Protection circuit for detecting current abnormity of light source and stage lamp provided with protection circuit

Abstract

The utility model relates to the field of stage lamps, in particular to a protection circuit for detecting current abnormity of a light source and a stage lamp provided with the protection circuit, which comprise a light source access, a light source driving module, a current detection module, a singlechip module and a power-off protection module, the current detection module is connected between the light source driving module and the single-chip microcomputer module, the input end of the power-off protection module is connected to the single-chip microcomputer module, and the output end of the power-off protection module is connected to the light source access; the problem that a light source drive circuit is short-circuited or components are damaged due to abnormal current of a light source module in the stage lamp is solved. The current detection module is directly connected into the detected current loop in the light source driving module, so that a low-cost and high-precision current detection scheme is realized, the light source driving module is protected from being burnt out, and the effect of prolonging the service life of the light source driving module is realized.

Description

Technical Field

[0001] The utility model relates to the field of stage lamps, and more specifically, to a protection circuit for detecting abnormal current of a light source and a stage lamp provided with the protection circuit. Background Art

[0002] At present, due to the pursuit of high illumination and high luminous flux in our stage lighting source modules or LEDs, the manufacturers' light source modules or LEDs are becoming more and more expensive. Therefore, in order to reduce the cost of use, when using stage lights, monitor the current of the light source module in real time to avoid frequent replacement of the light source module. There are two types of abnormal current. One is that when the LED driver is affected by temperature or nearby high-frequency lines, strong electrical interference and other factors in the chassis, the LED driver becomes unstable and the current is abnormal; the other is that the LED driver circuit is short-circuited or improper manual operation causes damage to components, resulting in abnormal current. Both abnormalities will cause abnormal current of the LED light source and burnout. Utility Model Content

[0003] The utility model aims to overcome at least one defect (shortcoming) of the above-mentioned prior art and provides a protection circuit for detecting abnormal light source current and a stage light provided with the same, which are used to solve the problems of abnormal current of the light source module in the stage light, being affected by the temperature in the chassis or the high-frequency lines and strong electric interference nearby, and being affected by the short circuit of the light source driving circuit or the damage of components caused by improper manual operation.

[0004] The technical solution adopted by the utility model is a protection circuit for detecting abnormal current of a light source, comprising a light source path, which also includes a light source driving module, a current detection module, a single-chip computer module and a power-off protection module. The light source path is used to supply power to the light source driving module. The current detection module is connected between the light source driving module and the single-chip computer module, and is used to detect the current size of the light source driving module and output an abnormal signal to the single-chip computer module. The input end of the power-off protection module is connected to the single-chip computer module, and is used to receive the abnormal signal of the single-chip computer module. The output end of the power-off protection module is connected to the light source path, and is used to control the disconnection of the light source path.

[0005] It is beneficial to energize the light source driving module and drive the light source to emit light through the light source path; it is beneficial to monitor the current change of the light source driving module in real time through the current detection module to avoid the problem of excessive current burning out components; it is beneficial to receive the monitoring abnormal signal of the light source driving module through the single-chip computer module and send it to the power-off protection module to avoid the light source path continuing to power the light source driving module under abnormal current, causing the light source driving module to burn out and affecting its service life.

[0006] Furthermore, the light source driving module includes a driving end, a detection end and a signal end, the driving end is connected to the light source path, and the detection end is connected to the current detection module.

[0007] It is beneficial to receive the power supply of the light source path through the voltage input terminal; it is beneficial to directly connect the current detection module in series in the current loop to be measured through the detection terminal, which is convenient for the installation and connection of the circuit; it is beneficial to realize the transmission of PWM signal waves between the light source driving module and the single-chip computer module through the signal terminal, thereby improving the accuracy of signal transmission.

[0008] Furthermore, the current detection module includes a current detection unit, an inductance unit and several capacitor units, the current detection unit includes a detection pin, an integrated pin, a power pin, an output pin, a filter pin and a ground pin, the capacitor unit includes a first capacitor, a second capacitor, a third capacitor and a fourth capacitor, the detection pin is connected to the detection end, the integrated pin is connected to the first capacitor, the power pin is connected to the second capacitor, the output pin is connected to the inductance unit, the third capacitor includes two, which are respectively connected to the two ends of the inductance unit, the filter pin is connected to the fourth capacitor, and the ground pin is simultaneously connected to the second capacitor, the third capacitor and the fourth capacitor.

[0009] It is beneficial to form multiple input signals of the temperature compensation circuit through the detection pin and the integrated pin, input the starting voltage through the power pin, connect to the output end of the temperature compensation circuit through the output pin and the filter pin, and form the grounding protection of the circuit through the ground pin; it is beneficial to filter the input signal of the light source driving module through the first capacitor, absorb the high-frequency current in the power supply voltage through the second capacitor and guide it to the ground, connect the third capacitor in series at both ends of the inductor unit to adjust the frequency response, realize selective amplification of the signal and filter the signal, and eliminate common-mode interference through the fourth capacitor.

[0010] Furthermore, the single-chip microcomputer module includes a voltage monitoring terminal, a voltage output terminal and a signal sending terminal. The voltage monitoring terminal is used to monitor the abnormal signal output by the current detection unit. The signal sending terminal is connected to the signal terminal. The voltage output terminal is connected to the power-off protection module through a switch control module.

[0011] It is beneficial to receive the abnormal current signal detected by the current detection unit through the voltage monitoring end and output an analog voltage signal; output a disconnection signal for controlling the power-off protection module through the voltage output end; and communicate signals with the light source driving module through the signal sending end.

[0012] Furthermore, the switch control module includes a transistor unit and a MOS tube unit. The switch control module turns on one side of the transistor through the high level output by the voltage output end, and transmits the output voltage to the input end of the power-off protection module through the MOS tube unit.

[0013] It is beneficial to output a high level through the voltage output end, so that the transistor in the control module is turned on on one side, and the voltage is transmitted to the input end of the power-off protection module through the MOS tube unit, so that the power-off protection module starts the power-off instruction, controls the light source path to no longer supply power to the light source driving module, and realizes the effect of cutting off power supply in the case of abnormal current, protecting the light source path and the light source driving module.

[0014] Furthermore, it also includes an analog-to-digital conversion unit, which is connected between the output pin of the current detection unit and the voltage monitoring end of the single-chip computer module, and includes a first resistor, a second resistor and a filter capacitor. The first resistor is connected in series to the output pin and is used to change the resistance value following the output voltage. The second resistor is used for voltage division, and the filter capacitor is used for smoothing the output.

[0015] It is beneficial to convert the analog signal output by the current detection unit into a digital signal through the analog-to-digital conversion unit, and transmit the digital signal to the voltage monitoring end of the single-chip microcomputer module; it is beneficial to realize the resistance value following the output voltage change through the first resistor, and divide the voltage through the second resistor, so that the single-chip microcomputer module reads the analog voltage AD value between the first resistor and the second resistor more accurately.

[0016] Furthermore, the power-off protection module includes a relay unit and a diode unit, wherein the diode unit is connected to two ends of the relay unit, and the relay unit controls the disconnection of the light source path according to signal inputs from the two ends.

[0017] It is beneficial to receive the voltage of the control module through the relay unit and disconnect the light source path, so that the light source path cuts off the power supply to the light source driving module; it is beneficial to realize automatic switching through the diode unit.

[0018] Furthermore, the current detection unit is an integrated current detection chip of model MT9221CT.

[0019] It is beneficial to use the temperature compensation circuit inside the integrated current detection chip of this model to ensure excellent temperature characteristics over the entire operating temperature range, calibrate the sensitivity and static output voltage, and provide a typical accuracy of less than ±1.9% over the full temperature range, thus achieving a low-cost, high-precision current detection solution.

[0020] Furthermore, the relay unit is a G8P-1A4P relay, and the diode unit is a L4148 diode.

[0021] This is beneficial because the relay of this model has the characteristics of high heat resistance, and the diode of this model has the characteristics of high conductivity and high reliability of fast switching.

[0022] Furthermore, the light source connected to the light source passage is an LED or a laser light source.

[0023] It is conducive to adapting to various light sources.

[0024] A stage lamp comprises a chassis, a support arm pivotally connected to the upper part of the chassis, a lamp head pivotally connected to the inner side of the support arm, and the lamp head comprises the protection circuit.

[0025] It is beneficial to adapt various types of stage lights through the protection circuit.

[0026] Compared with the prior art, the beneficial effects of the utility model are: the current detection module is directly connected to the measured current loop in the light source driving module, and a low-cost, high-precision current detection solution can be implemented without complex peripheral circuits, thereby monitoring the abnormal current of the light source driving module in real time and immediately disconnecting its power supply to protect the light source driving module from being burned out, thereby achieving the effect of extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a connection diagram of the light source driving module, the current detection module and the analog-to-digital conversion unit of the utility model.

[0028] Figure 2 This is a connection diagram of the single chip microcomputer module and the switch control module of the utility model.

[0029] Figure 3 It is a connection diagram of the power-off protection module and the light source path of the utility model.

[0030] Figure 4 This is a schematic diagram of the structure of a stage light of the present utility model.

[0031] Figure 5 This is a schematic diagram of the protection circuit position A of the utility model.

[0032] Description of the accompanying drawings: chassis 10, support arm 20, lamp head 30, light source passage 100, light source driving module 200, current detection module 300, analog-to-digital conversion unit 310, single-chip computer module 400, switch control module 410, power-off protection module 500. DETAILED DESCRIPTION

[0033] The drawings of the present invention are only used for illustrative purposes and cannot be construed as limiting the present invention. In order to better illustrate the following embodiments, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0034] Example 1

[0035] like Figure 1-3 As shown, in this embodiment, a protection circuit for detecting abnormal light source current is provided, including a light source path 100, which also includes a light source driving module 200, a current detection module 300, a single-chip computer module 400 and a power-off protection module 500. The light source path 100 is used to supply power to the light source driving module 200. The current detection module 300 is connected between the light source driving module 200 and the single-chip computer module 400, and is used to detect the current size of the light source driving module 200 and output an abnormal signal to the single-chip computer module 400. The input end of the power-off protection module 500 is connected to the single-chip computer module 400, and is used to receive the abnormal signal of the single-chip computer module 400. The output end of the power-off protection module 500 is connected to the light source path 100, and is used to control the disconnection of the light source path 100.

[0036] In this embodiment, the light source driving module 200 is an LED driving module, the current detection module 300 is a current detection unit including a chip model MT9221CT, which is used to detect whether the LED driving module has current abnormality and convert it into an analog voltage output through current detection. The single-chip computer module 400 is an MCU, which monitors the analog voltage of the current detection unit and sends an abnormal signal to the power-off protection module 500. The power-off protection module 500 includes a relay unit, which is used to receive the abnormal signal and disconnect the power supply between the light source circuit and the LED driving module.

[0037] The light source driving module 200 includes a driving end, a detection end and a signal end. The driving end is connected to the light source passage 100 , and the detection end is connected to the current detection module 300 .

[0038] In this embodiment, the driving end is the LED driving power supply end, which is 48V OUT and is connected to JR2 in the light source path 100. The detection end is used to connect the LED driving module and the current detection module 300. The signal end is PWM, which is used to transmit the signal wave between the single-chip computer module 400MCU, so that the signal transmission is more accurate.

[0039] The current detection module 300 includes a current detection unit, an inductance unit and several capacitor units, the current detection unit includes a detection pin, an integrated pin, a power pin, an output pin, a filter pin and a ground pin, the capacitor unit includes a first capacitor, a second capacitor, a third capacitor and a fourth capacitor, the detection pin is connected to the detection end, the integrated pin is connected to the first capacitor, the power pin is connected to the second capacitor, the output pin is connected to the inductance unit, the third capacitor includes two, which are respectively connected to the two ends of the inductance unit, the filter pin is connected to the fourth capacitor, and the ground pin is simultaneously connected to the second capacitor, the third capacitor and the fourth capacitor.

[0040] In this embodiment, the current detection unit is Q5, the detection pins are IP+ pins 1 and 2, the integrated pins are IP- pins 3 and 4, the power pin is the VCC pin, the output pin is the VOUT pin, the filter pin is the FIL pin, and the ground pin is the GND pin; the inductor unit is L11; the first capacitor is C28, the second capacitor is C116, the third capacitors are C117 and C118, the fourth capacitor is C119, the ground terminal of the first capacitor C28 is PGND, the second capacitor C116, the third capacitors C117 and C118, and the ground terminal of the fourth capacitor C119 is AGND.

[0041] The single chip computer module 400 includes a voltage monitoring terminal, a voltage output terminal and a signal sending terminal. The voltage monitoring terminal is used to monitor the abnormal signal output by the current detection unit. The signal sending terminal is connected to the signal terminal. The voltage output terminal is connected to the power-off protection module 500 through the switch control module 410.

[0042] In this embodiment, the voltage monitoring terminal is an AD terminal, the voltage output terminal is an LED Power terminal, and the signal sending terminal is a PWM terminal.

[0043] The switch control module 410 includes a transistor unit and a MOS tube unit. The switch control module 410 turns on one side of the transistor through the high level output from the voltage output terminal, and transmits the output voltage to the input terminal of the power-off protection module 500 through the MOS tube unit.

[0044] In this embodiment, the switch control module 410 includes a transistor Q2, a MOS transistor Q1, a connector J2, and resistors R86, R99, R100, and R104.

[0045] It also includes an analog-to-digital conversion unit 310, which is connected between the output pin of the current detection unit and the voltage monitoring end of the single-chip computer module 400, and includes a first resistor, a second resistor and a filter capacitor. The first resistor is connected in series to the output pin to change the resistance value following the output voltage, the second resistor is used for voltage division, and the filter capacitor is used for smoothing the output.

[0046] In this embodiment, the input end of the analog-to-digital conversion unit 310 is connected to the output pin VOUT of the current detection unit, the filter capacitor is C125, the first resistor is R102, the second resistor is R103, the AD value read by the single-chip computer module 400MCU is between R102 and R103, and the connection is connected to the filter capacitor C125.

[0047] The power-off protection module 500 includes a relay unit and a diode unit. The diode unit is connected to two ends of the relay unit. The relay unit controls the disconnection of the light source path 100 according to signal inputs from the two ends.

[0048] In this embodiment, connector J1 is used to receive the output voltage of the switch control module 410, the relay unit is a G8P-1A4P model relay, the diode unit is a L4148 model diode, the diode unit is D1, the switch of the relay unit is K1, and the output voltage of the switch control module 410 provides voltage to the relay unit to make it disconnect, thereby completing the disconnection of the power supply of the LED driver module.

[0049] The current detection unit is an integrated current detection chip of the MT9221CT model.

[0050] In this embodiment, the MT9221CT model current detection chip includes a temperature sensor, an oscillator, cold end compensation, a bias current, undervoltage detection, a bandgap voltage reference, an adjuster, a phase generator, and a feedback device. The temperature sensor component is used to detect the ambient temperature and output a current signal; the oscillator is used to convert the DC signal of the temperature sensor into an AC signal; the cold end compensation is used to compensate for the temperature change error of the temperature sensor and output an adjustment signal; the bias current is used for the base DC current input of the feedback device; the undervoltage detection is used for automatic protection of the driving power supply end; the bandgap voltage reference is used to provide a stable voltage reference; the adjuster is used to automatically maintain a constant voltage; the phase generator is used to generate a phase; the feedback device includes a Hall plate, a differential operational amplifier unit and an overcurrent protection unit, and the Hall plate includes two interconnected Hall plates for eliminating offset; the differential operational amplifier unit is used to suppress common mode signals; the overcurrent protection unit automatically cuts off the connection between the driving power supply end and the light source driving module 200 according to the abnormal current signal.

[0051] The relay unit is a G8P-1A4P relay, and the diode unit is a L4148 diode.

[0052] In this embodiment, the G8P-1A4P model relay is a high-heat-resistant relay, which is suitable for LED lamps in high-heat conditions and controls the disconnection of power supply to the LED driver module; the L4148 model diode is a small single-switch diode with high conductivity and high reliability, and has a fast recovery time of 8ns to 4ns at only 300mA forward current, and is used for fast switching to detect the LED status.

[0053] The light source connected to the light source passage 100 is an LED or a laser light source.

[0054] In this embodiment, the light source is an LED.

[0055] The complete control route in this embodiment is as follows: the light source path 100 is a path formed by JR1 and JR2, K1 is a normally closed relay, JR1 is powered by a switching power supply, JR2 is externally connected to the light source driver module 200, and the light source driver module 200 in this embodiment is an LED driver module, and J1 and J2 are connected together. When the output voltage of the LED driver module passes through the current detection module 300Q5 to power the LED, when the current detection module 300Q5 detects that the current is abnormal, the AD value converted into the voltage will be monitored in real time by the single-chip module 400MCU, and the single-chip module 400MCU will output a high level through LED Power. At this time, Q2 in the control module is not turned on, Q1 is turned on, and J2 provides a 5V. Since J2 in the control module and J1 in the power-off protection module 500 are connected together, J1 provides a 5V to the relay unit, and the relay unit performs a disconnection action to cut off the power supply of the LED driver module, thereby achieving the effect of instant power off when the current is abnormal, protecting the LED driver module from always providing excellent temperature characteristics within the normal operating temperature range.

[0056] Example 2

[0057] like Figure 4 , 5 As shown, in this embodiment, a stage light is provided, including a chassis 10, a support arm 20 pivotally connected to the upper side of the chassis 10, a lamp head 30 pivotally connected to the inner side of the support arm 20, and the lamp head 30 includes the protection circuit.

[0058] In this embodiment, the protection circuit is adapted to various types of stage lights, and the protection circuit is disposed at any position A of the light source driving module 200 to detect whether its operating temperature exceeds a range.

[0059] Obviously, the above embodiments of the utility model are only examples for clearly explaining the technical solution of the utility model, and are not intended to limit the specific implementation methods of the utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the utility model shall be included in the protection scope of the claims of the utility model.

Claims

1. A protection circuit for detecting abnormal current of a light source, comprising a light source path (100), characterized in that: The invention also comprises a light source driving module (200), a current detection module (300), a single-chip computer module (400) and a power-off protection module (500); the light source path (100) is used to supply power to the light source driving module (200); the current detection module (300) is connected between the light source driving module (200) and the single-chip computer module (400) and is used to detect the current of the light source driving module (200) and output an abnormal signal to the single-chip computer module (400); the input end of the power-off protection module (500) is connected to the single-chip computer module (400) and is used to receive the abnormal signal from the single-chip computer module (400); the output end of the power-off protection module (500) is connected to the light source path (100) and is used to control the disconnection of the light source path (100).

2. A protection circuit for detecting abnormal light source current according to claim 1, characterized in that: The light source driving module (200) comprises a driving end, a detection end and a signal end, the driving end is connected to the light source passage (100), and the detection end is connected to the current detection module (300).

3. A protection circuit for detecting abnormal light source current according to claim 2, characterized in that: The current detection module (300) comprises a current detection unit, an inductance unit and a plurality of capacitor units; the current detection unit comprises a detection pin, an integration pin, a power pin, an output pin, a filter pin and a ground pin; the capacitor unit comprises a first capacitor, a second capacitor, a third capacitor and a fourth capacitor; the detection pin is connected to the detection end; the integration pin is connected to the first capacitor; the power pin is connected to the second capacitor; the output pin is connected to the inductance unit; the third capacitor comprises two capacitors, which are respectively connected to the two ends of the inductance unit; the filter pin is connected to the fourth capacitor; and the ground pin is simultaneously connected to the second capacitor, the third capacitor and the fourth capacitor.

4. A protection circuit for detecting abnormal light source current according to claim 3, characterized in that: The single-chip computer module (400) comprises a voltage monitoring terminal, a voltage output terminal and a signal sending terminal, the voltage monitoring terminal is used to monitor the abnormal signal output by the current detection unit, the signal sending terminal is connected to the signal terminal, and the voltage output terminal is connected to the power-off protection module (500) via a switch control module (410).

5. A protection circuit for detecting abnormal light source current according to claim 4, characterized in that: The switch control module (410) comprises a triode unit and a MOS tube unit. The switch control module (410) turns on one side of the triode through the high level outputted by the voltage output terminal, and transmits the output voltage to the input terminal of the power-off protection module (500) through the MOS tube unit.

6. A protection circuit for detecting abnormal light source current according to claim 4, characterized in that: It also includes an analog-to-digital conversion unit (310), the analog-to-digital conversion unit (310) being connected between the output pin of the current detection unit and the voltage monitoring terminal of the single-chip computer module (400), the analog-to-digital conversion unit (310) comprising a first resistor, a second resistor and a filter capacitor, the first resistor being connected in series to the output pin and used for following the change in resistance value of the output voltage, the second resistor being used for voltage division, and the filter capacitor being used for smoothing the output.

7. A protection circuit for detecting abnormal light source current according to claim 1, characterized in that: The power-off protection module (500) comprises a relay unit and a diode unit, wherein the diode unit is connected to two ends of the relay unit, and the relay unit controls the disconnection of the light source path according to signal inputs from the two ends.

8. The protection circuit for detecting abnormal light source current according to claim 3, characterized in that: The current detection unit is an integrated current detection chip of the MT9221CT model.

9. A protection circuit for detecting abnormal light source current according to claim 7, characterized in that: The relay unit is a G8P-1A4P relay, and the diode unit is a L4148 diode.

10. A protection circuit for detecting abnormal light source current according to any one of claims 1 to 9, characterized in that: The light source connected to the light source passage (100) is an LED or a laser light source.

11. A stage lamp, comprising a chassis (10), a support arm (20) pivotally connected to the upper side of the chassis (10), and a lamp holder (30) pivotally connected to the inner side of the support arm (20), wherein the lamp holder (30) comprises the protection circuit according to claim 10.

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