Page 2.3
6-CHANNEL BATTERY SIMULATOR MODULE 41-752
pickering
SECTION 2 - TECHNICAL DESCRIPTION
USING THE 41-752 BATTERY SIMULATOR
Sense Line Connections
The two sense lines for each channel of the battery simulator should be connected to the remote load so the battery
simulator corrects for any voltage drop in the connecting wires. If the sense wires are not connected to the remote
load the battery simulator will sense the voltage at the module front panel and regulate the voltage to the requested
value.
Isolation
Each battery simulator channel is fully isolated and can withstand a common voltage of up to 750V relative to PXI
ground.
It is recommended that one point of the battery simulator chain output is referred to a reference voltage (for example
ground on the most negative series cell) in order to avoid the unintended creation of high common mode voltages.
The connection to a reference voltage can be a low resistance connection (for example a wire) or a high value
resistance (e.g. 100kΩ) that can be easily driven by the user to the required output voltage.
Current Sinking
If the user wishes to allow the 41-752 to sink current (i.e. behave like a battery when connected to a charger) as well
as source current then the internal current sink should be set. The output regulator can only source current, so the
ability to sink current like a battery is achieved by adding a programmable current sink that loads the output with a
known amount of current even when there is no load current.
If the module is asked to sink a current from a charger then the regulator makes up the difference between the
charging current and the sink current that has been programmed.
The sink current programmed can limit the current that can be delivered to the load. The sink current is made to be
programmable so the user can set the current to suit the charger capacity. Normally the sink current should be set
to the maximum charger current expected.
It should be noted that the current sinks only operate correctly for output voltages above 0.5 Volts.
In applications where a charging simulator may be present and the output current required is 200mA or less it is
recommended that user sets the current sink to 100mA.
If the battery simulator channel is connected to a charger whose output current exceeds the sum of the current sink
set and the load current, the output voltage of the channel will rise above the set value of the channel voltage. Typically
it initially rises by 100mV above the set value for low excess currents and then then increases with increasing excess
charger current. The output voltage accuracy and regulation characteristics will be degraded. No damage will occur
to the channel for all reasonable charger implementations.
41-752-001
BATTERY SIMULATOR MODULE - ONE CHANNEL
Programmed
Current
Sink
Channel
Voltage
Source
+
–
Channel
Load
Charger
Current
Load
Current
Figure 2.3 - Connection of the Battery Simulator to a Charging Circuit
