×

Speed control circuit of brushless DC fan motor

  • US 20040164692A1
  • Filed: 02/23/2004
  • Published: 08/26/2004
  • Est. Priority Date: 06/25/2001
  • Status: Active Grant
First Claim
Patent Images

1. A speed control circuit of a brushless DC fan motor which is driven by a drive circuit, and controlled in the rotational speed thereof by controlling the voltage of a control input terminal of the drive circuit comprising:

  • a differential amplifier in which the voltage signal for controlling the speed is inputted in a first input terminal and the reference voltage signal is inputted in a second input terminal, wherein the differential amplifier is linear in the input-output characteristic, and can set a rise characteristic of a desired gradient, and give the voltage signal from the output terminal of the differential amplifier to the control input terminal of the drive circuit.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×