Potentiostat inverting type

An extended and improved potentiostat circuit is shown in Fig. 2.65. This circuit, the so-caUed inverting type, is widely used in practice as it is very reliable. One of the three OAs in Fig. 2.65, OA3, is connected to act as current follower. It keeps the working electrode input WORK at zero potential and outputs a voltage signal proportional to the electrolysis current. OA2 ensures that the reference electrode is kept free from current flow. OAl is the controlling amplifier. In this special case, it makes the potential at WORK equal to the inverted reference voltage I7ref. 

Fig. B4 Potentiostat circuit of non-inverting type with two level shifters connected to DAC, or ADC, respectively. For further explanations, see text...

A different type of potentiostat circuit is constructed by an adder-type OA circuit (Fig. 9) rather than the follower type of Fig. 8. The adder (or summing) OA input allows multiple control inputs for example, an offset potential may be added to a separate voltage ramp. Since the adder inputs are not high impedance, a voltage follower buffers the output of the reference electrode. Also, note that inverted control... 

---