A 0-10V small dimming fast start control circuit

Abstract

The present invention discloses a 0-10V small dimming fast start control circuit, comprising a voltage stabilizing diode D4 and a capacitor C3. The control circuit also comprises a photoelectric coupler U3 and a transistor Q6, wherein a first pin of the photoelectric coupler U3 is electrically connected to a C electrode of the transistor Q6, a second pin of the photoelectric coupler U3 is electrically connected to a PWM circuit, a third pin of the photoelectric coupler U3 is electrically connected to one end of a voltage stabilizing diode D12 and is grounded at the same time, a fourth pin of the photoelectric coupler U3 is electrically connected to the other end of the voltage stabilizing diode D12, one end of a resistor R26, and a PWM1 circuit, and the other end of the resistor R26 is connected to VCC1 through a diode D9. The present invention can realize a solution to the problem that the start-up time of a 0-10V dimming power supply is too long when a small dimming low voltage input is used.

Description

Technical Field

[0001] The invention relates to a 0-10V low-dimming fast-start control circuit. Background Art

[0002] 0-10V dimming is one of the main ways to implement dimming power supply in the current market. It has good compatibility and low cost and has been widely used in the market.

[0003] At present, the lighting market has higher and higher requirements for output flicker, which should be less than <30% or even no flicker. Considering the cost, electrolytic capacitors with larger capacitance (hereinafter referred to as large electrolytic capacitors) will be used.

[0004] Using large electrolytics can meet the requirements of stroboscopic lighting, but large electrolytics will conflict with the start-up time under low dimming. This is mainly because the energy transmitted by the power loop under low dimming is very small, and the LED characteristics require that it will only work when a certain VF voltage is reached. Under low dimming transmission energy, the time from charging the large electrolytic to turning on the LED will be longer, which results in a longer start-up time under low dimming. Summary of the invention

[0005] The technical problem to be solved by the present invention is to realize a solution to the problem that the startup time of a 0-10V dimming power supply is too long when the input voltage is low and the dimming is small. At the same time, it also solves the contradiction between the output having a large electrolytic charge (stroboscopic requirement) and the long time between the electrolytic charge to the load LED working voltage under low dimming, and provides a 0-10V low dimming fast startup control circuit.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A 0-10V low dimming fast start control circuit includes a voltage regulator diode D4 and a capacitor C3, characterized in that: the control circuit also includes a photocoupler U3 and a transistor Q6, wherein the first pin of the photocoupler U3 is electrically connected to the C electrode of the transistor Q6, the second pin of the photocoupler U3 is electrically connected to the PWM circuit, the third pin of the photocoupler U3 is electrically connected to one end of the voltage regulator diode D12 and is grounded at the same time, the fourth pin of the photocoupler U3 is electrically connected to the other end of the voltage regulator diode D12, one end of a resistor R26, and the PWM1 circuit, and the other end of the resistor R26 is connected to VCC1 through a diode D9; the B electrode of the transistor Q6 is electrically connected to one end of the voltage regulator diode D4 and one end of the capacitor C3 respectively, the other end of the capacitor C3 is electrically connected to the E electrode of the transistor Q6 through a resistor R5, and the other end of the voltage regulator diode D4 is connected to VCC through a resistor R4.

[0008] Preferably, the A end of the transformer T1 is electrically connected to one end of the diode D1 and one end of the capacitor C1, respectively, wherein the other end of the diode D1 is electrically connected to the other end of the capacitor C1 through the resistor R8, and the other end of the diode D1 is also electrically connected to one end of the polarity capacitor EC2, one end of the polarity capacitor EC3, one end of the resistor R1, and the first pin of the common-mode inductor, respectively.

[0009] Preferably, the B end of the transformer T1 is electrically connected to the other end of the polarity capacitor EC2, the other end of the polarity capacitor EC3, the other end of the resistor R1, and the third pin of the common-mode inductor, respectively; the second pin of the common-mode inductor is electrically connected to the fourth pin of the common-mode inductor through a number of LED lamps connected in series, and the other end of the polarity capacitor EC2 is grounded.

[0010] The present invention also provides another technical solution: a 0-10V low dimming fast start control circuit, the control circuit includes a photocoupler U3, a photocoupler U4, and a diode U5, wherein the first pin of the photocoupler U3 is electrically connected to the third pin of the photocoupler U4, the second pin and the third pin of the photocoupler U3 are both grounded, and the fourth pin of the photocoupler U3 is electrically connected to the PWM1 circuit; the fourth pin of the photocoupler U4 is electrically connected to the PWM circuit, the first pin of the photocoupler U4 is electrically connected to one end of the resistor R40 through the resistor R36, and the other end of the resistor R40 is electrically connected to the R end of the diode U5 and one end of the resistor R41, respectively, wherein the other end of the resistor R41 is electrically connected to the A end of the diode U5, and the K end of the diode U5 is electrically connected to the second pin of the photocoupler U4.

[0011] The beneficial effects achieved by the present invention are:

[0012] The circuit of the present invention is simple, reliable and low in cost. The present invention can solve the problem that the startup time of the 0-10V dimming power supply is too long when the input voltage is low and the dimming is small. At the same time, it also solves the contradiction between the output having large electrolysis (stroboscopic requirement) and the long time between the electrolysis charging to the load LED working voltage under low dimming. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0014] Figure 1 A circuit diagram of the present invention;

[0015] Figure 2 It is a circuit diagram of the secondary side of the power loop of the present invention;

[0016] Figure 3 FIG. 4 is a circuit diagram of an LED load of the present invention.

[0017] Figure 4 It is a statistical diagram of the startup time, voltage and current of the present invention;

[0018] Figure 5 It is a statistical diagram of the startup time, voltage and current of the present invention;

[0019] Figure 6 This is a circuit diagram of another technical solution of the present invention. DETAILED DESCRIPTION

[0020] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0021] From the relationship between the charging time and voltage of the capacitor: U=QC=QIT, it can be seen that when the capacitance and voltage are constant, the current I is inversely proportional to the time T.

[0022] Because the small dimming signal intervenes in the feedback too early after startup, the circuit transmission energy is very low, that is, I is very small, and the voltage U that the electrolysis needs to reach the LED working voltage is fixed, so the electrolysis charging time will become longer, and the smaller the current I, the longer the time. So if the small dimming does not intervene in the power line when the power supply is started, so that the transmission energy I reaches the maximum (consistent with the maximum dimming), the electrolysis charging T will become very short. Here we define a threshold value slightly lower than the LED working voltage. At this time, the dimming signal intervenes, so the electrolysis time after startup will be greatly shortened, that is, the startup time is shortened.

[0023] It is mentioned here that a threshold voltage slightly lower than the LED working voltage is set. If this voltage is higher than the LED working voltage, the power supply will work at maximum brightness after startup, then dim the light and then turn to low brightness, forming a flickering state. If the threshold voltage is low, the power supply startup time will be longer.

[0024] like Figures 1 to 3As shown, an embodiment of the present invention is provided: a 0-10V small dimming fast start control circuit, including a voltage regulator diode D4 and a capacitor C3, the control circuit also includes a photocoupler U3 and a transistor Q6, wherein the first pin of the photocoupler U3 is electrically connected to the C electrode of the transistor Q6, the second pin of the photocoupler U3 is electrically connected to the PWM circuit, the third pin of the photocoupler U3 is electrically connected to one end of the voltage regulator diode D12 and grounded at the same time, the fourth pin of the photocoupler U3 is electrically connected to the other end of the voltage regulator diode D12, one end of the resistor R26, and the PWM1 circuit, the other end of the resistor R26 is connected to VCC1 through a diode D9; the B electrode of the transistor Q6 is electrically connected to one end of the voltage regulator diode D4 and one end of the capacitor C3 respectively, the other end of the capacitor C3 is electrically connected to the E electrode of the transistor Q6 through a resistor R5, and the other end of the voltage regulator diode D4 is connected to VCC through a resistor R4. The A end of the transformer T1 is electrically connected to one end of the diode D1 and one end of the capacitor C1, wherein the other end of the diode D1 is electrically connected to the other end of the capacitor C1 through the resistor R8, and the other end of the diode D1 is also electrically connected to one end of the polar capacitor EC2, one end of the polar capacitor EC3, one end of the resistor R1, and the first pin of the common mode inductor. The B end of the transformer T1 is electrically connected to the other end of the polar capacitor EC2, the other end of the polar capacitor EC3, the other end of the resistor R1, and the third pin of the common mode inductor; the second pin of the common mode inductor is electrically connected to the fourth pin of the common mode inductor through a number of LED lights connected in series, and the other end of the polar capacitor EC2 is grounded.

[0025] The circuit components of this embodiment are mainly composed of a voltage-stabilizing diode, a resistor, a capacitor, a transistor and an optocoupler. This circuit utilizes the threshold characteristics of the voltage-stabilizing diode. When VCC reaches the breakdown voltage value of the voltage-stabilizing diode, it will be turned on and Q6 will be turned on. At this time, the PWM signal and the optocoupler will intervene in the feedback loop and transmit the signal to the primary dimming control IC to achieve dimming. In this way, when the voltage does not reach the breakdown voltage of the voltage-stabilizing diode, the dimming control IC works in the maximum dimming state without a dimming signal (the feedback loop is open), the power circuit transmits high energy, and the large electrolytic charging is very fast, which greatly shortens the startup time of the entire circuit. Among them, VCC is the auxiliary winding of the transformer, and it can form a proportional relationship with the large electrolytic voltage Vout through different windings of the transformer. The present invention adopts an open-loop feedback loop to solve the problem that the slow startup time is caused by the slow electrolytic charging under the circuit transmission energy under the 0-10V small dimming feedback.

[0026] like Figure 6As shown, another embodiment of the present invention is provided: a 0-10V small dimming fast start control circuit, the control circuit includes a photocoupler U3, a photocoupler U4, and a diode U5, wherein the first pin of the photocoupler U3 is electrically connected to the third pin of the photocoupler U4, the second pin and the third pin of the photocoupler U3 are both grounded, and the fourth pin of the photocoupler U3 is electrically connected to the PWM1 circuit; the fourth pin of the photocoupler U4 is electrically connected to the PWM circuit, the first pin of the photocoupler U4 is electrically connected to one end of the resistor R40 through the resistor R36, and the other end of the resistor R40 is electrically connected to the R end of the diode U5 and one end of the resistor R41, respectively, wherein the other end of the resistor R41 is electrically connected to the A end of the diode U5, and the K end of the diode U5 is electrically connected to the second pin of the photocoupler U4.

[0027] The PWM1 circuit of the present invention generates a signal for the primary side dimming IC to work, and the PWM1 circuit is a common circuit.

[0028] The PWM circuit of the present invention generates a 0-10V signal through an IC device. There are many transducer ICs on the market, such as SY5867FAC of SILERGY, IW337 of IWATT, etc.

[0029] Figure 4 The startup time of the circuit in this article is 3.69S. Rectangle: input voltage; thin line: electrolytic voltage; thick line: output current.

[0030] Figure 5 To increase the startup time of the circuit of this scheme by 0.9S, rectangle: input voltage; thin line: electrolysis voltage; thick line: output current.

[0031] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A 0-10V dimming fast start control circuit, comprising a voltage regulator diode D4 and a capacitor C3, characterized in that: The control circuit also includes a photocoupler U3 and a transistor Q6, wherein a first pin of the photocoupler U3 is electrically connected to a C electrode of the transistor Q6, a second pin of the photocoupler U3 is electrically connected to a PWM circuit, a third pin of the photocoupler U3 is electrically connected to one end of a voltage-stabilizing diode D12 and is grounded, a fourth pin of the photocoupler U3 is electrically connected to the other end of the voltage-stabilizing diode D12, one end of a resistor R26 and a PWM1 circuit, and the other end of the resistor R26 is connected to an auxiliary winding VCC1 of a transformer T1 through a diode D9; a B electrode of the transistor Q6 is electrically connected to one end of a voltage-stabilizing diode D4 and one end of a capacitor C3, respectively, the other end of the capacitor C3 is electrically connected to an E electrode of the transistor Q6 through a resistor R5, and the other end of the voltage-stabilizing diode D4 is connected to an auxiliary winding VCC of a transformer T1 through a resistor R4; The A end of the transformer T1 is electrically connected to one end of the diode D1 and one end of the capacitor C1, respectively, wherein the other end of the diode D1 is electrically connected to the other end of the capacitor C1 through the resistor R8, and the other end of the diode D1 is also electrically connected to one end of the polar capacitor EC2, one end of the polar capacitor EC3, one end of the resistor R1 and the first pin of the common mode inductor; The B end of the transformer T1 is electrically connected to the other end of the polar capacitor EC2, the other end of the polar capacitor EC3, the other end of the resistor R1 and the third pin of the common mode inductor respectively; the second pin of the common mode inductor is electrically connected to the fourth pin of the common mode inductor through a plurality of LED lamps connected in series, and the other end of the polar capacitor EC2 is grounded; The PWM1 circuit generates the signal for the primary dimming IC to work; The PWM circuit generates a 0-10V signal which is converted by the IC.

2. A 0-10V dimming fast start control circuit, characterized by: The control circuit includes a photocoupler U3, a photocoupler U4 and a diode U5, wherein the first pin of the photocoupler U3 is electrically connected to the third pin of the photocoupler U4, the second pin of the photocoupler U3 and its third pin are both grounded, and the fourth pin of the photocoupler U3 is electrically connected to the PWM1 circuit; the fourth pin of the photocoupler U4 is electrically connected to the PWM circuit, the first pin of the photocoupler U4 is electrically connected to one end of the resistor R40 through the resistor R36, and the other end of the resistor R40 is electrically connected to the R end of the diode U5 and one end of the resistor R41, respectively, wherein the other end of the resistor R41 is electrically connected to the A end of the diode U5, and the K end of the diode U5 is electrically connected to the second pin of the photocoupler U4; The large electrolytic voltage Vout is connected between the resistor R36 and the resistor R40; The PWM1 circuit generates the signal for the primary dimming IC to work; The PWM circuit generates a 0-10V signal which is converted by the IC.

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