As a result of the specific method used in transforming an operational amplifier into a power supply, some restrictions are placed on the general behavior of the power supply. 

The most important of these are:

(1) The large output capacitor Co limits the bandwidth.

(2) The use of a fixed DC input voltage means that the output voltage can only be one polarity, the opposite of the reference polarity.

(3) The series regulator can conduct current in only one direction. This, together with the fact that the rectifier has a given polarity, means that the power supply can only deliver current to the load, and cannot absorb current from the load.

    0129-9535-23S Special design steps have been added to the design of most Agilent low voltage supplies to permit a significant reduction in the size of the output capacitor merely by changing straps on the rear terminal strip. In Agilent’s line of Bipolar Power Supply/Amplifiers this output capacitor is virtually eliminated by using a special feedback design. In addition, BPS/A instruments are capable of AC output, conduct current in either direction, and their outputs are continuously variable through zero.