Patent number 8710760 is assigned to
The following quote was obtained by the news editors from the background information supplied by the inventors: "The present disclosure relates to a power supply apparatus for Light Emitting Diode (LED), and more particularly, to a power supply apparatus for LED, which protects an LED from an overcurrent that is momentarily generated when the LED is connected to the power supply apparatus for LED.
"In installing a lighting device, generally, the lighting device is installed in a state where an input power has been disconnected, and thereafter, the power is applied.
"However, due to the working environment, a lighting device may be sometimes required to be installed while a power is being supplied continuously. In this case, a power supply apparatus for a lighting device operates in a no-load state.
"FIG. 1 is a circuit diagram illustrating a related art power supply apparatus for LED.
"As illustrated in FIG. 1, when a lighting device such as an LED 2 is mounted on a power supply apparatus 1 for LED, a high current rapidly flows in the LED 2 because energy stored in the power supply apparatus 1 for LED is momentarily applied to the LED 2 due to the low impedance of the LED 2. Particularly, as the number of LEDs 2 is reduced, a higher surge current flows in the LED 2.
"Therefore, a current flowing in the LED 2 is rapidly increased and thus deviates from a normal range, thereby damaging the LED 2. Due to this, the service life of the LED 2 is shortened.
"Moreover, when the current deviating from the normal range flows, the current does fatal damage to the power supply apparatus 1 for LED as well as the LED 2, thereby threatening a user's safety."
In addition to the background information obtained for this patent, VerticalNews journalists also obtained the inventors' summary information for this patent: "Embodiments provide a power supply apparatus for LED, which allows a current equal to or less than a predetermined current to flow in an LED through control when the LED is connected to the power supply apparatus for LED, thereby protecting the LED from an overcurrent.
"However, the present invention should not be construed as limited to the embodiments set forth herein, and it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
"In one embodiment, a power supply apparatus for Light Emitting Diode (LED) includes: a transformer including a primary winding, a secondary winding receiving a power induced from the primary winding, and a tertiary winding receiving the power induced from the primary winding; a first output unit connected to the secondary winding of the transformer, and outputting a first power current to an LED in a first operating condition; and a second output unit connected to the tertiary winding of the transformer, and outputting a second power current to the LED in a second operating condition.
"The first output unit may include: a first rectifier rectifying a power induced to the secondary winding of the transformer; and a first smoother smoothing the power rectified by the first rectifier to output the first power current.
"The second power current may be a power current equal to or lower than a predetermined power current lower than the first power current.
"The second operating condition may correspond to a time when the LED is initially connected.
"The second output unit may include: a second rectifier rectifying a power induced to the tertiary winding of the transformer; a second smoother smoothing the power rectified by the second rectifier; and a voltage divider voltage-dividing the power smoothed by the second smoother to allow the second power current to flow in the LED.
"The second output unit may disconnect an output of the first power current in the second operating condition, and allow the second power current smoothed by the second smoother to be applied to the LED.
"The second output unit may further include a first switch turned on or off by the power which is voltage-divided by the voltage divider.
"The power supply apparatus may further include: a second switch turned on according to the turned-on of the first switch; a first voltage dropper connected to the second switch in parallel; a second voltage dropper connected to the second switch in series, and connected to the first voltage dropper in parallel; and a third voltage dropper connected in series between the secondary winding of the transformer and the first voltage dropper.
"The power supply apparatus may further include: a comparator comparing a reference power and a power, which is voltage-divided by one of the first to third voltage droppers, to output a control signal based on the compared result; and a driver controlling the power, induced to the secondary and tertiary windings of the transformer, according to the control signal outputted from the comparator.
"The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims."
URL and more information on this patent, see: Cho,
Keywords for this news article include: Electronics,
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