Abstract: A very high voltage generator switchable between n levels for supplying a capacitative receiver, such as the screen of a polychrome display tube, and comprising a high voltage DC power source suitable for delivering two extreme levels of voltage straddling the n DC voltage levels. The power source is connected to the receiver via at least one series assembly of transistors for each direction of conduction between the power source and the receiver; each series assembly is associated with a control channel for the transistors elaborating an image signal of the error voltage between the value of voltage at the terminals of the receiver and the required level for the operation of each assembly as a switch, at least one of the control channels also comprising a modulator in which the image signal modulates the voltage of an oscillator for the operation of the corresponding assembly as a switching and regulating circuit connected in series with the receiver.