The process for controlling the power supply of a telephone of a cellular radiotelephone network, of which the transmission power is controlled by the network according to a power class indicated by the telephone, consists of. First, a seed layer is formed on the substrate by combining a first precursor with a reducing agent by CVD. Both punches are able to move in translation andor rotation with respect to one another, and the ejector is arranged so as to expel cores from each punch. Alternatively, whether the small-size-paper passing ratio is higher than a predetermined value is used as the predetermined condition.