DALI fault detection circuit based on primary winding and driving power supply

Abstract

The utility model provides a DALI fault detection circuit based on a primary winding, the DALI fault detection circuit based on the primary winding comprises a power supply module and a DALI fault feedback module, the DALI fault feedback module comprises an abnormal feedback circuit and a DALI control module, and the abnormal feedback circuit is composed of a fault state detection circuit and a constant current dimming control chip. The fault state detection circuit is coupled with the input end of the primary winding through the fault detection winding, and the abnormal state detection end of the DALI control module is used for detecting the fault state. Under a primary winding constant current dimming architecture, the circuit can provide a fault state detection function, timely feed back a fault signal to a DALI control module, and then send the fault signal to a DALI control system through a DALI signal line, so that the DALI-2 protocol requirement is met, the number of detection ports of the DALI control module is reduced, and the production cost is reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of driving power supplies, and in particular to a DALI fault detection circuit and a driving power supply based on a primary winding. Background Art

[0002] With the rapid development of intelligent lighting technology, DALI (Digital Addressable Lighting Interface), an efficient and flexible lighting control protocol, has been widely used in various lighting projects due to its simple structure, easy installation, intuitive operation, and powerful functions. In particular, with the promotion of the DLAI-2 protocol, the demand for LED driver power supplies that comply with this protocol standard has increased significantly.

[0003] The DALI-2 protocol not only places higher demands on the dimming performance of LED lamps, but also explicitly stipulates that LED drivers must have fault detection capabilities, including real-time monitoring and feedback of output open and short-circuit conditions, to ensure the stability and reliability of the lighting system. However, while existing technical solutions can accurately detect anomalies when faults occur and meet the requirements of the DALI-2 protocol, they generally suffer from relatively high costs.

[0004] For example, the comparative document CN202110807188.0 discloses a DALI dimming and color adjustment driver power supply. When the output is in a normal constant current working state, the voltage from C- to SGND is greater than the voltage regulation value of the Zener diode, and the Zener diode is turned on. After the resistor voltage divider and current limiting, the transistor is driven to turn on, so that its collector is low, and thus the ERC output is low. At this time, the DALI control module detects that ERC is at a low level and considers that the output state is normal. When the output is in an open circuit state, the voltage from C- to SGND cannot turn on the Zener diode, the transistor is not turned on, the collector voltage is 5V, and the ERC output is high. The DALI control module detects that ERC is at a high level and considers that the output state is an open circuit fault. When the output is short-circuited, the voltage from C- to SGND equals the voltage from LED+ to SGND (typically 48V). Zener diodes ZD3 and ZD4 conduct, and after current limiting through resistor divider, transistor Q3 turns on. At this point, transistor Q1 is off, and the ERC output is high. The DALI control module detects the high ERC level and deems the output a short-circuit fault. However, this solution's fault detection circuitry includes separate circuits for cold and warm light, making it complex and costly. Utility Model Content

[0005] The purpose of the present disclosure is to overcome the deficiencies in the prior art and to provide a DALI fault detection circuit and driver based on a primary winding that is low in cost and can save a dimming module detection port.

[0006] The purpose of this disclosure is achieved through the following technical solutions:

[0007] A DALI fault detection circuit based on a primary winding includes a power supply module and a DALI fault feedback module. The power supply module includes a rectifier circuit and a power conversion isolation circuit. The input end of the rectifier circuit is used to connect to an external constant current power supply, the output end of the rectifier circuit is connected to the primary winding input end of the power conversion isolation circuit, and the secondary winding output end of the power conversion isolation circuit is used to connect to an LED load.

[0008] The DALI fault feedback module includes an abnormal feedback circuit and a DALI control module. The abnormal feedback circuit includes a fault state detection circuit and a constant current dimming control chip. The current control end of the constant current dimming control chip is connected to the input end of the power conversion isolation circuit, and the PWM output end of the DALI control module is connected to the signal input end of the constant current dimming control chip.

[0009] The fault state detection circuit includes a fault detection winding, a first resistor, a second resistor, and a first capacitor. The fault detection winding is coupled to the primary winding input end of the power conversion isolation circuit. The first end of the first resistor is connected to the output end of the fault detection winding, and the second end of the first resistor is connected to the first end of the second resistor. The abnormal state detection end of the DALI control module is respectively connected to the second end of the first resistor and the first end of the first capacitor, and the second end of the second resistor and the second end of the first capacitor are grounded.

[0010] In one embodiment, the fault state detection circuit further includes a second capacitor, a first end of the second capacitor is connected to the first end of the first resistor, and a second end of the second capacitor is grounded.

[0011] In one embodiment, the fault state detection circuit further includes a first current-conducting diode, wherein the anode of the first current-conducting diode is connected to the output end of the fault detection winding, and the cathode of the first current-conducting diode is connected to the first end of the first resistor.

[0012] In one embodiment, the power conversion isolation circuit further includes a second current-conducting diode, the anode of the second current-conducting diode is connected to the secondary winding output end of the power conversion isolation circuit, and the cathode of the second current-conducting diode is used to be connected to the LED load.

[0013] In one embodiment, the power conversion isolation circuit further includes a first polarity capacitor, wherein a positive electrode of the first polarity capacitor is used to be connected to the LED load, and a negative electrode of the first polarity capacitor is grounded.

[0014] In one embodiment, the first polarity capacitor is an adjustable polarity capacitor.

[0015] In one embodiment, the rectifier circuit includes a rectifier module and a second polarity capacitor, the input end of the rectifier module is used to connect to an external constant current power supply, the output end of the rectifier module is connected to the positive electrode of the second polarity capacitor, the positive electrode of the second polarity capacitor is connected to the primary winding input end of the power conversion isolation circuit, and the negative electrode of the second polarity capacitor is grounded.

[0016] In one embodiment, the second polarity capacitor is an adjustable polarity capacitor.

[0017] In one embodiment, at least one of the first resistor and the second resistor is an adjustable resistor.

[0018] A driving power supply includes the DALI fault detection circuit based on the primary winding as described in any one of the above items.

[0019] Compared with the prior art, the present disclosure has at least the following advantages:

[0020] 1. In the above-mentioned DALI fault detection circuit based on the primary winding, since the secondary winding output end and the fault detection winding have the same winding direction and a fixed turns ratio, the voltages at the secondary winding output end and the fault detection winding output end are proportional. As a result, the fault state detection circuit can promptly feed back the voltage signals of the secondary winding output end and the LED load to the abnormal state detection end of the DALI control module through the fault detection winding output end. The DALI signal line then sends a corresponding fault signal to the DALI control system. This allows the DALI fault detection circuit based on the primary winding to meet the DALI-2 protocol requirements, while reducing the number of detection ports of the DALI control module H1, thereby reducing the production cost of the DALI fault detection circuit based on the primary winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 1 is a schematic structural diagram of a DALI fault detection circuit based on a primary winding according to an embodiment;

[0023] Figure 2 for Figure 1The partial circuit diagram of the DALI fault detection circuit based on the primary winding is shown. DETAILED DESCRIPTION

[0024] To facilitate understanding of the present disclosure, a more comprehensive description of the present disclosure will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present disclosure. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure.

[0025] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. The terms used herein in the specification of this disclosure are intended only to describe specific embodiments and are not intended to limit this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] In order to better understand the technical solutions and beneficial effects of the present disclosure, the present disclosure is further described in detail below with reference to specific embodiments:

[0028] like Figure 1 and Figure 2 As shown, a DALI fault detection circuit 10 based on a primary winding according to an embodiment of the present disclosure includes a power supply module 100 and a DALI fault feedback module 200. The power supply module 100 includes a rectifier circuit BD1 and a power conversion isolation circuit T1. The input end of the rectifier circuit BD1 is used to connect to an external constant current power supply, the output end of the rectifier circuit BD1 is connected to the primary winding input end T1A of the power conversion isolation circuit T1, and the secondary winding output end T1B of the power conversion isolation circuit T1 is used to connect to an LED load.

[0029] The DALI fault feedback module 200 includes an abnormal feedback circuit and a DALI control module H1. The abnormal feedback circuit includes a fault state detection circuit and a constant current dimming control chip U1. The current control terminal DRAIN of the constant current dimming control chip U1 is connected to the input terminal of the power conversion isolation circuit T1, and the PWM output terminal PWM-Out of the DALI control module H1 is connected to the signal input terminal DIM of the constant current dimming control chip U1.

[0030] The fault state detection circuit includes a fault detection winding T1C, a first resistor R1, a second resistor R2, and a first capacitor. The fault detection winding T1C is coupled to the primary winding input terminal T1A of the power conversion isolation circuit T1. The first end of the first resistor R1 is connected to the fault detection winding output terminal T1C, and the second end of the first resistor R1 is connected to the first end of the second resistor R2. The abnormal state detection terminal FD of the DALI control module H1 is respectively connected to the second end of the first resistor R1 and the first end of the first capacitor C4. The second end of the second resistor R2 and the second end of the first capacitor C4 are grounded.

[0031] In this embodiment, when the output is in a normal constant current operating state, since the secondary winding output terminal T1B of the power conversion isolation circuit T1 is used to be connected to the LED load, the LED load clamps the output voltage of the secondary winding output terminal T1B, thereby maintaining the secondary winding output terminal T1B at a fixed voltage value. Moreover, since the secondary winding output terminal T1B and the fault detection winding T1C have the same winding direction, the voltage at the fault detection winding output terminal T1C and the voltage at the secondary winding output terminal T1B are proportional to the number of turns of the secondary winding, thereby maintaining the voltage at the fault detection winding output terminal T1C at another fixed voltage value. After the voltage at the fault detection winding output terminal T1C is divided by the first resistor R1 and the second resistor R2 in series, the voltage is divided by the first resistor R1 and the second resistor R2 in series. The second end of the resistor R1 provides a fixed voltage value to the abnormal state detection terminal FD of the DALI control module H1, thereby allowing the DALI control module H1 to obtain a stable voltage value through the abnormal state detection terminal FD and determine that the circuit is in a normal operating state. At the same time, the PWM output terminal PWM-Out of the DALI control module H1 outputs a high-level signal to the signal input terminal DIM of the constant current dimming control chip U1, so that the constant current dimming control chip U1 is in an operating state, thereby allowing the current to pass through the primary winding input terminal T1A of the power conversion isolation circuit T1 and the current control terminal DRAIN of the constant current dimming control chip U1 to form a loop with the ground terminal, so that the DALI fault detection circuit 10 based on the primary winding is in a normal operating state.

[0032] Furthermore, when the LED load is in a short-circuit abnormal state, the voltage of the secondary winding output terminal T1B drops to 0V. Since the voltage of the fault detection winding output terminal T1C and the voltage of the secondary winding output terminal T1B are proportional to the number of turns of the secondary winding, the voltage of the fault detection winding output terminal T1C also drops to 0V. Therefore, the abnormal state detection terminal FD of the DALI control module H1 is connected to the fault detection winding output terminal T1C through the first resistor and also obtains a 0V voltage. As a result, the DALI control module H1 detects a 0V voltage signal through the abnormal state detection terminal FD, determines that the circuit is in a short-circuit state, and then passes A short-circuit fault signal is sent through the DALI signal line in the DALI control module H1. At the same time, the PWM output terminal PWM-Out of the DALI control module H1 outputs a low-level signal to the signal input terminal DIM of the constant-current dimming control chip U1, so that the constant-current dimming control chip U1 is in a closed state, thereby preventing the current from passing through the primary winding input terminal T1A of the power conversion isolation circuit T1 and the current control terminal DRAIN of the constant-current dimming control chip U1 to form a loop with the ground terminal, thereby preventing the short-circuit fault from damaging the DALI fault detection circuit 10 based on the primary winding due to the short circuit.

[0033] Furthermore, when the LED load is in an open circuit abnormal state, the secondary winding output terminal T1B is not clamped by the LED load. Since the voltage of the fault detection winding output terminal T1C and the voltage of the secondary winding output terminal T1B are proportional to the number of turns of the coil, the fault detection winding output terminal T1C also loses its fixed voltage. Therefore, the abnormal state detection terminal FD of the DALI control module H1 detects the voltage change in the open circuit abnormal state through the fault detection winding output terminal T1C, and then outputs a pulse level signal to the constant current dimming control chip U1 through the PWM output terminal PWM-Out. The signal input terminal DIM causes the constant current dimming control chip U1 to operate in pulse mode and control the secondary winding output terminal T1B to output a pulse voltage through the current control terminal DRAIN. Then, the pulse voltage is divided by the first resistor R1 and the second resistor R2 in series, and then output to the abnormal state detection terminal FD of the DALI control module H1. The DALI control module H1 then detects the pulse voltage signal through the abnormal state detection terminal FD, determines that the circuit is in an open circuit state, and finally sends an open circuit fault signal through the DALI signal line within the DALI control module H1.

[0034] In the primary-winding-based DALI fault detection circuit 10, since the secondary-winding output terminal T1B and the fault detection winding T1C have the same winding direction and a fixed turns ratio, the voltages at the secondary-winding output terminal T1B and the fault detection winding T1C are proportional. This allows the fault detection circuit to promptly feed back the voltage signals of the secondary-winding output terminal T1B and the LED load to the abnormal-state detection terminal FD of the DALI control module H1 via the fault detection winding output terminal T1C. The fault signal is then transmitted to the DALI control system via the DALI signal line. This allows the primary-winding-based DALI fault detection circuit 10 to meet the DALI-2 protocol requirements, while reducing the number of detection ports on the DALI control module H1 and thus the production cost of the primary-winding-based DALI fault detection circuit 10.

[0035] like Figure 2 As shown, in one embodiment, the fault state detection circuit further includes a second capacitor C3, a first end of the second capacitor C3 being connected to the first end of the first resistor R1, and a second end of the second capacitor C3 being grounded. In this embodiment, since the capacitor has the function of storing and releasing electrical energy, the second capacitor C3 plays a role in signal filtering and voltage stabilization in the fault state detection circuit. Moreover, since the first resistor R1 and the second resistor R2 are connected in series, the second capacitor C3, the first resistor R1, and the second resistor R2 together form an RC filter circuit, thereby ensuring that the abnormal state detection terminal FD of the DALI control module H1 can obtain a stable voltage and feedback it to the DALI control module H1, thereby improving the stability of the fault state detection circuit.

[0036] like Figure 2 As shown, in one embodiment, the fault detection circuit further includes a first current-conducting diode D2. The anode of the first current-conducting diode D2 is connected to the fault detection winding output terminal T1C, and the cathode of the first current-conducting diode D2 is connected to the first end of the first resistor R1. In this embodiment, the primary function of the first current-conducting diode D2 is to utilize its unidirectional conduction characteristics to ensure that current can only flow from the fault detection winding output terminal T1C to the first resistor R1, thereby preventing reverse current from affecting the fault detection circuit. Specifically, when the circuit is in normal operation or an open circuit abnormal state, the fault detection winding output terminal T1C will output a certain current. Because the first current-conducting diode D2 has unidirectional conduction for current, the output current from the fault detection winding output terminal T1C can only flow unidirectionally through the first current-conducting diode D2 to the first resistor R1. This ensures that when transient voltage fluctuations or reverse currents occur in the circuit, the first current-conducting diode D2 can effectively reduce the impact of the transient voltage fluctuations or reverse currents on the fault detection circuit, thereby improving the stability of the fault detection circuit.

[0037] like Figure 2 As shown, in one embodiment, the power conversion isolation circuit T1 further includes a second current-conducting diode D1. The anode of the second current-conducting diode D1 is connected to the secondary winding output terminal T1B of the power conversion isolation circuit T1, and the cathode of the second current-conducting diode D1 is connected to the LED load. In this embodiment, when the circuit is in normal operation, the secondary winding output terminal T1B provides a stable current to the LED load. Because the second current-conducting diode D1 has unidirectional conductivity for current, the current can only flow from the secondary winding output terminal T1B of the power conversion isolation circuit T1 to the LED load, thereby preventing reverse current from flowing at the LED load end and causing damage to the power conversion isolation circuit T1.

[0038] like Figure 2 As shown, in one embodiment, the power conversion isolation circuit T1 also includes a first polarity capacitor C2, the positive electrode of the first polarity capacitor C2 is used to connect to the LED load, and the negative electrode of the first polarity capacitor C2 is grounded. In this embodiment, when the circuit is in normal working state, the secondary winding output terminal T1B provides a constant current to the LED load. At this time, the first polarity capacitor C2 acts as an energy storage element, which can absorb or release electrical energy when the voltage fluctuates, so that the LED load end obtains a stable voltage and reduces the impact of voltage fluctuations on the LED load. In the short circuit abnormal state, since the voltage of the secondary winding output terminal T1B quickly drops to 0V, the voltage of the LED load end also drops accordingly. At this time, the first polarity capacitor C2 can quickly discharge and absorb transient energy in the circuit to prevent damage to the LED load due to voltage mutation. At the same time, the discharge process of the first polarity capacitor C2 also helps to speed up the speed at which the DALI control module H1 detects the short circuit state and improves the sensitivity of the fault response. In the open circuit abnormal state, the secondary winding output terminal T1B will output a pulse voltage. The first polarity capacitor C2 can smooth the pulse voltage to reduce the impact of voltage fluctuations on the LED load, thereby protecting the LED load from the impact of transient voltage changes and ensuring that the LED load is in a stable working state.

[0039] like Figure 1 and Figure 2 As shown, in one embodiment, the first polarity capacitor C2 is an adjustable polarity capacitor. In this embodiment, when the first polarity capacitor C2 is an adjustable polarity capacitor, the capacitance of the polarity capacitor can be adjusted according to the actual application scenario and requirements. When the LED load changes, the capacitance is adjusted to maintain the stability of the output voltage of the secondary winding output terminal T1B. This helps to reduce voltage fluctuations caused by load changes, thereby ensuring that the power conversion isolation circuit T1 and the LED load can maintain stable operation, thereby improving the stability of the DALI fault detection circuit 10 based on the primary winding.

[0040] like Figure 2 As shown, in one embodiment, the rectifier circuit BD1 includes a rectifier module and a second-polarity capacitor C1. The input end of the rectifier module is used to connect to an external constant-current power supply, the output end of the rectifier module is connected to the positive electrode of the second-polarity capacitor C1, the positive electrode of the second-polarity capacitor C1 is connected to the primary winding input end T1A of the power conversion isolation circuit T1, and the negative electrode of the second-polarity capacitor C1 is grounded. In this embodiment, the rectifier module converts the AC power provided by the external constant-current power supply into DC power and outputs it to the second-polarity capacitor C1. When the rectifier module outputs DC power, the second-polarity capacitor C1 acts as a filter capacitor. The second-polarity capacitor C1 can absorb high-frequency noise and ripple in the circuit, making the DC power output to the power conversion isolation circuit T1 more stable. In addition, the second-polarity capacitor C1 also has a certain energy storage function. When the circuit is instantly started or the load suddenly changes, the second-polarity capacitor C1 can quickly release or absorb electrical energy to maintain the stability of the output voltage of the rectifier circuit BD1, thereby ensuring that the power conversion isolation circuit T1 can operate stably and normally.

[0041] like Figure 1 and Figure 2 As shown, in one embodiment, the second polarity capacitor C1 is an adjustable polarity capacitor. In this embodiment, when the second polarity capacitor C1 is an adjustable polarity capacitor, the capacitance of the polarity capacitor can be adjusted according to actual application scenarios and requirements. When the LED load changes, the output voltage of the rectifier circuit BD1 is maintained stable by adjusting its capacitance. This helps to reduce voltage fluctuations caused by load changes, thereby ensuring that the power conversion isolation circuit T1 and the LED load can maintain stable operation, thereby improving the stability of the primary winding-based DALI fault detection circuit 10.

[0042] like Figure 1 and Figure 2As shown, in one embodiment, at least one of the first resistor R1 and the second resistor R2 is an adjustable resistor. In this embodiment, the first resistor R1 and the second resistor R2 act as a series voltage divider in the fault state detection circuit. The resistance values ​​of the first resistor R1 and the second resistor R2 will affect the voltage signal received by the abnormal state detection terminal FD of the DALI control module H1. By adjusting the resistance values ​​of the first resistor R1 and the second resistor R2, the sensitivity and threshold of the fault detection circuit can be precisely adjusted to adapt to different LED load characteristics and application scenarios. Specifically, when the LED load changes, by adjusting the resistance values ​​of the first resistor R1 and the second resistor R2, the voltage signal received by the abnormal state detection terminal FD of the DALI control module H1 can be maintained within a stable range, thereby reducing the impact of voltage fluctuations caused by load changes on the fault detection circuit, thereby improving the stability and reliability of the DALI fault detection circuit 10 based on the primary winding.

[0043] A driving power supply includes a DALI fault detection circuit 10 based on a primary winding as described above. In this embodiment, when the output is in a normal constant current working state, since the secondary winding output terminal T1B of the power conversion isolation circuit T1 is used to connect to the LED load, the LED load clamps the output voltage of the secondary winding output terminal T1B, thereby maintaining the secondary winding output terminal T1B at a fixed voltage value. Moreover, since the secondary winding output terminal T1B and the fault detection winding T1C have the same winding direction, the voltage at the fault detection winding output terminal T1C and the voltage at the secondary winding output terminal T1B are proportional to the number of turns of the secondary winding, thereby maintaining the voltage at the fault detection winding output terminal T1C at another fixed voltage value. After the voltage at the fault detection winding output terminal T1C is divided in series by the first resistor R1 and the second resistor R2, the voltage is divided by the first resistor R1 and the second resistor R2. The second end of the resistor R1 provides a fixed voltage value to the abnormal state detection terminal FD of the DALI control module H1, thereby allowing the DALI control module H1 to obtain a stable voltage value through the abnormal state detection terminal FD and determine that the circuit is in a normal operating state. At the same time, the PWM output terminal PWM-Out of the DALI control module H1 outputs a high-level signal to the signal input terminal DIM of the constant current dimming control chip U1, so that the constant current dimming control chip U1 is in an operating state, thereby allowing the current to pass through the primary winding input terminal T1A of the power conversion isolation circuit T1 and the current control terminal DRAIN of the constant current dimming control chip U1 to form a loop with the ground terminal, so that the DALI fault detection circuit 10 based on the primary winding is in a normal operating state. Furthermore, when the LED load is in a short-circuit abnormal state, the voltage of the secondary winding output terminal T1B drops to 0V. Since the voltage of the fault detection winding output terminal T1C and the voltage of the secondary winding output terminal T1B are proportional to the number of turns of the secondary winding, the voltage of the fault detection winding output terminal T1C also drops to 0V. Therefore, the abnormal state detection terminal FD of the DALI control module H1 is connected to the fault detection winding output terminal T1C through the first resistor and also obtains a 0V voltage. As a result, the DALI control module H1 detects a 0V voltage signal through the abnormal state detection terminal FD, determines that the circuit is in a short-circuit state, and then passes A short-circuit fault signal is sent through the DALI signal line in the DALI control module H1. At the same time, the PWM output terminal PWM-Out of the DALI control module H1 outputs a low-level signal to the signal input terminal DIM of the constant-current dimming control chip U1, so that the constant-current dimming control chip U1 is in a closed state, thereby preventing the current from passing through the primary winding input terminal T1A of the power conversion isolation circuit T1 and the current control terminal DRAIN of the constant-current dimming control chip U1 to form a loop with the ground terminal, thereby preventing the short-circuit fault from damaging the DALI fault detection circuit 10 based on the primary winding due to the short circuit.Furthermore, when the LED load is in an open circuit abnormal state, the secondary winding output terminal T1B is not clamped by the LED load. Since the voltage of the fault detection winding output terminal T1C and the voltage of the secondary winding output terminal T1B are proportional to the number of turns of the coil, the fault detection winding output terminal T1C also loses its fixed voltage. Therefore, the abnormal state detection terminal FD of the DALI control module H1 detects the voltage change in the open circuit abnormal state through the fault detection winding output terminal T1C, and then outputs a pulse level signal to the constant current dimming control chip U1 through the PWM output terminal PWM-Out. The signal input terminal DIM causes the constant current dimming control chip U1 to operate in pulse mode and control the secondary winding output terminal T1B to output a pulse voltage through the current control terminal DRAIN. Then, the pulse voltage is divided by the first resistor R1 and the second resistor R2 in series, and then output to the abnormal state detection terminal FD of the DALI control module H1. The DALI control module H1 then detects the pulse voltage signal through the abnormal state detection terminal FD, determines that the circuit is in an open circuit state, and finally sends an open circuit fault signal through the DALI signal line within the DALI control module H1.

[0044] Compared with the prior art, the present disclosure has at least the following advantages:

[0045] 1. In the primary-winding-based DALI fault detection circuit 10 described above, since the secondary-winding output terminal T1B and the fault detection winding T1C have the same winding direction and a fixed turns ratio, the voltages at the secondary-winding output terminal T1B and the fault detection winding T1C are proportional. This allows the fault detection circuit to promptly feed back the voltage signal of the secondary-winding output terminal T1B and the LED load via the fault detection winding output terminal T1C to the abnormal state detection terminal FD of the DALI control module H1. The fault signal is then sent to the DALI control system via the DALI signal line. This allows the primary-winding-based DALI fault detection circuit 10 to meet the DALI-2 protocol requirements, while reducing the number of detection ports on the DALI control module H1 and thus the production cost of the primary-winding-based DALI fault detection circuit 10.

[0046] The above-described embodiments merely represent several implementation methods of the present disclosure. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the scope of the present disclosure, all of which fall within the scope of protection of the present disclosure. Therefore, the scope of protection of the disclosed patent shall be determined by the appended claims.

Claims

1. A DALI fault detection circuit based on primary winding, characterized in that: The DALI device comprises a power supply module and a DALI fault feedback module. The power supply module comprises a rectifier circuit and a power conversion isolation circuit. The input end of the rectifier circuit is used to connect to an external constant current power supply. The output end of the rectifier circuit is connected to the primary winding input end of the power conversion isolation circuit. The secondary winding output end of the power conversion isolation circuit is used to connect to an LED load. The DALI fault feedback module includes an abnormal feedback circuit and a DALI control module. The abnormal feedback circuit includes a fault state detection circuit and a constant current dimming control chip. The current control terminal of the constant current dimming control chip is connected to the input terminal of the power conversion isolation circuit, and the PWM output terminal of the DALI control module is connected to the signal input terminal of the constant current dimming control chip. The fault state detection circuit includes a fault detection winding, a first resistor, a second resistor, and a first capacitor. The fault detection winding is coupled to the primary winding input end of the power conversion isolation circuit. The first end of the first resistor is connected to the output end of the fault detection winding, and the second end of the first resistor is connected to the first end of the second resistor. The abnormal state detection end of the DALI control module is respectively connected to the second end of the first resistor and the first end of the first capacitor, and the second end of the second resistor and the second end of the first capacitor are grounded.

2. The DALI fault detection circuit based on the primary winding according to claim 1, characterized in that: The fault state detection circuit further includes a second capacitor, a first end of the second capacitor is connected to the first end of the first resistor, and a second end of the second capacitor is grounded.

3. The DALI fault detection circuit based on the primary winding according to claim 2, characterized in that: The fault state detection circuit further includes a first current-conducting diode, wherein an anode of the first current-conducting diode is connected to the output end of the fault detection winding, and a cathode of the first current-conducting diode is connected to the first end of the first resistor.

4. The DALI fault detection circuit based on the primary winding according to claim 1, characterized in that: The power conversion isolation circuit further includes a second current-conducting diode, the anode of the second current-conducting diode is connected to the secondary winding output end of the power conversion isolation circuit, and the cathode of the second current-conducting diode is used to be connected to the LED load.

5. The DALI fault detection circuit based on the primary winding according to claim 4, characterized in that: The power conversion isolation circuit further includes a first polarity capacitor, wherein the positive electrode of the first polarity capacitor is used to be connected to the LED load, and the negative electrode of the first polarity capacitor is grounded.

6. The DALI fault detection circuit based on the primary winding according to claim 5, characterized in that: The first polarity capacitor is an adjustable polarity capacitor.

7. The DALI fault detection circuit based on the primary winding according to claim 1, characterized in that: The rectifier circuit includes a rectifier module and a second polarity capacitor, the input end of the rectifier module is used to connect to an external constant current power supply, the output end of the rectifier module is connected to the positive pole of the second polarity capacitor, the positive pole of the second polarity capacitor is connected to the primary winding input end of the power conversion isolation circuit, and the negative pole of the second polarity capacitor is grounded.

8. The DALI fault detection circuit based on the primary winding according to claim 7, characterized in that: The second polarity capacitor is an adjustable polarity capacitor.

9. The DALI fault detection circuit based on the primary winding according to claim 1, characterized in that: At least one of the first resistor and the second resistor is an adjustable resistor.

10. A driving power supply, characterized in that: The DALI fault detection circuit based on the primary winding comprises the DALI fault detection circuit according to any one of claims 1 to 9.

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