A field deflection circuit in a picture display device having a sawtooth generator provided with a storage element, for example a capacitor, a first device for causing the quantity of information stored in the storage element to change in one direction during a first part of a field period, and a second device for causing the quantity to change in the opposite direction during a remaining second part of the field period so that an essentially sawtooth-shaped variation is produced. The sawtooth generator is also provided with a control loop for rendering a mean value of the change during the second part of the field period equal to a mean value of the change during the first part of the field period.