indicates the amount of output current or voltage
that is available in excess of the rated output.
Although the supply can be operated in this Shaded
region without being damageci,
it
cannot be guar-
anteed to meet all of its p8riormance specifica-
tions.
However,
if
the line voltage is maintained
above 11SVac, the supply will probably operate
within its specifications.
3-14 OPTIONAL OPERATING MODES
3-15 REMOTE PROGRAMMING, CONSTANT CURRENT
3-16 Either a resistance or a voltage source can
be used to control the constant current output of
the supply.
The CURRENT control on the front
pane 1 is disabled when remote programming the
supply.
3-17 Resistance Proarammino (Fiaure 3-3).
In
this mode, the output current varies at a rate de-
termined by the remote resistance programming co-
efficient.
This coefficient is different for each
output current range, as shown in Table 1-1 of
this manual.
The programming coefficient is de-
tennined by the constant current programming cur-
rent which is adjusted to 500
±S~~
at the factory.
If greater programming accuracy is required,
it
can
be aChieved
by
changing resistor R35 as outlined
in Section V.
•
+
AO AI
A2 A3
'< - )
PROGRAMMING
~?'
RESISTOR
...-:
L-
Figure 3-3.
Remote Resistance Programming,
Constant Current
~
3-18 Use stable, low noise, low temperature co-
efficient programming resistors to maintain the
power supplies temperature coefficient and stabil-
ity specifications.
A switch may be used to set
discrete values of output current.
A rI).ake-before-
break type of switch should be used s'ince the out-
put current will exceed the maximum rating of the
power supply
if
the switch contacts open during
the switching interval.