A generator is provided inside equipment, such as a sprayer, having a high voltage cascade including a voltage-gain transformer and a voltage multiplier arranged at the output of the transformer. The transformer is a double or multiple transformer, including at least two elementary transformers, whereof respective primary windings are mounted electrically in parallel, and whereof respective secondary windings are mounted electrically in series, the arrangement reducing a diameter of the cascade to facilitate incorporation in the sprayer or other equipment. The invention is applicable to painting robots for the automotive industry.