LED street lamp driving power supply

Abstract

The utility model discloses an LED street lamp driving power supply, which belongs to the technical field of LED driving, comprises a PFC (Power Factor Correction) circuit, an isolated flyback conversion circuit, a 5V voltage stabilizer, a temperature sensor, a comparator, a main controller, a PWM (Pulse-Width Modulation) driver and an LED driver, and solves the technical problems of high-efficiency energy conversion of the LED power supply and temperature detection of the driving power supply. According to the utility model, the power factor is improved, so that the utilization efficiency of electric energy is improved, the load of a power grid is reduced, a stable VCC power supply is provided, a guarantee is provided for the normal work of a subsequent circuit, one path of temperature detection is added, and the comparator is used for detecting the real-time temperature of a heating element in the isolated flyback conversion circuit; the LED lamp dimming circuit can be combined with an LED driver to dim an LED lamp, so that a cooling effect is achieved, a heating element in the isolated flyback conversion circuit is protected, the service life is prolonged, and the LED lamp dimming circuit is low in cost, high in reliability and easy to maintain.

Description

Technical Field

[0001] The utility model belongs to the technical field of LED driving, and particularly relates to a driving power supply for an LED street lamp. Background Technique

[0002] With the continuous development of LED lighting technology, LED street lamps have gradually become the mainstream lighting devices. However, there are still some deficiencies in the existing LED street lamp driving power supplies:

[0003] The power factor of traditional LED street lamp driving power supplies is relatively low, which not only increases the power grid load but also reduces the power utilization efficiency.

[0004] The existing LED street lamp driving power supplies generally lack temperature monitoring and control functions and cannot monitor the system temperature in real time. When the ambient temperature or working temperature is too high, it is easy to cause damage to the LED lamp or failure of the driving power supply.

[0005] Many LED street lamp driving power supplies do not consider the impact of power fluctuations and high-frequency interference on the system in their design. Especially, the power supply stability of the control circuit is insufficient, which easily leads to unstable system operation and affects the service life and lighting effect of the LED lamp. Content of the Utility Model

[0006] The purpose of the utility model is to provide a driving power supply for an LED street lamp, which solves the technical problems of high-efficiency energy conversion of the LED power supply and temperature detection of the driving power supply.

[0007] To achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A driving power supply for an LED street lamp includes a PFC circuit, an isolated flyback conversion circuit, a 5V voltage regulator, a temperature sensor, a comparator, a main controller, a PWM driver, and an LED driver. The input end of the PFC circuit is connected to the mains electricity, and the output end outputs the VIN power supply. The input end of the isolated flyback conversion circuit is connected to the VIN power supply, and the output end outputs the VCC power supply. The input end of the 5V voltage regulator is connected to the VCC power supply, and the output end outputs the 5V power supply;

[0009] The temperature sensor is used to collect the temperature of the isolated flyback conversion circuit. The temperature sensor is connected to the comparator, the comparator is connected to the main controller, the input end of the PWM driver is connected to an IO port of the main controller, the output end of the PWM driver is connected to the LED driver, and the LED driver is connected to an external LED lamp string;

[0010] The 5V power supply supplies power to the temperature sensor, the comparator, the main controller, and the PWM driver;

[0011] The VCC power supply supplies power to the LED driver.

[0012] Preferably, the PFC circuit consists of a PFC chip and its peripheral circuits. The model of the PFC chip is NCP1654, the model of the 5V voltage regulator is LM7805, the model of the temperature sensor is PT100, the model of the comparator is LM358, and the model of the main controller is 98C2051.

[0013] Preferably, the isolated flyback conversion circuit includes a power supply chip IC1, a resistor R2, a capacitor C1, an inductor L1, a capacitor C2, a capacitor C3, a resistor R1, a resistor R5, a capacitor C5, a diode D1, a diode D2, an inductor L2, a capacitor C6, and a resistor R7. The D terminal of the power supply chip IC1 is connected to one end of the resistor R2 through the inductor L1. The other end of the resistor R2 is connected to the VIN power supply. The connection node of the resistor R2 and the inductor L1 is connected to the ground wire through the capacitor C1. The FB terminal of the power supply chip IC1 is connected to the negative electrode of the diode D2 through the resistor R1, and the BP terminal is connected to the S terminal of the power supply chip IC1 through the capacitor C3. The S terminal of the power supply chip IC1 outputs the VCC power supply through the inductor L2 and is connected to the positive electrode of the diode D2. The S terminal of the power supply chip IC1 is also connected to the negative electrode of the diode D1. The positive electrode of the diode D1 is connected to the ground wire. The connection node of the resistor R1 and the FB terminal of the power supply chip IC1 is also connected to one end of the resistor R5. The other end of the resistor R5 is connected to the S terminal of the power supply chip IC1. The negative electrode of the diode D2 is also connected to the S terminal of the power supply chip IC1 through the capacitor C5. One end of the capacitor C6 is connected to the positive electrode of the diode D2, and the other end is connected to the ground wire. The resistor R7 is connected in parallel with the capacitor C6.

[0014] Preferably, the model of the power supply chip IC1 is LNK306.

[0015] Preferably, the 5V voltage regulator includes a voltage regulation chip IC2, capacitors C10, C11, C13, and C14. The IN terminal of the voltage regulation chip IC2 is connected to the VCC power supply, the GND terminal is connected to the ground wire, and the OUT terminal outputs the 5V power supply. The capacitors C10 and C11 are filtering capacitors for the 5V power supply, and the capacitors C13 and C14 are high-frequency filtering capacitors for the 5V power supply.

[0016] Preferably, the PWM driver includes a driving chip IC3. The LED driver includes a driving chip IC4, a resistor R4, a resistor R3, a capacitor C4, a resistor R6, a resistor R9, a capacitor C7, a capacitor C9, a resistor R10, a resistor R8, a diode D3, a field effect transistor Q1, a diode D4, an inductor L3, and a capacitor C12. The pin 2 of the driving chip IC3 is connected to an IO port of the main controller, the pins 1 and 8 are connected to the 5V power supply, the pins 4 and 5 are connected to the ground wire, and the pins 7 and 6 are connected to the pin 3 of the driving chip IC4.

[0017] Pin 1 of the driving chip IC4 is connected to the ground wire through the resistor R4, pin 4 is connected to the VCC power supply through the resistor R3, and pin 5 is connected to the ground wire; pin 4 of the driving chip IC4 is also connected to the ground wire through the capacitor C4, and pin 4 of the driving chip IC4 is also connected to pin 2 of the inductor L3 through the resistor R9;

[0018] Pin 6 of the driving chip IC4 is connected to the G pole of the field effect transistor Q1 through the resistor R10. The positive pole of the diode D3 is connected to pin 6 of the driving chip IC4, and the negative pole is connected to the G pole of the field effect transistor Q1. The S pole of the field effect transistor Q1 is connected to pin 7 of the driving chip IC4, and the D pole is connected to pin 1 of the inductor L3. Pin 8 of the driving chip IC4 is connected to pin 7 of the driving chip IC4 through the resistor R8. Pin 8 of the driving chip IC4 is also connected to the VCC power supply, pin 9 is connected to the VCC power supply through the capacitor C7, pin 10 is connected to the VCC power supply, and the resistor R6 is connected between pin 1 and pin 10 of the driving chip IC4;

[0019] The negative pole of the diode D4 is connected to pin 1 of the inductor L3, the positive pole is connected to the ground wire, one end of the capacitor C12 is connected to pin 2 of the inductor L3, the other end is connected to the ground wire, and pin 2 of the inductor L3 is connected to the external LED lamp bead.

[0020] Preferably, the model of the driving chip IC4 is LM3409, and the model of the driving chip IC3 is TC4420.

[0021] The LED street lamp driving power supply of the present invention solves the technical problems of efficient energy conversion of the LED power supply and temperature detection of the driving power supply. The present invention adopts the design of a PFC circuit plus an isolated flyback conversion circuit, which improves the power factor, thereby improving the power utilization efficiency, reducing the power grid load, and providing a stable VCC power supply to ensure the normal operation of the subsequent circuit. The present invention adds a temperature detection circuit, uses a comparator to detect the real-time temperature of the heating element in the isolated flyback conversion circuit, can dim the LED lamp in combination with the LED driver, thereby achieving the effect of temperature reduction, protecting the heating element in the isolated flyback conversion circuit, and improving the service life. The present invention has low cost, strong reliability and simple maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the schematic block diagram of the present invention;

[0023] Figure 2 is the circuit diagram of the isolated flyback conversion circuit and the 5V voltage regulator of the present invention;

[0024] Figure 3 is the circuit diagram of the PWM driver and the LED driver of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] A kind of LED street lamp driving power supply shown by Figures 1-3 includes a PFC circuit, an isolated flyback conversion circuit, a 5V voltage regulator, a temperature sensor, a comparator, a main controller, a PWM driver and an LED driver.

[0026] The input end of the PFC circuit is connected to the mains power supply, and the output end outputs the VIN power supply. After the mains power supply passes through the PFC circuit (NCP1654 and its peripheral circuit), a stable high-voltage DC power supply VIN is output, improving the input power factor and power utilization rate of electric energy.

[0027] The input end of the isolated flyback conversion circuit is connected to the VIN power supply, and the output end outputs the VCC power supply. The isolated flyback conversion circuit includes a power chip IC1, a resistor R2, a capacitor C1, an inductor L1, a capacitor C2, a capacitor C3, a resistor R1, a resistor R5, a capacitor C5, a diode D1, a diode D2, an inductor L2, a capacitor C6 and a resistor R7. The D end of the power chip IC1 is connected to one end of the resistor R2 through the inductor L1. The other end of the resistor R2 is connected to the VIN power supply. The connection node of the resistor R2 and the inductor L1 is connected to the ground wire through the capacitor C1. The FB end of the power chip IC1 is connected to the negative electrode of the diode D2 through the resistor R1, and the BP end is connected to the S end of the power chip IC1 through the capacitor C3. The S end of the power chip IC1 outputs the VCC power supply through the inductor L2 and is connected to the positive electrode of the diode D2. The S end of the power chip IC1 is also connected to the negative electrode of the diode D1. The positive electrode of the diode D1 is connected to the ground wire. The connection node of the resistor R1 and the FB end of the power chip IC1 is also connected to one end of the resistor R5. The other end of the resistor R5 is connected to the S end of the power chip IC1. The negative electrode of the diode D2 is also connected to the S end of the power chip IC1 through the capacitor C5. One end of the capacitor C6 is connected to the positive electrode of the diode D2, and the other end is connected to the ground wire. The resistor R7 is in parallel with the capacitor C6.

[0028] The VIN power supply is input to the isolated flyback conversion circuit (LNK306 and its peripheral circuit), and through energy storage and release, a stable VCC power supply is output to provide the working voltage for the subsequent circuit.

[0029] The input end of the 5V voltage regulator is connected to the VCC power supply, and the output end outputs the 5V power supply. The 5V voltage regulator includes a voltage regulating chip IC2, capacitors C8, C10, C11, C13 and C14. The IN end of the voltage regulating chip IC2 is connected to the VCC power supply, the GND end is connected to the ground wire, and the OUT end outputs the 5V power supply. The capacitors C10 and C11 are filtering capacitors for the 5V power supply, and the capacitors C13 and C14 are high-frequency filtering capacitors for the 5V power supply. The high-frequency filtering capacitors are used to filter the high-frequency interference generated by the LED driver, so as to provide a stable power supply for the main controller.

[0030] The temperature sensor is used to collect the temperature of the isolated flyback conversion circuit. The temperature sensor is connected to a comparator, the comparator is connected to the main controller, and the input end of the PWM driver is connected to an IO port of the main controller.

[0031] The output end of the PWM driver is connected to the LED driver, and the LED driver is connected to an external LED lamp string;

[0032] The PWM driver includes a driving chip IC3, and the LED driver includes a driving chip IC4, a resistor R4, a resistor R3, a resistor R9, a capacitor C4, a resistor R6, a capacitor C7, a capacitor C9, a resistor R10, a resistor R8, a diode D3, a field-effect transistor Q1, a diode D4, an inductor L3, and a capacitor C12. The 2nd pin of the driving chip IC3 is connected to an IO port of the main controller, the 1st and 8th pins are connected to the 5V power supply, the 4th and 5th pins are connected to the ground wire, and the 7th and 6th pins are connected to the 3rd pin of the driving chip IC4;

[0033] After being driven by the driving chip IC3, the PWM driving signal controls the MOSFET switch inside the LED driver to adjust the current of the inductor L3 and the external LED lamp, realizing intelligent dimming of the LED lamp.

[0034] The 1st pin of the driving chip IC4 is connected to the ground wire through the resistor R4, the 4th pin is connected to the VCC power supply through the resistor R3, and the 5th pin is connected to the ground wire; the 4th pin of the driving chip IC4 is also connected to the ground wire through the capacitor C4, and the 4th pin of the driving chip IC4 is also connected to the 2nd pin of the inductor L3 through the resistor R9;

[0035] The 6th pin of the driving chip IC4 is connected to the G pole of the field-effect transistor Q1 through the resistor R10. The positive pole of the diode D3 is connected to the 6th pin of the driving chip IC4, and the negative pole is connected to the G pole of the field-effect transistor Q1. The S pole of the field-effect transistor Q1 is connected to the 7th pin of the driving chip IC4, and the D pole is connected to the 1st pin of the inductor L3. The 8th pin of the driving chip IC4 is connected to the 7th pin of the driving chip IC4 through the resistor R8. The 8th pin of the driving chip IC4 is also connected to the VCC power supply, the 9th pin is connected to the VCC power supply through the capacitor C7, the 10th pin is connected to the VCC power supply, and the resistor R6 is connected between the 1st pin and the 10th pin of the driving chip IC4;

[0036] The negative pole of the diode D4 is connected to the 1st pin of the inductor L3, the positive pole is connected to the ground wire, one end of the capacitor C12 is connected to the 2nd pin of the inductor L3, the other end is connected to the ground wire, and the 2nd pin of the inductor L3 is connected to the external LED lamp beads.

[0037] The 5V power supply powers the temperature sensor, the comparator, the main controller, and the PWM driver;

[0038] The VCC power supply powers the LED driver.

[0039] The temperature sensor (PT100) can monitor the temperature of the isolated flyback conversion circuit in real time. The temperature signal is transmitted to the comparator (LM358) and compared with the preset temperature threshold. The comparison result is transmitted to the main controller (98C2051). In this embodiment, the main controller can output a PWM signal through the PWM driver (TC4420) according to the temperature signal to adjust the working state of the LED driver (LM3409) and control the brightness of the LED lamp.

[0040] The PFC circuit consists of a PFC chip and its peripheral circuits. The model of the PFC chip is NCP1654. The model of the 5V voltage regulator is LM7805. The model of the temperature sensor is PT100. The model of the comparator is LM358. The model of the main controller is 98C2051. The model of the power supply chip IC1 is LNK306. The model of the driver chip IC4 is LM3409. The model of the driver chip IC3 is TC4420.

[0041] The LED street lamp driving power supply of the present utility model solves the technical problems of high-efficiency energy conversion of the LED power supply and temperature detection of the driving power supply. The present utility model adopts the design of a PFC circuit plus an isolated flyback conversion circuit, which improves the power factor, thereby improving the power utilization efficiency, reducing the power grid load, and providing a stable VCC power supply to ensure the normal operation of the subsequent circuits. The present utility model adds a temperature detection channel. A comparator is used to detect the real-time temperature of the heating elements in the isolated flyback conversion circuit, and the LED lamp can be dimmed in combination with the LED driver, thereby achieving a cooling effect, protecting the heating elements in the isolated flyback conversion circuit, and improving the service life. The present utility model has low cost, strong reliability, and simple maintenance.

Claims

1. An LED street lamp driving power supply, characterized in that: It includes a PFC circuit, an isolated flyback conversion circuit, a 5V voltage regulator, a temperature sensor, a comparator, a main controller, a PWM driver, and an LED driver. The input terminal of the PFC circuit is connected to the mains power supply, and the output terminal outputs the VIN power supply. The input terminal of the isolated flyback conversion circuit is connected to the VIN power supply, and the output terminal outputs the VCC power supply. The input terminal of the 5V voltage regulator is connected to the VCC power supply, and the output terminal outputs the 5V power supply; The temperature sensor is used to collect the temperature of the isolated flyback conversion circuit. The temperature sensor is connected to the comparator, the comparator is connected to the main controller. The input terminal of the PWM driver is connected to an IO port of the main controller, the output terminal of the PWM driver is connected to the LED driver, and the LED driver is connected to an external LED string; The 5V power supply supplies power to the temperature sensor, the comparator, the main controller, and the PWM driver; The VCC power supply supplies power to the LED driver.

2. The LED street lamp driving power supply according to claim 1, characterized in that: The PFC circuit is composed of a PFC chip and its peripheral circuit. The model of the PFC chip is NCP1654. The model of the 5V voltage regulator is LM7805. The model of the temperature sensor is PT100. The model of the comparator is LM358. The model of the main controller is 98C2051.

3. The LED street lamp driving power supply according to claim 1, wherein: The isolated flyback conversion circuit includes a power chip IC1, a resistor R2, a capacitor C1, an inductor L1, a capacitor C2, a capacitor C3, a resistor R1, a resistor R5, a capacitor C5, a diode D1, a diode D2, an inductor L2, a capacitor C6, and a resistor R7. The D terminal of the power chip IC1 is connected to one end of the resistor R2 through the inductor L1. The other end of the resistor R2 is connected to the VIN power supply. The connection node of the resistor R2 and the inductor L1 is connected to the ground wire through the capacitor C1. The FB terminal of the power chip IC1 is connected to the negative electrode of the diode D2 through the resistor R1, and the BP terminal is connected to the S terminal of the power chip IC1 through the capacitor C3. The S terminal of the power chip IC1 outputs the VCC power supply through the inductor L2 and is connected to the positive electrode of the diode D2. The S terminal of the power chip IC1 is also connected to the negative electrode of the diode D1. The positive electrode of the diode D1 is connected to the ground wire. The connection node of the resistor R1 and the FB terminal of the power chip IC1 is also connected to one end of the resistor R5. The other end of the resistor R5 is connected to the S terminal of the power chip IC1. The negative electrode of the diode D2 is also connected to the S terminal of the power chip IC1 through the capacitor C5. One end of the capacitor C6 is connected to the positive electrode of the diode D2, and the other end is connected to the ground wire. The resistor R7 is connected in parallel with the capacitor C6.

4. The LED street lamp driving power supply according to claim 3, wherein: The model of the power chip IC1 is LNK306.

5. The LED street lamp driving power supply according to claim 1, characterized in that: The 5V voltage regulator includes a voltage regulation chip IC2, capacitors C8, C10, C11, C13, and C14. The IN terminal of the voltage regulation chip IC2 is connected to the VCC power supply, the GND terminal is connected to the ground wire, and the OUT terminal outputs the 5V power supply. The capacitors C10 and C11 are filtering capacitors for the 5V power supply. The capacitors C13 and C14 are high-frequency filtering capacitors for the 5V power supply.

6. An LED street lamp driving power supply according to claim 1, characterized in that: The PWM driver includes a driving chip IC3, and the LED driver includes a driving chip IC4, a resistor R4, a resistor R3, a resistor R9, a capacitor C4, a resistor R6, a capacitor C7, a capacitor C9, a resistor R10, a resistor R8, a diode D3, a field effect transistor Q1, a diode D4, an inductor L3, and a capacitor C12. The pin 2 of the driving chip IC3 is connected to an IO port of the main controller, the pins 1 and 8 are connected to the 5V power supply, the pins 4 and 5 are connected to the ground wire, and the pins 7 and 6 are connected to the pin 3 of the driving chip IC4. The pin 1 of the driving chip IC4 is connected to the ground wire through the resistor R4, the pin 4 is connected to the VCC power supply through the resistor R3, and the pin 5 is connected to the ground wire. The pin 4 of the driving chip IC4 is also connected to the ground wire through the capacitor C4, and the pin 4 of the driving chip IC4 is also connected to the pin 2 of the inductor L3 through the resistor R9. The pin 6 of the driving chip IC4 is connected to the G pole of the field effect transistor Q1 through the resistor R10. The positive pole of the diode D3 is connected to the pin 6 of the driving chip IC4, and the negative pole is connected to the G pole of the field effect transistor Q1. The S pole of the field effect transistor Q1 is connected to the pin 7 of the driving chip IC4, and the D pole is connected to the pin 1 of the inductor L3. The pin 8 of the driving chip IC4 is connected to the pin 7 of the driving chip IC4 through the resistor R8. The pin 8 of the driving chip IC4 is also connected to the VCC power supply, the pin 9 is connected to the VCC power supply through the capacitor C7, the pin 10 is connected to the VCC power supply, and the resistor R6 is connected between the pin 1 and the pin 10 of the driving chip IC4. The negative pole of the diode D4 is connected to the pin 1 of the inductor L3, and the positive pole is connected to the ground wire. One end of the capacitor C12 is connected to the pin 2 of the inductor L3, and the other end is connected to the ground wire. The pin 2 of the inductor L3 is connected to an external LED lamp bead.

7. The LED street lamp driving power supply according to claim 6, characterized in that: The model of the driving chip IC4 is LM3409, and the model of the driving chip IC3 is TC4420.

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