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dccharacter писал(а):А как так - по земле? Земли же связаны?!?!?!

=DeaD= писал(а):

dccharacter писал(а):А как так - по земле? Земли же связаны?!?!?!

Берете схему замера ёмкости на батарейке, цепляете одной точкой к фазе в 220В - землёй, и всё, помеха приходит по земле

Noise Susceptibility
The existing noise, which affects capacitive touch appli-
cations, should always be considered. The factors
affecting how to protect against noise are very applica-
tion-specific. The PICDEM Touch Sense 2 Demo Board,
for example, is open on both the front and back. A
hatched ground pattern was added to the back of the
board wherever possible to minimize the effects of noise
that could be introduced from the bottom of the board.
The cross hatched pattern provides a good path to
conduct unwanted noise to ground, and at the same
time, it does not cause an appreciable increase in the
capacitance of the touch sensors due to the coupling
effect of the sensor pad through the PC board material
to the ground plane.
Some applications may have a completely shielded
enclosure which would allow for less ground plane
added to the PC board. Another consideration is the
proximity of the capacitive touch sensors to other noise
producing circuitry on the board, such as communication
busses, inverting power supplies for back lighting dis-
plays, RF radio transmitters such as those used for Wi-Fi
or other radio based communications, and so on. In the
case of a radio transmitter and capacitive touch sensors,
it is best to read the buttons only when the RF transmitter
is disabled.