X-10 (was Re: controlling power)

From: Richard Erlacher <edick_at_idcomm.com>
Date: Wed Jun 27 01:43:17 2001

'seems the prices have gone down some since I last looked.

I looked into the X10 stuff about a decade back and it was about $120 to get
into the things, IIRC. Then you had to have an outlet into which to plug them,
----- Original Message -----
From: "Dave McGuire" <mcguire_at_neurotica.com>
To: <classiccmp_at_classiccmp.org>
Sent: Tuesday, June 26, 2001 4:51 PM
Subject: Re: X-10 (was Re: controlling power)

> On June 26, Richard Erlacher wrote:
> > communication via the power mains, isn't it? My notion to date has been
> > the X-10 stuff is a mite costly, considering that one could hook up a triac,
> > MOC30-something isolated triac driver, and a PIC, e.g. one of the 14-pin or
> > even 8-pin parts, and put the thing in the box with the switch.
> Costly? A 300W dimmer module costs like nine bucks. When I add up the
> price of the components required to duplicate that, I have trouble
> figuring out where they're making a profit.
well ... the 12C508 costs $0.35, the logic-input triac probably costs $0.30 ...
they can probably make a buck.
They require a central controller, though, don't they? What do those cost?
> They're all PIC-based, by the way...the modern dimmer modules contain
> 12c508 chips.
> > It would be an interesting job, actually, though the MCU would be largely
> > wasted. It's smaller than an equivalent set of CMOS logic, though.
> Well, the 12c508 is a *tiny* processor with a *tiny* control store...
It probably has more than enough control store, as it just has to count up and
down for each pair of interruptions of a pair of beams of light. The
12C-whatevers don't have much I/O, though. The arrangement I had in mind
wouldn't require the aid of a central controller and the communication with it,
but would require it be able to "see" a pair of photosensors, e.g.
phototransistors, and pulse an LED at a fairly high rate, in order to determine
which way the interruption was traveling, thereby making it possible to
determine when there were no more people downstream of the control, indicating,
therefore, that nobody would benefit from the turned-on light. Including a
small transformer and regulator, the best I could do probably wouldn't cost
under $9, though, but it would fit in the box with the light switch and wouldn't
need a master controller.
> -Dave McGuire
Received on Wed Jun 27 2001 - 01:43:17 BST

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