LED Terminal and Its LED Driver Power Supply

Abstract

The present invention discloses an LED terminal and an LED driving power supply thereof. The LED driving power supply includes: an access module connected to an external programmer or dimmer, including a control positive terminal and a control negative terminal, and configured to receive a programming signal from the programmer through the control positive terminal and the control negative terminal and output the programming signal to the MCU in a programming mode, the programming mode including an in-circuit programming mode and an off-line programming mode, and the programming signal being a superimposed signal of a DC voltage signal and a digital programming signal; an isolation module connected to the control positive terminal, and configured to extract the DC voltage signal from the programming signal and allow the DC voltage signal to pass through in the off-line programming mode; and isolate the dimming signal in the dimming mode; a voltage stabilizing module, whose input terminal is respectively connected to the output terminal of the isolation module and the power positive terminal of the internal power supply module, and whose output terminal is connected to the power supply terminal of the MCU. Implementing the technical solution of the present invention can simplify the existing three-wire programming into two-wire programming, reduce the cost of the LED driving power supply, and also simplify the user operation.

Description

Technical Field

[0001] The present invention relates to the field of LEDs, and particularly to an LED terminal and its LED driving power supply. Background Art

[0002] An LED driving power supply refers to a power supply that converts external primary electrical energy into secondary electrical energy required by an LED. The input electrical energy of the LED driving power supply includes alternating current and direct current, and the output electrical energy is generally a constant current that can change with the forward voltage of the LED. The LED driving power supply is mainly applied to the fields of LED lighting, LED displays, and LED backlights. Among them, LED lighting has the highest requirements for driving control technology and is currently the main application field of the LED driving power supply, with the broadest market prospects.

[0003] In the prior art, the demand for using software to control an LED driving power supply is increasing day by day. It uses software to control and adjust many functions of the power supply, such as output voltage and current, over-temperature protection, time control, light decay compensation, etc. As Figure 1 shown, the user sends data from the control software on the computer to the programmer, and the programmer then transmits the signal to the programmable LED driving power supply through corresponding conversion. Therefore, the programmable LED driving power supply is easier to operate and more powerful, and the market demand is very large. However, the existing programmable LED driving power supplies also have some problems:

[0004] First of all, whether in the offline mode or the online mode, the programmable LED driving power supply needs to be able to be programmed normally. However, in the offline mode, the power input terminal of the programmable LED driving power supply is not connected to the mains power, that is, the power is not energized. At this time, each functional module inside the LED driving power supply cannot work, and thus normal programming cannot be performed. In addition, during programming, the programmer needs to be correspondingly connected to the control terminal output line of the LED driving power supply. Therefore, the existing programmable LED power supplies are usually three-wire programming control power supplies. As Figure 2 shown, there are three output lines at the control terminal. Among them, the VCC2 line is used to provide a voltage signal inside the LED driving power supply in the offline mode to ensure that the programming module inside the LED driving power supply can work normally in the offline state (the programming module must work normally when there is power supply). The DIM+ line provides a programming signal during programming (it is a PWM signal composed of a series of high and low levels). At the same time, when not programmed, this line also receives a dimming control signal (a common three-in-one dimming signal on the market, namely voltage, PWM, and resistance signals). The DIM- line is the common ground wire for VCC and DIM+. Therefore, if the existing programmable LED driving power supply can achieve normal programming, at least three output connection lines are required, resulting in increased costs and inconvenience for users. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an LED terminal and its LED driving power supply in view of the technical defects of high cost and inconvenient use existing in the prior art.

[0006] The technical solution adopted by the present invention to solve its technical problem is to construct an LED driving power supply, which includes an internal power module and an MCU, and further includes:

[0007] An access module connected to an external programmer or dimmer, including a control positive terminal and a control negative terminal, and is used to receive a programming signal from the programmer through the control positive terminal and the control negative terminal and output it to the MCU in the programming mode, and, in the dimming mode, receive a dimming signal from the dimmer through the control positive terminal and the control negative terminal and output it to the MCU, wherein, the programming mode includes an in-circuit programming mode and an off-line programming mode, and the programming signal is a superimposed signal of a DC voltage signal and a digital programming signal;

[0008] An isolation module, connected to the control positive terminal, and is used to extract the DC voltage signal from the programming signal and pass the DC voltage signal in the off-line programming mode; isolate the dimming signal in the dimming mode;

[0009] A voltage stabilizing module, whose input terminal is respectively connected to the output terminal of the isolation module and the positive power terminal of the internal power module, and whose output terminal is connected to the power supply terminal of the MCU, and moreover, the voltage stabilizing module is used to perform voltage stabilizing processing on the DC voltage signal output by the isolation module in the off-line programming mode, and, perform voltage stabilizing processing on the power supply voltage signal output by the internal power module in the dimming mode and the in-circuit programming mode.

[0010] Preferably, the isolation module includes a voltage stabilizing diode ZD1, wherein, the negative electrode of the voltage stabilizing diode ZD1 is connected to the control positive terminal, the positive electrode of the voltage stabilizing diode ZD1 is connected to the input terminal of the voltage stabilizing module, wherein, the reverse breakdown voltage of the voltage stabilizing diode ZD1 is less than the voltage value of the DC voltage signal and greater than the voltage value of the high-level signal in the dimming signal.

[0011] Preferably, the voltage stabilizing module includes a resistor R1, a voltage stabilizing diode ZD3, and a triode Q10, wherein, the first end of the resistor R1 is the input terminal of the voltage stabilizing module, the second end of the resistor R1 is respectively connected to the negative electrode of the voltage stabilizing diode ZD3 and the base of the triode Q10, the positive electrode of the voltage stabilizing diode ZD3 is connected to the control negative terminal, the collector of the triode Q10 is connected to the first end of the resistor R1, and the emitter of the triode Q10 is the output terminal of the voltage stabilizing module.

[0012] Preferably, the voltage stabilizing module includes a resistor RP21, a resistor RP30, a resistor RP16, a capacitor CP1, a three-terminal adjustable reference voltage source UP2, and a triode QP10. Among them, the first terminal of the resistor RP21 is the input terminal of the voltage stabilizing module and is connected to the collector of the triode QP10. The emitter of the triode QP10 is the output terminal of the voltage stabilizing module. The second terminal of the resistor RP21 is respectively connected to the base of the triode QP10, the first terminal of the capacitor CP1, and the cathode of the three-terminal adjustable reference voltage source UP2. The anode of the three-terminal adjustable reference voltage source UP2 is grounded. The control terminal of the three-terminal adjustable reference voltage source UP2 is connected to the second terminal of the capacitor CP1. The resistor RP30 and the resistor RP16 are connected in series between the emitter of the triode QP10 and the ground. The connection point of the resistor RP30 and the resistor RP16 is connected to the second terminal of the capacitor CP1.

[0013] Preferably, it further includes at least one of the following:

[0014] A first anti-reverse module connected between the internal power supply module and the voltage stabilizing module and used to prevent the DC voltage signal output by the isolation module from flowing back into the internal power supply module;

[0015] A second anti-reverse module connected between the isolation module and the voltage stabilizing module and used to prevent the power supply voltage signal output by the internal power supply module from flowing back into the isolation module;

[0016] A first processing module connected between the access module and the MCU and used to process the programming signal input through the control positive terminal and the control negative terminal;

[0017] A second processing module connected between the access module and the MCU and used to process the dimming signal input through the control positive terminal and the control negative terminal;

[0018] A feedback module used to control the signal on the control positive terminal according to the feedback signal output by the programming sending terminal of the MCU when programming is completed.

[0019] Preferably, the first anti-reverse module includes a diode D1. Among them, the positive electrode of the diode D1 is connected to the positive power supply terminal of the internal power supply module, and the negative electrode of the diode D1 is connected to the input terminal of the voltage stabilizing module;

[0020] The second anti-reverse module includes a diode D3. Among them, the positive electrode of the diode D3 is connected to the output terminal of the isolation module, and the negative electrode of the diode D3 is connected to the input terminal of the voltage stabilizing module.

[0021] Preferably, the feedback module includes MOS transistor Q2, resistor R8, resistor R19, and triode Q5. Among them, the gate of the MOS transistor Q2 is connected to the programming transmission end of the MCU, the source of the MOS transistor Q2 is connected to a high level, the drain of the MOS transistor Q2 is sequentially connected to the control negative terminal through the resistor R8 and the resistor R19, the connection point between the resistor R8 and the resistor R19 is connected to the base of the triode Q5, the emitter of the triode Q5 is connected to the control negative terminal, and the collector of the triode Q5 is connected to the control positive terminal.

[0022] Preferably, the first processing module includes resistor R27 and resistor R34. Among them, the first end of the resistor R27 is connected to the control positive terminal, the second end of the resistor R27 is respectively connected to the control negative terminal and the ground terminal of the MCU through the resistor R34, and the second end of the resistor R27 is connected to the programming receiving end of the MCU.

[0023] Preferably, the second processing module includes resistor R2, resistor R3, and zener diode ZD2. Among them, the first end of the resistor R2 is connected to the control positive terminal, the second end of the resistor R2 is respectively connected to the control negative terminal and the ground terminal of the MCU through the resistor R3, the second end of the resistor R2 is connected to the dimming end of the MCU, the negative electrode of the zener diode ZD2 is connected to the second end of the resistor R2, and the positive electrode of the zener diode ZD2 is connected to the control negative terminal.

[0024] The present invention also constructs an LED terminal, which includes an LED load and also includes the above-mentioned LED driving power supply.

[0025] Implementing the technical solution of the present invention, the access module has only two terminals, namely the control positive terminal and the control negative terminal. When performing offline programming on the LED driving power supply, although the internal power supply module does not output a supply voltage, since the programming signal is a superimposed signal of a DC voltage signal and a digital programming signal, and the isolation module can extract the DC voltage signal from the programming signal and send it to the voltage stabilizing module for voltage stabilizing processing, and then the MCU can be powered. When performing online programming or dimming on the LED driving power supply, the internal power supply module outputs a supply voltage, and the supply voltage signal is subjected to voltage stabilizing processing by the voltage stabilizing module and then can power the MCU. Therefore, the three-wire programming in the prior art can be simplified to two-wire programming, reducing the cost of the LED driving power supply and also simplifying the user operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0027] Figure 1 is the programming system diagram of the LED driving power supply;

[0028] Figure 2 is a schematic structural diagram of an existing LED driver power supply;

[0029] Figure 3 is a logic structure diagram of Embodiment 1 of the LED driver power supply of the present invention;

[0030] Figure 4 is a circuit diagram of Embodiment 2 of the LED driver power supply of the present invention;

[0031] Figure 5 is a system structure diagram for dimming multiple parallel LED driver power supplies of the present invention;

[0032] Figure 6A 、 Figure 6B is a circuit diagram of Embodiment 3 of the LED driver power supply of the present invention. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] Figure 3It is the logic structure diagram of the first embodiment of the LED driving power supply of the present invention. The LED driving power supply of this embodiment includes an access module 11, an isolation module 12, a voltage stabilization module 13, an internal power supply module 14, and an MCU 15. Among them, the access module 11 is connected to an external programmer (not shown) or a dimmer (not shown), and includes a control positive terminal DIM+ and a control negative terminal DIM-. The access module 11 is used to receive a programming signal from the programmer through the control positive terminal DIM+ and the control negative terminal DIM- and output it to the MCU 15 in the programming mode, and, in the dimming mode, receive a dimming signal from the dimmer through the control positive terminal DIM+ and the control negative terminal DIM- and output it to the MCU 15. Among them, the programming mode includes an in-circuit programming mode and an off-line programming mode, and the programming signal is a superimposed signal of a DC voltage signal and a digital programming signal. The isolation module 12 is connected to the control positive terminal DIM+, and is used to extract the DC voltage signal from the programming signal and pass the DC voltage signal in the off-line programming mode; isolate the dimming signal in the dimming mode. The input end of the voltage stabilization module 13 is respectively connected to the output end of the isolation module 12 and the positive power supply end of the internal power supply module 14, and its output end is connected to the power supply end of the MCU. Moreover, the voltage stabilization module 13 is used to perform voltage stabilization processing on the DC voltage signal output by the isolation module 12 in the off-line programming mode, and, in the dimming mode and the in-circuit programming mode, perform voltage stabilization processing on the power supply voltage signal output by the internal power supply module 14.

[0035] In the technical solution of this embodiment, the access module has only two terminals, namely the control positive terminal and the control negative terminal. When performing off-line programming on the LED driving power supply, although the internal power supply module 14 does not output a power supply voltage, since the programming signal is a superimposed signal of a DC voltage signal and a digital programming signal, and the isolation module 12 can extract the DC voltage signal from the programming signal and send it to the voltage stabilization module 13 for voltage stabilization processing, and then the MCU 15 can be powered. When performing in-circuit programming or dimming on the LED driving power supply, the internal power supply module 14 outputs a power supply voltage, and the power supply voltage signal can be used to power the MCU 15 after being voltage-stabilized by the voltage stabilization module 13. Therefore, the three-wire programming in the prior art can be simplified to two-wire programming, reducing the cost of the LED driving power supply and simplifying the user operation.

[0036] Further, in an alternative embodiment, the LED driving power supply of this embodiment further includes at least one of the following: a first reverse connection prevention module, a second reverse connection prevention module, a first processing module, a second processing module, and a feedback module. The first reverse connection prevention module is connected between the internal power supply module and the voltage stabilization module, and is used to prevent the DC voltage signal output by the isolation module from flowing back to the internal power supply module; the second reverse connection prevention module is connected between the isolation module and the voltage stabilization module, and is used to prevent the power supply voltage signal output by the internal power supply module from flowing back to the isolation module; the first processing module is connected between the access module and the MCU, and is used to process the programming signals input through the control positive terminal and the control negative terminal; the second processing module is connected between the access module and the MCU, and is used to process the dimming signals input through the control positive terminal and the control negative terminal; the feedback module is used to control the signal on the positive terminal according to the feedback signal output by the programming sending terminal of the MCU when the programming is completed.

[0037] Figure 4 FIG. 4 is a circuit diagram of Embodiment 2 of the LED driving power supply of the present invention. The LED driving power supply of this embodiment includes an access module 11, an isolation module 12, a voltage stabilization module 13, an internal power supply module, an MCU 15, a first reverse connection prevention module, a second reverse connection prevention module, a feedback module 16, a first processing module 17, and a second processing module 18.

[0038] In this embodiment, the access module 11 includes a control positive terminal DIM+ and a control negative terminal DIM-. These two control terminals are connected to the two output terminals of an external programmer in the programming mode and are connected to the two output terminals of an external dimmer in the dimming mode, that is, the dimming terminal and the programming terminal share the same connection. Moreover, the control positive terminal DIM+ is connected to the programming receiving terminal (pin 1) of the MCU 15 through the first processing module 17, and the control positive terminal DIM+ is also connected to the dimming terminal (pin 2) of the MCU 15 through the second processing module 18. Of course, in other embodiments, the first processing module 17 and the second processing module 18 can also be omitted.

[0039] In this embodiment, the isolation module 12 includes a voltage stabilizing diode ZD1. The negative electrode of the voltage stabilizing diode ZD1 is connected to the control positive terminal DIM+, the positive electrode of the voltage stabilizing diode ZD1 is connected to the input terminal of the voltage stabilization module through the second reverse connection prevention module, and the reverse breakdown voltage of the voltage stabilizing diode ZD1 is less than the voltage value of the DC voltage signal and greater than the voltage value of the high-level signal in the dimming signal. Of course, in other embodiments, the second reverse connection prevention module can also be omitted.

[0040] In this embodiment, the voltage stabilizing module 13 includes a resistor R1, a voltage stabilizing diode ZD3, and a triode Q10. Among them, the first end of the resistor R1 is the input end of the voltage stabilizing module 13. The second end of the resistor R1 is respectively connected to the negative electrode of the voltage stabilizing diode ZD3 and the base of the triode Q10. The positive electrode of the voltage stabilizing diode ZD3 is connected to the control negative end DIM-. The collector of the triode Q10 is connected to the first end of the resistor R1. The emitter of the triode Q10 is the output end of the voltage stabilizing module 13, that is, the output voltage VDD. In addition, the voltage stabilizing module 13 may further include capacitors C25 and C15. The capacitor C25 is connected between the input end of the voltage stabilizing module 13 and the ground, and the capacitor C15 is connected between the output end of the voltage stabilizing module 13 and the ground.

[0041] In this embodiment, the first reverse connection prevention module includes a diode D1, and the second reverse connection prevention module includes a diode D3. Among them, the positive electrode of the diode D1 is connected to the positive power supply end VCC of the internal power supply module, and the negative electrode of the diode D1 is connected to the input end of the voltage stabilizing module 13, that is, the first end of the resistor R1. The positive electrode of the diode D3 is connected to the positive electrode of the voltage stabilizing diode ZD1, and the negative electrode of the diode D3 is connected to the input end of the voltage stabilizing module 13. Moreover, the voltage value of the power supply voltage signal output by the internal power supply module is greater than the voltage value of the DC voltage signal output by the isolation module 12.

[0042] In this embodiment, the feedback module 16 includes an MOS transistor Q2, a resistor R8, a resistor R19, and a triode Q5. Among them, the gate of the MOS transistor Q2 is connected to the programming transmission end (pin 19) of the MCU 15. The source of the MOS transistor Q2 is connected to the output end of the voltage stabilizing module 13. Of course, in other embodiments, it may also be connected to other high-level voltages. The drain of the MOS transistor Q2 is sequentially connected to the control negative end DIM- through the resistor R8 and the resistor R19. The connection point between the resistor R8 and the resistor R19 is connected to the base of the triode Q5. The emitter of the triode Q5 is connected to the control negative end DIM-. The collector of the triode Q5 is connected to the control positive end DIM+. In addition, the feedback module 16 further includes a resistor R7, and the resistor R7 is connected between the source and the gate of the MOS transistor Q2.

[0043] In this embodiment, the first processing module 17 includes a resistor R27 and a resistor R34. Among them, the first end of the resistor R27 is connected to the control positive end DIM+. The second end of the resistor R27 is respectively connected to the control negative end DIM- and the ground terminal (pin 3) of the MCU 15 through the resistor R34. The second end of the resistor R27 is also connected to the programming reception end (pin 1) of the MCU 15.

[0044] In this embodiment, the second processing module 18 includes a resistor R2, a resistor R3, and a zener diode ZD2. Among them, the first end of the resistor R2 is connected to the control positive terminal DIM+, the second end of the resistor R2 is connected to the control negative terminal DIM- and the ground terminal of the MCU 15 through the resistor R3 respectively, the second end of the resistor R2 is also connected to the dimming terminal (pin 2) of the MCU 15, the negative electrode of the zener diode ZD2 is connected to the second end of the resistor R2, and the positive electrode of the zener diode ZD2 is connected to the control negative terminal DIM-. In addition, the second processing module 18 does not include a capacitor C1. The first end of the capacitor C1 is connected to the second end of the resistor R2, and the second end of the capacitor C1 is grounded.

[0045] The working principle of the LED drive power supply in this embodiment is described below:

[0046] In the off-line programming mode, the control positive terminal DIM+ and the control negative terminal DIM- are connected to an external programmer for receiving the programming signal output by the programmer. And the programming signal is a superimposed signal of a DC voltage signal and a digital programming signal, where the amplitude of the DC voltage signal is greater than the sum of the reverse breakdown voltage of the zener diode ZD1 and the conduction voltage of the diode D3. In addition, the internal power supply module is not powered on in the off-line mode and thus cannot provide a power supply voltage signal, that is, the voltage at VCC is 0. However, when the programming signal is input to the control positive terminal DIM+ and the control negative terminal DIM-, since the amplitude of the DC voltage signal in the programming signal is greater than the sum of the reverse breakdown voltage of the zener diode ZD1 and the conduction voltage of the diode D3, when the DC voltage signal passes through the zener diode ZD1, it will break down the zener diode ZD1 and turn on the diode D3, and then reach the voltage regulation module 13. In the voltage regulation module 13, the capacitor C25, the resistor R1, the zener diode ZD3, the triode Q10, and the capacitor C15 form a linear voltage regulation circuit. Among them, the capacitor C25 is a filter capacitor to ensure the stability of the input voltage signal. The voltage signal is regulated by the resistor R1 and the zener diode ZD3. At this time, the base voltage of the triode Q10 is equal to the regulated value of the zener diode ZD3, and the base of the triode Q10 is powered on and then turns on. The voltage signal is filtered by the capacitor C15 and then reaches the power supply terminal (pin 5) of the MCU 15, so that the MCU15 can be powered on and work. At this time, the emitter voltage of the triode Q10 is equal to the base voltage minus U BE, since the base voltage is clamped by the zener diode ZD3, the voltage on the capacitor C15 is also a stable voltage. Therefore, even in the off-line programming mode, the MCU 15 can still be powered on and operate normally. When the MCU 15 operates normally, the programming signal input at the control positive terminal DIM+ is divided by the resistors R27 and R34 and then sent to the programming receiving terminal (pin 1) of the MCU 15. Moreover, the voltage division by the resistors R27 and R34 can reduce the input programming signal to ensure that pin 1 of the MCU 15 is not broken down. At the same time, when pin 1 of the MCU 15 is receiving the programming signal normally, its programming sending terminal (pin 19) outputs a high level. At this time, the gate and source of the MOS transistor Q2 are both at a high level and it is not conducting. When the MCU 15 determines that the programming signal obtained at its pin 1 has been received completely, it will output a short low-level feedback signal through its pin 19. This feedback signal makes the source voltage of the MOS transistor (PMOS transistor) Q2 higher than the gate voltage, and then it conducts. At this time, the VDD signal is divided by the resistors R8 and R19 and applied to the base of the triode Q5. The base of the triode Q5 gets a high level and then conducts, causing the control positive terminal DIM+ to be pulled down to a low potential. In this way, the external programmer can judge that the MCU 15 has received the programming signal according to the level of the control positive terminal DIM+. The pin 19 of the MCU 15 sends the feedback programming signal to the external programmer through repeated high and low signals.

[0047] In the on-line programming mode, since the internal power supply module is normally connected to the mains power, it can output a supply voltage signal, that is, there is a supply voltage signal at VCC. This supply voltage signal can be provided by an auxiliary winding or an auxiliary source small board, etc. When the voltage value of this supply voltage signal is greater than the voltage value of the DC voltage signal in the programming signal, even if there is an input programming signal at the control positive terminal DIM+, due to the larger voltage value of the supply voltage signal, the isolation module 12 still has no output. At this time, the supply voltage signal output by the internal power supply module is supplied to the MCU 15 after passing through the diode D1 and the voltage regulation module 13. Of course, in other embodiments, the voltage value of the supply voltage signal output by the internal power supply module can also be set to be less than the voltage value of the DC voltage signal in the programming signal. In this way, even in the on-line programming mode, the DC voltage signal in the programming signal input by the external programmer still supplies power to the MCU 15. In addition, the functions of the internal components of the voltage regulation module 13, the first processing module 17 and the feedback module 16 can refer to the corresponding descriptions in the off-line programming mode and will not be elaborated here.

[0048] In the dimming mode, since the internal power supply module is normally connected to the mains power, it can output a supply voltage signal. That is, the supply voltage signal is present at VCC. At this time, the supply voltage signal output by the internal power supply module powers the MCU15 after passing through the diode D1 and the voltage regulation module 13. Additionally, in this mode, the control positive terminal DIM+ and the control negative terminal DIM- are connected to an external dimmer to receive the dimming signal output by the dimmer. Then, the second processing module 18 processes this dimming signal. Specifically, the resistors R2 and R3 divide the voltage of the dimming signal. At the same time, the voltage of resistor R3 is regulated. When the divided voltage is too high, the zener diode ZD2 clamps the voltage to protect pin 2 of the MCU15 from being broken down. The processed dimming signal is sent to pin 2 of the MCU15, and the MCU 15 performs the normal dimming function. And the stability of the input dimming signal is a basic requirement for the dimming function. By setting the regulated voltage value of the zener diode ZD1, it is ensured that the input dimming signal will not break down the zener diode ZD1. At this time, the dimming signal is normal and not affected by the internal power supply module.

[0049] Regarding the zener diode ZD1, it should also be noted that: as Figure 5 shown, when using the dimmer 20 to dim multiple parallel-connected LED driver power supplies 10, if there is no zener diode ZD1, the input dimming signal will be simultaneously controlled by the signal at node 1 (the input terminal of the voltage regulation module 13). If the input dimming signal is higher than the signal at node 1, the diode D3 will conduct, resulting in a decrease in the input dimming signal. When multiple units are used in parallel, it is inevitable that a certain unit will malfunction. For example, when one of them malfunctions or has no output, the power supply will hiccup (turn on and off) or have no output. In this way, the supply voltage signal VCC output by the internal power supply module will no longer be a stable voltage signal, and further problems will occur with the signal at node 1. When the dimming signal input at the control positive terminal DIM+ is higher than the sum of the conduction voltage drop of the diode D3 and the voltage at node 1, the diode D3 will conduct, forcing the voltage signal at the control positive terminal DIM+ to be clamped to the sum of the voltage at node 1 and the voltage drop of the diode D3. Since node 1 is no longer a stable voltage signal at this time, the signal at the control positive terminal DIM+ will also be unstable. The dimming signals of all other parallel-connected LED driver power supplies will also be unstable. This will cause problems with all parallel-connected LED driver power supplies. Therefore, it is necessary to add the zener diode ZD1. By adjusting the regulated voltage value of ZD1, the sum of the regulated voltage value of the zener diode ZD1 and the voltage drop of D3 is made higher than the input signal at the control positive terminal DIM+. In this way, it is ensured that no matter how the signal at node 1 changes, the input dimming signal can never conduct the diode D3, thus ensuring the stability of the input dimming signal.

[0050] As described above, by adjusting the regulated voltage value of the voltage-regulating diode ZD1, it can be achieved that when in the off-line programming mode, the voltage of the programming signal (DC voltage signal + digital programming signal) input by the external programmer is relatively high, causing the voltage-regulating diode ZD1 to be broken down. The programming signal input from the control positive terminal DIM+ can be normally supplied to the MCU 15 through the voltage-regulating diode ZD1 and the diode D3 to complete the off-line programming work. In the on-line dimming mode, the control positive terminal DIM+ and the control negative terminal DIM- become dimming function ports, which can receive the dimming signal output by the external dimmer. The high level of the dimming signal is relatively small and cannot break down the voltage-regulating diode ZD1, so that the input dimming signal is not controlled by the signal at node 1. This ensures the parallel use of the dimming terminals of multiple machines.

[0051] Figure 6A 、 Figure 6B FIG. Figure 6B is the circuit diagram of the third embodiment of the LED driving power supply of the present invention. The LED driving power supply of this embodiment includes an access module 11, an isolation module 12, a voltage regulation module 13, an internal power supply module, an MCU 15, a first reverse connection prevention module, a second reverse connection prevention module, a feedback module 16, a first processing module 17, and a second processing module 18. Moreover, the circuit structures and working principles of the isolation module 12, the MCU 15, the first reverse connection prevention module, the second reverse connection prevention module, the feedback module 16, and the first processing module 17 of this embodiment are the same as those of the Figure 4 embodiment shown, and will not be described in detail here. Only the different parts will be described below:

[0052] In the access module 11, the access module 11 includes a control positive terminal DIM1, a control negative terminal (not shown), and a current limiting unit. The current limiting unit includes a resistor RP55, and the control positive terminal DIM1 is connected to the intermediate control terminal DIM2 through the resistor RP55. Among them, the control positive terminal and the control negative terminal are used to connect the two output terminals of the external programmer in the programming mode and the two output terminals of the external dimmer in the dimming mode; the current limiting unit is used to limit the current when a short circuit or other faults occur in the subsequent circuit, so as to avoid affecting the previous circuit and the LED driving power supply with parallel machine control.

[0053] In the voltage regulation module 13, the voltage regulation module includes a resistor RP21, a resistor RP30, a resistor RP16, a capacitor CP1, a three-terminal adjustable reference voltage source UP2, and a triode QP10. Among them, the first end of the resistor RP21 is the input end of the voltage regulation module and is connected to the collector of the triode QP10, and the triode QP10 is the output end of the voltage regulation module. The second end of the resistor RP21 is respectively connected to the base of the triode QP10, the first end of the capacitor CP1, and the cathode of the three-terminal adjustable reference voltage source UP2. The anode of the three-terminal adjustable reference voltage source UP2 is grounded, the control stage of the three-terminal adjustable reference voltage source UP2 is connected to the second end of the capacitor CP1, and the resistor RP30 and the resistor RP16 are connected in series between the emitter of the triode QP10 and the ground, and the connection point of the resistor RP30 and the resistor RP16 is connected to the second end of the capacitor CP1. In addition, the voltage regulation module 13 may further include capacitors CP13, CP16, CP25, CP15, and CP14. Among them, the capacitors CP13, CP16, and CP25 are connected between the input end of the voltage regulation module and the ground, and the capacitors CP15 and CP14 are connected between the output end of the voltage regulation module and the ground. In this embodiment, whether it is the power supply voltage signal output by the internal power supply module or the DC voltage signal output by the isolation module, when it is sent to the voltage regulation module 13, the capacitors CP13, CP16, and CP25 are filter capacitors to ensure the stability of the input voltage signal. The voltage signal passes through the resistor RP21 and the capacitor CP1 to turn on the three-terminal adjustable reference voltage source UP2 for voltage regulation. At this time, the base voltage of the triode QP10 is equal to the regulated voltage value of the three-terminal adjustable reference voltage source UP2, and the base of the triode QP10 is powered on and then conducts. The voltage signal is filtered by the capacitors CP15 and CP14 and then reaches the power supply terminal (pin 5) of the MCU 15, so that the MCU 15 can be powered on and work.

[0054] In the second processing module 18, the second processing module 18 includes resistors RP3, RP17, RP22, RP4, zener diode DP6, capacitors CP4, CP5, CP3. Among them, resistors RP3, RP17, RP22, RP4 are connected in series between the intermediate control terminal DIM2 (this intermediate control terminal is connected to the control positive terminal DIM1 through resistor R55) and the ground. The connection point between resistor RP22 and resistor RP4 is connected to pin 2 of MCU15. Capacitor CP3 is connected in parallel with resistor R4. The first end of capacitor CP5 is connected to the connection point between resistor RP17 and resistor RP22, and the second end of capacitor CP5 is grounded. The first end of capacitor CP4 is connected to the connection point between resistor RP3 and resistor RP17, and the second end of capacitor CP4 is grounded. The negative electrode of zener diode DP6 is connected to the first end of capacitor CP4, and the positive electrode of zener diode DP6 is grounded. When the external dimming signal is sent to the intermediate control terminal DIM2 through the control positive terminal DIM1 and resistor RP55, resistors RP3, RP17, RP22, R4 divide the voltage signal. The divided voltage is sent to pin 2 of MCU 15. At the same time, zener diode DP6 stabilizes the voltage to prevent the dimming signal from being too large and breaking down pin 2 of the MCU. In addition, capacitors CP4, CP5, CP3 filter the voltage sent to pin 2 of MCU 15. In addition, since the second processing module of this embodiment is composed of multiple resistors and capacitors, while realizing voltage division, it also constitutes an integrating circuit (resistor RP17, capacitor CP5), so as to receive and integrate the PWM dimming signal into a fixed voltage signal to realize PWM dimming.

[0055] In addition, for the intermediate control terminal DIM2, a constant current source with a controllable output current (the presence or absence of the control current) can also be connected. The current magnitude is in the microampere level. When the dimming signal is a resistance value, the resistor is connected between Figure 2 DIM1 and DIM-(GND). When the power supply of the constant current source flows through different resistance values, different voltages are generated to realize resistance dimming control. By controlling the presence or absence of the constant current source, the voltage between DIM1 and DIM-(GND) when there is no dimming signal input can be controlled, so that when there is no signal input or an external dimming control failure occurs, the power supply output current is the maximum or minimum. For example, in tunnel lighting, by setting the constant current source to have no input and the power supply to be negative logic dimming, when there is no signal input or an external dimming control failure occurs, the power supply output current is the maximum, ensuring that the lamp is the brightest and meeting the lighting requirements.

[0056] The present invention also constructs an LED terminal, which includes an LED load and the above-mentioned LED driving power supply. Among them, the LED load can be an LED lamp, an LED screen, etc.

[0057] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. An LED driving power supply, comprising an internal power supply module and an MCU, characterized in that, Also included are: An access module connected to an external programmer or dimmer, including a control positive terminal and a control negative terminal, and configured to receive a programming signal from the programmer through the control positive terminal and the control negative terminal and output it to the MCU in a programming mode, and, in a dimming mode, receive a dimming signal from the dimmer through the control positive terminal and the control negative terminal and output it to the MCU, wherein the programming mode includes an in-line programming mode and an off-line programming mode, and the programming signal is a superimposed signal of a DC voltage signal and a digital programming signal; An isolation module, connected to the control positive terminal, and configured to extract the DC voltage signal from the programming signal and allow the DC voltage signal to pass through in an off-line programming mode; isolate the dimming signal in a dimming mode; A voltage stabilizing module, whose input terminal is respectively connected to the output terminal of the isolation module and the positive power terminal of the internal power supply module, and whose output terminal is connected to the power supply terminal of the MCU. Moreover, the voltage stabilizing module is configured to perform voltage stabilizing processing on the DC voltage signal output by the isolation module in an off-line programming mode, and perform voltage stabilizing processing on the power supply voltage signal output by the internal power supply module in a dimming mode and an in-line programming mode; A first anti-reverse module connected between the internal power supply module and the voltage stabilizing module, and configured to prevent the DC voltage signal output by the isolation module from flowing back to the internal power supply module; A second anti-reverse module connected between the isolation module and the voltage stabilizing module, and configured to prevent the power supply voltage signal output by the internal power supply module from flowing back to the isolation module; The isolation module includes a zener diode ZD1, wherein the negative electrode of the zener diode ZD1 is connected to the control positive terminal, and the positive electrode of the zener diode ZD1 is connected to the input terminal of the voltage stabilizing module. Wherein, the reverse breakdown voltage of the zener diode ZD1 is less than the voltage value of the DC voltage signal and greater than the voltage value of the high-level signal in the dimming signal.

2. The LED driving power supply according to claim 1, wherein The voltage stabilizing module includes a resistor R1, a zener diode ZD3, and a triode Q10. Wherein, the first end of the resistor R1 is the input terminal of the voltage stabilizing module, the second end of the resistor R1 is respectively connected to the negative electrode of the zener diode ZD3 and the base of the triode Q10, the positive electrode of the zener diode ZD3 is connected to the control negative terminal, the collector of the triode Q10 is connected to the first end of the resistor R1, and the emitter of the triode Q10 is the output terminal of the voltage stabilizing module.

3. The LED driving power supply according to claim 1, wherein The voltage stabilizing module includes resistor RP21, resistor RP30, resistor RP16, capacitor CP1, three-terminal adjustable reference voltage source UP2, and triode QP10. Among them, the first terminal of resistor RP21 is the input terminal of the voltage stabilizing module and is connected to the collector of triode QP10. The emitter of triode QP10 is the output terminal of the voltage stabilizing module. The second terminal of resistor RP21 is respectively connected to the base of triode QP10, the first terminal of capacitor CP1, and the cathode of three-terminal adjustable reference voltage source UP2. The anode of three-terminal adjustable reference voltage source UP2 is grounded. The control terminal of three-terminal adjustable reference voltage source UP2 is connected to the second terminal of capacitor CP1. Resistor RP30 and resistor RP16 are connected in series between the emitter of triode QP10 and the ground. The connection point of resistor RP30 and resistor RP16 is connected to the second terminal of capacitor CP1.

4. The LED driving power supply according to any one of claims 1-3, characterized in that, It further includes at least one of the following: A first processing module connected between the access module and the MCU and used to process the programming signals input through the control positive terminal and the control negative terminal; A second processing module connected between the access module and the MCU and used to process the dimming signals input through the control positive terminal and the control negative terminal; A feedback module used to control the signal on the control positive terminal according to the feedback signal output by the programming sending terminal of the MCU when programming is completed.

5. The LED driving power supply according to claim 4, characterized in that, The first reverse connection prevention module includes diode D1. Among them, the positive pole of diode D1 is connected to the positive power terminal of the internal power supply module, and the negative pole of diode D1 is connected to the input terminal of the voltage stabilizing module; The second reverse connection prevention module includes diode D3. Among them, the positive pole of diode D3 is connected to the output terminal of the isolation module, and the negative pole of diode D3 is connected to the input terminal of the voltage stabilizing module.

6. The LED driving power supply according to claim 4, wherein, The feedback module includes MOS tube Q2, resistor R8, resistor R19, and triode Q5. Among them, the gate of MOS tube Q2 is connected to the programming sending terminal of the MCU. The source of MOS tube Q2 is connected to a high level. The drain of MOS tube Q2 is sequentially connected to the control negative terminal through resistor R8 and resistor R19. The connection point of resistor R8 and resistor R19 is connected to the base of triode Q5. The emitter of triode Q5 is connected to the control negative terminal. The collector of triode Q5 is connected to the control positive terminal.

7. The LED driving power supply according to claim 4, wherein The first processing module includes resistor R27 and resistor R34. Among them, the first terminal of resistor R27 is connected to the control positive terminal. The second terminal of resistor R27 is respectively connected to the control negative terminal and the grounding terminal of the MCU through resistor R34. The second terminal of resistor R27 is connected to the programming receiving terminal of the MCU.

8. The LED driving power supply according to claim 4, characterized in that, The second processing module includes a resistor R2, a resistor R3, and a zener diode ZD2. Among them, a first end of the resistor R2 is connected to the control positive terminal, a second end of the resistor R2 is respectively connected to the control negative terminal and the ground terminal of the MCU through the resistor R3, the second end of the resistor R2 is connected to the dimming terminal of the MCU, a negative electrode of the zener diode ZD2 is connected to the second end of the resistor R2, and a positive electrode of the zener diode ZD2 is connected to the control negative terminal.

9. An LED terminal, comprising an LED load, characterized in that, It further includes the LED driving power supply according to any one of claims 1-8.

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