Charged internal combustion engine

The engine has a charging fan (31) that is disposed upstream of and in series with a compressor of one of number of exhaust-driven superchargers (14-16), and a motor (34). Each supercharger has a line connection via a respective valve mechanism to an output of the fan. A computer (19) has stored requirements profiles for the sole release of the mechanism of one supercharger that is to be engaged in a staggered operation. All valve mechanisms are adjusted as a function of speed of a related supercharger and a combustion air operating pressure. The electric motor drives the charging fan.