HP Lab Series User Manual

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•
•••
Al
AZ
-
GNO
+
+S
AIO
00
Figure
3-4.
Remote
Voltage
Pregramming
(Constant
Voltage)
3-23
The
impedan~e
(Rx)
looking
into
the
external
programming
voltage
source
should
be
approximate-
ly
1000
ohms
if
the
temperature
and
stability
spec-
ifications
of
the
power
supply
are
to
be
maintained.
3-24
Methods
of
voltage
programming
with
gain
are
discussed
in
Application
Note
90,
Power Supply
Handbook:
available
at
no
charge
from
your
local
Hewlett-Packard
Sales
Office.
3-25
REMOTE
PROGRAMMING, CONSTANT
CURRENT
3-26
Either
a
resistance
or
a
voltage
source
can
be
used
to
control
the
constant
current
output
of
the
supply.
The
CURRENT
controls
on
the
front
panel
are
disabled
according
to
the
following
pro-
cedures.
3-27
Resistance
Programming
(Figure
3-5).
In
this
mode,
the
output
current
varies
at
a
rate
determined
by
the
programming
coefficient
- 75K ohms
per
Amp
for
Model
6207B,
and
lSOK
ohms
per
Amp
for
Model
62098.
The
programming
accuracy
is
10%
of
the
programmed
current.
If
greater
prc)gramming
accu-
racy
is
required,
lt
may
be
achieved
by
changing
resistor
Rl9
(see
Paragraph
5-82).
3-28
Use
stable,
low
noise,
low
temperature
coef-
PROGRAM
Ml
NG
RESISTOR
Figure
3-5.
Remote
Resistance
Programming
(Constant
Current)
3-3
ficient
(less
than
30ppm!°C)
programming
resistors
to
maintain
the
power
supply
t~ture
coefficient
and
stability
specifications.
A
switch
may
be
used
to
set
discrete
values
Of
output
CWTent. A
make-
before-break
type
of
switch
should
be
used
since
·
the
output
current
will
exceed
the
maximum
rating
of
the
power
supply
if
the
switch
contacts
open
during
t,. -
:;\~-!t-:::hing
interval.
------1CAUTI011tN-----
If
the
programming
terminals
(Al
and
A4)
should
apen
at
any
time
during
this
mode,
the
output
current
will
rise
to
a
value
that
may
damage
the
power
sup-
ply
and/or
the
load.
To
avoid
this
pos-
sibility,
connect
a lSK
resistor
across
the
programming
terminals
and
in
paral-
lel
with
a remote programming
resistor.
Like
the
programming
resistor,
the
lSK
resistor
shol.ild
be
of
the
low
noise,
low
temperature
coefficient
type.
3-29
Voltage
Programming
(Figure
3-6).
In
this
mode,
the
output
current
will
vary
linearly
with
changes
in
the
programming
voltage.
The
program-
ming
voltage
should
not
exceed
1.8
Volts.
Voltage
in
excess
of
1~8
Volts
will
result
in
excessive
power
dissipa.tion
in
the
instrument.
and
·possible
damage.
Al
A2·A3
A4
AS
A6 A7
AB
A9
-S
-
GHO
+
+S
AIO
't::J'~'~'
REFERENCE
RL
VOLTAGE
Figure
3-6.
Remote
Voltage
Programming
(Constant
Current)
3-30
The
output
current for Model 6207B
supplies
will
be
the
programming
voltage
divided
by
7.5 ohms.
For Model 6209B
supplies,
it
will
be
the
program-
ming
voltage
divided
by 15
ohms.
The
current
re-
quired
from
the
voltage
source
will
be
less
than
25
microamperes.
The
impedance
(Rx)
as
seen
looking
into
the
programming
voltage
source
should
be
ap-
proximately
500
ohms
if
the
temperature
coefficient
and
stability
specifications
of
the
power
supply
are
to
be
maintained.
The programming
accuracy
is
10%
of
the
programmed
current.
3-31
REMOTE
SENSING (See Figure
3-7)
3-32
Remote
sensing
is
used
to
maintain
good
reg-

HP Lab Series Specifications

General

Brand	HP
Model	Lab Series
Category	Power Supply
Language	English