Subject: From: Date:

RE: [ECS] Need help troubleshooting Garnet Bailey Mon, 7 Feb 2000 21:33:28 -0700

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Well guys, to set things a bit straighter, houses run on what amounts to a
center tapped 220V - that gives 110V on each side of the center tap - not a
multi-phase setup as you would find in industrial sites. That is AC volts
and is an RMS rating. 220V RMS = 311 V peak = 622 V peak to peak. That pops
400V caps really nicely. You also have to watch since MOST capacitors are
rated for "working volts DC". 600V is marginal for inside an electrical
box - I have seen 600V caps blow on 220VAC complete with flames and black
smoke.
Now, since the impedances involved on the power lines are so low, a .01 and
a .1 uf capacitor present very low impedance paths to the 100KHz X10 signal.
For the record, at X10 frequencies, a .1uf capacitor is about 16 ohms and a
.01 is about 160 ohms. The .1uf is better, but you will likely find it
doesn't matter much.
If you MUST use a capacitor, buy a few cheap fuse holders and fuses and wire
them in series with the capacitor.
The real phase couplers are transformer coupled, tuned circuits. Quite a
nice design actually, since it couples ONLY the 100KHz X10 signal and not
the noise. Plus it is transformer coupled which means electrical isolation.
Does that help?

-----Original Message-----
From: Dario Greggio [mailto:adpm@ipsnet.it]
Sent: February 2, 2000 4:04 PM
To: ecs-list@netbloc.com
Subject: Re: [ECS] Need help troubleshooting


Scott Danks wrote:
>
> I have really not seen what is inside a coupler.  Does anyone have a
schematic?
>
> >>> "Bill Walters" <wtwalters@home.com> 02/02 10:39 AM >>>
> My 2-cents worth here.......
>
> If a .01 mfd capacitor was "safe", everyone would be using them, there
would
> be no X-10 coupler and that would be the end of it....
>
> Are you really ready to trust your home to this method, just to save $40
or
> so dollars?

I think it should be a .1 mF, but a .01 could be good as well.

1uF = 3000ohm at 50 Hz = 1 ohm at 130KHz (X10 carrier... I suppose)
.01uF=30000ohm at 50 Hz = 10 ohm at X10 frequency.

both could be good. Usually you use .1uF to cope with AC spikes and
others. Must be 400VAC to work properly!
--
Ciao,
Dario
--
ADPM Synthesis sas - Torino
--
http://www.geocities.com/adpm99

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