Improved Electric Fan Speed Control for A/C Condenser and Engine Cooling Systems

A two-speed DC motor utilizing a dual armature winding has been developed as an improved solution to fan speed control with respect to cost, reliability, power conversion efficiency, electro-magnetic compatibility, speed flexibility, and packaging concerns. This development provides a simple means to select fan speeds optimally satisfying the air conditioning and engine cooling systems demand for heat rejection with lower noise and power consumption.

This two-speed motor can also be employed in a two-fan system to output a variable voltage to speed control a second conventional fan motor. In this manner, the second motor acquires these advantages of the dual-wind motor. In addition, system advantages are gained by commonizing the RFI suppression for each motor and, in simplifying the vehicular wire harness connection to the two-fan system.