
69-21Human Occupancy Detectors
detection area is situated where the hands are normally being placed. Figure 69.20c illustrated the faucet
ha
ving
a li
ght
pi
pe
an
d
th
e
pa
rts
th
at
ar
e
no
rmally
ne
eded
fo
r
di
spensing
wa
ter
. Fi
gure
69.21 sh
ows
a
bl
ock
di
agram
of th
e
wa
ter
o
w
co
ntrol
sy
stem
. e li
ght
pi
pe
ca
n
be a bu
ndle
of th
e
opt
ical
b
ers
or a
so
lid
tr
anslucent
ro
d
mo
lded
of po
lycarbonate
re
sin
. Us
ually,
th
e
em
itted
li
ght
is mo
dulated
by pu
lses
.
i
s
he
lps
to se
parate
th
e
re
ected
li
ght
sig
nals
in
to
a ba
ckground
(a
mbient)
co
mponent
an
d
th
at
co
n-
trolled
by th
e
pu
lsing
LE
D
dr
iver,
sin
ce
th
e
amb
ient
li
ght
is a dc or sl
ow-changing
sig
nal
. No
te
th
at