1-13
Remote Sensin
. To remote sense with auto-series operation,
set SENSE switch of the master unit and set SENSE switch of the
slave unit to remote.
Remote Analo
Volta
e Pro
rammin
. To remote analo
pro-
ram with auto-series operation, connect pro
ram (external) volt-
a
es to the "CV" or "CC"" terminal of the master unit and set "CV"
or "CC" switch of the master unit to remote.
AUTO-TRACKING OPERATON
Auto-trackin
operation of power supplies is similar to auto-series
operation except that the master and slave supplies have the
same output polarit
with respect to a common bus or
round.
This operation is useful where simultaneous turn-up, turn-down or
proportional control of all power supplies is required.
Fi
ure 14 and Fi
ure 15 show two and three supplies connected
in auto-trackin
with their ne
ative output terminals connected
to
ether as a common or
round point. For two units in auto-
trackin
a fraction R2/(R1+R2) of the output of the master suppl
is provided as one of the inputs to the comparison amplifier of the
slave suppl
, thus controllin
the slave's output. The master sup-
pl
in an auto-trackin
operation must be the positive suppl
hav-
in
the lar
est output volta
e. Turn-up and turn-down of the
power supplies are controlled b
the master suppl
. In order to
maintain the temperature coefficient and stabilit
specifications of
the power suppl
, the external resistor should be stable, low
noise, low temperature.
Determinin
Resistors. External resistors control the fraction of
the master unit's volta
e that is supplied from the slave unit. For
two units in auto-trackin
the ratio R1 and R2 is
R2/(R1+R2 = (Vs/Vm)
Where Vm = master output volta
e
Vs = slave output volta
e
It is recommended to connect a 0.1 ยตF capacitor in paral-
lel with R2 in two supplies operation or R2 and R4 in
three supplies operation to ensure the stable operation.
Settin
Volta
e and Current. Use the master unit's VOLTAGE con-
trol to set the output volta
e from both units. When the master is in
CV operation, the master's output volta
e(Vm) is the same as its
volta
e settin
, and the slave's output volta
e for two units operation
is Vm(R2/(R1+R2)). The VOLTAGE control of the slave unit is dis-
abled. Set the CURRENT controls of master and slave units above
the required currents to assure CV operation of master and slave
units.
Overvolta
e Protection. Set the OVP shutdown volta
e in each
unit so that it shuts down at a volta
e hi
her than its output volt-
a
e durin
auto-trackin
operation. When a master unit shuts
down, it pro
rams an
slave units to zero output. When a slave
unit shuts down, it shuts down onl
itself.
Remote Sensin
. To include remote sensin
with auto-trackin
operation independentl
, set up each unit for remote sensin
accordin
to the remote-sensin
instructions under previous
para
raph.
Remote Analo
Pro
rammin
.
To simultaneousl
remote pro-
ram both units' output volta
es, set up onl
the master unit for
remote volta
e pro
rammin
accordin
to the remote pro
ram-
min
instructions. To var
the fraction of the output volta
e contri-
bution b
the slave unit, connect a variable resistor in place of R2
in two units operation. To independentl
remote pro
ram each
unit's output current settin
, set up each unit for remote control of
output current accordin
to the instructions under "Remote Pro-
rammin
, Constant Current" para
raph.
Fi
ure 14. Auto-Trackin
Operation of Two Supplies
Fi
ure 15. Auto-Trackin
Operation of Three Supplies
MASTER
SLAVE
CV CC SENSE
LOCAL
REMOTE
OUT
+S -S
+
_
CV CC
VREF
A1 A2 A3 A4 A5
+
+
M/S 1 M/S 2
__
MASTER
SLAVE
CV CC SENSE
LOCAL
REMOTE
OUT
+S
-S
+
_
CV CC
VREF
A1 A2 A3 A4 A5
+
+
M/S 1 M/S 2
_
_
MASTER POWER SUPPLY
SLAVE POWER SUPPLY
R1 R2
LOAD
LOAD
MASTER
SLAVE
CV CC SENSE
LOCAL
REMOTE
OUT
+S
-S
+
_
CV CC
VREF
A1 A2 A3 A4 A5
+
+
M/S 1 M/S 2
__
MASTER POWER SUPPLY
MASTER
SLAVE
CV CC SENSE
LOCAL
REMOTE
OUT
+S
-S
+
_
CV CC
VREF
A1 A2 A3 A4 A5
+
+
M/S 1 M/S 2
__
SLAVE POWER SUPPLY(S1)
MASTER
SLAVE
CV CC SENSE
LOCAL
REMOTE
OUT
+S
-S
+
_
CV CC
VREF
A1 A2 A3 A4 A5
+
+
M/S 1 M/S 2
__
SLAVE POWER SUPPLY(S2)
R1 R2
R3 R4
Vs1 =
R2
R1+
R2
Vm
Where
Vm = masters unit's output volta
e
Vs1 = slave(S1) unit's output volta
e
Vs2 = slave(S2) unit's output volta
e
LOAD
LOAD
LOAD
Vs2 =
R4
R3+
R4
Vs1
