Patent Application
20120013479
1. Field of the Invention
The present invention relates to an error detection module of a Light Emitting Diode (LED) system and driving device; in particular, to a LED system and driving device with error detection utilizing a high voltage error detection module to determine whether any errors occur in the LED module and the driving device.
2. Description of Related Art
Rapid development in Light Emitting Diode (LED) technologies has spawned a variety of applications of LED in various fields; e.g., display screens or lighting apparatus and the like. Because of the widespread applications of LED, how to ensure the proper operation of LED has been one of the issues that need to be carefully handled.
Short-circuit often causes damages to the LED module as the result of the heat generated accordingly. Absent proper detection and protection measures, the short-circuited LED module could even cause fire. Plus, when the driving circuit of the LED module does not operate properly such as being shut down or partially malfunctioning, unnecessary waste of energy may result when no such detection/protection measure for the LED module is in place.
The present invention is to provide a Light Emitting Diode (LED) system and driving device with error detection as well as an error detection module, thereby detecting whether any short-circuits in the LED module or whether the driving circuit operates normally.
To achieve the aforementioned objectives, in accordance with one embodiment of the present invention, an error detection module of a LED system and driving device is provided, wherein the error detection module is electrically coupled to a LED module, a driving circuit of the LED module and a control module, thereby providing a detection signal to the error detection module before a determination signal to the control module may be generated. The control module is electrically connected to the LED module and the driving circuit for receiving the determination signal and generating a control signal based on the received determination signal.
The error detection module includes a high voltage determination unit and a reverse current protection unit. The high voltage determination unit is used to compare the detection signal with a reference signal; suppose the detection signal is greater than the reference signal in voltage level, the determination signal will be outputted. The reverse current protection unit is electrically coupled to the high voltage determination protection unit thereby preventing the current from flowing back to the LED module and the driving circuit.
Herein the high voltage determination unit may be a comparator, and the reverse current protection unit may include a field effect transistor and a transistor control unit. The transistor control unit controls the conductivity of the field effect transistor thereby preventing the current from flowing back to the LED module and the driving circuit.
The summary illustrated hereinbefore as well as the embodiments set forth as below are all for further explaining the technical means and achieves effects of the present invention; whereas the embodiments and drawings described in the present disclosure are simply directed to be referential, rather than being intended to limit the present invention.
The LED module 101 is an illuminating component featuring higher lighting efficiency than conventional light sources and also a longer lifespan. The driving circuit 103 is electrically coupled to the LED module 101 for driving the LED module 101 and adjusting the brightness of the LED module 101 based on user's settings or in accordance with environmental conditions.
The error detection module 105 is electrically coupled to the driving circuit 103, which may operate to acquire a detection signal Sdet from the driving circuit 103 and accordingly determine whether the driving circuit 103 operates normally, or any short-circuit in the LED module 101; if the determination indicates that driving circuit 103 operates abnormally or the LED module 101 is short-circuited, a determination signal Serr is outputted representing the occurrence of errors in the circuit. Herein the detection signal Sdet may be a voltage signal of a certain potential. Suppose the voltage levels of the voltage signals differ when the driving circuit 103 operates normally and abnormally, the error detection module 105 may accordingly decide that the errors may occur on the part of the circuitry before outputting the determination signal Serr to the control module 107.
The control module 107 is electrically coupled to the LED module 101, the driving circuit 103 and the error detection module 105. Upon the receipt of the determination signal Serr issued by the error detection module 105, the control module 107 outputs a control signal SLED or Sdrv so as to interrupt operations of the LED system to prevent damages in the circuitry or unnecessary waste of electrical power.
Nevertheless, it goes without saying that the protective safety measures performed by the control module 107 mentioned as above can be optionally configured in accordance with the user's requirements, herein not being restricted in any sense. For example, in addition to the interruption to the LED system, in another implementation a warning signal may be sent to an electronic device, such as a cellular phone or a personal computer, for reminding the user of the current status in the LED system.
Refer next to
The error detection module 105 includes a high voltage determination unit 1051 and a reverse current protection unit. The high voltage determination unit 1051 may be a comparator, which compares the detection signal Sdet with a reference signal VREF in order to output a determination signal Serr.
In the present embodiment, if the driving circuit 103 does not operation normally (e.g., malfunction or turn off), the voltage level in the detection signal Sdet may climb. And thus the receipt of the detection signal Sdet and setting the voltage level of the reference signal VREF to be lower than the voltage level of the detection signal when the driving circuit 103 operates normally may implement a mechanism that is capable of determining if there is any occurrence of malfunctioning in the driving circuit 103 or the LED module 101. thereby making the reference signal VREF than the voltage under normal operations, in the event that the driving circuit 103 operates abnormally, it is thus possible to output the determination signal Serr indicting the existence of errors by means of the high voltage determination unit 1051. For example, when the driving circuit 103 or the LED module 101 operates normally the detection signal Sdet may be around 10 Volts; but as the driving circuit 103 is OFF, the detection signal Sdet may dramatically climb to 60 Volts. Therefore, the high voltage determination unit 1051 may determine the occurrence of errors according to the reference signal lower than 10 Volts.
Alternatively, in case that a certain portion in the LED module 101 may be short-circuited, the voltage in the detection signal Sdet may increase as well. Therefore, the high voltage determination unit 1051 may be configured to determine the existence of short-circuit in the LED module 101 according to the predetermined and configurable voltage level of the reference signal. It is worth noting that the determination signal may be outputted only after a predetermined number of the LED modules 101 are short-circuited. In other words, when the number of the LED modules 101 that are short-circuited does not exceed the predetermined number, no detection signal may be outputted. To achieve this, the voltage level of the reference signal may be configured so that the high voltage determination unit 1051 may not output the determination signal until after the voltage level of the reference signal has been reached as the result of the short-circuits of the LED modules. For example, the voltage in the detection signal Sdet is 10 Volts when the entire LED modules 101 operate normally, and the voltage of the detection signal may rise 3 to 5 Volts with each short-circuited LED. When the determination signal Serr is configured to be generated only after more than three (3) LEDs are short-circuited, the voltage in the reference signal VREF may be modified so that when the voltage level of the determination signal reaches the voltage level of the modified reference signal the determination signal could be outputted.
The reverse current protection unit has a field effect transistor 1053 and a transistor control unit 1055, in which the field effect transistor 1053 is used to prevent the current from flowing back to the driving circuit 103 and the LED module 101 via the error detection module 105, thereby further protecting the driving circuit 103 and the LED module 101 from damages.
The voltages V1 and V2 may be the driving voltages of the integral LED system, and the field effect transistor 1053 may be conducted when both of the voltages V1 and V2 are normally supplied (that is, the LED system is in operation), further causing the error detection module 105 to detect any presence of error. In other words, when any of the voltages V1 and V2 is not normally supplied, the LED system may not be in operation, requiring no error detection. Thus, the field effect transistor 1053 may not be conducted and the error detection module 105 may be opened without unexpected current flowing back to the driving circuit 103 and the LED module 101 from the error detection module 105, thereby improving stability of the circuitry.
The aforementioned descriptions set forth the illustrations for the embodiments and drawings of the present invention. The scope of the present invention should be based on the following claims, and all changes, alternation or substitutions that those skilled ones in the art can conveniently consider without departing from the field of the present invention should be deemed as being encompassed by the scope of the present invention.
