire back to the cockpit to operate the
anchor winch from there. At present the power is switched for up and down from
foot switches at the bow.

What is best - solenoids or relays? What is the difference please?
Peter H
NZ yacht Herodotus

On Sun, 07 Aug 2005 22:31:59 +1000, Peter Hendra
wrote:


=What is best - solenoids or relays? What is the difference please?

A relay is a mechanical arrangement of electrical contacts actuated by
a coil. Run current through the windings of the relay coil and it
becomes a magnet. The magnetic force attracts a soft-iron armature,
which then moves and imparts its motion to the contacts, making (or
breaking) the circuit, depending on the arrangement of the contacts.

A solenoid is also a coil, usually with a hollow center into which is
inserted a soft-iron rod. Current through the coil generates a
magnetic field, as in the relay coil, and the rod (armature) is either
pulled into the coil or expelled from the coil, depending on the
design. Mechanical springs would normally hold the armature in some
de-energized (power-off) position, either in or out of the solenoid
core.

If your winch has two heavy-duty electrical terminals (+ and -) then
you would probably want to use a relay close to the winch with its
heavy-duty contacts in series with the battery supply to the winch for
control. As you had planned, energize the relay coil from the cockpit
over an appropriate circuit.

If your winch has two heavy-duty terminals and one lighter-duty
terminal, chances are it has its motor contacts inside the housing.
You would connect battery to the heavy-duty terminals, and energize
the lighter-duty terminal from the cockpit through an appropriate
circuit.

Your engine starter is a good example of a solenoid-actuated
high-current switch.

Of course, most winches are reversible, and now you're getting into
another can of mollusks!

Cheers--
Terry--WB4FXD
Edenton, NC

Peter Hendra wrote:
Hi,
I am contemplating running a light wire back to the cockpit to
operate the anchor winch from there. At present the power is switched
for up and down from foot switches at the bow.

What is best - solenoids or relays? What is the difference please?
Peter H
NZ yacht Herodotus

Unless you have an absolutely flawless chain guide system up at the bow, you
will gain nothing from a cockpit remote for the anchor chain. Foul-ups will
have you running up the deck at frequent intervals, and the best place to
operate an electric windlass from is the foredeck.

If your anchor windlass is anything like mine or the majority that I'm aware
of, you already have a set of solenoids under the deck that are activated by
your foot switches. If so, you can just attach a set of wires in parallel to
the foot switch, then to a NO-OFF-NO toggle switch.

I did this on a 15 foot light cable lanyard that allows me to walk out on
the bowsprit and 'jog' the windlass as I ensure the anchor is entering the
roller 'right-side-up'.

I have considered having plug in the cockpit to allow me to be at the engine
controls but then I couldn't be sure the anchor was coming in clear of the
bobstay and properly entering the bow roller.

For dropping the anchor, I prefer a gravity drop, rather than power down so
the cockpit control wouldn't work for that.

My experience and opinion, FWIW

--
Steve
s/v Good Intentions

"Peter Hendra" wrote in message
...
Hi,
I am contemplating running a light wire back to the cockpit to operate the
anchor winch from there. At present the power is switched for up and down
from
foot switches at the bow.

What is best - solenoids or relays? What is the difference please?
Peter H
NZ yacht Herodotus