Leader LPS-151 - Page 6

5.
OPERATING PRECAUTIONS
5.1 INPUT POWER
Line
voltage
should
be within
±10%
of rated voltage
(lOOV, 120V, 200V or
234V),
Units shipped
within theU.S.
are set for 120Vac. Permissible operating range is 108 to 132
Vac.
To
adapt the unit to other voltages, see Section 7.5.
5.2
OUTPUT
TERMINALS
1 .
Connecting COM
terminal
(10)
or
(
16)
to case ground ter-
minal
(8)
renders both COM terminals grounded to the
case,
2. In the case where a voltage output
in
the 25
to
50
volt
range
is
obtained
by a connection across the +25V and —25V
terminals, ensure
that
both
COM
terminals are un-
grounded ,
3.
In all cases, ensure that connections to the output terminals
of the
power
supply are made
with lead wire of a sufficient
rating for the
current being
drawn from the supply.
5.3 GENERAL
1
.
ITie red zones
on
the
voltmeter and ammeter indicate out
of specification readings. Do not
operate
the power supply
under
conditions that cause red zone readings.
2. When replacing the fuse, ensure that the AC line cord has
been
removed from the power source.
3. When long lead wires are used to connect a load to the
power supply, currents may be induced in the leads by
stray
electromagnetic
fields. These currents may cause os-
cillation in the power supply. In order to maintain the
power supply stable, connect an appropriately valued elec-
trolytic capacitor at
the
load.
Also
note that
the use of long
lead
wires tends to increase voltage regulation.
5,4
ENVIRONMENTAL
CONSIDERATIONS
1 . Avoid operation
of
the power supply under the
following
conditions:
a.
Dusty environments
b. High
humidity
c. Poor ventilation
d. Near
other
power sources
e.
Exposed
to direct sunlight
2. The ambient
temperature
for power supply
operation
should
be
in the range from
0"^
to 35^C
{32°
to 95“F)
.
3. Ensure
that
the power supply is kept
well
ventilated. This
includes keeping the
area
around the supply clear* espe-
cially
the heat sink section.
6, POWER
SUPPLY
OPERATION
For all
operation,
the power cord
must
be connected to an
AC power source
of
the proper
voltage
and
frequency. The
unit
is
turned on by pushing
the POWER button
(1)
in. The
green LED
(2)
should
light when the
unit
is
turned on.
6.1 +6V
RANGE SOURCE
1 ,
Operation
at a Constant
Voltage
a. Press the
+6V
METER
selector button
(5),
b.
Turn
the CURRENT control
(17)
fully clockwise.
c. Use
the
voltage control
(
18)
to set the
voltage
to the de-
sired
level
on
the
VOLTMETER
(19),
(Clockwise
r-ota-
tion
of the control causes
voltage
to increase.)
d. The load
may
now^ be connected to the supply.
2.
Operation using
current
limiting.
a. Press
the
±6V
METER selector
button
(5).
b. Ensure
that
the CURRENT control
(17)
is
turned to its
ful
1
y
COunterc
lock
w1 se pos
iti o n
.
c. Using the
VOLTAGE control
(18),
set the
output
vol-
tage
to the desired
level
.
d.
Short
circuit output terminals
(15)
and
(16).
The volt-
meter will
indicate
zero volts.
e.
Using
the CURRENT
control
(17),
set the current limit-
ing to the
desired
value on the
AMMETER
(23).
Rotat-
ing the CURRENT
control
(17)
clockwise raises
the
current
limit
setpoint.
f. Remove the short
circuit
from output terminals
(15)
and
(16).
g.
The load may
now^
be connected to the
supply.
6.2 ±25V
RANGE SOURCES
The
±25
V sources may be
operated in one of two
modes.
In the FIXED
TRACKING mode* the
output
of the
-25V
source
will track the setting
of
the -^25V source in a
1
: 1 ratio.
In the
VARIABLE
TRACKING RATIO
mode,
the output of
the
-25
V source tracks the
output
of the +25V source
by a
ratio that is
adjusted
by the user,
6.2.1. FIXED
TRACKING
mode, constant
voltage
opera-
tion
a.
Push the REFERENCE
±25V METER selector
button
(3),
b.
Ensure
that the TRACKING
RATIO selector switch
(7)is in the
FIXED position.
c. Turn CURRENT
controls
(12)
and
(14)
to
their
fully
clockwise
po.sitions.
d. Turn the REFERENCE
±25
V control
(6)
to the desired
positive
voltage level. This
will
also
cause the —25V
source to be set
at the same voltage
with
the
opposite po-
larity.
To
confirm
this, press the
TRACKING
METER —25V
selector button (4).
It
should indicate the same
voltage
magnitude
as the
±25V
range
reading, within 1.5%,
After the
comparison,
press the
REFERENCE
-I-25V
METER selector
button
(3)
again.
e.
The
load
may now be
connected
to the supply.
4