From: email@example.com (ThatsWatt)
Subject: Re: 2 Switch, light bulb either/or thing.
Date: 8 Oct 2002 19:10:53 -0700
References: <firstname.lastname@example.org> <email@example.com> <firstname.lastname@example.org>
NNTP-Posting-Date: 9 Oct 2002 02:10:53 GMT
email@example.com (john jardine) wrote in message news:<firstname.lastname@example.org>...
> Jim Thompson wrote in message news:...
> > On Tue, 08 Oct 2002 07:40:59 -0700,
> > John Larkin ,
> > In Newsgroup: sci.electronics.design,
> > Article: ,
> > Entitled: "Re: 2 Switch, light bulb either/or thing.",
> > Wrote the following:
> > |On Tue, 8 Oct 2002 22:15:48 +0800, "Rheilly Phoull"
> > | wrote:
> > |
> > |>What would be wrong with "2 way" switches in this application ??
> > |>
> > |
> > |I think 'two way' is SPDT, and 'three way' is DPDT. So 'two way' is
> > |good enough here.
> > |
> > |John
> > I *think* SPDT are called "three-way" for some unknown reason ?:-(
> > ...Jim Thompson
> > --
> > | James E.Thompson, P.E. | mens |
> > | Analog Innovations, Inc. | et |
> > | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
> > | Phoenix, Arizona Voice:(480)460-2350 | |
> > | Jim-T@analog_innovations.com Fax:(480)460-2142 | Brass Rat |
> > | http://www.analog-innovations.com | 1962 |
> > For proper E-mail replies SWAP "-" and "_"
> > I love to cook with wine. Sometimes I even put it in the food.
> So the DPCO halfway up the stairs would be a '4 way' ??:).
Thanks for the responces so far,
I am actually looking for the name of the circuit not the switches.
The switches are definetly SPDT, which I should have noted are not
"Normal" light switches which are SPST. Although this circuit is
fairly common, it does not seem to have a name attributed to it e,g, a
"Either or" or a "Fredīs circuit". Anyway, switches and the
nomenclature involved with them is fairly deep, a SPST (Single Pole
Single Throw" or a DPDT(Double Pole Double Throw) switch are
"inventive" names for switch configurations but until you "play
around" with them you probably not understand the profoundness of
I eventually realised switches are like hinges. A SPDT switch has a
single Pivot point but with two possible alternate points of contact.
These are the switches in the referred-to web site. They could be
correctly referred to as "3 way" switches because they have three
terminals. One for the "Pole" and two for the "Throws". And for that
matter they could be correctly referred to as "two way" switches
because a common terminal can only be diverted to two other terminals.
Does anybody have any other conventions for naming switches?