User manual

39
© 2008, Elektro-Automatik GmbH & Co. KG
EN
6.12 Functions of the terminal System Bus
6.12.1 Two-quadrants operation
The Share Bus pin (only usable in combination with the
power supplies PS9000 and PSI9000) can be used to set
up a system for two-quadrants operation. In order to use
this operation the System Bus pins have to be wired as
follows:
Connect Pin 5 (Share Bus EL9000) with Pin 5 (Share Bus
PS9000/PSI9000) and Pin 6 (AGND EL9000) with Pin 6
(AGND PS9000).
In this Share Bus operation the electronic load operates as
the leading component and the PS9000/PSI9000 as the
depending one. The Share Bus signal voltage is linearly
controlled by the electronic load in a range of -10V to +10V.
While the signal voltage is positive, the electronic load draws
current from the EUT (the EUT supplies energy) and if it‘s
negative the power supply supplies current to the EUT (the
EUT consumes energy).
Typical applications for the two-quadrants operation are:
• Battery tests with automatic charge and discharge cycles
• Automotive electronic tests with simulation of transients
like for example voltage break-ins during engine starts
• Cyclic charging and discharging of capacitors
6.12.2 Selecting the regulation speed
The regulation speed (or time) of the load has deliberately
been set to slow and lies at typical 50ms (only for CV and
CP mode). By this setting it is accomplished that critical
feeding sources like power supplies with unknown regulati-
on characteristics can be loaded steadily and run free from
unwanted oscillation. The dynamics is then situated at the
givenminimalregulationtime.See„2.Technicalspecica-
tions“, section „Dynamics“.
If a better regulation dynamics is required, it can be activa-
ted by switching the load to fast regulation. This is done at
the terminal System Bus, Pin 7 (FastReg) and 6 (AGnd).
If these pins are shorted, the fast regulation becomes ac-
tive. By default, the slow regulation is active. Changing this
conguration must only happen while the load is completely
switched off from the mains!
6.12.3 Crossowadjustment(two-quadrantoperation)
Operating the load in combination with a power supply of
the series PS9000/PSI9000 necessarily requires the use
of the Share Bus, which is used by the load to control the
power supply. The pins 2 (I-Cross) and 3 (I-Cross-Rtn) of the
terminal System Bus are used to connect a resistor (0,25W)
whichinjectsacrossowcurrentbetweenthepowersupply
and the load. This current effects that load and power supply
are permanently active and thus can react faster to set value
changes. Following applies:
R=0-->Crossowcurrentapprox.10%ofnom.currentof
the device
R=innite-->Crossowcurrent=0(default)
Handling the device
Thecrossowcurrentcanbecontinuouslyadjustedwiththe
resistor from 0 to 10% of the nominal current of the load.
In practice, this is only used in a little number of special ap-
plications where extremely fast load changes are required
between the two quadrants. Common applications like, for
example, automotive start-up transients after DIN40839 do
not require this feature.
6.12.4 Remote sense
The remote sense feature is described in section „5. Instal-
lation“.
6.12.5 Pin assignment of terminal System Bus
Pin 1 = Sense (+)
Pin 2 = I-Cross
Pin 3 = I-Cross-Rtn
Pin 4 = Sense (-)
Pin 5 = Share Bus
Pin 6 = AGnd
Pin 7 = FastReg