Section 4: Source-measure considerations Model 2461 Interactive SourceMeter® Instrument Reference Manual4-16 2461-901-01 A/November 2015Sink operationWhen the Model 2461 is operating as a sink, voltage and current have opposite polarities and theinstrument is dissipating power rather than sourcing it. The instrument can be forced into sinkoperation by an external source, such as a battery, or an energy storage device, such as a capacitor.For detail on the sink region, see Operating boundaries (on page 4-4).For example, if a 12 V battery is connected to the voltage source (HI to battery high) that isprogrammed for +10 V, sink operation occurs in the second quadrant (source +V and measure –I).Carefully consider and configure the output-off state, source, and limits before connecting the Model2461 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 thedevice. Failure to consider the output-off state, source, and limits may result in damage to theinstrument or to the device under test (DUT).When using the current source as a sink, always set the voltage limit and configure overvoltageprotection (OVP) to levels that are higher than the external voltage level. Failure to do so could resultin 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 theoperating boundaries, the source limit is reached. When the sink limit is reached, the source valueturns yellow and the limit annunciator is active.Battery charge and dischargeTo prevent personal injury or damage to the Model 2461, do not attempt to chargenonrechargeable batteries. Some of the batteries that can be charged with a Model 2461are nickel cadmium (Ni-Cd), nickel metal hydride (Ni-MH), lithium ion (Li-ion), rechargeablealkaline, and lead acid. If you are working with a battery type that is not listed here, pleasecontact your local Keithley office, sales partner, or distributor, or call one of ourApplications Engineers to get technical assistance.Always follow the battery manufacturer's requirements for charging or dischargingbatteries using a Model 2461. Failure to properly charge or discharge batteries may causethem to leak or explode, resulting in personal injury and property damage. Overvoltage andcurrent 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.
