Newsgroups: sci.electronics
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!cass.ma02.bull.com!mips2!bubba!sje
From: sje@xylos.ma30.bull.com (Steven J. Edwards)
Subject: Re: Security light switches and CF blubs
Organization: Bull HN, Worldwide Information Systems, Billerica, Mass., USA
Date: 21 May 91 14:23:16
Message-ID: <SJE.91May21142316@xylos.ma30.bull.com>
In-Reply-To: steve@maths.warwick.ac.uk's message of 21 May 91 13:59:18 GMT
References: <1991May21.135918.27168@cs.warwick.ac.uk>
Sender: @mips2.ma30.bull.com

In article <1991May21.135918.27168@cs.warwick.ac.uk> steve@maths.warwick.ac.uk (Steve Rumsby) writes:

> I'm just about to move into a new house. Being a security conscious person,
> I was planning to install a few smart light switches, the sort that switch
> lights on and off either when it gets dark, or according to a timer. Also,
> being an environmentally friendly sort of person, I was planning to sprinkle
> compact fluorescent bulbs around the place.

> Now the problem. After a small amount of research, I have been unable to find
> any smart switches which say they will work with fluorescent bulbs. Arrrgghh!
> Those lights which will be automatically controlled are some of the ones which
> I would want to use CF bulbs with.

> Now the questions. Why is this so? These switches are basically just switches,
> right? I understand why dimmers don't work, but these things are just on/off
> switches. Does anybody (preferably UK based) make a similar device which will
> work with CF bulbs? Also, anybody know of a cheap source (UK based, again) of
> CF bulbs? These things are unbelievably expensive in high street electrical
> shops (eg. 11w bulbs - 15.50 pounds each).

	Those switches you mention actually pass a small current
though the lamp's filament when the lamp switch is turned on.  This
allows the darkness control to be overridden by manually turning the
lamp switch off and then on again; this turns on the lamp without
having to fiddle with the darkness sensor module.  Because flourescent
lights do not allow passage of small DC current, they will not work
with these types of darkness sensors.

      == Steven J. Edwards           Bull HN Information Systems Inc. ==
      == (508) 294-3484              300 Concord Road         MS 820A ==
      == sje@xylos.ma30.bull.com     Billerica, MA 01821          USA ==
"That Government which Governs the Least, Governs Best." -- Thomas Jefferson
