Protection circuit for dimming interface of dimming power supply and implementation method of protection circuit

Abstract

The invention discloses a protection circuit for a dimming interface of a dimming power supply, which comprises overvoltage / overcurrent protection circuits respectively connected in series between a dimming signal external interface DIM + OUT and a dimming signal input end DIM + and between a dimming signal external interface DIM-OUT and a dimming signal input end DIM-, a clamping circuit and an anti-reverse connection circuit are respectively connected between the dimming signal input end DIM + and the dimming signal input end DIM-; the invention also discloses an implementation method of the protection circuit for the dimming interface of the dimming power supply. Voltage clamping is achieved through the voltage dependent resistor VR1, the temperature of the positive temperature coefficient thermistor RT1 rises rapidly, the resistance value of the positive temperature coefficient thermistor RT1 rises to the megohm level, connection between an abnormal signal and the dimming signal input end is cut off, a dimming interface is effectively prevented from being damaged, and lamp damage caused by misconnection of mains supply or lightning stroke surge is avoided. Through the arrangement of the filter circuit and the surge absorption circuit, filtering and surge absorption are realized, and the dimming interface is effectively prevented from being damaged.

Description

Technical Field

[0001] This invention belongs to the field of dimming interface protection technology, specifically relating to a protection circuit for the dimming interface of a dimming power supply and its implementation method. Background Technology

[0002] In the LED industry, more and more products have dimming capabilities, making the protection of dimming ports increasingly important.

[0003] However, current LED light sources and luminaires still have the following limitations in their technological applications:

[0004] 1. During the installation of dimmable lighting fixtures, because the dimmer wire and the mains power port are close together, the dimmer wire may be mistakenly connected to the mains power during installation. If the dimmer port does not have protective measures, the high voltage of the mains power will damage the dimmer port, causing the lighting fixture to explode or even cause a fire.

[0005] 2. Although there are solutions for protecting the dimming port, most of them are for pulse undervoltage protection. The lamp can still be damaged if the mains power is misconnected. This is because most dimming ports use low-voltage and low-energy devices.

[0006] 3. During equipment use, lightning surge voltage and spike pulse signals may be encountered, which may damage the dimming port. Summary of the Invention

[0007] The purpose of this invention is to provide a protection circuit for the dimming interface of a dimming power supply, thereby solving the problems mentioned in the background art. The protection circuit provided by this invention for the dimming interface of a dimming power supply effectively prevents damage to the lamps caused by misconnection to mains power or lightning surges.

[0008] Another objective of this invention is to provide a method for implementing a protection circuit for a dimming interface of a dimming power supply.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a protection circuit for a dimming power supply dimming interface, comprising overvoltage / overcurrent protection circuits respectively connected in series between the external dimming signal interface DIM+OUT and the dimming signal input terminal DIM+, and between the external dimming signal interface DIM-OUT and the dimming signal input terminal DIM-, wherein a clamping circuit and a reverse connection protection circuit are respectively connected between the dimming signal input terminal DIM+ and the dimming signal input terminal DIM-.

[0010] In this invention, the overvoltage / overcurrent protection circuit includes a fuse or fusible resistor F1 and a thermistor RT1, wherein the fuse or fusible resistor F1 and the thermistor RT1 are connected in series between the external interface DIM+OUT of the dimming signal and the input terminal DIM+ of the dimming signal, and between the external interface DIM-OUT of the dimming signal and the input terminal DIM- of the dimming signal, respectively.

[0011] In this invention, the clamping circuit further includes a clamping element VR1, which is connected in parallel between the dimming signal input terminal DIM+ and the dimming signal input terminal DIM-.

[0012] In this invention, the clamping element VR1 is a varistor, a TSS transistor, or a TVS transistor.

[0013] In this invention, the reverse connection protection circuit includes a diode D1, the negative terminal of which is connected to the external interface DIM+OUT of the dimming signal, and the positive terminal of which is connected to the input terminal DIM+ of the dimming signal.

[0014] Furthermore, in this invention, the reverse connection protection circuit also includes a diode D2, the negative terminal of which is connected to the dimming signal input terminal DIM+, and the positive terminal of the dimming signal input terminal DIM+ is connected to the dimming signal input terminal DIM-.

[0015] Furthermore, the present invention also includes a filtering circuit, which includes a capacitor C1 connected in parallel between the dimming signal input terminal DIM+ and the dimming signal input terminal DIM-.

[0016] The invention further includes a surge absorption circuit, which includes surge absorption element FB1 and surge absorption element FB2. Surge absorption element FB1 and surge absorption element FB2 are respectively connected in series between the external interface DIM+OUT of the dimming signal and the input terminal DIM+ of the dimming signal, and between the external interface DIM-OUT of the dimming signal and the input terminal DIM- of the dimming signal.

[0017] In this invention, surge absorption element FB1 and surge absorption element FB2 are ferrite beads or inductors.

[0018] Furthermore, in this invention, the method for implementing a protection circuit for a dimming power supply dimming interface includes the following steps:

[0019] (i) When the signal is normal, the clamping circuit does not start;

[0020] (ii) When an abnormal signal is input, the clamping circuit performs voltage clamping, causing the thermistor RT1 in the overvoltage / overcurrent protection circuit to heat up rapidly and its resistance to the megohm level, thus cutting off the connection between the abnormal signal and the dimming signal input terminal.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. This invention uses a varistor VR1 to achieve voltage clamping, which causes the positive temperature coefficient thermistor RT1 to heat up rapidly, raising its resistance to the megohm level. This disconnects the abnormal signal from the dimming signal input terminal, effectively preventing damage to the dimming interface and avoiding damage to the lamps caused by accidental connection to mains power or lightning surges.

[0023] 2. This invention achieves filtering and surge absorption through the setting of filtering circuit and surge absorption circuit, effectively preventing damage to the dimming interface. Attached Figure Description

[0024] Figure 1 This is a circuit connection block diagram of the present invention.

[0025] Figure 2 This is a circuit diagram from Embodiment 1 of the present invention.

[0026] Figure 3 This is a circuit diagram from Embodiment 2 of the present invention.

[0027] Figure 4 This is a circuit diagram from Embodiment 3 of the present invention.

[0028] Figure 5 This is a circuit diagram from Embodiment 4 of the present invention.

[0029] In the diagram: 1. External interface for dimming signal; 2. Overvoltage / overcurrent protection circuit; 3. Clamping circuit; 4. Reverse connection protection circuit; 5. Filtering circuit; 6. Surge absorption circuit; 7. Dimming signal input terminal. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0033] In the description of this invention, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used merely for distinction in description and have no special meaning.

[0034] Example 1

[0035] Please see Figures 1-2 This embodiment provides the following technical solution: a protection circuit for a dimming power supply dimming interface, including a fuse F1 and a positive temperature coefficient thermistor RT1 connected in series between the external dimming signal interface DIM+OUT and the dimming signal input terminal DIM+, and between the external dimming signal interface DIM-OUT and the dimming signal input terminal DIM-. A clamping circuit 3 and a reverse connection protection circuit 4 are connected between the dimming signal input terminal DIM+ and the dimming signal input terminal DIM-, respectively. The clamping circuit 3 includes a clamping element VR1, which is connected in parallel between the dimming signal input terminal DIM+ and the dimming signal input terminal DIM-. The reverse connection protection circuit 4 includes a diode D1 and a diode D2. The negative terminal of the diode D1 is connected to one end of the fuse F1, the positive terminal of the diode D1 is connected to the dimming signal input terminal DIM+, the negative terminal of the diode D2 is connected to the dimming signal input terminal DIM+, and the positive terminal of the dimming signal input terminal DIM+ is connected to the dimming signal input terminal DIM-.

[0036] Specifically, the clamping element VR1 is a varistor, a TSS transistor, or a TVS transistor, and in this embodiment, a varistor is preferred.

[0037] By adopting the above technical solution, when the signal is normal, the clamping circuit 3 does not start; when an abnormal signal is input, the abnormal signal passes through the fuse F1 and the diode D1, and is clamped by the varistor VR1, causing the positive temperature coefficient thermistor RT1 to heat up rapidly, raising its resistance to the megohm level, cutting off the connection between the abnormal signal and the dimming signal input terminal, effectively preventing damage to the dimming interface.

[0038] Example 2

[0039] like Figure 3 As shown, the difference between this embodiment and embodiment 1 is that, specifically, when the equipment is working in an area with good working conditions and without special requirements, the fuse F1, diode D1 and diode D2 can be removed, moved or swapped in position without affecting its working principle and product performance.

[0040] Example 3

[0041] Please see Figure 4 As shown, this embodiment provides the following technical solution: a protection circuit for a dimming power supply dimming interface, including a fuse resistor F1 and a positive temperature coefficient thermistor RT1 connected in series between the external dimming signal interface DIM+OUT and the dimming signal input terminal DIM+, and between the external dimming signal interface DIM-OUT and the dimming signal input terminal DIM-, respectively; the negative terminal of diode D1 is connected to the external dimming signal interface DIM+OUT and the dimming signal input terminal DIM+; the positive terminal of diode D1 is connected to one end of the positive temperature coefficient thermistor RT1; and a TSS transistor VR1 is connected in parallel between the positive terminal of diode D1 and one end of the fuse resistor F1.

[0042] By adopting the above technical solution, when the signal is normal, the clamping circuit 3 does not start; when an abnormal signal is input, the abnormal signal passes through the fuse F1 and the diode D1, and is clamped by the varistor VR1, causing the positive temperature coefficient thermistor RT1 to heat up rapidly, raising its resistance to the megohm level, cutting off the connection between the abnormal signal and the dimming signal input terminal, effectively preventing damage to the dimming interface.

[0043] Example 4

[0044] Please see Figure 5 The difference between this embodiment and embodiment 3 is that, specifically, when the equipment is working in an area with good working conditions and without special requirements, any component among the fuse resistor F1, diode D1 and capacitor C1 can be removed, moved or swapped without affecting its working principle and product performance.

[0045] Example 5

[0046] The difference between this embodiment and embodiment 1 is that, specifically, it also includes a filter circuit 5 and a surge absorption circuit 6. The surge absorption circuit 6 includes inductors FB1 and FB2, which are connected in series between the external interface DIM+OUT and the input terminal DIM+ of the dimming signal, and between the external interface DIM-OUT and the input terminal DIM- of the dimming signal, respectively. The filter circuit includes a capacitor C1, which is connected in parallel between the input terminal DIM+ and the input terminal DIM- of the dimming signal.

[0047] By adopting the above technical solutions, filtering and surge absorption can be achieved.

[0048] In summary, this invention uses a varistor VR1 to achieve voltage clamping, causing the positive temperature coefficient thermistor RT1 to rapidly heat up, raising its resistance to the megohm level. This disconnects the abnormal signal from the dimming signal input, effectively preventing damage to the dimming interface and avoiding damage to the lamps caused by incorrect connection to mains power or lightning surges. Furthermore, this invention utilizes a filter circuit and a surge absorption circuit to achieve filtering and surge absorption, effectively preventing damage to the dimming interface.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A protection circuit for a dimming interface of a dimming power supply, characterized in that: It includes overvoltage / overcurrent protection circuits connected in series between the external interface DIM+OUT and the input terminal DIM+ of the dimming signal, and between the external interface DIM-OUT and the input terminal DIM- of the dimming signal. Clamping circuit and reverse connection protection circuit are connected between the input terminals DIM+ and DIM- of the dimming signal.

2. The protection circuit for a dimming interface of a dimming power supply according to claim 1, characterized in that: The overvoltage / overcurrent protection circuit includes a fuse or fusible resistor F1 and a thermistor RT1, wherein the fuse or fusible resistor F1 and the thermistor RT1 are connected in series between the external interface DIM+OUT of the dimming signal and the input terminal DIM+ of the dimming signal, and between the external interface DIM-OUT of the dimming signal and the input terminal DIM- of the dimming signal, respectively.

3. The protection circuit for a dimming interface of a dimming power supply according to claim 1, characterized in that: The clamping circuit includes a clamping element VR1, which is connected in parallel between the dimming signal input terminal DIM+ and the dimming signal input terminal DIM-.

4. A protection circuit for a dimming interface of a dimming power supply according to claim 3, characterized in that: The clamping element VR1 is a varistor, a TSS transistor, or a TVS transistor.

5. A protection circuit for a dimming interface of a dimming power supply according to claim 1, characterized in that: The reverse polarity protection circuit diode D1 includes a negative terminal of diode D1 connected to the external interface DIM+OUT of the dimming signal, and a positive terminal of diode D1 connected to the input terminal DIM+ of the dimming signal.

6. A protection circuit for a dimming interface of a dimming power supply according to claim 5, characterized in that: The reverse connection protection circuit also includes a diode D2, the negative terminal of which is connected to the dimming signal input terminal DIM+, and the positive terminal of the dimming signal input terminal DIM+ is connected to the dimming signal input terminal DIM-.

7. A protection circuit for a dimming interface of a dimming power supply according to claim 1, characterized in that: It also includes a filter circuit, which includes a capacitor C1 connected in parallel between the dimming signal input terminal DIM+ and the dimming signal input terminal DIM-.

8. A protection circuit for a dimming interface of a dimming power supply according to claim 1, characterized in that: It also includes a surge absorption circuit, which includes surge absorption element FB1 and surge absorption element FB2. Surge absorption element FB1 and surge absorption element FB2 are connected in series between the external interface DIM+OUT of the dimming signal and the input terminal DIM+ of the dimming signal, and between the external interface DIM-OUT of the dimming signal and the input terminal DIM- of the dimming signal, respectively.

9. A protection circuit for a dimming interface of a dimming power supply according to claim 8, characterized in that: The surge absorption elements FB1 and FB2 are magnetic beads or inductors.

10. A method for implementing a protection circuit for a dimming interface of a dimming power supply according to any one of claims 1-9, characterized in that, Includes the following steps: (i) When the signal is normal, the clamping circuit does not start; (ii) When an abnormal signal is input, the clamping circuit performs voltage clamping, causing the thermistor RT1 in the overvoltage / overcurrent protection circuit to heat up rapidly and its resistance to the megohm level, thus cutting off the connection between the abnormal signal and the dimming signal input terminal.

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