A high-voltage transformer has a plurality of elementary transformers. Each elementary transformer comprises an elementary primary circuit configured to be powered by an elementary primary voltage, an elementary secondary circuit comprising at least one secondary winding and at least one capacitor that is connected to the terminals of a secondary winding, and an elementary magnetic circuit configured to couple the elementary primary circuit and the elementary secondary circuit. The output voltage of the transformer is equal to the sum of the elementary balanced secondary voltages, and the elementary primary circuits are connected to one another so as to form a common circuit with the elementary transformers. The common circuit is configured to be supplied by a primary voltage, which is equal to the sum of the elementary primary voltages.