SENSORLESS COMMUTATION CIRCUIT AND SENSORLESS DRIVING APPARATUS FOR BRUSHLESS MOTOR
First Claim
1. A sensorless commutation circuit for a brushless motor, comprising:
- a voltage divided unit, outputting a voltage divided signal according to a phase voltage signal of the brushless motor;
a control signal output unit, outputting a filter control signal, wherein the filter control signal has a same switching cycle as a pulse width modulation control signal that drives the brushless motor;
a switch unit, coupled to the control signal output unit and the voltage divided unit, outputting a comparison signal according to the filter control signal and the voltage divided signal; and
a comparison unit, coupled to the switch unit, and outputting a correct commutation signal according to the comparison signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A sensorless commutation circuit and sensorless driving apparatus for a brushless motor includes a voltage divided unit, a control signal output unit, a switch unit and a comparison unit. The voltage divided unit outputs a voltage divided signal according to a phase voltage signal of the brushless motor. The control signal output unit outputs a filter control signal, wherein the filter control signal has a same switching cycle as a pulse width modulation control signal that drives the brushless motor. The switch unit is coupled to the control signal output unit and the voltage divided unit, and outputs a comparison signal according to the filter control signal and the voltage divided signal. The comparison unit is coupled to the switch unit, and outputs a correct commutation signal according to the comparison signal.
6 Citations
10 Claims
-
1. A sensorless commutation circuit for a brushless motor, comprising:
-
a voltage divided unit, outputting a voltage divided signal according to a phase voltage signal of the brushless motor; a control signal output unit, outputting a filter control signal, wherein the filter control signal has a same switching cycle as a pulse width modulation control signal that drives the brushless motor; a switch unit, coupled to the control signal output unit and the voltage divided unit, outputting a comparison signal according to the filter control signal and the voltage divided signal; and a comparison unit, coupled to the switch unit, and outputting a correct commutation signal according to the comparison signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A sensorless driving apparatus for a brushless motor, comprising:
-
a micro controller, outputting a pulse width modulation control signal according to a phase voltage signal; an inverter, coupled to the micro controller, for switching the pulse width modulation control signal to a phase voltage signal of the brushless motor; and a sensorless commutation circuit, coupled to the micro controller and the inverter, the sensorless commutation circuit comprising; a voltage divided unit, outputting a voltage divided signal according to the phase voltage signal of the brushless motor; a control signal output unit, outputting a filter control signal, wherein the filter control signal has a same switching cycle as the pulse width modulation control signal; a switch unit, coupled to the control signal output unit and the voltage divided unit, outputting a comparison signal according to the filter control signal and the voltage divided signal; and a comparison unit, coupled to the switch unit, and outputting the correct commutation signal according to the comparison signal.
-
Specification