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Re: 120 khz X-10 / INSTEON 'filters' ; was Re: X10 Interference from the Cellet Cellphone Charger



I used those Corcom filters in most of the industrial automation equipment I
built over the years.  As you say, some of the capacitive input filters are
not at all friendly to X10.  The low-pass XPPF 5A plug-in X10 filter can be
found on eBay for about 10 bucks including shipping, and even less if you
buy several.

That air-gap is an Interesting idea on isolating your system.  We have a
Leviton surge protector at our main panel, but I haven't found any "earth"
ground for the house.  Our water main is plastic due to the alkalinity of
the soil.  All utilities come in underground, and the ground reference must
be out at the underground utility bunker, if there is one at all.

Jeff

"Marc_F_Hult" <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote in message
news:a3r4g3l997vn2triu0k2po1utnntf5up9t@xxxxxxxxxx
> Thanks Jeff. It makes sense that folks interested in a clean X-10/INSTEON
> signal would optimize the depth of the notch at 120/121khz.
>
> The 20-amp version of the CORCOM R Series filters that I use
>
> www.econtrol.org\CORCOM R Series schematic.htm
>
> in my air-gap switch and power conditioning unit
>
> www.econtrol.org\power_conditioning.htm
>
> is down 44db at 500khz but only -4 db at 125khz. This should clean up any
> X-10/INSTEON 2nd harmonic, but doesn't do much for the fundamental and
> lower. I would be better off leaving the 0.22uf caps in place in the
> 8-component X-10 filters I am adding if my only concern were to attenuate
> the X-10/INSTEON fundamental but there's also sub-120khz garbage from
> triac
> dimmers and various switchers so I think I'll leave them in.
>
> Folks looking for a less expensive way to filter small, noisy power
> supplies like the Cellet Cellphone charger than the standard
> X-10/Leviton/ACT options might consider the smaller (eg) CORCOM filters or
> equivalents. The 1 and 3amp versions of the filter series I cited are
> spec'd as 25-30 db down at 125khz and so should do a good job cleaning up
> in-band X-10/INSTEON noise. They are typically available as New Old Stock
> for a couple of bucks on eBay. I have a big box full I should put up for
> sale in my porch sale.
>
> However, the capacitor input (C-L-etc) filter versions such as the
> CORCOM's
> I cite and use may attenuate significantly ("signal suck") compared to the
> inductor-input (L-C-etc ) of the commercial X-10 filters unless they are
> isolated by an inductor in a cascade of filters as in my case.
>
> ... Marc
> Marc_F_Hult
> www.ECOntrol.org
>
> On Tue, 02 Oct 2007 04:12:28 GMT, "Jeff Volp" <JeffVolp@xxxxxxx> wrote in
> message  <MyjMi.163139$ax1.94584@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>:
>
>>Several X10 filters are bandstop, including the little Leviton 6287.  You
>>can make a pretty efficient 120KHz trap with a small inductor and
> capacitor.
>>However, a low-pass needs much larger components to have the same
>>attenuation at 120KHz.  The Leviton 6288 and XPPF are low-pass with an
>>initial break at 13Khz.  As you know, they are rated 5A, but run warm (and
>>stink) when pushed that hard.  FYI, the AF120 schematic I have shows the
>>inductors are 7.2uH, and all caps are 0.22uF.  The fuse may be needed for
> UL
>>approval if the center cap is not rated for across-line applications.
>>Interestingly, the center cap on the little 6287 is listed as 1.0uF.
>>
>>Since these filters were designed as companions for X10 modules, they
>>probably take advantage of the bandpass characteristics of the modules
>>themselves.  The module's input network will attenuate out-of-band
> signals,
>>so the in-line filters only have to block in-band noise.
>>
>>Jeff
>>
>>"Marc_F_Hult" <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote in message
>>news:4243g31r2rvv6mg43a5g3uli7lji7jsrid@xxxxxxxxxx
>>>
>>>I recently added what I thought were going to be "X-10 filters" to the
>>> relay controlled air-gap disconnect and filter unit that I use to
> protect
>>> and isolate (i.e., "filter") X-10 and INSTEON ~120khz signals from the
> AC
>>> circuit used for audio and instrumentation.
>>>
>>> These are X-10 PR brand , model " XPF 20-amp Wired in-Filter " with a
>>> documentation sheet dated 10/98.
>>>
>>> To my surprise, they are  band-stop, rather than low-pass, filters.
>>>
>>> The low-pass part of the design is  L-C-L-C-L with 7.7 uH ferrite stick
>>> inductors (measured at 1 kHz) in series and 1.0uF capacitors to neutral.
>>> But the three inductors are each bypassed with 0.22uF capacitors. My
> need
>>> and intention is to filter high frequencies from the power line so I
>>> removed them.
>>>
>>> Interestingly, ACT's popular AF120 filter uses an L-C-L configuration
> with
>>> 8.0 ufd toroidal inductors, 2.2uF cap that presumably has a lower cutoff
>>> frequency and lower slope. It also has 0.22uf  bypass caps on each
>>> inductor. There is a 1-amp fast-blow AGC fuse in series with the 2.2uF
>>> capacitor's signal path to neutral. The AF120 is marked as "No User
>>> Serviceable Parts Inside  Tampering Voids Warranty" on the sticker/label
>>> that serves to seal the case. So if the internal fuse were to blow,
>>> filtering performance would suffer but the user would have no indication
>>> of
>>> decreased attenuation. (The AF120 also has a user-accessible 15amp fuse
> in
>>> series with the load but that's not what I am referring to.)
>>>
>>> I haven't done a SPICE model or other calculation of these devices/
>>> schematics in part because I haven't located  the reference that I had
> on
>>> measured/estimated typical impedances of household AC networks/circuits.
>>>
>>> My question is why are these filters bandstop and not lowpass? Is this
> for
>>> circuit protection as implied by AF120's internal fuse. Or to purposely
>>> transmit X-10 across the filters? Or ?
>>>
>>> ... Marc
>>> Marc_F_Hult
>>> www.ECOntrol.org
>>




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