Electronic switch module with an integrated flyback diode

Patent metadata

Field	Value
Publication number	US-11477889-B2
Application number	US-201916449755-A
Country	US
Kind code	B2
Filing date	Jun 24, 2019
Priority date	Jun 28, 2018
Publication date	Oct 18, 2022
Grant date	Oct 18, 2022

Abstract

An electronic module is provided including power switches mounted on a circuit board and configured as an inverter circuit for an electric motor. A sliding member is coupled to an actuator. A power contact switch is provided including a first conductive body, a second conductive body, and a contact switch. The first and second conductive bodies are mounted on a first surface of the circuit board and include pins received through through-holes of the circuit board to make electrical contact with two conductive tracks on a second surface of the circuit board. The contact switch pivotably is secured to the first conductive body and pivotably moveable by the sliding member to make contact with the second conductive body with movement of the actuator. A flyback diode is electrically connected between the first and second conductive track on the second surface of the circuit board parallel to the power contact switch.

First claim

The invention claimed is:

1. An electronic module comprising:
a circuit board defining a longitudinal axis and having a first surface and a second surface;
a plurality of power switches mounted on the circuit board and configured as an inverter circuit to supply electric power from a power supply to an electric motor;
a sliding member coupled to an actuator, the actuator causing movement of the sliding member in a direction substantially perpendicular to the longitudinal axis of the circuit board;
a first conductive body mounted on the first surface of the circuit board, the first conductive body including a terminal tab coupled to a positive node of the power supply and a first pin received through a first through-hole of the circuit board to make electrical contact with a first conductive track on the second surface of the circuit board;
a second conductive body mounted on the first surface of the circuit board, the second conductive body including a second pin received through a second through-hole of the circuit board to make electrical contact with a second conductive track on the second surface of the circuit board;
a contact switch pivotably secured to the first conductive body and pivotably moveable by the sliding member to make contact with the second conductive body with movement of the actuator; and
a flyback diode mounted on the second surface of the circuit board and electrically connected between the first conductive track and the second conductive track, the flyback diode being electrically parallel to a current path formed between the first and second conductive bodies via the contact switch.

2. The electronic module of claim 1 , further comprising a module housing having a bottom surface and a plurality of side walls extending from the bottom surface to form an open face, the module housing receiving the circuit board through the open face and retaining the circuit board within the plurality of side walls substantially parallel to the bottom surface and at a distance from the bottom surface.

3. The electronic module of claim 2 , wherein the sliding member is supported within the module housing and the actuator is disposed outside the module housing.

4. The electronic module of claim 1 , wherein the plurality of power switches comprises a plurality of high-side power switches disposed between the positive node of the power supply and the electric motor, and a plurality of low-side power switches disposed between a negative node of the power supply and the electric motor.

5. The electronic module of claim 4 , further comprising a main conductive track disposed on the first surface of the circuit board, the main conductive track including an axial portion that extends along the longitudinal axis of the circuit board arranged to make electrical contact with the plurality of high-side power switches, and a traversal portion arranged to make electrical contact with the second pin of the second conductive body.

6. The electronic module of claim 5 , wherein the second conductive body is mounted on the traversal portion of the main conductive track.

7. The electronic module of claim 5 , wherein each of the plurality of power switches is mounted on the second surface of the circuit board, the plurality of high-side power switches being disposed opposite the axial portion of the main conductive track and connected to the main conductive track via a plurality of conductive vias.

8. The electronic module of claim 7 , further comprising a plurality of heat sinks discretely mounted on the first surface of the circuit board opposite the plurality of power switches and in thermal contact with the plurality of power switches.

9. The electronic module of claim 8 , wherein three of the plurality of heat sinks are mounted on the axial portion of the main conductive track.

10. The electronic module of claim 1 , wherein the contact switch is pivotably attached and electrically connected to the first conductive body via a pivot attachment member, further comprising a compression spring disposed between the contact switch and the first conductive member to bias the contact switch into contact with the second conductive body.

11. The electronic module of claim 10 , wherein the sliding member comprises a main body and a rib projecting from the main body towards the first conductive member, the rib being formed along an axis normal to the first surface of the circuit board.

12. The electronic module of claim 11 , wherein the contact switch includes a contact leg arranged to make contact with the second conductive member and an engagement leg projecting substantially perpendicularly from the contact leg, and wherein the rib engages the engagement leg to force the contact leg out of contact with the second conductive member against a biasing force of the compression spring when the actuator is disengaged.

13. The electronic module of claim 1 , wherein the flyback diode is disposed partially on a gap formed between the first conductive track and the second conductive track.

14. The electronic module of claim 13 , wherein the flyback diode includes a first terminal mounted on the first conductive track and a second terminal mounted on the second conductive track.

15. A power tool comprising:
a housing including a motor housing and a handle portion, the handle portion housing an electronic module according to claim 1 , and the motor housing supporting the electric motor.

Assignees

• Black & Decker Inc

Inventors

• Lewis Joshua M
• Grove Michael D

Classifications

• H01H9/54

  Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere · CPC title

• H05K1/115

  Via connections; Lands around holes or via connections (H05K1/112 takes precedence) · CPC title

• H05K1/0206

  by printed thermal vias · CPC title

• H01H2013/525

  using a return spring acting perpendicular to the actuating direction · CPC title

• H05K3/284

  for encapsulating mounted components (H05K1/185 takes precedence) · CPC title