Speed control circuit of brushless DC fan motor

摘要: There is provided a brushless DC fan motor which can eliminate an oscillator for PWM, control the speed at low cost with high accuracy, and efficiently adjust temperature in housing electronic appliances when radiating heat housing. The rotational thereof controlled by controlling voltage of input terminal drive circuit comprises differential amplifier signal inputted first reference second terminal. linear input-output characteristic, set rise characteristic desired gradient, accuracy without using PWM signal. from output given to circuit.