Re: Camera on Power-Line Adapters

[E D <napinc7@xxxxxxxxx>]

Hi Les,

If you can modify the wiring to the sign to provide a dedicated 120vac to t=
he sign for video, and then install an EMI filter such as ferrite beads on =
it, and then have your powerline adapter, you should be able to mitigate th=
e line interference from the sign lighting.

So the order should be from sign to building: sign fluorescent bulbs > ball=
ast for bulbs > wiring to ballast > several ferrite EMI filters on wiring t=
o ballast > main wiring line for sign lighting from building. This should i=
solate line EMI to stay on the sign side and not pollute the signal back to=
 the building.

The order for the separate dedicated 120vac line to the sign for video, whi=
ch will have the Powerline adapters, starting from the building should be: =
120vac power feed line with several ferrite EMI filters on it > dedicated s=
ingle outlet for powerline adapter only > line to sign as needed > dedicate=
d single outlet for Powerline Adapter only  > short a/c line with several f=
errite EMI filters on it > dedicated single outlet for video.   =20

It may help to imagine an extension cord with 2 separate single outlets at =
each end. One end is the power source with EMI filter on line, then a singl=
e outlet for the Powerline adapter only, extension cord length in the middl=
e as needed, another single outlet for the 2nd Powerline adapter only, shor=
t length of cable with EMI filter, outlet for power. This way, your powerli=
ne adapters are on a shielded length of cable that should not receive EMI i=
nterference.=20

Perhaps the "ham sandwich" with mustard/cheese on both sides picture might =
be better. So you have bread/ac, then cheese/EMI filters, then mustard/PL a=
dapter, the ham/wireline, then mustard/PL adapter, then cheese/EMI filters,=
 and then Bread/whatever you are powering. As long as everything stays in t=
hat order, you should be able to mitigate the EMI. I can't believe I just w=
rote that!

Below I have included some information on interference, etc.

Ferrite beads prevent interference in two directions: from a device or to a=
 device.[1] A conductive cable acts as an antenna =E2=80=93 if the device p=
roduces radio frequency energy, this can be transmitted through the cable, =
which acts as an unintentional radiator. Conversely, if there are other sou=
rces of EMI, the beads prevents the cable from acting as an antenna and rec=
eiving interference from these other devices. This is particularly common o=
n data cables and on medical equipment.

Ferrite chokes are also called ferrite blocks, beads, rings or cores or EMI=
 filters. They are available at electronics stores, Ebay, Amazon, etc.

EMI is caused by one device inducing voltage (generating a discrete voltage=
 without a direct electrical connection) within a second component.  Induce=
d voltage occurs when devices are not properly shielded, are laid out impro=
perly (e.g. coiled around objects or run parallel for the entire distance),=
 use high frequency AC voltage, or are grounded improperly.  Because ballas=
ts typically generate a humming or buzzing noise =E2=80=93 electronic balla=
sts are quieter than traditional magnetic ballasts, but the hum still exist=
s =E2=80=93 remotely mounted ballasts are sometimes preferred.  Remotely in=
stalled electronic ballasts generate substantial amounts of EMI due to thei=
r higher operating frequencies (magnetic ballasts operate at 60 Hz while el=
ectronic ballasts are typically operated at 20-60 KHz, that=E2=80=99s 50 to=
 200 times greater).  If the connection cables are unshielded, the high fre=
quency will convert the cables into a powerful antenna, creating an electro=
magnetic field that can affect radios, Wi-Fi connections, and cell signals.=
  In a fluorescent system, the fluorescent lamp itself is capable of radiat=
ing electromagnetic waves at frequencies of 10 KHz to 100 MHz depending on =
the electronic ballast connected to it.

Conducted EMI =E2=80=93 interference added to the local power network of in=
terconnected devices that do not necessarily share a direct power or signal=
 source.

Radiated EMI =E2=80=93 generated electromagnetic fields inherent to electro=
nic devices. Typically associated with solar flares.

The simplest way to remember the difference is that conducted EMI is genera=
ted by physical contacts, while radiated EMI is radiated through the air.

The geometry and electromagnetic properties of coiled wire over the ferrite=
 bead result in an impedance for high-frequency signals, attenuating high f=
requency EMI/RFI electronic noise. ... The ferrite creates an inductor with=
 a very low Q factor. This loss heats the ferrite, but normally it is a neg=
ligible amount of heat.


These links should get you started on what the EMI filters look like and co=
sts-

https://www.ebay.com/i/322486401466?chn=3Dps

https://www.amazon.com/dp/B01JMTCC5U/ref=3Dasc_df_B01JMTCC5U5344251/?tag=3D=
hyprod-20&creative=3D395033&creativeASIN=3DB01JMTCC5U&linkCode=3Ddf0&hvadid=
=3D194024095585&hvpos=3D1o1&hvnetw=3Dg&hvrand=3D757014320374929470&hvpone=
=3D&hvptwo=3D&hvqmt=3D&hvdev=3Dc&hvdvcmdl=3D&hvlocint=3D&hvlocphy=3D9010865=
&hvtargid=3Dpla-502908792392

In your case, I believe that conducted EMI is your biggest problem. The fil=
ters should not be much of an economic outlay. The electrician might be oth=
erwise, but I am assuming that the owner/customer is footing that bill.=20

Have a safe and great entire New Year.