Combination emergency light and nightlight

1. Field of Invention

The invention relates to emergency lights and nightlights, for illuminating an area of a wall in a hallway, kitchen, bedside area or any household area that might need emergency lighting and more particularly to a small light being rechargeable by induction charging, and an illumination unit thereof being adapted to remove from the light to be used as a portable light.

2. Description of Related Art

Emergency light is a battery powered lighting device that comes on automatically when a building experiences a power outage or in the event of fire. However, conventional emergency lights are bulky and thus are not portable.

There have been numerous suggestions in prior patents for emergency light. For example, U.S. Pat. No. 6,336,729 discloses an emergency light device.

Nightlights are well known small light sources and are typically in indoor dark area.

Thus, continuing improvements in the exploitation of combination emergency light and nightlight are constantly being sought.

It is therefore one object of the invention to provide an induction charged rechargeable light, which when plugged into an AC 120 v electrical wall outlet can be used as nightlight. Moreover, the light has an illumination unit served as an emergency light during power outages. The illumination unit is also removable so as to be used independently as a portable light.

The above and other objects, features and advantages of the invention will become apparent from the following detailed description taken with the accompanying drawings.

FIG. 1 is a side elevation of a preferred embodiment of light according to the invention;

FIG. 2 is a detailed circuit representation of the charging unit of FIG. 1 ; and

FIG. 3 is a detailed circuit representation of the illumination unit of FIG. 1 .

Referring to FIG. 1 , a light 1 in accordance with a preferred embodiment of the invention is shown. The light 1 is small and aims to illuminate an area of a wall in a hallway, kitchen, bedside area or any household area that might need emergency lighting. The light 1 comprises a nightlight 2 , an illumination unit 3 , and a transformer 4 .

The illumination unit 3 is cylindrical as shown. Alternatively, the illumination unit 3 can be shaped other than cylinder. The illumination unit 3 can be used as a portable light as detailed later.

The transformer 4 comprises a large winding 41 mounted in the nightlight 2 , and a small winding 42 mounted in the illumination unit 3 . Alternatively, the small winding 42 is mounted in the nightlight 2 and the large winding 41 is mounted in the illumination unit 3 in other embodiments. The large winding 41 is adapted to generate electromagnetic induction by co-acting with the small winding 42 for charging and achieving other purposes as detailed later.

Referring to FIG. 2 specifically, the components of the nightlight 2 are discussed in detail below. The nightlight 2 is adapted to mate with, for example, a wall outlet to obtain AC (alternating current) power (e.g., 120V AC) therefrom. The nightlight 2 comprises two light-emitting diodes (LEDs) (not shown), an auto/on/off selector switch (not shown), a sensor (not shown), and a charging unit 21 including an input 22 , a voltage decreasing circuit 23 , a full-wave rectifier 24 , a vibration circuit 25 , and an output 26 .

For example, AC 120V power is supplied from a wall outlet to the input 22 . And in turn, voltage value of the AC power is decreased by the voltage decreasing circuit 23 which comprises series connected capacitor C 1 and resistor R 1 and resistor R 9 which is parallel connected to capacitor C 1 . Voltage with decreased value is in turn rectified and filtered by the full-wave rectifier 24 which comprises a bridge rectifier BR 1 for rectifying purpose and a capacitor C 2 for filtering. The vibration circuit 25 then generates a vibration signal to the output 26 . Finally, the vibration signal is sent from the output 26 to the large winding 41 . The vibration circuit 25 comprises capacitors C 3 , C 4 , C 5 , resistors R 2 , R 3 , and transistor Q 1 .

Referring to FIG. 3 specifically, the components of the illumination unit 3 are discussed in detail below. The illumination unit 3 comprises a jack J 1 , an electromagnetic induction control circuit 32 , a display control circuit 33 , a half-wave rectifier 34 , a voltage stabilizing circuit 35 , a lithium battery protection circuit 36 , a sensor (not shown), and an on/off switch (not shown).

The small winding 42 is electrically connected to the jack J 1 . AC energy is transferred from the large winding 41 to the small winding 42 when an electromagnetic induction is generated. AC is then rectified by diode D 3 so as to control the cut-off and conduction of transistors Q 3 , Q 4 . And in turn, on, off, and blinking of six LEDs L 1 , L 2 , L 3 , L 4 , L 5 , and L 6 (see an enlarged view of “LED” on the bottom of FIG. 3 ) can be controlled by the transistors Q 3 , Q 4 during charging. Preferably, dim, bright, and blinking of the LEDs L 1 to L 6 means fully charged, activation, and charging states of the illumination unit 3 respectively.

The electromagnetic induction control circuit 32 comprises diode D 3 , resistor R 1 , capacitor C 2 , and transistor Q 1 . The display control circuit 33 comprises a switch S 1 , resistors R 2 , R 3 , R 4 , R 6 , a capacitor C 5 , transistors Q 3 , Q 4 , an integrated circuit (IC) U 1 , and six LEDs L 1 , L 2 , L 3 , L 4 , L 5 , and L 6 . Note that the number of LEDs can be more or less in other embodiments.

Diode D 5 of the half-wave rectifier 34 is for rectifying the AC energy supplied from the jack J 1 to generate DC (direct current). Zener Diode D 1 and capacitor C 1 of the voltage stabilizing circuit 35 are for voltage stabilization and filter. Resistor R 6 of the display control circuit 33 is for limiting voltage value. States of transistors Q 3 , Q 4 , and IC U 1 can be controlled by switching the switch S 1 on or off by triggering. As a result, on, off, and blinking of the LEDs L 1 , L 2 , L 3 , L 4 , L 5 , and L 6 can be controlled.

The lithium battery protection circuit 36 is electrically connected to the display control circuit 33 . The lithium battery protection circuit 36 comprises resistors R 5 , R 7 , R 8 , capacitors C 3 , C 4 , C 5 , and ICs IC 2 , IC 3 . IC IC 2 is for monitoring the charging voltage of a rechargeable lithium battery BAT in order to prevent over voltage or over current (i.e., overcharging) from occurring. Moreover, IC IC 2 is for monitoring whether the lithium battery BAT is too low or a short circuit being occurred during discharge. The IC IC 3 is adapted to disable the circuit for the protection of the lithium battery BAT if any irregularity occurs.

An individual may insert prongs (not numbered) of the light 1 into, for example, a wall outlet to activate the charging unit 21 so as to charge the rechargeable lithium battery BAT of the illumination unit 3 by transferring AC energy by electromagnetic induction from the large winding 41 in the nightlight 2 to the small winding 42 in the illumination unit 3 . The charging will be stopped when the rechargeable lithium battery BAT is fully charged.

The light 1 can be used as a typical nightlight. For example, an individual may slide the selector switch to auto mode so that the nightlight 2 is adapted to turn on automatically when surrounding area becomes dark because it has a sensor. Alternatively, the individual may slide the selector switch to on mode so that the nightlight 2 may be on continuously. Still alternatively, the individual may slide the selector switch to off mode so as to disable the nightlight 2 .

The LEDs L 1 to L 6 of the illumination unit 3 will emit light automatically as sensed by the sensor thereof when experiencing a power outage, i.e., an absence of AC.

Further, the illumination unit 3 will be disabled when it senses a termination of the activating condition, such as the restoration of AC. Still further, the illumination unit 3 can be removed from the nightlight 2 to be used independently as a portable light. Preferably, the LEDs L 1 to L 6 of the illumination unit 3 emit light (i.e., turned on) immediately after removing from the nightlight 2 . Still preferably, the sensor of the illumination unit 3 may disable the LEDs L 1 to L 6 (i.e., turned off) immediately after placing the illumination unit 3 in the nightlight 2 and electrically connecting thereto. An individual may turn off the illumination unit 3 by pressing the switch thereof after removing from the nightlight 2 .

While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.