Patent Application
20120326623
The present disclosure relates to a socket adaptor for a light emitting diode (LED) lamp. More particularly, the socket adaptor includes a built-in AC-DC convertor.
A socket adapter for conventional light bulbs (incandescent light bulbs) have a larger external screw base, combined with an internal, smaller screw socket, so that a light bulb having a small screw socket is adapted to a large receiving socket (i.e., a lamp holder). Such a socket adaptor does not usually include any built-in power adapter because the conventional light bulb does not generally require any conversion of electric power.
Recently, an LED light bulb has been developed and has become popular as a replacement of an incandescent light bulb, because of its low power consumption and long life characteristic. An LED can be driven by AC or DC power. In an AC mode, the LED does not light up in a reverse cycle of the AC power. When the AC power is rectified, the LED can be lit up in a full-wave rectified alternating DC mode. For a DC mode, the AC power should be converted to DC power, and therefore an AC-DC converter that converts AC current to DC current is necessary.
There are two known methods for providing DC power to an LED lamp. One method is providing an AC-DC convertor (a DC power supply) in the LED lamp itself. In such a case, heat will build-up in the LED lamp due to the presence of both the DC power supply and the LED lamp, and cost of the LED lamp will increase. Further, it will be necessary to replace the entire LED lamp together with the AC-DC convertor if either one of the LED lamp or the AC-DC convertor fails.
Another method is providing an external AC-DC convertor (DC power supply), for example, in a wall switch or in a lighting fixture. This method avoids the heat build-up in the lamp. Since the increase in temperature in the LED lamp will reduce the efficiency of the LED, such as an external convertor may be desirable in terms of the efficiency of the LED lamp. The external AC-DC convertor, however, frequently requires a box for housing the convertor and a driver circuit, an AC power inlet and a DC output cable, which reduces flexibility of installment of the LED lamps. Having a separately attached AC-DC power convertor is also troublesome since it requires the end-user to install and hide the power supply somewhere away from the LED lamps. This involves additional installment cost.
An example of an external AC-DC convertor for LED lamps is found in U.S. Patent Application Publication No. 2010/0109558, the entirety of which is incorporated herein by reference.
Accordingly, there is a need for a compact and low cost AC-DC conversion system for an LED lamp as a replacement of an incandescent light bulb, which overcomes the foregoing problems.
In order to solve one or more of the foregoing problems associated with the conventional AC-DC conversion system for an LED lamp, the present disclosure addresses one or more of the foregoing needs for an AC-DC conversion system for the LED lamp which is compact and low cost.
In one exemplary embodiment, a socket adaptor for an LED lamp includes an adaptor body and an AC-DC converter disposed in the adaptor body. The adaptor body may include a holder having an internal thread for receiving an external thread of an LED lamp. The adaptor body may further include an external thread for attaching the socket adaptor to a lamp socket. The adaptor body may further include an outer base contact disposed at an end of the socket adaptor, and the outer base contact and the external thread are configured to receive AC power.
The adaptor body may include a GU standard base for attaching the socket adaptor to a GU standard lamp socket, and the adaptor body may further include an outer base contact disposed at an end of the socket adaptor, and the outer base contact and the external thread are configured to receive AC power. The GU standard base may include a first terminal and a second terminal configured to receive AC power.
In any of the above socket adaptors, the holder may further include an inner base contact, and the inner base contact and the internal thread are configured to provide DC power to the LED lamp. Further, in any of the above socket adaptors, the adaptor body may include a bi-pin holder having two holes for receiving a bi-pin electrode of an LED lamp. The adaptor body may further include an external thread for attaching the socket adaptor to a lamp socket or a GU standard base for attaching the socket adaptor to a GU standard lamp socket.
In any of the above socket adaptors, the AC-DC convertor includes a diode-based rectifier and a wave-shaping circuit, and the AC-DC convertor is configured to provide a pulsed DC current. The AC-DC convertor may further include a voltage surge protector and an over-current limiter. The AC-DC convertor may be disposed on a circuit board, and the circuit board may be sealed by an insulating material in the adaptor body. The insulating material may be, for example, epoxy or silicone.
In any of the above socket adaptors, the external thread may have crimping dimples.
In the socket adaptor according to one example of the present disclosure, the adaptor body includes a holder for receiving an LED lamp and the holder is configured according to industrial standards. The adaptor body also includes an external base for attaching the socket adaptor to the lamp holder and the external base is configured according to the industrial standards.
In another example, a lamp system includes any of the above socket adaptors, and an LED lamp coupled to the socket adaptor. The LED lamp is driven by a DC current provided by the socket adaptor.
The socket adaptor of the present disclosure, together with further objects and advantages, can be better understood by reference to the following detailed description and the accompanying drawings.
In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent to those skilled in the art that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.
The lamp holder (a lamp socket) 110 has a lamp holder screw socket (e.g., an internal thread) 107, and fixing holes 102 and 103 for fixing the lamp holder to, for example, a ceiling.
The socket adaptor 106 includes a socket body 111 having an adaptor base (e.g., an internal thread) 105 for receiving the LED lamp screw base 109, and an adaptor screw base (e.g., an external thread) 104 for attaching the socket adaptor 106 to the lamp holder 110. The socket adaptor 106 includes a built-in AC-DC convertor so that the AC power provided through the lamp holder 110 is converted to DC power for driving the LED lamp 108.
In this example, the diameter of the adaptor base 104 is smaller than the diameter of the lamp holder screw socket 107. The adaptor base 104 and lamp holder screw socket 107 are the E-type base-socket (i.e., Edison base-socket).
The GU lamp holder 210 has recesses (e.g., a lamp socket) 207, and fixing holes 202 for fixing the GU lamp holder 210 to, for example, a ceiling.
The socket adaptor 206 includes a socket body 211 having an adaptor base (e.g., an internal thread) 205 for receiving the LED lamp screw base 209 and prongs (i.e., a GU base) 204 for attaching the socket adaptor 206 to the recesses 207 of the lamp holder 210. The socket adaptor 206 includes a built-in AC-DC convertor so that the AC power provided through the lamp holder 210 is converted to DC power for driving the LED lamp 208.
The socket adaptor 320 includes an adaptor housing 301 having an internal screw socket (an internal thread) 303 for receiving an LED lamp. The opening part of the adaptor housing 301 has a tapered edge 319. The other end of the socket adaptor has a portion having a smaller diameter, on which a screw base 302 (an external thread) functioning as one external electrode is attached by using a potting material 318. A screw base contact 306 functioning as the other external electrode is disposed at the bottom of the socket adaptor 320. The screw base 302 is insulated from the screw base contact 306 by a screw base insulation 304. The screw base insulation includes, but not limited to, ceramics or high temperature-resistant plastics.
The screw socket 303 is made of a conductive material (e.g., metal) and functions as one inner electrode. A screw socket contact 307 is disposed on the bottom of the opening part of the adaptor housing 301 and functions as the other inner electrode. The screw socket 303 is insulated from the screw socket contact 307 by a part of the adaptor housing 301.
Inside the socket adaptor 320, the AC-DC convertor 300 is disposed. The AC-DC convertor 300 includes a circuit board 305 having an upper surface on which upper surface components 308 are disposed and a lower surface on which lower surface components 309 are disposed. The AC-DC convertor 300 includes a diode-based rectifier and a wave-shaping circuit, and may be configured to provide a pulsed DC current or a constant DC current. For example, as disclosed in US 2010/0109558, a full-wave rectifier (e.g., MB6S provided by Fairchild Semiconductor) and a current limiting diode (e.g., CMJH180 provided by Central Semiconductor) may be utilized in the AC-DC convertor 300. Optionally, a voltage surge suppressor (e.g., varistor TVR14241 provided by TKS, Thinking Electronics Industrial Co. Ltd) or an over-current protection device (e.g., a resettable fuse 60R010 provided by Littlefuse) may also be utilized.
The AC-DC convertor 300 is disposed in the socket adaptor 320 at the bottom of the socket adaptor 320, preferably within a space between the bottom of the adaptor housing 301 and screw base contact 306. Preferably, the AC-DC convertor 300 is sealed in the socket adaptor 320 by the potting material 318. The potting material is an insulating material, for example, epoxy or silicone.
The AC-DC convertor 300 is configured to receive the AC power from the lamp holder via the screw base 302 and the screw base contact 306, and to provide the converted DC power to the LED lamp via the screw socket 303 and the screw socket contact 307. The circuit board 305 and the screw socket 303 is connected by a PCB (print-circuit board) connection 311, a screw socket connection 310 and a wiring therebetween, and the circuit board 305 and the screw socket contact 307 is connected by a PCB connection 315, a screw base connection 314 and a wiring therebetween. The circuit board 305 and the screw base 302 is connected by a PCB connection 312, a screw base connection 313 and a wiring therebetween, and the circuit board 305 and the screw base contact 306 is connected by a PCB connection 316, a screw base connection 317 and a wiring therebetween.
The AC voltage may be 100-277 V (e.g., 100, 110, 120, 230, 240 or 277 V). After rectification and current limiting action, the DC voltage to the LED is the AC rms value less than the rms value drop across the rectifier and the current limiting diodes. The output DC may be a DC pulse, and the DC level varies with the time cycle (e.g., a frequency of 120 Hz or 100 Hz) depending on the AC input frequency. The frequency of the DC pulse is doubled due to the full-wave rectification.
As shown in
Various types of LED lamps, sockets or bases may be utilized for the socket adaptor of the present disclosure. For example, when the LED lamp 151 has a bi-pin connector as shown in
The shape and configuration of a holder portion for receiving an LED lamp may be any types of lamp sockets according to the industrial standard as shown in, for example,
One of the advantages the socket adaptor of the present disclosure is that an LED lamp does not require its own built-in AC-DC power convertor and does not require a separate cable-attached AC-DC power convertor. Further, the socket adaptor having the AC-DC convertor enables a cooling function of the LED lamp by arranging the AC-DC power convertor, away from the LED lamp, inside the socket adapter. When the base of the socket adapter is attached to the socket connected to the AC power supply, the heat generated by the power supply can be dissipated through the adapter's connection to the AC power socket.
Further, another advantage of the present socket adaptor is that one socket adapter can be used for different LED lamps. By separating the socket adapter, which includes the AC-DC power convertor, from the LED lamps itself, high volume manufacturing of a standard part can be realized and thus the manufacturing cost can be reduced. It also helps to simplify inventory management.
Another advantage is that even if the AC-DC power convertor fails, the LED lamps can still continue to be used by only replacing the socket adapter. Conversely, if the LED lamp fails, the socket adaptor can still be used by simply replacing the failed LED lamp with a new LED lamp, which lowers replacement costs.
Yet another advantage of separating the AC-DC power convertor from the LED lamp is that different specifications of the AC-DC power convertor (e.g., different DC voltages) can be used for the same lamp. For example, a customer may want to use a higher wattage power supply to get more lumen output from the LED lamps. Another customer may want a high efficacy lamp but accepting a lower lumen output. By giving selection of the suitable socket adaptor in view of the LED lamps, the same product can meet the needs of different users.
The use of the socket adapter with an AC-DC power convertor is also advantageous for a drop-in replacement of halogen lamps that is powered up by directly using the AC power. Halogen lamp fixtures include various types of sockets including screw sockets and GU-type sockets. By utilizing the present socket adapter, a common LED lamp can be retrofitted into the various types of halogen lamp sockets.
Similarly, the LED lamps are frequently retrofitted into existing incandescent lamp sockets having various shapes. To meet all the needs of different sockets, it would be necessary to make as many types of LED lamps in view of the various types of socket in the market. However, by utilizing the present socket adaptor having a standard base, the LED lamp can be used in the different types of lamp sockets, which makes it easier for the user to replace the incandescent lamp with an energy efficient LED lamp.
Although certain specific examples have been disclosed, it is noted that the present teachings may be embodied in other forms without departing from the spirit or essential characteristics thereof. The present examples described above are considered in all respects as illustrative and not restrictive. The patent scope is indicated by the appended claims, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
