Patent ID: 8807956

Claim:
A fan system comprising: a first control module external to a motor housing of a fan assembly and comprising a speed module, wherein the fan assembly comprises a fan and the motor housing; and a cable comprising a first set of conductors configured to connect a motor in the motor housing to a first connector, a second set of conductors configured to connect a second connector to the first control module, wherein the second connector is configured to connect to the first connector, a third set of conductors configured to connect the first control module to a third connector, wherein the second set of conductors, the second connector, the first control module, the third set of conductors, and the third connector are implemented as an assembly, and wherein the assembly is removable from the cable via the second connector and the third connector, and fourth set of conductors configured to connect a fourth connector to a second control module, wherein the fourth connector is configured to connect to the third connector, and wherein the second control module is separate from the first control module and is configured to generate a control signal, wherein the first control module is configured to detect an induced voltage in a first stator coil within the fan housing, via the first set of conductors and the second set of conductors, without receiving a signal from a sensor in the fan housing, the speed module is configured to (i) control a speed of the fan based on the control signal, (ii) detect a position of the fan based on the induced voltage in the first stator coil, and (iii) adjust the speed of the fan from a first speed to a second speed based on the position, and the first speed and the second speed are greater than zero.