Discharge state indicator

Patent metadata

Field	Value
Publication number	US-9989596-B2
Application number	US-201213417443-A
Country	US
Kind code	B2
Filing date	Mar 12, 2012
Priority date	Dec 29, 2005
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

A circuit for displaying the state of a battery that is almost discharged features a battery, an inductive load, and a controllable switch connected in series. The circuit also includes a display element connected in series with the inductive load and the battery. The controllable switch is opened when a voltage of the battery is lower than a first threshold level and is only closed again when the voltage of the battery is greater than a second threshold level. The circuit may also include a control circuit having a comparator which compares the voltage of the battery with the first threshold level and the second threshold level and triggers the controllable switch accordingly.

First claim

What is claimed is:

1. A battery-operated shaver comprising:
a discharge state indicator circuit comprising:
a battery,
an inductive load connected to the battery,
a controllable switch connected in series with the inductive load and the battery, and
a display element connected in series with the inductive load and the battery, wherein when a voltage of the battery is lower than a first threshold level the controllable switch opens to change a state of the display element and a voltage that is induced in the inductive load is added to the voltage of the battery sufficient for operating the display device.

2. The battery-operated shaver of claim 1 , wherein the controllable switch prevents operation of the inductive load when the voltage of the battery is lower than a second threshold level.

3. The battery-operated shaver of claim 1 , wherein the second threshold level is greater than the first threshold level.

4. The battery-operated shaver of claim 1 , wherein the inductive load has a higher electric power consumption than the display element.

5. The battery-operated shaver of claim 1 , wherein the inductive load comprises an electric motor.

6. The battery-operated shaver of claim 5 , wherein the controllable switch prevents operation of the electric motor when the voltage of the battery is lower than a second threshold level.

7. The battery-operated shaver of claim 6 , wherein the second threshold level is greater than the first threshold level.

8. The battery-operated shaver of claim 6 , further comprising a mechanical switch connected in series with the controllable switch, the inductive load, and the battery.

9. The battery-operated shaver of claim 8 , wherein the electric motor is prevented from operation even when the mechanical switch is closed.

10. The battery-operated shaver of claim 1 , wherein the display element comprises a light-emitting diode.

11. The battery-operated shaver of claim 10 , wherein the light-emitting diode flashes indicating a nearly discharged state of the battery.

12. The battery-operated shaver of claim 1 , wherein the controllable switch comprises a transistor.

13. The battery-operated shaver of claim 12 , wherein a collector-emitter segment of the transistor is connected in series with the inductive load and the battery.

14. The battery-operated shaver of claim 12 , further comprising a control circuit having an input terminal connected to the battery and an output terminal connected to a base terminal of the transistor, wherein the control circuit is configured to control the transistor based on the voltage of the battery.

15. The battery-operated shaver of claim 12 , wherein the display element is connected in parallel with a collector-emitter segment of the transistor.

Assignees

• Klemm Torsten
• Roenneberg Gerrit
• Gillette Co Llc

Inventors

• Klemm Torsten
• Rönneberg Gerrit

Classifications

• G01R31/3682 Primary

  Physics · mapped topic

• B26B19/388

  Sensors; Control · CPC title

• B26B19/3873

  Electric features; Charging; Computing devices · CPC title

• G01R31/3646 Primary

  for indicating electrical conditions or variables, e.g. visual or audible indicators · CPC title