Section 4: Source-measure considerations
Model 2461 Interactive SourceMeter® Instrument Reference Manual
4-16
2461-901-01 A/November 2015
Sink operation
When the Model 2461 is operating as a sink, voltage and current have opposite polarities and the
instrument is dissipating power rather than sourcing it. The instrument can be forced into sink
operation by an external source, such as a battery, or an energy storage device, such as a capacitor.
For detail on the sink region, see
(on page 4-4).
For example, if a 12 V battery is connected to the voltage source (HI to battery high) that is
programmed for +10 V, sink operation occurs in the second quadrant (V and measure –I).
Carefully consider and configure the output-off state, source, and limits before connecting the Model
2461 to a device that can deliver energy. Devices that can deliver energy include voltage sources,
batteries, capacitors, and solar cells. Configure instrument settings before making connections to the
device. Failure to consider the output-off state, source, and limits may result in damage to the
instrument or to the device under test (DUT).
When using the current source as a sink, always set the voltage limit and configure overvoltage
protection (OVP) to levels that are higher than the external voltage level. Failure to do so could result
in excessive current flow into the Model 2461 (> 100 mA) and incorrect measurements.
When the instrument is operating as a sink and you set source or limit values that exceed the
operating boundaries, the source limit is reached. When the sink limit is reached, the source value
turns yellow and the limit annunciator is active.
Battery charge and discharge
To prevent personal injury or damage to the Model 2461, do not attempt to charge
nonrechargeable batteries. Some of the batteries that can be charged with a Model 2461
are nickel cadmium (Ni-Cd), nickel metal hydride (Ni-MH), lithium ion (Li-ion), rechargeable
alkaline, and lead acid. If you are working with a battery type that is not listed here, please
contact your local Keithley office, sales partner, or distributor, or call one of our
Applications Engineers to get technical assistance.
Always follow the battery manufacturer's requirements for charging or discharging
batteries using a Model 2461. Failure to properly charge or discharge batteries may cause
them to leak or explode, resulting in personal injury and property damage. Overvoltage and
current protection should be provided in the charge circuit, external to the instrument,
when charging batteries without built-in protection.
Do not charge or discharge batteries that exceed 100 V at 1.0 A, 20 V at 4.0 A, 10 V at 5.0 A,
or 7 V at 7 A.
