LED numerical control constant current driving power supply with improved structure

Abstract

The invention discloses an LED numerical control constant current driving power supply with an improved structure, which comprises an input protection circuit, one end of the input protection circuit is connected with an EMI filter circuit, one end of the EMI filter circuit is connected with a rectification circuit, one end of the rectification circuit is connected with a manual encoder, one end of the manual encoder is connected with a PSoC chip, and the other end of the PSoC chip is connected with a power supply. One side of the PSoC chip is provided with an inductance matching unit, one end of the inductance matching unit is connected with an output rectification filter circuit, one end of the output rectification filter circuit is connected with an optocoupler feedback circuit, the circuit completes a constant current function, and the circuit is high in control precision from test data; from the test process, the circuit is stable and reliable, the phenomena of element damage and function failure do not occur after long-time work, and the circuit has short circuit and open circuit protection functions; the current fluctuation coefficient of the LED numerical control constant-current driving power supply is effectively reduced, the driving efficiency is higher, the circuit ensures the stability degree of current signal receiving of LED equipment, and the service life of an LED is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of LED numerical control constant current drive power supplies, and particularly to an LED numerical control constant current drive power supply with an improved structure. Background Technique

[0002] LED, also known as a light-emitting diode, is a solid-state semiconductor component that can directly convert electrical energy into light. LEDs have the characteristics of high luminous efficiency, long lifespan, energy conservation, diverse colors, environmental friendliness, and low energy consumption, and are widely used in many occasions. The application of LEDs is becoming more and more extensive, bringing unlimited development space to the entire LED industry. In order to meet the needs of various LED light sources, many different drive methods have been adopted.

[0003] An LED drive power supply is a converter that converts the power network into a current or voltage suitable for the characteristics of LED lighting devices. The LED drive power supply must have advantages such as high efficiency, overvoltage protection, small volume, and convenient use. LED light sources are constant current types and require a constant current drive circuit. However, if the constant current accuracy of the LED constant current power supply is not high and the current accuracy is easily affected by the environment, the attenuation and failure rate of the LED light source are extremely high, and it may even be scrapped in an instant during charging. Therefore, researching the LED constant current drive power supply has high practical significance.

[0004] An LED constant current drive power supply is a voltage converter that converts the power supply into a specific voltage and current to drive the LED to emit light. It is generally divided into DC-DC type and AC-DC type. Usually, the inputs of LED drive power supplies include high-voltage industrial frequency AC, low-voltage DC, high-voltage DC, low-voltage high-frequency AC, etc.

[0005] However, traditional LED numerical control constant current drive power supplies have the following disadvantages:

[0006] Common types of LED drive power supplies include single-stage flyback LED drive power supplies, electrolytic-capacitor-free LED drive power supplies, etc. However, there are obvious power supply instability situations in the actual application process of the drive power supply. Summary of the Invention

[0007] The purpose of the present invention is to provide an LED numerical control constant current drive power supply with an improved structure to solve the problem that common types of LED drive power supplies include single-stage flyback LED drive power supplies, electrolytic-capacitor-free LED drive power supplies, etc., but there are obvious power supply instability situations in the actual application process of the drive power supply as mentioned in the above background technique.

[0008] To achieve the above object, the present invention provides the following technical solution: An LED numerical control constant current drive power supply with an improved structure, including an input protection circuit, one end of the input protection circuit is connected to an EMI filter circuit, one end of the EMI filter circuit is connected to a rectification circuit, one end of the rectification circuit is connected to a manual encoder, one end of the manual encoder is connected to a PSoC chip, there is an inductance matching on one side of the PSoC chip, one end of the inductance matching is connected to an output rectification and filtering circuit, one end of the output rectification and filtering circuit is connected to an optocoupler feedback circuit, one end of the optocoupler feedback circuit is connected to a controller, one end of the controller is connected to the other end of the inductance matching, one end of the PSoC chip is connected to a power factor correction circuit and a transformer, one end of the power factor correction circuit and one end of the transformer are both connected to the end opposite to the inductance matching.

[0009] As a preferred technical solution of the present invention, the transformer includes a storage inductor L, a transistor VT, a boost diode VD, and a filter capacitor C. One end of the storage inductor L is respectively connected to one end of the transistor VT and one end of the boost diode VD. The other end of the boost diode VD is connected to one end of the filter capacitor C. The other end of the filter capacitor C is connected to the other end of the transistor VT. For the transistor VT, the storage inductor L, the boost diode VD, and the filter capacitor C components, the base signal of the transistor is controlled to be cyclically turned on and off. In the boost state, by turning on the triode, electrical energy is stored in the inductor, and the inductor current rises linearly, and is represented by “+” on the left and “−” on the right. The load is provided by the capacitor. When the transistor is turned off, the induced current decreases, the induced potential is “−” on the left and “+” on the right, and the inductor potential overlaps with the input voltage, so that the diode VD is turned on, and together they provide power to the load and charge the capacitor C. Thus, the DC low voltage of the drive power supply is converted into DC high voltage, and the reverse operation of the boost transformer can achieve the buck control of the drive power supply. When the transformer performs the boost or buck task, the internal circuit itself adjusts the current, thereby increasing the voltage drop of the current limiting resistor, and thus reducing the voltage fluctuation amplitude to achieve the purpose of voltage stabilization.

[0010] As a preferred technical solution of the present invention, the EMI filter circuit includes filter capacitor C 1 、filter capacitor C 2 、filter capacitor C 3 、filter capacitor C 4 and a common mode inductor L. One end of the common mode inductor L is connected in parallel with filter capacitor C 1 ,the other end of the common mode inductor L is connected in parallel with filter capacitor C 2 ,the common mode inductor L and filter capacitor C 3 one end and filter capacitor C 4is connected to one end of the filter capacitor C 3 The other end of is connected to the filter capacitor C 4 The other ends of both are grounded.

[0011] As a preferred technical solution of the present invention, the output rectifier filter circuit includes a phase comparator, a low-pass filter, a voltage-controlled oscillator, a two-phase drive circuit, a USM, waveform transformation, and phase shift. One end of the phase comparator is connected to one end of the low-pass filter, the other end of the low-pass filter is connected to one end of the voltage-controlled oscillator, the other end of the voltage-controlled oscillator is connected to one end of the two-phase drive circuit, the other end of the two-phase drive circuit is respectively connected to one end of the waveform transformation and one end of the USM, the two-phase drive circuit is respectively connected to the phase comparator and the phase shift through the waveform transformation, one end of the phase shift is connected to the opposite end of the low-pass filter, and a load is connected to the surface of the USM.

[0012] As a preferred technical solution of the present invention, the optocoupler feedback circuit includes a connector JP3, capacitors C1, C2, C5, C6, diodes D3, D4, D5, D6, capacitor C7, capacitor C3, resistors R1, R2, transistors Q1, Q2, resistor R4, resistor R6, resistor R7, connectors J1, J2, capacitor C4, and integrated circuit U1. The 2-pin of the connector J3 is respectively connected to one end of the capacitor C1, one end of the diode D3, one end of the capacitor C2, and one end of the diode D4. The 1-pin of the connector J3 is respectively connected to one end of the diode D5, one end of the capacitor C5, one end of the diode D6, and one end of the capacitor C6. The other end of the capacitor C1 is respectively connected to one end of the capacitor C7, one end of the capacitor C3, and one end of the transistor Q1. The other end of the transistor Q1 is respectively connected to one end of the transistor Q2 and one end of the resistor R4. The other end of the resistor R4 is respectively connected to one end of the resistor R6, the 1-pin of the connector J1, and the 1-pin of the connector JP2. The 2-pin of the connector JP1 is respectively connected to the other end of the resistor R6, one end of the resistor R7, and the 3-pin of the integrated circuit U1.

[0013] As a preferred technical solution of the present invention, the other end of the capacitor C2, the other ends of the diodes D4 and D5, the other end of the capacitor C5, the 2-pin of the connector JP2, the other end of the resistor R7, the 2-pin of the integrated circuit U1, and the other end of the capacitor C3 are all grounded.

[0014] As a preferred technical solution of the present invention, the power factor correction circuit includes a capacitor C6, a resistor R5, a diode D4, and an inductor T2. One end of the resistor R5 is connected to one end of the capacitor C6 and one end of the diode D4. The other end of the resistor R5 is connected to the other end of the capacitor C6. The other end of the diode D4 is connected to one end of the inductor T2. The other end of the inductor T2 is connected to the opposite end of the capacitor C6.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1. The circuit achieves the constant current function. From the test data, the control accuracy of this circuit is high. From the test process, the circuit is stable and reliable, and no component damage or function failure occurs during long-term operation. It has short-circuit and open-circuit protection functions.

[0017] 2. The current fluctuation coefficient of the LED numerical control constant current drive power supply is effectively reduced, and the drive efficiency is higher. This circuit ensures the smoothness of the current signal received by the LED device and extends the lifespan of the LED. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the architecture of the present invention;

[0019] Figure 2 is a circuit diagram of the transformer of the present invention;

[0020] Figure 3 is a circuit diagram of the EMI filter circuit of the present invention;

[0021] Figure 4 is a circuit diagram of the output rectifier and filter circuit of the present invention;

[0022] Figure 5 is a circuit diagram of the optocoupler feedback circuit of the present invention;

[0023] Figure 6 is a circuit diagram of the power factor correction circuit of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] Please refer to Figures 1-6, the present invention provides an LED numerical control constant current drive power supply with an improved structure, including an input protection circuit. One end of the input protection circuit is connected to an EMI filter circuit. One end of the EMI filter circuit is connected to a rectification circuit. One end of the rectification circuit is connected to a manual encoder. One end of the manual encoder is connected to a PSoC chip. There is an inductance matching on one side of the PSoC chip. One end of the inductance matching is connected to an output rectification and filtering circuit. One end of the output rectification and filtering circuit is connected to an optocoupler feedback circuit. One end of the optocoupler feedback circuit is connected to a controller. One end of the controller is connected to the other end of the inductance matching. One end of the PSoC chip is connected to a power factor correction circuit and a transformer. One end of the power factor correction circuit and one end of the transformer are both connected to the end directly opposite to the inductance matching.

[0026] The transformer includes a storage inductor L, a transistor VT, a boost diode VD, and a filter capacitor C. One end of the storage inductor L is respectively connected to one end of the transistor VT and one end of the boost diode VD. The other end of the boost diode VD is connected to one end of the filter capacitor C. The other end of the filter capacitor C is connected to the other end of the transistor VT. For the components of the transistor VT, the storage inductor L, the boost diode VD, and the filter capacitor C, the base signal of the transistor is controlled to be cyclically turned on and off. In the boost state, by turning on the triode, electrical energy is stored in the inductor, causing the inductor current to rise linearly, and is represented by “+” on the left and “-” on the right. The load is provided by the capacitor. When the transistor is turned off, the induced current decreases, and the induced potential is “-” on the left and “+” on the right. The inductor potential overlaps with the input voltage, so that the diode VD is in the on state, and together they supply power to the load and charge the capacitor C. Thus, the drive power supply DC low voltage is converted to DC high voltage. The reverse operation of the boost transformer can achieve the buck control of the drive power supply. When the transformer performs the boost or buck task, the internal circuit itself adjusts the current, thereby increasing the voltage drop of the current limiting resistor, and thus reducing the voltage fluctuation amplitude to achieve the purpose of voltage stabilization.

[0027] The EMI filter circuit includes filter capacitor C 1 , filter capacitor C 2 , filter capacitor C 3 , filter capacitor C 4 and a common mode inductor L. One end of the common mode inductor L is connected in parallel with filter capacitor C 1 . The other end of the common mode inductor L is connected in parallel with filter capacitor C 2 . The common mode inductor L is connected to one end of filter capacitor C 3 and one end of filter capacitor C 4 . The other end of filter capacitor C 3 and the other end of filter capacitor C 4 are both grounded.

[0028] The output rectifying and filtering circuit includes a phase comparator, a low-pass filter, a voltage-controlled oscillator, a two-phase drive circuit, a USM, waveform transformation, and phase shift. One end of the phase comparator is connected to one end of the low-pass filter, the other end of the low-pass filter is connected to one end of the voltage-controlled oscillator, the other end of the voltage-controlled oscillator is connected to one end of the two-phase drive circuit, the other end of the two-phase drive circuit is respectively connected to one end of the waveform transformation and one end of the USM. The two-phase drive circuit is respectively connected to the phase comparator and the phase shift through the waveform transformation. One end of the phase shift is connected to the opposite end of the low-pass filter, and a load is connected to the surface of the USM.

[0029] The optocoupler feedback circuit includes a connector JP3, capacitors C1, C2, C5, C6, diodes D3, D4, D5, D6, capacitor C7, capacitor C3, resistors R1, R2, transistors Q1, Q2, resistor R4, resistor R6, resistor R7, connectors J1, J2, capacitor C4, and integrated circuit U1. The 2-pin of connector J3 is respectively connected to one end of capacitor C1, one end of diode D3, one end of capacitor C2, and one end of diode D4. The 1-pin of connector J3 is respectively connected to one end of diode D5, one end of capacitor C5, one end of diode D6, and one end of capacitor C6. The other end of capacitor C1 is respectively connected to one end of capacitor C7, one end of capacitor C3, and one end of transistor Q1. The other end of transistor Q1 is respectively connected to one end of transistor Q2 and one end of resistor R4. The other end of resistor R4 is respectively connected to one end of resistor R6, the 1-pin of connector J1, and the 1-pin of connector JP2. The 2-pin of connector JP1 is respectively connected to the other end of resistor R6, one end of resistor R7, and the 3-pin of integrated circuit U1.

[0030] The other end of capacitor C2, the other end of diode D4, the other end of diode D5, the other end of capacitor C5, the 2-pin of connector JP2, the other end of resistor R7, the 2-pin of integrated circuit U1, and the other end of capacitor C3 are all grounded.

[0031] The power factor correction circuit includes capacitor C6, resistor R5, diode D4, and inductor T2. One end of resistor R5 is respectively connected to one end of capacitor C6 and one end of diode D4. The other end of resistor R5 is connected to the other end of capacitor C6. The other end of diode D4 is connected to one end of inductor T2. The other end of inductor T2 is connected to the opposite end of capacitor C6.

[0032] In the present invention, the series switch adjustable regulated power supply in the circuit uses IRF640 as the regulating transistor. IRF640 belongs to the third generation of Power MOSFETS of Vishay, featuring fast switching, durability, low on-resistance, and high efficiency. The reference voltage chip uses TL431, which is a three-terminal adjustable shunt reference voltage source with good thermal stability. For the main circuit diagram of the power supply conversion, the buck part of the circuit uses the MC34063 chip dedicated to DC-DC converter control to obtain DC 12V and 5V respectively for supplying the integrated operational amplifier and the single-chip microcomputer. The MC34063 chip can form a buck converter with the least external components and is extremely convenient to use. The control of the constant current source current is achieved by controlling the voltage of the power regulating transistor. The main circuit of the constant current source mainly completes the sampling of analog signals and receives the control signals sent by the single-chip microcomputer, thereby achieving the purpose of constant current. The microprocessor, as the control core of the constant current source, directly determines the changes and conversion states of the constant current source current and voltage in each link. The control circuit selects the AT89S52 single-chip microcomputer as the main control chip, pre-sets the current value through the keyboard, and outputs the corresponding digital signal to the D / A converter. The analog signal output by the D / A converter is sent to the operational amplifier to control the magnitude of the main circuit current. The circuit selects the LCD12864 liquid crystal module as the display, and the system keyboard uses an independent keyboard, with four function keys set, namely the setting key, current increase, current decrease, and reserved key. The A / D acquisition circuit selects the 10-bit serial AD converter TLC1549, and the digital-to-analog conversion circuit selects the DAC8512 chip. The overcurrent protection circuit is not designed separately but integrated in the series switch power supply circuit composed of IRF640. When the output current is higher than the rated value, the voltage drop across the protection resistor R4 increases, causing the protection transistor Q2 to conduct and IRF640 to turn off; when it is detected again that the load current drops below the set current, the voltage drop across the protection resistor R4 decreases, causing the protection transistor Q2 to cut off and IRF640 to work, switching the constant voltage mode back to the constant current mode again to achieve the purpose of overcurrent protection.

[0033] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An LED digital controlled constant current driving power supply with an improved structure, including an input protection circuit, characterized in that: One end of the input protection circuit is connected to an EMI filter circuit, one end of the EMI filter circuit is connected to a rectifier circuit, one end of the rectifier circuit is connected to a manual encoder, one end of the manual encoder is connected to a PSoC chip, one side of the PSoC chip is provided with an inductor match, one end of the inductor match is connected to an output rectifier filter circuit, one end of the output rectifier filter circuit is connected to an optocoupler feedback circuit, one end of the optocoupler feedback circuit is connected to a controller, one end of the controller is connected to the other end of the inductor match, one end of the PSoC chip is connected to a power factor correction circuit and a transformer, one end of the power factor correction circuit and one end of the transformer are both connected to the end directly opposite to the inductor match.

2. The LED digital controlled constant current driving power supply with an improved structure according to claim 1, characterized in that: The transformer includes an energy storage inductor L, a transistor VT, a boost diode VD and a filter capacitor C. One end of the energy storage inductor L is respectively connected to one end of the transistor VT and one end of the boost diode VD, the other end of the boost diode VD is connected to one end of the filter capacitor C, and the other end of the filter capacitor C is connected to the other end of the transistor VT.

3. The LED digital controlled constant current driving power supply with an improved structure according to claim 1, characterized in that: The EMI filtering circuit includes a filter capacitor C1, a filter capacitor C2, a filter capacitor C3, a filter capacitor C4 and a common mode inductor L, one end of the common mode inductor L is connected in parallel with the filter capacitor C1, the other end of the common mode inductor L is connected in parallel with the filter capacitor C2, the common mode inductor L is connected to one end of the filter capacitor C3 and one end of the filter capacitor C4, and the other end of the filter capacitor C3 and the other end of the filter capacitor C4 are both grounded.

4. The LED digital controlled constant current driving power supply with an improved structure according to claim 1, characterized in that: The output rectification and filtering circuit includes a phase comparator, a low-pass filter, a voltage-controlled oscillator, a two-phase drive circuit, a USM, waveform transformation and phase shifting. One end of the phase comparator is connected to one end of the low-pass filter, the other end of the low-pass filter is connected to one end of the voltage-controlled oscillator, the other end of the voltage-controlled oscillator is connected to one end of the two-phase drive circuit, the other end of the two-phase drive circuit is respectively connected to one end of the waveform transformation and one end of the USM, the two-phase drive circuit is respectively connected to the phase comparator and the phase shifting through waveform transformation, one end of the phase shifting is connected to the end directly opposite to the low-pass filter, and a load is connected to the surface of the USM.

5. The LED digital controlled constant current driving power supply with an improved structure according to claim 1, characterized in that: The optocoupler feedback circuit includes a connector JP3, a capacitor C1, a capacitor C2, a capacitor C5, a capacitor C6, a diode D3, a diode D4, a diode D5, a diode D6, a capacitor C7, a capacitor C3, a resistor R1, a resistor R2, a transistor Q1, a transistor Q2, a resistor R4, a resistor R6, a resistor R7, a connector J1, a connector J2, a capacitor C4 and an integrated circuit U1, wherein two ends of the connector J3 are respectively connected to one end of the capacitor C1, one end of the diode D3, one end of the capacitor C2 and one end of the diode D4, and one end of the connector J3 is respectively connected to the diode One end of the tube D5, one end of the capacitor C5, one end of the diode D6 and one end of the capacitor C6 are connected, the other end of the capacitor C1 is respectively connected to one end of the capacitor C7, one end of the capacitor C3 and one end of the transistor Q1, the other end of the transistor Q1 is respectively connected to one end of the transistor Q2 and one end of the resistor R4, the other end of the resistor R4 is respectively connected to one end of the resistor R6, one end pin of the connector J1 and one end pin of the connector JP2, and two end pins of the connector JP1 are respectively connected to the other end of the resistor R6, one end of the resistor R7 and three end pins of the integrated circuit U1.

6. The LED digital controlled constant current driving power supply with an improved structure according to claim 5, characterized in that: The other end of the capacitor C2, the other end of the diode D4, the other end of the diode D5, the other end of the capacitor C5, two pins of the connector JP2, the other end of the resistor R7, two pins of the integrated circuit U1 and the other end of the capacitor C3 are all grounded.

7. The LED digital controlled constant current driving power supply with an improved structure according to claim 1, characterized in that: The power factor correction circuit includes a capacitor C6, a resistor R5, a diode D4 and an inductor T2, one end of the resistor R5 is respectively connected to one end of the capacitor C6 and one end of the diode D4, the other end of the resistor R5 is connected to the other end of the capacitor C6, the other end of the diode D4 is connected to one end of the inductor T2, and the other end of the inductor T2 is connected to the opposite end of the capacitor C6.

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