Patent ID: 8674641
Filing Date: 2014-03-18
Classification: H02P,H03K

Abstract:
1. A cooling system configured to control a temperature associated with an integrated circuit, the cooling system comprising: a brushless motor configured to drive a cooling device based on a rotational speed of the motor; a temperature monitoring input configured to receive an environmental temperature signal indicating a temperature associated with an integrated circuit; a clock input configured to receive a clock signal having a predetermined duty cycle; a motor controller configured to receive the environmental temperature signal from the temperature monitoring input and the clock signal from the clock input and coupled to the brushless motor to control the rotational speed of the motor using at least a speed control method by: wherein the motor controller includes a pulse generating circuit comprising: a minimum duty cycle setup circuit configured to generate a minimum voltage signal that is output to the control pulse output circuit, wherein the minimum voltage signal is compared with the direct current voltage signal, to determine the duty cycle of the control pulse signal, wherein when the voltage of the direct current voltage signal is above the voltage of the minimum voltage signal, the duty cycle of the control pulse signal is determined by the triangular signal and the minimum voltage signal, as wherein Dm is a minimum duty cycle of the control pulse signal, Vh, VI represents a high and low voltage of the triangular signal, and Vmin is the voltage of the minimum voltage signal; wherein, when the voltage of the direct current voltage signal is below the voltage of the minimum voltage signal, the duty cycle of the control pulse signal is determined by the triangular signal and the direct current voltage signal, as wherein D is a duty cycle of the control pulse signal and Vcf is the voltage of the direct current voltage signal.