DALI protocol transceiver circuit and LED driver power supply

Abstract

The present invention relates to the field of electronic circuit technology, and discloses a DALI protocol transceiver circuit and an LED driving power supply. The circuit includes a constant current circuit, a first optocoupler, a voltage-controlled output circuit and a receiving circuit; the constant current circuit, the first optocoupler and the voltage-controlled output circuit are connected in sequence; the constant current circuit receives a DALI signal from a DALI bus, transmits the DALI signal to the first optocoupler, and enables the first optocoupler to generate a corresponding first transmission signal according to the DALI signal; the voltage-controlled output circuit receives the first transmission signal, generates a corresponding control signal according to the voltage value of the first transmission signal and outputs it to the outside; the receiving circuit accesses an external feedback signal, and transmits the feedback signal to the DALI bus. The embodiment of the present invention can improve the accuracy of dimming based on the DALI protocol.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a DALI protocol transceiver circuit and an LED drive power supply. Background Art

[0002] DALI (Digital Addressable Lighting Interface) dimming is an emerging technology with rich functions that can meet the digital control of LED lights. It occupies an important position in the future smart home and has good market development prospects.

[0003] In the prior art, a DALI lamp controller receives and sends DALI signals through a DALI protocol transceiver circuit. The DALI lamp controller generally receives and sends DALI signals through a DALI protocol transceiver circuit. The control side receives and sends DALI signals to and from the controlled side through the DALI protocol transceiver circuit. In the prior art, the signal current value range sent by the control side is limited by the signal current receiving range of the controlled side. Generally speaking, the signal current receiving range of the controlled side is narrow, resulting in a narrow signal current value range that can be selected by the control side. The difficulty of designing the signal transmission structure of the control side is increased, and the risk of the controlled side returning an erroneous signal is also increased. Summary of the invention

[0004] The purpose of the present invention is to provide a DALI protocol transceiver circuit and an LED driver power supply, aiming to improve the accuracy of dimming based on the DALI protocol.

[0005] In a first aspect, a DALI protocol transceiver circuit is provided, including a constant current circuit, a first optical coupler, a voltage-controlled output circuit and a receiving circuit;

[0006] The constant current circuit, the first optical coupler and the voltage-controlled output circuit are connected in sequence;

[0007] The constant current circuit receives a DALI signal from the DALI bus, and transmits the DALI signal to the first optical coupler, so that the first optical coupler generates a corresponding first transmission signal according to the DALI signal;

[0008] The voltage-controlled output circuit receives the first transmission signal, generates a corresponding control signal according to the voltage value of the first transmission signal, and outputs the control signal to the outside;

[0009] The receiving circuit receives the external feedback signal and transmits the feedback signal to the DALI bus.

[0010] In some embodiments, the voltage-controlled output circuit includes a first voltage-controlled subcircuit and a second voltage-controlled subcircuit;

[0011] The first voltage-controlled subcircuit is connected to a DC voltage;

[0012] The second voltage-controlled subcircuit is respectively connected to the light-receiving side of the first optical coupler and the first voltage-controlled subcircuit, collects the first transfer signal, and controls the first voltage-controlled subcircuit according to the voltage value of the first transfer signal, so that the first voltage-controlled subcircuit outputs a control signal that is adapted to the level waveform of the first transfer signal.

[0013] In some embodiments, the first voltage-controlled subcircuit includes a first voltage-controlled switch, the first voltage-controlled switch being connected to a DC voltage and pulling an output node of the first voltage-controlled subcircuit down to ground;

[0014] The second voltage-controlled subcircuit includes a second voltage-controlled switch, which controls the second voltage-controlled switch to be turned on or off according to the collected first transfer signal, so as to control the first voltage-controlled switch to be turned off or on, thereby realizing the output of the control signal.

[0015] In some embodiments, the first voltage-controlled switch and the second voltage-controlled switch are both MOS tubes.

[0016] In some embodiments, the receiving circuit includes a second optical coupler and a third voltage-controlled subcircuit;

[0017] The second optical coupler is connected to the external feedback signal and the third voltage-controlled sub-circuit, generates a corresponding second transmission signal according to the feedback signal and transmits it to the third voltage-controlled sub-circuit;

[0018] The third voltage-controlled subcircuit includes a third voltage-controlled switch, which is controlled to be turned on or off according to the received second transfer signal to control the voltage change on the DALI bus, thereby realizing the transmission of the feedback signal.

[0019] In some embodiments, the receiving circuit further includes a voltage stabilization subcircuit;

[0020] The voltage stabilizing subcircuit includes a voltage stabilizing tube, the anode of the voltage stabilizing tube is grounded, the cathode of the voltage stabilizing tube is connected to the light receiving side of the first optocoupler, the light emitting side of the first optocoupler, the light receiving side of the second optocoupler and the control end of the third voltage-controlled switch are connected in sequence.

[0021] In some embodiments, the constant current circuit includes a first switch subcircuit and a second switch subcircuit;

[0022] The first switch subcircuit includes a first switch element and a first voltage-dividing resistor, a first end of the first switch element is connected to the DALI bus through the first voltage-dividing resistor, and a second end of the first switch element is connected to the light-emitting side of the first optocoupler;

[0023] The second switch subcircuit includes a second switch element and a second voltage-dividing resistor, wherein a first end of the second switch element is connected to the DALI bus, a second end of the second switch element is connected to a control end of the first switch element and is grounded via the second voltage-dividing resistor, and the control end of the second switch element is connected to a first end of the first switch element;

[0024] The first switch sub-circuit and the second switch sub-circuit are turned on when the voltage level is low.

[0025] In some embodiments, the first switch element and the second switch element are both PNP transistors.

[0026] In some embodiments, the DALI protocol transceiver circuit further includes a rectifier circuit;

[0027] The rectifier circuit connects the DALI bus and the constant current circuit, rectifies the DALI signal carried by the DALI bus, and transmits the rectified DALI signal to the constant current circuit.

[0028] In a second aspect, an LED driving power supply is provided, comprising the DALI protocol transceiver circuit of the first aspect.

[0029] The beneficial effects of the present invention are as follows: during the DALI signal transmission process, the DALI protocol transceiver circuit converts and processes the DALI signal and outputs it to the lighting fixture, the constant current circuit outputs the processed DALI signal to the first optocoupler, the first optocoupler generates a first transfer signal based on the processed DALI signal, the current value of the DALI signal affects the current value of the first transfer signal, and the voltage-controlled output circuit generates a control signal based on the voltage value of the first transfer signal, the voltage-controlled output circuit itself is not sensitive to the current value of the first transfer signal, and the control signal generated by the voltage-controlled output circuit based on the voltage value of the first transfer signal is little affected by the current value of the DALI signal, and the DALI signal transmission has high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The figure is a schematic diagram of the structure of a DALI protocol transceiver circuit provided by an embodiment. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the present invention will be further described below in conjunction with the embodiments and drawings.

[0032] In the embodiments of the present invention, "several" means an indefinite quantity, "multiple" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0033] In the embodiments of the present invention, the terms "comprises," "comprising," or any other variations thereof are intended to cover a non-exclusive inclusion, and in addition to the listed elements, may also include other elements not explicitly listed.

[0034] In order to solve the above technical problems, the embodiment of the present invention provides a DALI protocol transceiver circuit, which can be applied to lighting fixtures. The lighting fixture control end sends a DALI signal to the lighting fixture through the DALI bus, and the lighting fixture receives the DALI signal through the hardware circuit in the embodiment of the present invention, and responds accordingly to the received DALI signal. The hardware circuit of the present invention has two input lines connected to the DALI bus. The DALI bus includes two communication buses, DALI+ and DALI-, and the DALI signal is transmitted through these two communication buses. The DALI protocol stipulates that when the voltage difference between the two buses meets 9.5V-22.5V, the DALI signal is a high-level signal, and when it meets 0-6.5V, the DALI signal is a low-level signal. The hardware circuit of the embodiment of the present invention is mainly used in DALI dimming products (such as lighting fixtures based on DALI dimming), and is used to accurately read DALI information to help pass DALI certification.

[0035] According to a first aspect of the present invention, a DALI protocol transceiver circuit is provided.

[0036] like Figure 1 As shown, the DALI protocol transceiver circuit includes a constant current circuit 100 , a first optical coupler 200 , a voltage-controlled output circuit 300 and a receiving circuit 400 .

[0037] The constant current circuit 100 , the first optical coupler 200 , and the voltage-controlled output circuit 300 are connected in sequence.

[0038] The constant current circuit 100 receives a DALI signal from the DALI bus, and transmits the DALI signal to the first optocoupler 200, so that the first optocoupler 200 generates a corresponding first transmission signal according to the DALI signal. The voltage-controlled output circuit 300 receives the first transmission signal, generates a corresponding control signal according to the voltage value of the first transmission signal, and outputs it to the outside.

[0039] The receiving circuit 400 receives an external feedback signal and transmits the feedback signal to the DALI bus.

[0040] Specifically, the output end of the constant current circuit 100 is connected to the light-emitting side of the first optical coupler 200, the input end of the voltage-controlled output circuit 300 is connected to the light-receiving side of the first optical coupler 200, and the output end of the voltage-controlled output circuit 300 is connected to the lighting fixture ( Figure 1 The RX interface in the receiving circuit 400 is connected to the input end of the lighting fixture ( Figure 1 The output end of the receiving circuit 400 is connected to the DALI bus.

[0041] The signal sending process is specifically as follows: the constant current circuit 100 processes the received DALI signal and outputs the processed DALI signal; the light-emitting side of the first optocoupler 200 generates a corresponding first transfer signal after receiving the processed DALI signal, and the light-receiving side of the first optocoupler 200 outputs the first transfer signal, and the first transfer signal flows to the voltage-controlled output circuit 300 connected to the first optocoupler 200; the voltage-controlled output circuit 300 obtains the first transfer signal, and the voltage-controlled output circuit 300 generates a control signal corresponding to the voltage value of the first transfer signal according to the real-time voltage value of the first transfer signal, and outputs the lighting fixture, thereby completing the signal sending process.

[0042] In this embodiment, the DALI protocol transceiver circuit converts and processes the DALI signal and outputs it to the lighting fixture. The constant current circuit 100 outputs the processed DALI signal to the first optocoupler 200. The first optocoupler 200 generates a first transfer signal based on the processed DALI signal. The current value of the DALI signal affects the current value of the first transfer signal, and the voltage-controlled output circuit 300 generates a control signal based on the voltage value of the first transfer signal. The voltage-controlled output circuit 300 itself is not sensitive to the current value of the first transfer signal. The control signal generated by the voltage-controlled output circuit 300 based on the voltage value of the first transfer signal is little affected by the current value of the DALI signal, and the DALI signal transmission has high accuracy.

[0043] In one embodiment of the present invention, generating a control signal may be detecting the high and low level values ​​of the first transmission signal based on the magnitude relationship between the real-time voltage value of the first transmission signal and the preset voltage value. When the detection is a low level, the corresponding generated control signal is a low level, and when the detection is a high level, the corresponding generated control signal is a high level.

[0044] Before the signal receiving process, the lighting fixture receives the control signal and parses the DALI command from the control signal, generates a corresponding dimming signal according to the DALI command, and uses the dimming signal to perform dimming control on the lighting fixture. The signal receiving process is specifically as follows: the lighting fixture generates a corresponding feedback signal according to the DALI command it has parsed, and transmits the feedback signal to the receiving circuit 400. The feedback signal is a high or low level signal, which is used to respond to the lighting fixture control terminal through the DALI bus. The receiving circuit 400 transmits the feedback signal to the DALI bus, and changes the voltage on the DALI bus based on the feedback signal to achieve the transmission of the feedback signal.

[0045] In one embodiment of the present invention, the voltage-controlled output circuit 300 at least includes:

[0046] The first voltage control sub-circuit 310 is connected to a DC voltage VCC;

[0047] The second voltage-controlled subcircuit 320 is connected to the first voltage-controlled subcircuit 310 and the light-receiving side of the first optical coupler 200, respectively, collects the first transmission signal, and controls the first voltage-controlled subcircuit 310 according to the voltage value of the first transmission signal, so that the first voltage-controlled subcircuit 310 outputs a control signal;

[0048] The level waveform of the first transfer signal is adapted to the level waveform of the control signal.

[0049] The input end of the first voltage-controlled sub-circuit 310 is connected to the DC voltage VCC, and the output end of the first voltage-controlled sub-circuit 310 serves as the output end of the voltage-controlled output circuit 300, and is used to output a control signal. The DC voltage VCC may be output as a high-level control signal, and the DC voltage VCC may not be output as a low-level control signal.

[0050] The second voltage-controlled sub-circuit 320 obtains the first transfer signal from the light-receiving side of the first optocoupler 200. The second voltage-controlled sub-circuit 320 detects the high and low level values ​​of the first transfer signal according to the magnitude relationship between the real-time voltage value of the first transfer signal and the preset voltage value. When the first transfer signal is detected to be at a high level, the second voltage-controlled sub-circuit 320 controls the first voltage-controlled sub-circuit 310 to output a high-level control signal. When the first transfer signal is detected to be at a low level, the second voltage-controlled sub-circuit 310 controls the first voltage-controlled sub-circuit 310 to output a low-level control signal.

[0051] The first voltage-controlled sub-circuit 310 at least includes:

[0052] The first voltage-controlled switch Q1 is connected to the DC voltage VCC and pulls the output node of the first voltage-controlled sub-circuit 310 down to the ground.

[0053] The second voltage-controlled sub-circuit 320 at least includes:

[0054] The second voltage-controlled switch Q2 is controlled to be turned on or off according to the collected first transfer signal, so as to control the first voltage-controlled switch Q1 to be turned off or on, thereby realizing the output of the control signal.

[0055] The first voltage-controlled subcircuit 310 also includes a first resistor R1 and a second resistor R2. The control end of the first voltage-controlled switch Q1 is connected to one end of the first resistor R1. The first end of the first voltage-controlled switch Q1 is connected to one end of the second resistor R2 and serves as the output end of the voltage-controlled output circuit 300. The second end of the first voltage-controlled switch Q1 is grounded. The other end of the first resistor R1 and the other end of the second resistor R2 are connected to a DC voltage VCC. The control end of the second voltage-controlled switch Q2 is connected to the emitter of the light-receiving side of the first optical coupler 200. The first end of the second voltage-controlled switch Q2 is connected to the control end of the first voltage-controlled switch Q1. The second end of the second voltage-controlled switch Q2 is grounded.

[0056] The first voltage-controlled switch Q1 is a voltage-type switch element, and the second voltage-controlled switch Q2 is a voltage-type switch element.

[0057] Specifically, the second voltage-controlled switch Q2 collects the first transfer signal. When the voltage value of the first transfer signal meets the turn-on voltage value of the second voltage-controlled switch Q2, the second voltage-controlled switch Q2 is turned on, and the level of the control end of the first voltage-controlled switch Q1 is pulled down by the turned-on second voltage-controlled switch Q2, and the first voltage-controlled switch Q1 is adjusted to the first turn-on state (on or off). When the voltage value of the first transfer signal does not meet the turn-on voltage value of the second voltage-controlled switch Q2, the second voltage-controlled switch Q2 is turned off, and the level position of the control end of the first voltage-controlled switch Q1, the first voltage-controlled switch Q1 is in the second turn-on state (on or off).

[0058] Exemplarily, the first voltage-controlled switch Q1 is turned on by a high level trigger and turned off by a low level trigger, and the second voltage-controlled switch Q2 is also turned on by a high level trigger and turned off by a low level trigger. When the voltage value of the first transfer signal satisfies the high level, the second voltage-controlled switch Q2 is turned on, pulling down the level of the control end of the first voltage-controlled switch Q1, so that the first voltage-controlled switch Q1 is turned off, and the voltage-controlled output circuit 300 outputs a high-level control signal. When the voltage value of the first transfer signal satisfies the low level, the second voltage-controlled switch Q2 is turned off, the control end of the first voltage-controlled switch Q1 maintains a high level, the first voltage-controlled switch Q1 is turned on and pulls the DC voltage VCC down to the ground, and the voltage-controlled output circuit 300 outputs a low-level control signal.

[0059] In one embodiment of the present invention, the first voltage-controlled switch Q1 is a MOS transistor, and the second voltage-controlled switch Q2 is also a MOS transistor. More specifically, the first voltage-controlled switch Q1 is an N-type MOS transistor, and the second voltage-controlled switch Q2 is also an N-type MOS transistor.

[0060] In one embodiment of the present invention, the receiving circuit 400 at least includes:

[0061] A second optical coupler 410, the second optical coupler 410 is connected to an external feedback signal, the second optical coupler 410 is connected to a third voltage-controlled sub-circuit 420, and the second optical coupler 410 generates a corresponding second transmission signal according to the feedback signal and transmits the second transmission signal to the third voltage-controlled sub-circuit 420;

[0062] The third voltage-controlled sub-circuit 420 at least includes a third voltage-controlled switch Q3, which controls the third voltage-controlled switch Q3 to be turned off or on according to the received second transfer signal to control the voltage change on the DALI bus and transmit the feedback signal to the DALI bus.

[0063] The light-emitting side of the second optocoupler 410 is connected to the lighting fixture, receives the feedback signal emitted by the lighting fixture, and generates a corresponding second transmission signal according to the received feedback signal. The second optocoupler 410 transmits the second transmission signal to the third voltage-controlled switch Q3 through its light-receiving side, adjusts the third voltage-controlled switch Q3 from on to off or from off to on, and changes the voltage of the DALI bus during the on-off switching process of the third voltage-controlled switch Q3. When the third voltage-controlled switch Q3 is on, the voltage of the DALI bus is lowered, and when the third voltage-controlled switch Q3 is off, the voltage of the DALI bus is maintained.

[0064] In one embodiment of the present invention, the receiving circuit 400 at least further includes:

[0065] The voltage stabilizing subcircuit 430 includes a voltage stabilizing tube ZD; the cathode of the voltage stabilizing tube ZD is connected to the light receiving side of the first optocoupler 200, the anode of the voltage stabilizing tube ZD is grounded, and the light emitting side of the first optocoupler 200, the light receiving side of the second optocoupler 410 and the control end of the third voltage-controlled switch Q3 are connected in sequence.

[0066] The principle of the voltage stabilizing subcircuit 430 is: when the voltage loaded on the voltage stabilizing tube ZD is greater than its voltage stabilizing value, the current on the voltage stabilizing tube ZD flows through the constant current circuit 100 and the light-emitting side of the first optocoupler 200 and the voltage stabilizing tube ZD to the ground, thereby realizing overvoltage protection of the hardware circuit. In this embodiment, since the voltage-controlled output circuit 300 is a voltage-type control circuit topology, the signal current value range of the input DALI signal is large, and a voltage stabilizing tube ZD with a larger voltage stabilizing value can be selected, which has a higher voltage stabilizing value, and can avoid the third voltage-controlled switch Q3 batch conduction threshold Vgs (th) biased to the upper limit, the driving voltage is insufficient, and the third voltage-controlled switch Q3 cannot reach saturation conduction (i.e., semi-conducting state), thereby improving the accuracy of feedback signal transmission.

[0067] In one embodiment of the present invention, the constant current circuit 100 at least includes:

[0068] A first switch subcircuit 110, the first switch subcircuit 110 at least comprises a first voltage-dividing resistor R11 and a first switch element Q11. A first end of the first switch element Q11 is connected to the DALI bus through the first voltage-dividing resistor R11, and a second end of the first switch element Q11 is connected to the light-emitting side of the first optical coupler 200;

[0069] A second switch subcircuit 120, the second switch subcircuit 120 at least includes a second voltage-dividing resistor R12 and a second switch element Q12. A first end of the second switch element Q12 is connected to the DALI bus, a second end of the second switch element Q12 is connected to a control end of the first switch element Q11 and is grounded through the second voltage-dividing resistor R12, and a control end of the second switch element Q12 is connected to a first end of the first switch element Q11;

[0070] The first switch sub-circuit 110 is turned on when the voltage level is low, and the second switch sub-circuit 120 is also turned on when the voltage level is low.

[0071] More specifically, the first switch element Q11 is a PNP transistor, and the second switch element Q12 is also a PNP transistor.

[0072] In an embodiment of the present invention, the DALI protocol transceiver circuit further includes a rectifier circuit 500 .

[0073] The rectifier circuit 500 is connected to the constant current circuit 100 and the DALI bus, rectifies the DALI signal carried by the DALI bus, and transmits the rectified DALI signal to the constant current circuit 100 .

[0074] The rectifier circuit 500 is respectively connected to the DALI bus, the input end of the constant current circuit 100 and the output end of the receiving circuit 400, receives the DALI signal in the DALI bus, rectifies the received DALI signal, and outputs the DALI signal to the constant current circuit 100 after rectification. The rectifier circuit 500 of this embodiment can effectively ensure that information transmission can still be performed when the DALI signal is connected in reverse.

[0075] According to the second aspect of the present invention, an LED driving power supply is proposed, which includes the above-mentioned DALI protocol transceiver circuit. The specific structure of the DALI protocol transceiver circuit refers to the above-mentioned embodiment. Since the LED driving power supply of the second aspect of the present invention adopts all the technical solutions of all the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0076] In summary, in the DALI protocol transceiver circuit and LED driving power supply provided by the present invention, during the DALI signal transmission process, the DALI protocol transceiver circuit converts and processes the DALI signal and outputs it to the lighting fixture, the constant current circuit outputs the processed DALI signal to the first optocoupler, the first optocoupler generates a first transmission signal based on the processed DALI signal, the current value of the DALI signal affects the current value of the first transmission signal, and the voltage-controlled output circuit generates a control signal based on the voltage value of the first transmission signal, the voltage-controlled output circuit itself is not sensitive to the current value of the first transmission signal, and the control signal generated by the voltage-controlled output circuit based on the voltage value of the first transmission signal is little affected by the current value of the DALI signal, and the DALI signal transmission has high accuracy.

[0077] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] In this document, the terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of elements other than those listed and may also include additional elements not expressly listed.

[0079] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A DALI protocol transceiver circuit, characterized in that: It includes a constant current circuit, a first optical coupler, a voltage-controlled output circuit and a receiving circuit; The constant current circuit, the first optical coupler and the voltage-controlled output circuit are connected in sequence; The constant current circuit receives a DALI signal from the DALI bus, and transmits the DALI signal to the first optical coupler, so that the first optical coupler generates a corresponding first transmission signal according to the DALI signal; The voltage-controlled output circuit receives the first transmission signal, generates a corresponding control signal according to the voltage value of the first transmission signal, and outputs the control signal to the outside; The receiving circuit receives an external feedback signal and transmits the feedback signal to the DALI bus; The voltage-controlled output circuit includes a first voltage-controlled subcircuit and a second voltage-controlled subcircuit; The first voltage control subcircuit is connected to a DC voltage; The second voltage-controlled subcircuit is connected to the light-receiving side of the first optical coupler and the first voltage-controlled subcircuit, respectively, collects the first transfer signal, and controls the first voltage-controlled subcircuit according to the voltage value of the first transfer signal, so that the first voltage-controlled subcircuit outputs a control signal that is adapted to the level waveform of the first transfer signal; The first voltage-controlled subcircuit includes a first voltage-controlled switch, the first voltage-controlled switch is connected to a DC voltage and pulls down an output node of the first voltage-controlled subcircuit to ground; The second voltage-controlled subcircuit includes a second voltage-controlled switch, which controls the second voltage-controlled switch to be turned on or off according to the collected first transfer signal, so as to control the first voltage-controlled switch to be turned off or on, thereby realizing the output of the control signal; The receiving circuit includes a second optical coupler and a third voltage-controlled subcircuit; The second optical coupler is connected to an external feedback signal and to the third voltage-controlled sub-circuit, generates a corresponding second transmission signal according to the feedback signal and transmits the second transmission signal to the third voltage-controlled sub-circuit; The third voltage-controlled subcircuit includes a third voltage-controlled switch, and the third voltage-controlled switch is controlled to be turned on or off according to the received second transmission signal to control the voltage change on the DALI bus, thereby realizing the transmission of the feedback signal; The receiving circuit also includes a voltage stabilizing subcircuit; The voltage stabilizing subcircuit includes a voltage stabilizing tube, the anode of the voltage stabilizing tube is grounded, the cathode of the voltage stabilizing tube is connected to the light receiving side of the first optocoupler, and the light emitting side of the first optocoupler, the light receiving side of the second optocoupler and the control end of the third voltage-controlled switch are connected in sequence.

2. The DALI protocol transceiver circuit according to claim 1, characterized in that: The first voltage-controlled switch and the second voltage-controlled switch are both MOS tubes.

3. The DALI protocol transceiver circuit according to claim 1, characterized in that: The constant current circuit comprises a first switch subcircuit and a second switch subcircuit; The first switch subcircuit includes a first switch element and a first voltage-dividing resistor, a first end of the first switch element is connected to the DALI bus through the first voltage-dividing resistor, and a second end of the first switch element is connected to the light-emitting side of the first optocoupler; The second switch subcircuit includes a second switch element and a second voltage-dividing resistor, a first end of the second switch element is connected to the DALI bus, a second end of the second switch element is connected to the control end of the first switch element and is grounded through the second voltage-dividing resistor, and the control end of the second switch element is connected to the first end of the first switch element; The first switch sub-circuit and the second switch sub-circuit are turned on when the voltage level is low.

4. The DALI protocol transceiver circuit according to claim 3, characterized in that: The first switch element and the second switch element are both PNP transistors.

5. The DALI protocol transceiver circuit according to claim 1, characterized in that: Also includes a rectifier circuit; The rectifier circuit is connected to the DALI bus and the constant current circuit, rectifies the DALI signal carried by the DALI bus, and transmits the rectified DALI signal to the constant current circuit.

6. An LED driving power supply, characterized in that: The invention comprises the DALI protocol transceiver circuit as described in any one of claims 1 to 5.

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