A DALI dimming and color adjustment driver power supply

Abstract

The present invention relates to a DALI dimming and color adjustment driving power supply, comprising a flyback isolation constant voltage output circuit, a first cold light adjustment circuit, a second warm light adjustment circuit, a no-load dummy load removal circuit, a fault detection circuit and a DALI module circuit; the flyback isolation constant voltage output circuit is respectively connected to the cold light adjustment circuit and the warm light adjustment circuit, and the first cold light adjustment circuit and the second warm light adjustment circuit are both connected to the no-load dummy load removal circuit and the fault detection circuit; the flyback isolation constant voltage output circuit is connected to the DALI module circuit; the fault detection circuit comprises a W fault detection circuit and a C fault detection circuit, the cold light adjustment circuit is connected to the C fault detection circuit, and the warm light adjustment circuit is connected to the W fault detection circuit, and the problem of lamp jitter in the dimming and color adjustment process of the DALI driving power supply is solved by applying a DC‑DC analog dimming IC.

Description

Technical Field

[0001] The present invention belongs to the field of circuit technology, and in particular relates to a DALI dimming and color adjustment driving power supply. Background Art

[0002] DALI Technology Introduction: DALI is the abbreviation of "Digital Addressable Lighting Interface". It is a data transmission protocol that defines the digital communication method between lighting appliances and system equipment controllers. The biggest feature of the DALI system is that each lamp has an independent address, and a certain lamp can be controlled individually, and 255 levels of dimming and color adjustment accuracy, 16 lighting groups and 16 lighting scenes can be achieved.

[0003] The existing dual-color DALI power supply solves the problem of flickering lights during dimming and color adjustment by using a DC-DC dimming IC to achieve dimming and cutting two MOS tubes for color adjustment, or by using two MOS tubes for dimming and color adjustment. There are also two PWM DC-DC ICs that optimize by reducing the frequency to below 500HZ when the duty cycle reaches below 50% during dimming and color adjustment. The MOS cutting method is easy to damage the MOS tube when the output is short-circuited, or one channel is loaded and the other is unloaded. The method of reducing the frequency through the PWM IC cannot meet the flicker requirements during the entire dimming process.

[0004] That is, when the existing two-color DALI driver is dimming and adjusting the color of the DALI system host, because some scene applications require the delay time of the light-off process to be set to 2 seconds or more, the light will shake when the brightness is reduced by about 50%-10% from the original during the process from the brightest to the off, thereby affecting the customer experience. Similarly, when the DALI system host is adjusting the color, the principle is that the brightness of one light is reduced and the brightness of the other light is increased, which is a dimming process, and the problem of color temperature jump will also occur in the middle. Summary of the invention

[0005] In order to solve the above technical problems, the present invention solves the problem of lamp flickering during dimming and color adjustment of DALI driving power supply by applying DC-DC analog dimming IC, and simultaneously solves the problem of DALI fault detection and lamp flickering during power failure when this IC is applied.

[0006] The present invention overcomes the shortcomings of other performances that are sacrificed in most of the prior arts to solve the problem of lamp jitter during DALI dimming and color adjustment. A DC-DC IC is used. This IC converts an externally input PWM signal into an analog signal inside the chip. When the external signal PWM duty cycle changes, this IC adjusts the on and off duty cycle of the internal MOS tube through a fixed high-frequency 400K frequency to achieve output current changes.

[0007] The present invention further provides a fault detection circuit and a no-load dummy load removal circuit to meet the requirement specified in the DALI protocol that the ERC and ERW pins of the DALI module need to detect a high level when no-load or short-circuited.

[0008] The specific technical solutions are as follows:

[0009] The present invention provides a DALI dimming and color adjustment driving power supply, including a flyback isolation constant voltage output circuit, a first cold light adjustment circuit, a second warm light adjustment circuit, a no-load dummy load removal circuit, a fault detection circuit and a DALI module circuit;

[0010] The flyback isolation constant voltage output circuit is connected to the cold light adjustment circuit and the warm light adjustment circuit respectively, and the first cold light adjustment circuit and the second warm light adjustment circuit are both connected to the no-load dummy load removal circuit and the fault detection circuit;

[0011] The flyback isolation constant voltage output circuit is connected to the DALI module circuit;

[0012] The fault detection circuit includes a W fault detection circuit and a C fault detection circuit, the cold light adjustment circuit is connected to the C fault detection circuit, and the warm light adjustment circuit is connected to the W fault detection circuit;

[0013] The C fault detection circuit includes an output no-load ERC high-level circuit, an output short-circuit ERC high-level circuit and an ERC driven circuit; the output no-load ERC high-level circuit is connected to the ERC driven circuit, and the output short-circuit ERC high-level circuit is connected to the ERC driven circuit; when no-load, C- to SGND is low level, C- to XV is low level, the triode Q1 is not conducting, and the ERC output is high level; when short-circuited, C- to SGND is high level, driving the triode Q3 to conduct, the triode Q1 is not conducting and the ERC output is high level;

[0014] The C fault detection circuit includes a voltage zener diode ZD3, a voltage zener diode ZD4, a resistor R28, a resistor R29, a resistor R45, a resistor R46, a resistor R47, a resistor R48, a transistor Q1 and a transistor Q3; in normal operation, the voltage from C- to SGND is greater than the voltage of ZD3, ZD3 is turned on, and the voltage is divided by resistors R46 and R45, and resistors R26 and R27 limit the current and drive the transistor Q1 to turn on, and the collector of the transistor Q1 is at a low level, ERC output is low level. When the circuit is open, the voltage from C- to SGND cannot turn on ZD3. Q1 is not conducting. The collector voltage is 5V. The voltage through R29 and R28, ERC is high level. When the circuit is short, the voltage from C- to SGND is equal to the voltage from LED+ to SGND, 48V. Zener diodes ZD3 and ZD4 are all conducting. After the resistors R48 and R47 divide the voltage and limit the current, diode Q3 is conducting. At this time, the transistor Q1 is not conducting, and ERC outputs high level.

[0015] The W fault detection circuit includes a Zener diode ZD5, a Zener diode ZD6, a resistor R30, a resistor R31, a resistor R43, a resistor R44, a resistor R24, a resistor R25, a circuit R22, a circuit 23, a transistor Q2 and a transistor Q4. When working normally, the voltage from W- to SGND is greater than the voltage of ZD6, ZD6 is turned on, and the voltage is divided by resistors R31 and R30, and resistors R24 and R25 limit the current and drive the transistor Q2 to turn on, and the collector of the transistor Q2 It is low level, ERC output is low level, when open circuit, the voltage from W- to SGND cannot turn on ZD3, Q2 is not conducting, the collector voltage is 5V, and the voltage through R23 and R22, ERC is high level, when short circuit, the voltage from W- to SGND is equal to the voltage from LED+ to SGND 48V, Zener diode ZD6 and Zener diode ZD5 are all turned on, and diode Q4 is turned on after voltage division and current limiting by resistor R43 and resistor R44. At this time, the transistor Q2 is not conducting, and ERC outputs a high level.

[0016] Preferably, the W fault detection circuit includes an output no-load ERW high level circuit, an output short-circuit ERW high level circuit and an ERW driven circuit; the output no-load ERW high level circuit is connected to the ERW driven circuit, and the output short-circuit ERW high level circuit is connected to the ERW driven circuit; when no-load, W- to SGND is a low level, W- to XV is a low level, the transistor Q2 is not conducting, and the ERW output is a high level; when short-circuited, W- to SGND is a high level, driving the transistor Q4 to conduct, the transistor Q2 is not conducting and the ERW output is a high level.

[0017] Preferably, the no-load dummy load removal circuit comprises a voltage stabilizing diode ZD2, a resistor R36, a resistor R37, a resistor R39, a resistor R40, a resistor R50, a triode Q5 and a triode Q6. When the circuit works normally, the maximum voltage from LED+ to W1- is 40V, and the voltage of ZD2 is 43V. At this time, the voltage stabilizing diode ZD2 is not turned on, and the triode Q6 is not turned on either. The triode Q5 is turned on after the voltage is limited by the voltage division of the resistor R39 and the resistor R40. The load resistor R50 allows the current to pass from LED+ to W1- through the conduction of the triode Q5, and the resistor R50 acts as a load.

[0018] When the power supply is unloaded, the voltage from LED+ to W1- is 48V. ZD2 is turned on and drives the transistor Q6 to turn on after the voltage division and current limiting of resistors R36 and R37, thereby lowering the base voltage of the transistor Q5. That is, the transistor Q5 is not turned on at this time, and R50 does not act as a load.

[0019] Preferably, the flyback isolated constant voltage output circuit includes an AC input rectification and filtering circuit, a T1 leakage inductance absorption circuit, a flyback main control circuit and a flyback circuit output rectification and filtering circuit, the AC input rectification and filtering circuit is connected to the T1 leakage inductance absorption circuit, the T1 leakage inductance absorption circuit is connected to the flyback circuit output rectification and filtering circuit, the flyback main control circuit is respectively connected to the T1 leakage inductance absorption circuit and the flyback circuit output rectification and filtering circuit, the AC input rectification and filtering circuit is used to output a DC voltage after rectification and filtering of the AC end input; the flyback main control circuit is used for main winding energy storage or energy release, the T1 leakage inductance absorption circuit is used to consume energy that is not fully released by the main winding, and the flyback circuit output rectification and filtering circuit is used for the output rectification and filtering circuit.

[0020] Preferably, the DALI module includes a DA+ signal input terminal, a DA- signal input terminal, an ERC cold light fault detection pin, an ERW warm light fault detection pin, a PWM dimming signal of a PC cold light BUCK circuit, and a PWM dimming signal of a PW warm light BUCK circuit.

[0021] Preferably, the DALI module power supply circuit includes a BUCK step-down circuit and U5, and outputs a VCC voltage of about 20V to pin 6 of IC U5 through an AC-DC isolation flyback circuit. U5 is a built-in MOS step-down IC that outputs 5V to power the DALI module. Compared with the prior art, the beneficial effects of the present invention are:

[0022] (1) The present invention uses two DC-DC analog dimming ICs and cooperates with a fault detection circuit to achieve DALI dimming without lamp shaking, and the DALI dimming is free of flicker throughout the entire process, and the short-circuit protection does not damage the device.

[0023] (2) The present invention compares the duty cycle of the PWM dimming signal with the internal reference of the chip to change the duty cycle of the main frequency to achieve current regulation, and cooperates with the designed peripheral circuit to achieve DALI dimming and color adjustment process without lamp shaking.

[0024] (3) The present invention uses a ZD3 voltage regulator and a no-load dummy load circuit to shield the DC level between C-SGND when normally loaded. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A diagram of a power supply function module provided by the present invention;

[0026] Figure 2 The schematic diagram of the DALI dimming and color adjustment driving power supply provided by the present invention;

[0027] Figure 3 The output no-load ERC high-level circuit provided by the present invention;

[0028] Figure 4 The output short-circuit ERC high-level circuit provided by the present invention;

[0029] Figure 5 The ERC driven circuit provided by the present invention;

[0030] Figure 6 A fault detection circuit diagram provided by the present invention;

[0031] Figure 7 A normal loaded circuit provided by the present invention;

[0032] Figure 8 The no-load dummy load removal circuit provided by the present invention;

[0033] Fig. 9 A no-load dummy load removal circuit diagram provided by the present invention;

[0034] Fig.10 The AC input rectification and filtering circuit diagram provided by the present invention;

[0035] Fig.11 The T1 leakage inductance absorption circuit diagram provided by the present invention;

[0036] Fig.12 A flyback main control circuit diagram provided by the present invention;

[0037] Fig.13 The flyback circuit output rectification and filtering circuit diagram provided by the present invention;

[0038] Fig.14 A flyback isolation constant voltage output circuit diagram provided by the present invention;

[0039] Fig.15A power supply circuit diagram of a DALI module provided by the present invention;

[0040] Fig.16 A circuit diagram of a DALI module provided by the present invention;

[0041] Fig.17 This is a DC-DC constant current drive IC and peripheral circuit diagram provided by the present invention. DETAILED DESCRIPTION

[0042] The drawings are only used for illustrative purposes and cannot be construed as limiting the present invention. In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the drawings. Here, the exemplary examples will be described in detail.

[0043] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0044] like Figure 1-2 As shown, the present invention provides a DALI dimming and color adjustment driving power supply, including a flyback isolation constant voltage output circuit, a first cold light adjustment circuit, a second warm light adjustment circuit, a no-load dummy load removal circuit, a fault detection circuit and a DALI module circuit;

[0045] The flyback isolation constant voltage output circuit is connected to the cold light adjustment circuit and the warm light adjustment circuit respectively, and the first cold light adjustment circuit and the second warm light adjustment circuit are both connected to the no-load dummy load removal circuit and the fault detection circuit;

[0046] The flyback isolation constant voltage output circuit is connected to the DALI module circuit;

[0047] The fault detection circuit includes a W fault detection circuit and a C fault detection circuit, the cold light adjustment circuit is connected to the C fault detection circuit, and the warm light adjustment circuit is connected to the W fault detection circuit;

[0048] like Figure 3-5 As shown, the C fault detection circuit provided by the present invention includes an output no-load ERC high-level circuit, an output short-circuit ERC high-level circuit and an ERC driven circuit; the output no-load ERC high-level circuit is connected to the ERC driven circuit, and the output short-circuit ERC high-level circuit is connected to the ERC driven circuit; when no-load, C- to SGND is a low level, C- to XV is a low level, the transistor Q1 is not conducting, and the ERC output is a high level; when short-circuited, C- to SGND is a high level, driving the transistor Q3 to conduct, the transistor Q1 is not conducting and the ERC output is a high level.

[0049] in Figure 3To output the unloaded ERC high level line, Figure 4 To output short circuit ERC high level line, Figure 3 and Figure 4 Common ERC driven line Figure 5 shown.

[0050] When no load (such as Figure 3 )C- to SGND is low level, then XV is low level Figure 5 Line Q1 is not conducting, and the ERC output is high level. Figure 4 )C- to SGND is high level to drive Q3 to turn on Figure 5 Line Q1 is not conducting and the ERC output is high.

[0051] Among them, the W fault detection circuit provided by the present invention has the same principle as the C fault detection circuit; the W fault detection circuit includes an output no-load ERW high-level circuit, an output short-circuit ERW high-level circuit and an ERW driven circuit; the output no-load ERW high-level circuit is connected to the ERW driven circuit, and the output short-circuit ERW high-level circuit is connected to the ERW driven circuit; when no-load, W- to SGND is a low level, W- to XV is a low level, the transistor Q2 is not conducting, and the ERW output is a high level; when short-circuited, W- to SGND is a high level, driving the transistor Q4 to conduct, the transistor Q2 is not conducting and the ERW output is a high level.

[0052] Specifically, Figure 6 As shown, the C fault detection circuit provided by the present invention includes a voltage zener diode ZD3, a voltage zener diode ZD4, a resistor R28, a resistor R29, a resistor R45, a resistor R46, a resistor R47, a resistor R48, a triode Q1 and a triode Q3; in normal operation, the voltage from C- to SGND is greater than the voltage of the voltage zener diode ZD3, the voltage zener diode ZD3 is turned on, and the voltage is divided by the resistors R46 and R45, and the resistors R26 and R27 limit the current and drive the triode Q1 to be turned on, and the triode Q1 collects the current Extremely low level, ERC output is low level, when open circuit, the voltage from C- to SGND cannot turn on the Zener diode ZD3, Q1 is not conducting, the collector voltage is 5V, and the voltage passing through R29 and R28, ERC is high level, when short circuit, the voltage from C- to SGND is equal to the voltage from LED+ to SGND 48V, Zener diodes ZD3 and ZD4 are all turned on, and diode Q3 is turned on after voltage division and current limiting by resistors R48 and R47. At this time, the transistor Q1 is not conducting, and ERC outputs a high level.

[0053] The W fault detection circuit includes a Zener diode ZD5, a Zener diode ZD6, a resistor R30, a resistor R31, a resistor R43, a resistor R44, a resistor R24, a resistor R25, a circuit R22, a circuit 23, a transistor Q2 and a transistor Q4. When working normally, the voltage from W- to SGND is greater than the voltage of ZD6, ZD6 is turned on, and the voltage is divided by resistors R31 and R30, and resistors R24 and R25 limit the current and drive the transistor Q2 to turn on, and the collector of the transistor Q2 It is low level, ERC output is low level, when open circuit, the voltage from W- to SGND cannot turn on ZD3, Q2 is not conducting, the collector voltage is 5V, and the voltage through R23 and R22, ERC is high level, when short circuit, the voltage from W- to SGND is equal to the voltage from LED+ to SGND 48V, Zener diode ZD6 and Zener diode ZD5 are all turned on, and diode Q4 is turned on after voltage division and current limiting by resistor R43 and resistor R44. At this time, the transistor Q2 is not conducting, and ERC outputs a high level.

[0054] like Figure 7-8 As shown, the no-load dummy load removal circuit provided by the present invention can be divided into a normal loaded circuit ( Figure 7 ) and no-load to dummy load line ( Figure 8 ),

[0055] During normal load (such as Figure 7 ) The voltage between LED+W1- is the voltage across the LED with load. After being divided by R39 and R40, Q5 is driven to conduct. At this time, R50 is connected to LED+ and W1- to act as a dummy load. Figure 8 ) shows that ZD2 is turned on and then R36 R37 is used to limit the current and drive Q6 to turn on, pulling down the base voltage of Q5. At this time, Q5 is not turned on and R50 cannot be connected to W1-, which is equivalent to removing the function of R50.

[0056] like Fig. 9 As shown, specifically, the no-load dummy load removal circuit provided by the present invention includes a voltage stabilizing diode ZD2, a resistor R36, a resistor R37, a resistor R39, a resistor R40, a resistor R50, a triode Q5 and a triode Q6. When the circuit works normally, the maximum voltage from LED+ to W1- is 40V, and the voltage of ZD2 is 43V. At this time, the voltage stabilizing diode ZD2 is not turned on, and the triode Q6 is not turned on. The triode Q5 is turned on after the voltage is limited by the voltage division of the resistor R39 and the resistor R40. The load resistor R50 allows the current to pass from LED+ to W1- through the conduction of the triode Q5, and the resistor R50 plays a load role;

[0057] When the power supply is unloaded, the voltage from LED+ to W1- is 48V. ZD2 is turned on and drives the transistor Q6 to turn on after the voltage division and current limiting of resistors R36 and R37, thereby lowering the base voltage of the transistor Q5. That is, the transistor Q5 is not turned on at this time, and R50 does not act as a load.

[0058] like Figure 10-13 As shown, the flyback isolation constant voltage output circuit provided by the present invention includes an AC input rectifier filter circuit ( Fig.10 )、T1 leakage inductance absorption circuit ( Fig.11 )、Flyback main control circuit( Fig.12 ) and the flyback circuit output rectifier filter circuit ( Fig.13 ), the AC input rectification and filtering circuit is connected to the T1 leakage inductance absorption circuit, the T1 leakage inductance absorption circuit is connected to the flyback circuit output rectification and filtering circuit, the flyback main control circuit is connected to the T1 leakage inductance absorption circuit and the flyback circuit output rectification and filtering circuit respectively, the AC input rectification and filtering circuit is used to output a DC voltage after rectification and filtering of the AC input; the flyback main control circuit is used for main winding energy storage or energy release, the T1 leakage inductance absorption circuit is used to consume the energy that is not fully released by the main winding, and the flyback circuit output rectification and filtering circuit is used for the output rectification and filtering circuit.

[0059] AC terminal LN input through Fig.11 After rectification and filtering, the output DC voltage HV is sent to the main winding end inductor 1-3 of the transformer. When U1 drives Q1 to turn on in the C2 line, the main winding stores energy. When U1 does not drive Q1 in the C2 line, the main winding 1-3 needs to release energy. At this time, the secondary D3 D4 is turned on, and the electrolytic CE4 CE2 CE7 stores energy and outputs a DC voltage. The energy that is not fully released in the main winding is Figure 2 of the absorption circuit consumption.

[0060] like Fig.14 As shown, specifically, in the flyback isolation constant voltage output circuit provided by the present invention, the AC input and the DALI signal input share a common terminal, the AC power is rectified and filtered to output a fluctuating DC voltage to the T11-3 pin and the drain of Q1, U1 is a PWM control IC, and the 4-pin outputs a PWM signal to control the conduction and cutoff of Q1, which is coupled to the 2-9 pin secondary through the transformer T1, and outputs a DC voltage of about V+48V after rectification and filtering by D4 and CE2 CE7. The other winding of the transformer is coupled to the 2-9 pin of the transformer through different turns, and then rectified and filtered by D5 and CE4 to output VCC of about 20V.

[0061] like Fig.15As shown, the DALI module power supply circuit includes a BUCK step-down circuit and U5. The VCC voltage of about 20V is output to the 6th pin of IC U5 through the AC-DC isolation flyback circuit. U5 is a built-in MOS step-down IC that outputs 5V to power the DALI module.

[0062] like Fig.16 As shown, the DALI module includes a DA+ signal input terminal, a DA- signal input terminal, an ERC cold light fault detection pin, an ERW warm light fault detection pin, a PWM dimming signal of a PC cold light BUCK circuit, and a PWM dimming signal of a PW warm light BUCK circuit.

[0063] like Figure 2 The overall schematic diagram of the dual-color DALI dimming color adjustment is shown. The overall schematic diagram consists of an AC-DC isolated constant voltage power supply output V+ ( Fig.14 ), two DC-DC constant current ICs are powered at the V+ terminal ( Fig.17 ), output common positive LED+, two negative poles C- and W- through current detection resistors and energy storage inductors to two ICs to achieve constant current and dimming control. 6 transistors Q1 Q2 Q3Q4 Q5 Q6 form a no-load and short-circuit detection circuit, output high and low levels to the ERC and ERW pins of DALI module P2 ( Figure 10 ), DA+ and DA- of the module are DALI signal inputs, PC and PW are two-way cold light and warm light PWM control signal outputs. U5 forms the power supply circuit of the DALI module and outputs 5V power to the DALI module ( Fig.16 ). The overall process diagram of each line module is as follows Figure 1 shown.

[0064] Fig.17 The DC-DC constant current driver IC and peripheral circuit provided by the present invention are as follows: Fig.17 As shown, U4A is a DC-DC constant current driver IC, C1A C2A is the V+ input filter capacitor, PC is the PWM dimming signal input, R1A is a pull-down resistor to prevent the instability of the IO port at the moment of powering on the DALI module, and eliminate the flashing phenomenon at the moment of powering on. The CF pin is connected to the capacitor C3A to the ground to filter out the AC ripple of the internal reference voltage of the IC. D1A is the BUCK DC-DC circuit freewheeling diode, B1A is a chip bead that can filter out the EMI problem generated by D1A, L1A is an energy storage inductor, R3A R4A R5A R6A is a current sensing resistor, and the voltage difference formed by the current at the C-end through the two ends of the resistor reaches the U4A pin SENN SEN to adjust the output current. C4X and CE5 are output filter capacitors, and LF3 is a common mode inductor to filter out the EMI problem of the high-frequency circuit. Q1 Q2 Q3 Q4 and ZD1 ZD3ZD4 and peripheral resistors and capacitors form a fault detection circuit.

[0065] The specific working principle is as follows: During normal operation, the output voltage between V+ and SGND is 48V, and the voltage across LED+ and C- is the LED load, with a design range of 28-40V. The actual voltage from C- to SGND is calculated to be 8-20V, ZD3 is designed as a 5.6V voltage regulator, and ZD4 is a 39V voltage regulator. At this time, ZD3 is turned on and drives Q1 to turn on after voltage division and current limiting through R45, R46, R27, and R26. The voltage drop of the collector of Q1 is zero, that is, the ERC voltage is low when the load is working normally. At the same time, during normal operation, since ZD1 is designed as a 43V voltage regulator for the dummy load circuit, the output is 28-40V, which is lower than the voltage value of 43V. At this time, it is not turned on, that is, Q4 is cut off. V+ drives Q3 to turn on after voltage division and current limiting through R32 and R33, and the dummy load R49 is turned on through Q3 and merged into both ends of CE5. When no-load, the addition of dummy load R49 will make IC work in intermittent mode. At this time, there is a triangle wave oscillation waveform with an amplitude of about 10V from C- to SGND. This waveform will turn on ZD3, so that ERC becomes a low level when no-load. This is inconsistent with the requirements of DALI certification. After adding the no-load dummy load circuit, C- to SGND can maintain a non-oscillating DC level of about 3V. Since the ZD3 voltage regulator is designed to be 5.6V, this voltage cannot turn on ZD3, Q1 is not turned on, and ERC is high. When LED+C- is short-circuited, the voltage on LED+ goes directly to C-, and the voltage from LED+ to SGND is 48V, that is, the voltage from C- to SGND is also 48V. The voltage regulation value of ZD3 is 5.6V, and the voltage regulation value of ZD4 is 39V. The total voltage regulation value is 44.6V, which is less than the 48V voltage at this time. ZD3 and ZD4 are both turned on. Q2 is turned on, which lowers the voltage on the collector of Q2 when ZD3 is turned on. Q is not turned on, and 5V outputs a high level through R29 R28, that is, ERC is a high level at this time. The working principle of LED+W- is the same as that of LED+C-.

[0066] The above detailed description is a specific description of one feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the scope of the technical solution of the present invention.

Claims

1. A DALI dimming and color adjustment driving power supply, characterized in that: It includes a flyback isolation constant voltage output circuit, a first cold light adjustment circuit, a second warm light adjustment circuit, a no-load dummy load removal circuit, a fault detection circuit and a DALI module circuit; The flyback isolation constant voltage output circuit is connected to the cold light adjustment circuit and the warm light adjustment circuit respectively, and the first cold light adjustment circuit and the second warm light adjustment circuit are both connected to the no-load dummy load removal circuit and the fault detection circuit; The flyback isolation constant voltage output circuit is connected to the DALI module circuit; The fault detection circuit includes a W fault detection circuit and a C fault detection circuit, the cold light adjustment circuit is connected to the C fault detection circuit, and the warm light adjustment circuit is connected to the W fault detection circuit; The C fault detection circuit includes an output no-load ERC high-level circuit, an output short-circuit ERC high-level circuit and an ERC driven circuit; the output no-load ERC high-level circuit is connected to the ERC driven circuit, and the output short-circuit ERC high-level circuit is connected to the ERC driven circuit; when no-load, C- to SGND is low level, C- to XV is low level, the triode Q1 is not conducting, and the ERC output is high level; when short-circuited, C- to SGND is high level, driving the triode Q3 to conduct, the triode Q1 is not conducting and the ERC output is high level; The C fault detection circuit includes a voltage zener diode ZD3, a voltage zener diode ZD4, a resistor R28, a resistor R29, a resistor R45, a resistor R46, a resistor R47, a resistor R48, a transistor Q1 and a transistor Q3; in normal operation, the voltage from C- to SGND is greater than the voltage of ZD3, ZD3 is turned on, and the voltage is divided by resistors R46 and R45, and resistors R26 and R27 limit the current and drive the transistor Q1 to turn on, and the collector of the transistor Q1 is at a low level, ERC output is low level. When the circuit is open, the voltage from C- to SGND cannot turn on ZD3. Q1 is not conducting. The collector voltage is 5V. The voltage through R29 and R28, ERC is high level. When the circuit is short, the voltage from C- to SGND is equal to the voltage from LED+ to SGND, 48V. Zener diodes ZD3 and ZD4 are all conducting. After the resistors R48 and R47 divide the voltage and limit the current, diode Q3 is conducting. At this time, the transistor Q1 is not conducting, and ERC outputs high level. The W fault detection circuit includes a Zener diode ZD5, a Zener diode ZD6, a resistor R30, a resistor R31, a resistor R43, a resistor R44, a resistor R24, a resistor R25, a circuit R22, a circuit 23, a transistor Q2 and a transistor Q4. When working normally, the voltage from W- to SGND is greater than the voltage of ZD6, ZD6 is turned on, and the voltage is divided by resistors R31 and R30, and resistors R24 and R25 limit the current and drive the transistor Q2 to turn on, and the collector of the transistor Q2 It is low level, ERC output is low level, when open circuit, the voltage from W- to SGND cannot turn on ZD3, Q2 is not conducting, the collector voltage is 5V, and the voltage through R23 and R22, ERC is high level, when short circuit, the voltage from W- to SGND is equal to the voltage from LED+ to SGND 48V, Zener diode ZD6 and Zener diode ZD5 are all turned on, and diode Q4 is turned on after voltage division and current limiting by resistor R43 and resistor R44. At this time, the transistor Q2 is not conducting, and ERC outputs a high level.

2. The DALI dimming and color adjustment driving power supply according to claim 1, characterized in that: The W fault detection circuit includes an output no-load ERW high-level circuit, an output short-circuit ERW high-level circuit and an ERW driven circuit; the output no-load ERW high-level circuit is connected to the ERW driven circuit, and the output short-circuit ERW high-level circuit is connected to the ERW driven circuit; when no-load, W- to SGND is a low level, W- to XV is a low level, the transistor Q2 is not conducting, and the ERW output is a high level; when short-circuited, W- to SGND is a high level, driving the transistor Q4 to conduct, the transistor Q2 is not conducting and the ERW output is a high level.

3. The DALI dimming and color adjustment driving power supply according to claim 1, characterized in that: The no-load dummy load removal circuit includes a voltage zener diode ZD2, a resistor R36, a resistor R37, a resistor R39, a resistor R40, a resistor R50, a triode Q5 and a triode Q6. When the circuit works normally, the maximum voltage from LED+ to W1- is 40V, and the voltage of ZD2 is 43V. At this time, the voltage zener diode ZD2 is not turned on, and the triode Q6 is not turned on. The triode Q5 is turned on after the voltage is limited by the voltage division of the resistor R39 and the resistor R40. The load resistor R50 allows the current to pass from LED+ to W1- through the conduction of the triode Q5, and the resistor R50 plays a load role; When the power supply is unloaded, the voltage from LED+ to W1- is 48V. ZD2 is turned on and drives the transistor Q6 to turn on after the voltage division and current limiting of resistors R36 and R37, thereby lowering the base voltage of the transistor Q5. That is, the transistor Q5 is not turned on at this time, and R50 does not act as a load.

4. The DALI dimming and color adjustment driving power supply according to claim 1, characterized in that: The flyback isolation constant voltage output circuit includes an AC input rectification and filtering circuit, a T1 leakage inductance absorption circuit, a flyback main control circuit and a flyback circuit output rectification and filtering circuit. The AC input rectification and filtering circuit is connected to the T1 leakage inductance absorption circuit, the T1 leakage inductance absorption circuit is connected to the flyback circuit output rectification and filtering circuit, the flyback main control circuit is connected to the T1 leakage inductance absorption circuit and the flyback circuit output rectification and filtering circuit respectively, the AC input rectification and filtering circuit is used to output a DC voltage after rectification and filtering of the AC end input; the flyback main control circuit is used for main winding energy storage or energy release, the T1 leakage inductance absorption circuit is used to consume the energy that is not fully released by the main winding, and the flyback circuit output rectification and filtering circuit is used for the output rectification and filtering circuit.

5. The DALI dimming and color adjustment driving power supply according to claim 1, characterized in that: The DALI module includes a DA+ signal input terminal, a DA- signal input terminal, an ERC cold light fault detection pin, an ERW warm light fault detection pin, a PWM dimming signal of a PC cold light BUCK circuit, and a PWM dimming signal of a PW warm light BUCK circuit.

6. The DALI dimming and color adjustment driving power supply according to claim 3, characterized in that: The DALI module power supply circuit includes a BUCK step-down circuit and U5. The 20V VCC voltage is output to pin 6 of IC U5 through an AC-DC isolation flyback circuit. U5 is a built-in MOS step-down IC that outputs 5V to power the DALI module.

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