5915313 United States Patent 5,915,313 Bender, et. Multiple bins can be formed within a seed hopper by a removable dividing wall. A switch assembly selectively discharges seed from one seed bin in response to control signals generated in a manual or an automatic mode. The control signals are generated using an operator input device in manual mode, and using location signals and a prescription type map in automatic mode.
Discharged seed is received by a distribution assembly for delivery to the row units.
The distribution assembly preferably includes a seed selector for separating individual seeds, and an air delivery system for delivering the individual seeds to the row units. The seed selector may include a rotatable drum driven by a variable-rate motor. The rotation rate determines the rate at which the seeds are dispensed and is controlled by rate control signals generated using the location signals and a prescription rate map. Martin et al. No. 95-1754 Jun. 1995.