Lighting device having resettable over-current protection function
地域：
Fujian
摘要
A lighting device having resettable over-current protection function includes a light source module, a power supplying module, a DC-to-DC converting module, an over-current short-circuit protection module, a reference voltage generating module and a self-locking protection module. The power supplying module generates an input voltage. The DC-to-DC converting module converts the input voltage into a driving voltage to drive the light source module. The over-current short-circuit protection module generates a voltage detecting by detecting a driving current passing through the light source module. The reference voltage generating module generates a reference voltage according to the input voltage and the voltage detecting signal. The self-locking protection module generates a control signal according to the input voltage and the reference voltage to turn off the over-current short-circuit protection module in order to perform a self-locking protection mode, such that the DC-to-DC converting module is disconnected from the light source module.
說明書
The present invention relates to a lighting device, in particular to a lighting device having resettable over-current protection function.
Currently, portable lighting devices such as flashlights, handheld spotlights, handheld work lights, headlamps, etc., are widely used. These portable lighting devices are all powered by batteries and achieve different lighting functions through circuits. In order to enhance the safety of these lighting devices, most currently available portable lighting devices have short-circuit protection mechanisms, such as fuses, comparator lockout protection circuits with amplifiers, and resettable fuses.
However, once the fuse of a lighting device melts, the user needs to repair the lighting device, which is highly inconvenient. The comparator lockout protection circuit with an amplifier can repeatedly activate the short-circuit protection function but is only suitable for specific lighting devices. Moreover, this protection circuit cannot trigger the short-circuit protection function when the duty cycle of the pulse width modulation (PWM) signal is very small. Therefore, the application of the comparator lockout protection circuit is greatly limited, and its safety still needs to be further improved.
Resettable fuses can also repeatedly activate the short-circuit protection function. However, after the short-circuit protection function is triggered, there will still be some current in the circuit of the lighting device, which will reduce the service life of the battery of the lighting device.
權(quán)利要求
What is claimed is:1. A lighting device having resettable over-current protection function, comprising:a light source module; a power supplying module configured to generate an input voltage; a DC (direct-current)-to-DC converting module configured to convert the input voltage into a driving voltage to drive the light source module; an over-current short-circuit protection module configured to generate a voltage detecting by detecting a driving current passing through the light source module; a reference voltage generating module configured to generate a reference voltage according to the input voltage and the voltage detecting signal; and a self-locking protection module configured to generate a control signal according to the input voltage and the reference voltage to turn off the over-current short-circuit protection module in order to perform a self-locking protection mode, whereby the DC-to-DC converting module is disconnected from the light source module. 2. The lighting device having resettable over-current protection function as claimed in claim 1 , further comprising an integral module configured to generate an integral signal according to the voltage detecting signal and output the integral signal to the self-locking protection module, whereby the self-locking protection module maintains the self-locking protection mode. 3. The lighting device having resettable over-current protection function as claimed in claim 2 , wherein the power supplying module has a power source positive electrode and a power source negative electrode, and the DC-to-DC converting module has an input terminal, a first output terminal and a second output terminal, wherein the input terminal is connected to the power source positive electrode, the first output terminal is connected to a positive electrode of the light source module, the second output terminal is connected to a first node and a grounding point, and a negative electrode of the light source module is connected to a second node. 4. The lighting device having resettable over-current protection function as claimed in claim 3 , wherein a combination of the over-current short-circuit protection module, the reference voltage generating module, the self-locking protection module and the integral module forms a resettable over-current protection circuit, and the resettable over-current protection circuit comprises a first transistor, a second transistor, a third transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a diode and a first capacitor. 5. The lighting device having resettable over-current protection function as claimed in claim 4 , wherein a first end of the first transistor is connected to a third node, a second end of the first transistor is connected to the second node, and a third end of the first transistor is connected to a fourth node, wherein a first end of the second transistor is connected to a fifth node, a second end of the second transistor is connected to the third node, and a third end of the second transistor is connected to a sixth node, wherein a first end of the third transistor is connected to the sixth node, a second end of the third transistor is connected to one end of the fifth resistor, and a third end of the third transistor is connected to the fifth node, wherein another end of the fifth resistor is connected to a seventh node, the seventh node is connected to the power source positive electrode, wherein two ends of the second resistor are connected to the seventh node and an eighth node respectively, and two ends of the first resistor are connected to the fifth node and the eighth node respectively, wherein two ends of the third resistor are connected to the first node and the fourth node, respectively, and two ends of the fourth resistor are connected to the second node and the third node respectively, wherein two ends of the sixth resistor are connected to the fourth node and the fifth node respectively, and two ends of the seventh resistor are connected to the first node and the sixth node respectively, wherein two ends of the first capacitor are connected to the first node and the fifth node respectively, and two ends of the diode are connected to the first node and the eighth node respectively. 6. The lighting device having resettable over-current protection function as claimed in claim 5 , wherein the first transistor, the second transistor and the third transistor are metal-oxide-semiconductor field-effect transistors or bipolar junction transistors. 7. The lighting device having resettable over-current protection function as claimed in claim 5 , wherein the diode is a Zener diode or a three-terminal voltage regulator. 8. The lighting device having resettable over-current protection function as claimed in claim 1 , wherein when the power supplying module is disconnected from the DC-to-DC converting module, the self-locking protection mode is automatically turned off. 9. The lighting device having resettable over-current protection function as claimed in claim 1 , wherein the power supplying module is a battery or a DC power source. 10. The lighting device having resettable over-current protection function as claimed in claim 1 , wherein the light source module is a light-emitting diode.
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