System is described for providing a local electrical power source at a header (22) of a combine harvester (10). An alternator (211) is mechanically coupled to a header backshaft (101). The header backshaft (101) is mechanically coupled to a drive mechanism of the combine harvester (10) to cause rotation of the header backshaft (101) which, in turn, causes the alternator (211) to generate electrical power. A power supply circuit transferred electrical power from the alternator (211) to one or more electric devices (223, 225, 227) mounted on the header (22). In some implementations, the header (22) does not include any physical cables between the combine (10) and the header (22).
