Brushless DC motor control unit

Patent metadata

Field	Value
Publication number	US-10848084-B2
Application number	US-201816101408-A
Country	US
Kind code	B2
Filing date	Aug 11, 2018
Priority date	Sep 15, 2017
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

An electrical switch unit for use with an electrical device to control operation of a DC motor of the electrical device, the electrical switch unit comprising: a housing which houses a pair of electrical switching contacts, and, an actuator operably connected with at least one of the pair of electrical switching contacts, the actuator being configured for movement relative to the pair of electrical switching contacts so as to arrange the pair of electrical switching contacts into at least one of a closed configuration wherein power is able to be supplied from the DC power source to the DC motor via the pair of electrical switching contacts, and, an opened configuration wherein power is not able to be supplied from the DC power source to the DC motor via the pair of electrical switching contacts; a signaling module associated with the electrical switch unit comprising signaling circuitry for sensing the movement of the actuator and outputting a signaling module signal indicative of the sensed movement or position of the actuator; a power module comprising at least one power switching device for controllably supplying power from the DC power source to the DC motor; a control module comprising control circuitry for receiving the signaling module signal, and responsive to the received signaling module signal, outputting a control module signal to control the at least one power switching transistor device of the power module wherein the at least one power switching device controllably supplies power from the DC power source to the DC motor to allow operation of the DC motor at a speed corresponding to the sensed movement or position of the actuator; and wherein, the signaling module is integrally connected to a first end of the control module that is located within the electrical switch unit housing to allow relatively direct electrical communication between the pair of electrical switching contacts and the control module, and, whereby the control module is configured to extend outwardly of the electrical switch housing so as to terminate at a distal second end.

First claim

What is claimed is:

1. An electrical switch unit for use with a variable speed electrical device to control operation of a DC motor of the electrical device, the electrical switch unit comprising:
a housing which houses a pair of electrical switching contacts, and, an actuator operably connected with at least one of the pair of electrical switching contacts, the actuator being configured for movement relative to the pair of electrical switching contacts in response to operation of a finger-operable trigger so as to arrange the pair of electrical switching contacts into at least one of a closed configuration wherein power is able to be supplied from a DC power source to the DC motor via the pair of electrical switching contacts, and, an opened configuration wherein power is not able to be supplied from the DC power source to the DC motor via the pair of electrical switching contacts;
a signaling module associated with the electrical switch unit comprising signaling circuitry for sensing the movement of the actuator and outputting a signaling module signal indicative of the sensed movement or position of the actuator;
a power module comprising at least one power switching device for controllably supplying power from the DC power source to the DC motor; and
a control module comprising control circuitry for receiving the signaling module signal, and responsive to the received signaling module signal, outputting a control module signal to control the at least one power switching device of the power module wherein the at least one power switching device controllably supplies power from the DC power source to the DC motor to allow operation of the DC motor at a speed corresponding to the sensed movement or position of the actuator;
wherein, the at least one of the pair of electrical switching contacts, the signaling module, the control module and the power module are integrally formed together in a single PCB, said PCB including at least one of electrical conductive pins, conductive pathways, and conductive buses integrally embedded in the PCB via which the at least one of the pair of electrical switching contacts, the signaling module, the control module and the power module are in electrical communication, and
the control module is configured to extend outwardly of the housing so as to terminate at a distal end of the control module.

2. An electrical switch unit as claimed in claim 1 wherein the DC motor is a brushless DC motor.

3. The electrical switch unit of claim 2 wherein the at least one power switching device includes a MOSFET device.

4. The electrical switch unit of claim 1 wherein the at least one power switching device includes a MOSFET device.

5. An electrical switch unit as claimed in claim 1 including a protective resin coating for protecting components of at least one of the signaling module, the control module and the power module.

6. An electrical switch unit as claimed in claim 1 including a heat dissipation and/or heat dispersion element arranged in thermal communication with a bottom region of the power module to allow heat dissipation from the power module.

7. An electrical switch unit as claimed in claim 1 including a first and second heat dissipation and/or heat dispersion element arranged in thermal communication with a bottom region and a top region of the power module respectively to allow heat transfer from the power module.

8. An electrical device comprising an electrical switch unit in accordance with claim 1 .

9. An electrical device as claimed in claim 8 wherein the electrical device includes at least one of an electrical power tool and an electrical gardening tool.

10. A customisable electrical switch unit for use with a variable speed electrical device to control operation of a DC motor of the electrical device, the electrical switch unit comprising:
a housing which houses a pair of electrical switching contacts, and, an actuator operably connected with at least one of the pair of electrical switching contacts, the actuator being configured for movement relative to the pair of electrical switching contacts in response to operation of a finger-operable trigger so as to arrange the pair of electrical switching contacts into at least one of a closed configuration wherein power is able to be supplied from a DC power source to the DC motor via the pair of electrical switching contacts, and, an opened configuration wherein power is not able to be supplied from the DC power source to the DC motor via the pair of electrical switching contacts;
a signaling module associated with the electrical switch unit comprising signaling circuitry for sensing the movement of the actuator and outputting a signaling module signal indicative of the sensed movement or position of the actuator;
a power module comprising at least one power switching device for controllably supplying power from the DC power source to the DC motor;
a control module comprising control circuitry for receiving the signaling module signal, and responsive to the received signaling module signal, outputting a control module signal to control the at least one power switching device of the power module wherein the at least one power switching device controllably supplies power from the DC power source to the DC motor to allow operation of the DC motor at a speed corresponding to the sensed movement or position of the actuator; and
an electrical connector interface having a plurality of connector pins via which the power module and the control module are able to be directly electrically connectable to a single PCB, said single PCB including at least one of the pair of electrical switching contacts and the signaling module integrally formed therein, and whereby said single PCB includes at least one of electrical conductive pins, conductive pathways, and conductive buses integrally embedded therein via which the at least one of the pair of electrical switching contacts, the signaling module, the control module and the power module are in electrical communication.

11. An electrical switch unit as claimed in claim 10 wherein the DC motor includes a brushless DC motor.

12. An electrical switch unit as claimed in claim 10 wherein the at least one power switching device includes a MOSFET device.

13. An electrical switch unit as claimed in claim 10 including a protective resin coating for protecting components of at least one of the signaling module, the control module and the power module.

14. An electrical switch unit as claimed in claim 10 including a heat dissipation and/or heat dispersion element arranged in thermal communication with a bottom region of the power module to allow heat dissipation from the power module.

15. An electrical switch unit as claimed in claim 10 including a first and second heat dissipation and/or heat dispersion element arranged in thermal communication with a bottom region and a top region of the power module respectively to allow heat transfer from the power module.

Assignees

• Defond Electech Co Ltd
• Defond Components Ltd

Inventors

• Nieh Cheng Chen
• Wong Wai Man
• Kong Ming Leong
• Kwok Pat On

Classifications

• B25F5/00 Primary

  Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for · CPC title

• H01H13/12

  Movable parts; Contacts mounted thereon · CPC title

• H02P6/08

  Arrangements for controlling the speed or torque of a single motor (H02P6/10, H02P6/28 take precedence) · CPC title

• H03K17/04123

  in field-effect transistor switches · CPC title

• H02P1/18

  for starting an individual DC motor · CPC title