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(The potentiometer
output),
than to cal-culate a corrected mechanical
ratio
(nf :nt,).
Figure 2./+-4 illustrates
the 5o5 cj-rcu|try
provided to pennit
sett-
ing the potentiometers
under actual 1oad.
Relay Kl is energized vhen
the conput,er is placed in the pot set node (depress POT SE"I button)
and
applies +lOO volts
reference
to the high ends of all
the grounded poten-
tj-ometers.
Note that the wiper remai-ns eorurected to the ?re-Patch Panel
termi-nation;
thus,
the r^riper nfeelsil
the impedance of the actual
load it
is patched to in the problem.
Even when the potentj-ometer is selected
for monitoring
via the readout pushbutton K1, the wiper remains eon-
nected to its
actual
load.
The readout pushbutton corurects the uiper
to a high impedance DVM or, in the absence of the DVM, a nul1 pot cir-
cuit.
The operator may then set the wiper for the attenuation
factor
required
in the problem.
The method of the setting
the ungrounded potentiometers
is quite
sirnilar
to the setting
the groirnded ones.
The 1ow ends are transfered
from the Pre-Patch Panel terminals
to ground in the pot set mode.
Figur.e 2.1*-5 shows schematics and syrnbols for the two types of
potentioneter
configurations.
The 505 potentiometer designation
(i.e.,
m:unber) is given within
the circular
syrnbol and the setting
is written
in cl-ose proximity
to the symbol.
In addition,
the high and low ends
of the ungrounded potentioneter(s)
are afso designated to indicate
elearly
both input
signal
sources,
i
The neon lanp located
at the left
si-de of the each potentiometer
ui11 light
uhen the potentiorneter
readout br-:.tton just
belor^r the poten-
tiometer
is pushed, and notify
the operator that this
potentioneter
con::ected to the readout system.
- 3 9 -
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