Granted Patent B2

US 12,588,117 · App. 18/535,385 · Granted Mar 24, 2026

Inventors: Li Zhang (Dongguan City, CN); Hao Cui (Dongguan City, CN); DanJun Guo (Dongguan City, CN)

Assignee: MILWAUKEE ELECTRIC TOOL CORPORATION

H05B45/10F21L4/005F21V15/01F21V23/003F21V23/02F21V23/0414H05B47/10H05B47/16H05B47/17F21Y2115/10

Abstract

Claims (58)

1 . A portable lighting device comprising:

a housing;

a light source supported by the housing;

a power source positioned within the housing and coupled to the light source, wherein the power source is configured to provide a drive current to the light source and an intensity of the light source is dependent on the drive current; and

an electronic processor positioned within the housing and coupled to the light source and the power source, wherein the electronic processor is configured to

monitor a voltage of the power source, and

execute a ramp-up algorithm to control the drive current based on the voltage of the power source, wherein the ramp-up algorithm is executed while the light source is outputting light;

wherein the electronic processor is configured to execute the ramp-up algorithm to:

determine that the power source is partially depleted; and

in response to determining that the power source is partially depleted, incrementally ramp-up the drive current provided to the light source from the power source to a high drive current for a high mode of operation for the light source instead of initially setting the drive current to the high drive current.

2 . The portable lighting device of claim 1 , further comprising an actuator positioned on the housing, wherein the electronic processor is configured to:

determine that the actuator has been actuated; and

execute the ramp-up algorithm in response to determining that the actuator has been actuated.

3 . The portable lighting device of claim 2 , wherein the ramp-up algorithm is executed before the electronic processor generates a signal used to control the drive current provided by the power source to the light source to be constant.

4 . The portable lighting device of claim 1 , wherein the electronic processor is configured to determine that the power source is partially depleted in response to determining that the voltage of the power source is less than a first voltage threshold.

5 . The portable lighting device of claim 4 , wherein the electronic processor is configured to initially set the drive current to the high drive current in response to determining that the voltage of the power source is not less than the first voltage threshold.

6 . The portable lighting device of claim 1 , wherein the light source includes at least one light emitting diode.

7 . A method of controlling a portable lighting device, the method comprising:

monitoring, with an electronic processor, a voltage of a power source,

wherein the electronic processor is positioned within a housing of the portable lighting device,

wherein the power source is coupled to a light source supported by the housing, and

wherein the power source is configured to provide a drive current to the light source, and wherein an intensity of the light source is dependent on the drive current; and

executing, with the electronic processor, a ramp-up algorithm to control the drive current based on the voltage of the power source, wherein the ramp-up algorithm is executed while the light source is outputting light;

wherein executing the ramp-up algorithm includes:

determining, with the electronic processor, that the power source is partially depleted; and

in response to determining that the power source is partially depleted, with the electronic processor, incrementally ramp-up the drive current provided to the light source from the power source to a high drive current for a high mode of operation for the light source instead of initially setting the drive current to the high drive current.

8 . The method of claim 7 , further comprising:

determining, with the electronic processor, that an actuator positioned on the housing has been actuated;

wherein executing the ramp-up algorithm includes executing the ramp-up algorithm in response to determining that the actuator has been actuated.

9 . The method of claim 8 , wherein executing the ramp-up algorithm includes executing the ramp-up algorithm before the electronic processor generates a signal used to control the drive current provided by the power source to the light source to be constant.

10 . The method of claim 7 , wherein determining that the power source is partially depleted includes determining that the power source is partially depleted in response to determining that the voltage of the power source is less than a first voltage threshold.

11 . The method of claim 10 , further comprising initially setting, with the electronic processor, the drive current to the high drive current in response to determining that the voltage of the power source is not less than the first voltage threshold.

12 . The method of claim 7 , wherein the light source includes at least one light emitting diode.

13 . A portable lighting device comprising:

a housing;

a light source supported by the housing;

a power source positioned within the housing and coupled to the light source, wherein the power source is configured to provide a drive current to the light source and an intensity of the light source is dependent on the drive current; and

an electronic processor positioned within the housing and coupled to the light source and the power source, wherein the electronic processor is configured to

monitor a time that the light source has been operating, and

execute a ramp-down algorithm to control the drive current based on the time that the light source has been operating;

wherein the electronic processor is configured to execute the ramp-down algorithm by repeating steps of:

decreasing the drive current, and

delaying a predetermined time period.

14 . The portable lighting device of claim 13 , wherein repeating the steps of decreasing the drive current and delaying the predetermined time period includes ramping down the drive current over a plurality of time stages;

wherein the electronic processor is configured to decrease the drive current such that the drive current reaches a respective predetermined value at an end of each time stage.

15 . The portable lighting device of claim 14 , wherein, during a final stage of the plurality of time stages, the electronic processor is configured to

monitor the drive current provided by the power source to the light source;

control a drive current pulse width modulation (PWM) duty cycle to be maintained at a constant value until the monitored drive current is less than a low drive current threshold; and

in response to determining that the monitored drive current is less than the low drive current threshold, control the drive current to cease providing the drive current to the light source to turn off the light source.

16 . The portable lighting device of claim 13 , wherein the electronic processor is configured to set, by executing a ramp-up algorithm, an initial value of the drive current that is decreased by the ramp-down algorithm.

17 . The portable lighting device of claim 16 , further comprising an actuator positioned on the housing, wherein the electronic processor is configured to:

determine that the actuator has been actuated; and

execute the ramp-up algorithm in response to determining that the actuator has been actuated.

18 . The portable lighting device of claim 17 , wherein the ramp-up algorithm is executed before the electronic processor generates a signal used to control the drive current provided by the power source to the light source to be constant;

wherein the ramp-up algorithm is executed by the electronic processor, in response to determining that the power source is partially depleted, to control the drive current based on the voltage of the power source; and

wherein the ramp-up algorithm is executed while the light source is outputting light.

19 . The portable lighting device of claim 13 , wherein the electronic processor is configured to decrease the drive current by reducing a pulse width modulation (PWM) duty cycle that controls when the power source provides the drive current to the light source.

20 . The portable lighting device of claim 13 , wherein the light source includes at least one light emitting diode.

Assignments (1)

Priority Claims (1)

Continuity (3)

References Cited (165)