Power blackout bulb

A blackout light bulb has a housing with an Edson screw at one end for screwing into a light fixture socket and a plurality of spaced apart LEDs mounted to its opposite end. A flexible stalk is connected to the housing between the Edison screw and the LEDs and can be bent into a selected shape for positioning a free end of the stalk as desired. A circuit board in the housing has an electronic circuit connected to the Edison screw, to the LEDs and to a photo cell at the free end of the stalk. A rechargeable battery in the housing is connected to the circuit board so that it is charged under certain normal conditions and so that it lights up the LEDs under other blackout conditions.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates generally to the field of lighting, and in particular to new and useful power blackout bulb that has an Edison screw to be screwed into a conventional Edison light socket, for example the standard socket in high-hat lighting fixtures.

The designation Exx is used to identify various Edison screws in common use today and refers to the diameter of the screw in millimeters. For example, an E12 Edison screw has a diameter of 12 mm. There are four common sizes of screw-in sockets used for line-voltage lamps: candelabra—E12 in North America and E11 in Europe; intermediate—E17 in North America and E14 (SmallES) in Europe; medium or standard—E26 (MES) in North America and E27 (ES) in Europe; and mogul—E39 in North America and E40 (GoliathES) in Europe.

Standard incandescent filament light bulbs that us the standard Edison screws are slowly being replaced by Compact Fluorescent Lights (CFL) and Light Emitting Diode (LED) bulbs that use the same screws so that they can fit in the same sockets, but use much less energy and are longer lasting as well.

Go to: http://eartheasy.com/live_energyeff_lighting.htm for a comprehensive explanation of the advantages of CFL and LED bulbs.

Light responsive light fixtures are known that use photo cells that sense the ambient light to active the fixture when the ambient light is low in order to illuminate an area at such times. Emergency lights are also know that sense a blackout or power failure condition illuminate are area at such time.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an emergency or blackout light that replaces one of the standard screw-in bulbs in an Edison screw socket in an area, the emergency light operating during normal periods when power is being suppled to the socket to charge a battery or other electric power storage element in the bulb, and when a sensor in the bulb senses that there is little or no ambient light and that there is also no power, e.g. because of a black-out condition, powers one or more LEDs in the bulb to illuminate the area. During low light conditions with power on, the blackout light's circuit continues to charge the battery or other power storage element like a capacitor (collectively called a battery herein for simplicity) and at the same time supplies a lower current to the LEDs for low illumination of the area.

Another object of the invention is to provide a blackout light bulb having a housing with an Edson screw at one end for screwing into a light fixture socket and a plurality of spaced apart LEDs mounted to its opposite end, with a flexible stalk connected to the housing between the Edison screw and the LEDs that can be bent into a selected shape for positioning a free end of the stalk as desired. A circuit board in the housing has an electronic circuit connected to the Edison screw, to the LEDs and to a photo cell at the free end of the stalk. A rechargeable battery in the housing is connected to the circuit board so that it is charged under certain normal conditions, and so that it lights up the LEDs under blackout conditions.

According to another object of the invention the circuit includes components for executing a first mode of operation during a high ambient light condition when the photo cell sends a first signal and AC power is being supplied by the Edison screw for charging the battery; a second mode of operation during an intermediate ambient light condition, when power is supplied to the socket, the photo cell sending a second signal to partly light the LED and charge the battery; a third mode of operation during a high ambient light condition with no power supplied to the socket, the photo cell sending the first signal and not lighting the LEDs and not charging the battery; and a fourth mode of operation during a low ambient light condition and no power supplied to the socket, the photo cell sending a third signal for fully lighting the LEDs until the battery is exhausted.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, in which like reference numerals are used to refer to the same or similar elements,FIGS. 1 and 2show a blackout light bulb10that comprises a generally cylindrical housing12having an illumination end12aand a base end12b. An Edson screw14such as an E26 screw, is connected to the base end12bof the housing12for screwing into a light fixture socket100of a light fixture such as a high hat fixture110shown inFIGS. 4A and 4B.

The invention includes a flexible stalk18having a first end connected to the housing12at a location about half way between the illumination end12aand the base end12bof the housing12. The flexible stalk18has an opposite free end that carries a photo cell34thereat, and the stalk itself is bendable into and holds any selected shape so that the free end of the stalk and therefore its photo cell can be positioning at any selected location with respect to the illumination end of the housing12. The inventor has found that by placing this free and its attached photo cell34near an outer rim132of the high hat fixture110as shown inFIGS. 4A,4B and5, the correct amount of ambient light reaches the photo cell, without being confused by or causing an undesired feedback condition by light coming from the LEDs mounted at the illumination end of the bulb10or from other sources.

As also shown inFIG. 4A, an electronic circuit board20with an electronic circuit30thereon, is mounted in the housing12and is electrically connected by wires42to the known contact sections of the Edison screw, for receiving AC power from the Edison screw when it is screwed into a light fixture socket100to which power is being supplied, such as 110 volts of AC power that is conventional in North America.

Returning toFIGS. 1 and 2, a plurality of spaced apart LEDs, LED1to LEDnare mounted to the illumination end12aof the housing, under a clear plastic dome16fixed, e.g. by permanent adhesive cement, around the perimeter of the base12a. The circuit board20shown inFIG. 4Aas well, is mounted in the housing and its circuit30is electrically connected to a rechargeable battery32that is mounted in the housing. The circuit30has components that operate to create a plurality of operating modes, at least one of the modes being for supplying electrical power for charging the battery32and at least one other one of the modes being for supplying electrical power from the charged battery32to the circuit for lighting the LEDs during a blackout condition.

With reference toFIG. 3, the photo cell34mounted at the free end of the stalk18and electrically connected to the circuit30by wires52, sends a first, low resistant signal to the circuit under a first high ambient light condition such as when there is day light, a second, medium resistance signal to the circuit under a second intermediate ambient light condition such as when other lighting is on from other light fixtures in the same area, and a third, high resistance signal to the circuit under a third low ambient light condition such as a night.

As will be explained in greater detail below, the circuit30includes conventional electronic components for executing: a first mode of operation during the first high ambient light condition when the photo cell sends the first signal and AC power is being supplied by the Edison screw14for charging the battery; a second mode of operation during the second intermediate ambient light condition when power is being supplied to the socket, the photo cell sending the second signal to partly light the LED and charge the battery32; a third mode of operation during a first high ambient light condition with no power supplied to the socket when the photo cell sends the first signal for not lighting the LEDs and not charging the battery; and a fourth mode of operation during the third low ambient light condition and no power supplied to the socket when the photo cell sends the third signal for fully lighting the LEDs to act as a blackout light of area until the battery is exhausted.

High hat fixtures110that are also called hi-hat fixtures, are most often used in groups as shown, for example, inFIG. 5, to illuminate an area of a house, office or other area, such as a family room or hallway. According to the invention, one high hat110in the group on a ceiling130is provided with the screw-in blackout bulb10of the invention so as to illuminate the area under the ceiling during a blackout period when there is no other ambient light available such as at night. The remaining high hats110contain conventional light bulbs120, such as flood or spot light bulbs for illuminating the area during normal times when light is needed.

FIG. 3illustrates the circuit30on circuit board20mounted in the bulb housing12. When the10bulb of the invention is screwed into the standard Edison socket100of the high hat ceiling fixture110and a wall switch is closed to supply power to the socket, 110 Volt AC current goes through capacitor C3though a rectifying bridge D1-D4to a diode D6and the power is reduced to 4.3 volts.

As discuses generally above, the circuit30is designed to accommodate four situations by containing conventional electrical components that are connect to operate as follows.

A. During day time hours with the power on, the photo cell34senses the higher ambient light level and its resistance will become lower so the current is block by transistor Q3and therefore the LEDs LED1to LED6will not light. The battery32is charged up to, e.g. 3.7 volts maximum during this time.

B. At night with the power on since the photo cell34senses no light or minimum light, the resistance will become higher and current will go through Q1, R3, R4and Q3at a low rate and make the LEDs partially light up. The battery will discharge power but maintain at 3.7 volts.

C. During the day (i.e. a high ambient light condition) but with a power blackout condition (i.e. no power to the light fixture socket), since the photo cell34senses light, it blocks Q3and the LEDs will not lite. The battery32will also not be charged or discharged.

D. At night time (i.e. low or not light condition) with a power blackout, due to the photo cell34sensing no light or minimum light, the resistance will become higher, block transistor Q1and current will go through R3, R4, Q2and Q3so that the LEDs LED1to LED6will light up at their maximum until the battery32is exhausted, which the inventor has found to be several hours on an initially fully charged battery32.

In the circuitry, Q1plays a major role to control the light intensity during power on/off. The photo cell32identifies day and night. Using a 3.2 volt lithium battery32can prolong the life time of the product up to 5 years.

Although 6 LEDs are shown in the circuit30and14inFIG. 3, any number of LEDs can used that can be accommodated by the circuit30and the battery32. Advantageously the blackout bulb of the invention has about 6 to 8 LEDs and can last three to four days without recharging.

Circuit30also has a master switch56for completely deactivating all battery charging and LED functions. Switch56is open primarily for periods of transport and storage. Before the blackout bulb10is to be screwed into its high hat fixture110for use, the switch56is closed and left closed for the duration of the bulbs use.

Returning toFIGS. 4A and 4B, the stalk18as shown in the enlargementFIG. 4B, has a outer flexible plastic sheath50, made for example of heat shrinking material, that contains a pair of wires52that connect the photo cell34to the circuit30, and a length of flexible, repeatedly bendable metal or plastic54, that can be bend into any desired shape and that keeps that shape so that the photo cell34can be placed near the perimeter132of the high hat110. Soldering wire has been found to be a good candidate for the bendable material52.