US-20260123807-A1 - DAUGHTER BOARD FOR VACUUM CLEANER

Abstract

One embodiment provide an air movement device including a housing, a motor within the housing and generating an airflow, a sensor terminal to detect water during operation of the motor, a circuit board including a controller coupled to the sensor terminal, and an electrostatic discharge protection circuit electrically connected between the sensor terminal and the controller. The electrostatic discharge protection circuit limits electrostatic discharge current between the sensor terminal and the controller.

Inventors

• Zichen Tan
• Jonathan S. Pinske

Assignees

• MILWAUKEE ELECTRIC TOOL CORPORATION

Dates

Publication Date

20260507

Application Date

20251104

Claims (20)

1. 1 . A power tool comprising: a sensor terminal; and an electrostatic discharge protection circuit connected to the sensor terminal and configured to limit electrostatic discharge current.
2. 2 . The power tool of claim 1 , wherein the electrostatic discharge protection circuit is configured to route an excess current to a ground connection.
3. 3 . The power tool of claim 1 , further comprising a controller electrically connected to the sensor terminal via the electrostatic discharge protection circuit.
4. 4 . The power tool of claim 1 , wherein the electrostatic discharge protection circuit is provided on a circuit board.
5. 5 . The power tool of claim 1 , further comprising: a housing; a hose connected to the housing; and a motor configured to generate an airflow through the hose and provide a suction force to draw debris and fluid into the housing.
6. 6 . The power tool of claim 2 , further comprising a battery pack, wherein the ground connection is a negative battery reference.
7. 7 . The power tool of claim 2 , further comprising an AC power source, wherein the ground connection is a protective earth ground connection.
8. 8 . The power tool of claim 2 , further comprising: a battery pack including a negative battery reference, and an AC power source including a protective earth ground connection.
9. 9 . The power tool of claim 8 , wherein the electrostatic discharge protection circuit includes a first current path configured to route the excess current to the negative battery reference and a second current path configured to route the excess current to the protective earth ground connection.
10. 10 . The power tool of claim 9 , wherein the electrostatic discharge protection circuit includes a first capacitor and a first resistor configured to limit the excess current along the first current path and a second capacitor and a second resistor configured to limit the excess current along the second current path.
11. 11 . The power tool of claim 10 , wherein the first capacitor and the first resistor are configured to absorb a transient current event of the excess current as the excess current is routed along the first current path.
12. 12 . The power tool of claim 10 , wherein the second capacitor and the second resistor are configured to absorb a transient current event of the excess current as the excess current is routed along the second current path.
13. 13 . A power tool comprising: a first circuit board configured to interface with a power source, the power source having a negative or ground connection; a second circuit board including: a sensor terminal; and an electrostatic discharge (ESD) protection circuit electrically connected to the sensor terminal, the ESD protection circuit configured to provide a current path to the negative or ground connection.
14. 14 . The power tool of claim 13 , wherein the sensor terminal includes one or more water sensing probes the one or more water sensing probes configured to output a signal to the ESD protection circuit in response to detecting water.
15. 15 . The power tool of claim 13 , further comprising: a first capacitor and a first resistor electrically connected to the current path, the first capacitor and the first resistor configured to absorb a transient current event.
16. 16 . The power tool of claim 13 , wherein the power source is a DC power source, the power tool further comprising: a DC motor control circuit provided on the first circuit board, the DC motor control circuit configured to drive a motor using power received power from the DC power source.
17. 17 . The power tool of claim 13 , wherein the power source is an AC power source, the power tool further comprising: an AC motor control circuit provided on the first circuit board, the AC motor control circuit configured to drive a motor using power received power from the AC power source.
18. 18 . The power tool of claim 13 , further comprising: a controller electrically provided on the first circuit board, wherein the second circuit board is configured to route a signal from the sensor terminal through the ESD protection circuit to the controller, the ESD protection circuit configured to prevent excess current from the sensor terminal from damaging the controller.
19. 19 . An air movement device comprising: a housing; a motor within the housing and configured to generate an airflow; and a sensor terminal configured to detect water during operation of the motor; a circuit board including a controller communicatively coupled to the sensor terminal; and an ESD protection circuit electrically connected between the sensor terminal and the controller, the ESD protection circuit configured to limit electrostatic discharge current between the sensor terminal and the controller.
20. 20 . The air movement device of claim 19 , wherein the ESD protection circuit is configured to route an excess current to a ground connection.

Description

RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63/716,537, filed November 5, 2024, the entire contents of which are incorporated herein by reference. FIELD The present disclosure relates to daughter board having an electrostatic discharge circuit for a vacuum cleaner. SUMMARY In some aspects, the techniques described herein relate to a power tool including a sensor terminal and an electrostatic discharge protection circuit connected to the sensor terminal and configured to limit electrostatic discharge current. In some aspects, the techniques described herein relate to a power tool including a first circuit board configured to interface with a power source, the power source having a negative or ground connection, a second circuit board including a sensor terminal, and an electrostatic discharge (ESD) protection circuit electrically connected to the sensor terminal, the ESD protection circuit configured to provide a current path to the negative or ground connection. In some aspects, the techniques described herein relate to an air movement device including a housing, a motor within the housing and configured to generate an airflow, and a sensor terminal configured to detect water during operation of the motor, a circuit board including a controller communicatively coupled to the sensor terminal, and an ESD protection circuit electrically connected between the sensor terminal and the electronic processor, the ESD protection circuit configured to limit electrostatic discharge current between the sensor terminal and the controller. In some examples, the techniques described herein relate to a power tool including a sensor terminal and an electrostatic discharge limiting circuit connected to the sensor terminal and configured to limit electrostatic discharge current. In some examples, the electrostatic discharge limiting circuit is configured to route an excess current to a ground connection. In some examples, the power tool further includes an electronic processor electrically connected to the sensor terminal via the electrostatic discharge limiting circuit. In some examples the electrostatic discharge limiting circuit is provided on a circuit board. In examples, the power tool further includes a housing, a hose connected to the housing, and a motor configured to generate an airflow through the hose and provide a suction force to draw debris and fluid into the housing. In some examples, the power tool includes a battery pack, wherein the ground connection is a negative battery reference. In some examples, the power tool further includes an AC power source, wherein the ground connection is a protective earth ground connection. In some examples, the power tool further includes a battery pack including a negative battery reference, and an AC power source including a protective earth ground connection. In some examples, the electrostatic discharge limiting circuit includes a first current path configured to route the excess current to the negative battery reference and a second current path configured to route the excess current from the sensor to the protective earth ground connection. In some examples, the electrostatic discharge limiting circuit includes a first capacitor and a first resistor configured to limit the excess current along the first current path and a second capacitor and a second resistor configured to limit the excess current along the second current path. In some examples, the first capacitor and the first resistor are configured to absorb a transient current event of the excess current as the excess current is routed along the first current path. In some examples, the second capacitor and the second resistor are configured to absorb a transient current event of the excess current as the excess current is routed along the second current path. BRIEF DESCRIPTION OF DRAWINGS FIGS. 1A and 1B are perspective views of a power tool, according to some aspects. FIG. 2 is a functional block diagram of an arrangement of circuit boards in a power tool, according to some aspects. FIG. 3 is a block diagram of a controller, a power source, and a motor of a power tool, according to some aspects. FIG. 4 is a circuit diagram of a circuit board of FIG. 2, according to some aspects. FIG. 5 is a plan view of the circuit board of FIG. 4, according to some aspects. DETAILED DESCRIPTION Before any embodiments are explained in detail, it is to be understood that the embodiments are not limited in application to the details of the configurations and arrangements of components set forth in the following description or illustrated in the accompanying drawings.  The embodiments are capable of being practiced or of being carried out in various ways.  Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting.  The use of “including,” “comprising,” or “having” and variations thereof ar