Patent Application
20110221344
1. Field of Invention
The invention relates to compact fluorescent lamps and more particularly to such a compact fluorescent lamp being operable in one of three different power sources (e.g., DC power supply, electronic transformer, and electrical transformer).
2. Description of Related Art
Halogen lamps are widely used in automobiles, outdoor lighting, indoor lighting, etc. For example, as shown in
Halogen lamps may get hotter than regular incandescent lamps because the heat is concentrated on a smaller envelope surface, and because the surface is closer to an internal tungsten filament. This high temperature is essential to their operation.
However, people stayed in a room lighted by halogen lamps may feel a degree of discomfort due to the high temperature. Moreover, they are not energy saving lighting sources. Thus, the need for improvement still exists.
It is therefore one object of the invention to provide a compact fluorescent lamp comprising a circuit assembly comprising a rectifier, a plurality of capacitors, a plurality of ICs, a plurality of inductors, a transformer for converting AC to DC, a plurality of diodes, and a PCB; a CFL electrically connected to the circuit assembly; a shade for enclosing the CFL; and a housing for mounting the circuit assembly therein.
Preferably, the lamp can operate in one of three different power sources (e.g., DC power supply, electronic transformer, and electrical transformer).
The above and other objects, features and advantages of the invention will become apparent from the following detailed description taken with the accompanying drawings.
Referring to
A compact fluorescent light bulb (CFL) 1 is electrically connected to a front end of a circuit assembly 2. Both the CFL 1 and the circuit assembly 2 are enclosed by a front cylindrical shade 4 and a rear cylindrical housing 3 respectively. The circuit assembly 2 as the subject of the invention is detailed below.
The circuit assembly 2 comprises a rectifier 21, two capacitors 22, two ICs (integrated circuits) 23, two inductors 24, a transformer 25 for converting AC (alternating current) to DC (direct current), a plurality of diodes 26, and a printed circuit board (PCB) 27. All above components of the circuit assembly 2 are electrically connected together.
Electrical connections of the circuit assembly 2 can be explained as follows. As shown in
In one preferred embodiment as discussed herein, a DC power supply 5 capable of converting AC into DC is provided. The DC power supply 5 has a socket 51 connected to the base of the housing 3 so that DC can be supplied from the power supply 5 to the circuit assembly 2 via the socket 51. In this case, the transformer 25 is bypassed.
Alternatively, the DC power supply 5 is replaced with an electronic transformer of high operating frequency (e.g., in the range of 18 KHz to 500 KHz) in another preferred embodiment. The electronic transformer is a step-down transformer, i.e., decreasing AC voltage and current values.
Still alternatively, the DC power supply 5 is replaced with an electrical transformer of low operating frequency in still another preferred embodiment. The electrical transformer is a step-down transformer, i.e., decreasing AC voltage and current values.
In the above two cases, the transformer 25 is activated to convert AC to DC with decreased DC voltage and current values. Advantageously, the circuit assembly 2 can operate normally when voltage variation is in the range of 2.5 to 21 V.
In brief, the CFL 1 can illuminate normally in each of the above three power sources (i.e., DC power supply, electronic transformer, and electrical transformer).
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.
