US 2011/0254498 A1 · Constant-Speed Control Circuit for BLDC Motors

Abstract

A speed-control circuit for a BLDC motor is provided. The speed-control circuit includes a pulse generator, a current source circuit, a filter circuit, an error amplification circuit and a PWM circuit. The pulse generator detects a speed signal of the BLDC motor to generate a pulse signal. The filter circuit is coupled to the current source circuit to generate an average signal. The error amplification circuit receives the average signal and a speed-reference signal for generating a speed-control signal. The PWM circuit generates a switching signal to drive the BLDC motor in response to the speed-control signal. A pulse width of the switching signal is determined by the speed-control signal.

Claims9

Dependent claims

A speed-control circuit for a BLDC (Brushless Direct Current) motor comprising:

a pulse generator, coupled to detect a speed signal of said BLDC motor for generating a pulse signal in response to a rising-edge or a falling-edge of said speed signal;
a current source circuit, controlled by said pulse signal;
a first filter circuit, coupled to said current source circuit, for generating an average signal;
an error amplification circuit, coupled to receive said average signal and a speed-reference signal for generating a speed-control signal;
and
a PWM (Pulse Width Modulation) circuit, generating a switching signal to drive said BLDC motor in response to said speed-control signal;
wherein a pulse width of said switching signal is determined by said speed-control signal.

4 more elements

Dependencies are inferred from the claim text.

Constant-Speed Control Circuit for BLDC Motors

Life of this patent

Constant-Speed Control Circuit for BLDC Motors

Life of this patent

Abstract

Claims9