
22-11Power Measurement
In the usual realization of the Hall multiplier (0.1% up to a few megahertz), shown in Figure 22.12a, the
ma
gnetic
in
duction
is pr
oportional
to th
e
lo
ad
cu
rrent,
an
d
th
e
opt
imal
po
larizing
cu
rrent
i
v
is set by
th
e
r
esistor
R
v
.
Fo
r
th
e
fr
equency
ra
nge
up to me
gahertz,
an al
ternative
ar
rangement
is sh
own
in Fi
gure
22.12
b,
in wh
ich
th
e
lo
ad
cu
rrent
I
L
flows directly into the Hall device, acting as a polarizing current,
an
d
th
e
ma
gnetic
fi
eld
is ge
nerated
by th
e
vo
ltage
v. In th
is
sa
me
wa
y,
th
e
te
mperature
in
flu-
ence
is re
duced
fo
r
li
ne-frequency
ap
plications
wi
th
co
nstant-amplitude
vo
ltages
an
d
va
riable
lo
adcu