Current Sinking OperationCurrent SinkingRegenerative OperationCurrent SinkingCurrent sinking, also referred to as downprogramming, is the ability to pull current into the positiveterminal of the DC power supply. For example, the power supply pulls or sinks current into the positiveterminal whenever a lower output voltage is programmed. This is necessary because stored energyfrom the power supply's output capacitor and external capacitance from the load including the wiringmust be discharged to lower the voltage at the output terminals.The ability to rapidly transition from a higher to a lower constant voltage level greatly improves thepower supply’s output response time. This is the most commonly used application of the regenerativefunction of the RPS, which is automatic and completely transparent to the user.The DC power supply can continuously sink up to 100% of its rated current for an indefinite time. Thistwo-quadrant sourcing and sinking capability of the DC power supply allows for seamless transitionsbetween sourcing and sinking current without changing the power supply’s output characteristics orintroducing any disruptive behavior. The following controls are provided to fully utilize the two-quadrant output capability of the supply.Current Limit control in voltage priority modeWhen operating in voltage priority mode, you can program a negative and positive current limit. Thiswill limit any current overshoots that may occur during rapid up- or down-programming.Current setting control in current priority modeWhen operating in current priority mode, you can program the output current to seamlessly cross thezero point when transitioning from positive to negative or negative to positive. Additionally, whenoperating in the negative current quadrant, you can program a negative current setting that will holdthe sink current at the specified value. This is useful, for example, for discharging a battery at aconstant current rate.If your application requires precise control of the source and sink currents, current slew controls areavailable to specify a current slew rate when sourcing and sinking current.Regenerative OperationRegenerative operation is automatic and requires no programming on the part of the user. Wheneverthe unit is sinking current, either by rapidly downprogramming the output, or by discharging an energysource such as a battery, the unit will direct the excess power back into the AC mains.4 Using the Regenerative Power System118 Keysight RP7900 Series Operating and Service Guide
