Controller for DC brushless motor integrated with a high voltage control system

• US 7,675,256 B2
• Filed: 06/17/2007
• Issued: 03/09/2010
• Est. Priority Date: 08/28/2006
• Status: Active Grant

• Current Assignee: Zhongshan Broad-Ocean Motor Company Limited
• Original Assignee: Zhongshan Broad-Ocean Motor Company Limited
• Inventors: Zeng, Maosen, Peng, Aiqian
• Primary Examiner(s): Ro; Bentsu
• Assistant Examiner(s): DINH, THAI T
• Application Number:
  US11/764,210
• Publication Number:
  US 20080050100A1
• Time in Patent Office: 996 Days
• Field of Search: 318/254.1, 318/400.01, 318/400.3, 318/400.38, 318/560, 318/577
• US Class Current: 318/400.01
• CPC Class Codes: H02P 2201/07 DC-DC step-up or step-down converter inserted between the power supply and the inverter supplying the motor, e.g. to control voltage source fluctuations, to vary the motor speed
• CPC Class Codes: H02P 6/34 Modelling or simulation for control purposes

Abstract

Taught herein is a controller for a direct current brushless motor connected to a high voltage control system, comprising a microprocessor and an input/output interface circuit connected between the high voltage control system and the microprocessor; wherein the input/output interface circuit is a step-down circuit for transforming a high voltage control signal into a low-voltage control signal. The controller enables the high voltage control system to cooperate with motor, therefore a user is not necessary to design a new high voltage control system when replacing the conventional AC motor with the DC brushless motor, which saves time, and reduces cost.

Claims

1. a controller for a direct current brushless motor connected to a high voltage control system, comprising

a microprocessor;

an input/output interface circuit connected between said high voltage control system and said microprocessor;

a rotor position sensing circuit;

an integrated power module;

a current-sensing circuit for sensing current flowing through the motor; and

a power source circuit for supplying power to said microprocessor, said integrated power module, said input/output interface circuit, said current-sensing circuit, and said rotor position sensing circuit;

wherein

said input/output interface circuit is a step-down circuit for transforming high voltage alternating current control signal into a low-voltage direct current control signal;

an input end of said rotor position sensing circuit is connected to an output end of said integrated power module;

an output end of said rotor position sensing circuit is connected to an input end of said microprocessor;

an input end of said current-sensing circuit is connected to an output end of the integrated power module;

an output end of the current-sensing circuit is connected to an input end of said microprocessor; and

said step-down rectifying circuit comprises a photoelectric isolation means.

2. The controller of claim 1, wherein said step-down rectifying circuit with said photoelectric isolation means is a resistance-type step-down circuit.

3. The controller of claim 2, wherein said resistance-type step-down circuit comprises:

a diode, a Zener diode, a first resistor, a second resistor, a third resistor, and a capacitor, and wherein said first diode is connected in series with said first resistor and said second resistor, and said Zener diode is connected between said first resistor and said second resistor and in parallel with said capacitor and said third resistor.

4. The controller of claim 1, wherein said step-down rectifying circuit with said photoelectric isolation means is a capacitance-type step-down circuit.

5. The controller of claim 4, wherein said capacitance-type step-down circuit comprises:

a capacitor, a first diode, a second diode, and a resistor, and wherein the capacitor is connected in series with the first diode and the resistor and the second diode is connected in parallel with the resistor.

6. The controller of claim 1, wherein said integrated power module comprises a gate drive circuit, an H-bridge inverter, and a temperature protection circuit.

7. The controller of claim 1, wherein said photoelectric isolation means comprises a light emitting diode and a phototransistor, said light emitting diode being connected in parallel with a capacitor and said phototransistor being connected in series with a resistor.