Portable lighting devices

Patent metadata

Field	Value
Publication number	US-9801256-B2
Application number	US-201615370794-A
Country	US
Kind code	B2
Filing date	Dec 6, 2016
Priority date	Aug 8, 2008
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A flashlight uses a reverse battery protection circuit to prevent current from flowing in a power control circuit when at least one battery is held in a reversed orientation, rather than a correct orientation, in a battery compartment of the flashlight.

First claim

What is claimed is:

1. A flashlight, comprising:
a light source;
a power source comprised of at least one battery held in a battery compartment;
a power control circuit that electrically couples the light source to the power source when said at least one battery is held in a correct orientation in the battery compartment; and
a reverse battery protection circuit that prevents current from flowing in the power control circuit when said at least one battery is held in a reversed orientation in the battery compartment; wherein
the reverse battery protection circuit is comprised of a p-channel metal-oxide semiconductor field-effect transistor (“PMOS”), a source of the PMOS is connected to a positive electrode of the at least one battery held in the correct orientation in the battery compartment or to a negative electrode of the at least one battery held in the reversed orientation in the battery compartment, a gate of the PMOS is connected to a ground, and a drain of the PMOS is connected to an internal voltage supply in the power control circuit.

2. A method for preventing a flashlight from operating when at least one battery is inserted into a battery compartment of the flashlight in a reversed orientation, comprising the steps of using a reverse battery protection circuit to prevent current from flowing in a power control circuit when said at least one battery is held in a reversed orientation, rather than a correct orientation, in the battery compartment and operating the flashlight in the desired mode of operation when the electrical circuit is reconnected after less than the preselected period of time.

Assignees

• Mag Instr Inc
• Mag Intstrument Inc

Inventors

• Maglica Anthony
• West Stacey

Classifications

• F21L4/005

  the device being a pocket lamp (F21L4/022, F21L4/045, F21L4/085 take precedence) · CPC title

• F21V23/0414

  specially adapted to be used with portable lighting devices · CPC title

• F21V23/0428

  the switch being part of, or disposed on the lamp head portion thereof · CPC title

• F21L4/045

  Pocket lamps · CPC title

• Y10T29/49828

  Progressively advancing of work assembly station or assembled portion of work · CPC title