Abstract: An intrinsically safe energy limited circuit for space-restricted applications includes a fuse and resistor in series with a protected circuit or component wherein the fuse dissipates most of the power when the protected circuit or component is short circuited.

Abstract: A single combination task lamp and flashlight instrument, providing separate flood and spot light beams, independently controlled in a three-state sequence by simple push button switches. The two kinds of light beams are produced by separate arrays of compact light emitting devices. both arrays are driven by a single, rechargeable battery powered electrical circuit that provides separate, regulated constant currents to the respective arrays of LEDs. The optics and electronics are constructed in a single, ruggedized, compact module. The module is enclosed within an elongated handle that positions the center of mass for optimum balance of the instrument and the control switches for convenient operation according to the sense of touch.

Abstract: An intrinsically safe energy limited circuit for space-restricted applications includes a fuse and resistor in series with a protected circuit or component wherein the fuse dissipates most of the power when the protected circuit or component is short circuited.

Abstract: A method is provided for reducing the power rating of a current limiting resistor (R) in a branch circuit having at least one protected element and the current limiting resistor connected between first and second nodes. The method includes the steps of: determining a maximum fault current in the branch circuit; determining a total current limiting resistance to limit the current in the branch circuit having the short-circuited elements to the maximum fault current; inserting a fuse having an intrinsic resistance in the branch circuit; and dividing the determined total current limiting resistance between the resistor (R) and the intrinsic resistance of the fuse.

Abstract: A method of using a single pole, single throw switch having normally open contacts in a conductive path in a non-intuitive manner in an electric circuit to sequentially provide three operable states including latched engagement (path closed, circuit OFF), momentary disengagement (path opened, circuit ON momentarily), and latched disengagement (path open, circuit ON until switch actuated again).

Abstract: An intrinsically safe energy limited circuit for space-restricted applications includes a fuse and resistor in series with a protected circuit or component wherein the fuse dissipates most of the power when the protected circuit or component is short circuited.

Abstract: A single drive circuit is configured to drive disparate current loads of first and second combinations of compact light emitting devices with respective regulated constant currents. Standard push ON, push OFF latching switches provide independent control of the two lighting loads wherein each switch operates in three states including momentary ON, continuous ON, and OFF. The circuit is readily adapted to providing continuous or pulsed drive to the lighting arrays. Circuits for dimming control, strobe control, and a low battery indicator are also described.

Abstract: A single combination task lamp and flashlight instrument, providing separate flood and spot light beams, independently controlled in a three-state sequence by simple push button switches. The two kinds of light beams are produced by separate arrays of compact light emitting devices. both arrays are driven by a single, rechargeable battery powered electrical circuit that provides separate, regulated constant currents to the respective arrays of LEDs. The optics and electronics are constructed in a single, ruggedized, compact module. The module is enclosed within an elongated handle that positions the center of mass for optimum balance of the instrument and the control switches for convenient operation according to the sense of touch.

Abstract: An electronic ballast circuit for a handheld fluorescent task lamp, comprising a self-starting electronic driver circuit operated by a power supply and operable to start and run at least first and second compact fluorescent bulbs from a single output; first and second receptacles for connecting the first and second bulbs to the single output; and a bulb accommodation circuit in the electronic driver circuit that enables operation of the electronic ballast circuit with either starter or non-starter type fluorescent bulbs and with either one or both bulbs.