Patent ID: 7629756

Claim:
A controller for operating first and second motors, the first motor operating at a first rate and producing a first current, the second motor operating at a second rate and producing a second current, the controller comprising: a processor configured to supply a control signal for driving the first and second motors and further configured to produce first and second sampling triggers, the control signal based on the first and second currents, the first sampling trigger coordinated with the first rate, the second sampling trigger coordinated with the second rate, the processor comprising a converter configured to sample the first and second currents in response to a third sampling trigger; and a logic circuit coupled to the processor and configured to produce the third sampling trigger from a logic OR of the first and second sampling triggers, the processor further configured to produce a modified pulse width in the first sampling trigger if a period between the first and second sampling triggers is less than a predetermined limit, the converter further configured to consecutively sample the first and second currents in response to the modified pulse width.