Novel LED driving power supply with stable current and voltage

Abstract

The utility model discloses a novel LED driving power supply with stable current and voltage, comprising an LED driving power supply which comprises an output adjustable constant current control circuit, an input adjustable constant current control circuit, a driving circuit and a constant voltage and constant current control circuit. The output adjustable constant-current control circuit, the input adjustable constant-current control circuit and the constant-voltage constant-current control circuit are all connected with the driving circuit, and the output adjustable constant-current control circuit comprises a CM7805, an R14, an R15, an Ri and a Ci. After the constant-voltage constant-current control circuit is connected with the direct-current power supply, the constant-voltage constant-current control circuit is started to control the input voltage and current, and the adjustable constant-current control circuit connected with the alternating-current power supply sets the input current and the output current within a certain range, so that the voltage stability and the current stability of the driving circuit are ensured, and the normal operation of the LED driving power supply is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of LED drive power supplies, in particular to a new type of LED drive power supply with stable current and voltage. Background Art

[0002] To put it simply, LED driver power supply is actually a type of power supply, but it is a specific power supply. This power supply uses voltage or current to drive the LED to emit light. Therefore, the input part of the LED driver power supply generally includes several parts: industrial frequency AC power, low-voltage DC, high-voltage DC, low-voltage high-frequency AC, etc.; and the output is mostly a constant current source that can change the voltage as the forward voltage drop value of the LED changes. The core components of the LED driver power supply include input filter devices, switch controllers, inductors, MOS switch tubes, feedback resistors, output filter devices, etc. In addition, some driver power supplies also have input overvoltage / undervoltage protection, open circuit protection, overcurrent protection, etc.

[0003] However, the traditional LED driver has the following disadvantages:

[0004] During the use of traditional LED driver power supplies, due to the different models and specifications of the external power supplies connected, it is easy to have excessive input current or insufficient input voltage, which affects the normal operation of the LED driver power supply. Utility Model Content

[0005] The purpose of the utility model is to provide a new type of LED driving power supply with stable current and voltage, so as to solve the problem that the traditional LED driving power supply proposed in the above background technology is prone to excessive input current or insufficient input voltage during use due to different models and specifications of the external power supply connected, thereby affecting the normal operation of the LED driving power supply.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a new type of LED driving power supply with stable current and voltage, including an LED driving power supply, the LED driving power supply including an output adjustable constant current control circuit, an input adjustable constant current control circuit, a driving circuit and a constant voltage constant current control circuit, the output adjustable constant current control circuit, the input adjustable constant current control circuit and the constant voltage constant current control circuit are all connected to the driving circuit, the output adjustable constant current control circuit includes CM7805, R14, R15, Ri and Ci, the input adjustable constant current control circuit includes ES, R11, R12, RF, RL, R13 and AI, and the constant voltage constant current control circuit includes N1, N2, VD1, VD2, C2, L1, C1, C3, R1, R2, R3, C4, R8, VD3, R10, U1, VD4, ICIA, ICIB, R4, U2, R5, C5, R9, R6 and R7.

[0007] Preferably, the 1-end pin of the CM7805 is connected to one end of Ci, the 2-end pin of the CM7805 is connected to one end of R14, the other end of R14 is connected to one end of R15, the other end of R15 and the 3-end pin of CM7805 are both connected to one end of Ri, and the other end of Ri is connected to the other end of Ci. A constant current source circuit can be formed by a three-terminal fixed output integrated voltage regulator. At this time, the integrated voltage regulator itself works in a suspended state. The resistor R=R14+R15 connected between the output end and the common end of the integrated voltage regulator determines the output current IO of the constant current source. It can be seen from the figure that the current IR flowing through the resistor R=Uo1 / R.

[0008] Preferably, one end of the ES is connected to one end of R11, the other end of the R11 is respectively connected to one end of R12 and one end of AI, the other end of the AI ​​is connected to one end of R13, the other end of the R12 is respectively connected to one end of RL and one end of RF, the other end of RF, the other end of R13 and the other end of ES are all grounded, R12 in the circuit is much larger than Rf, since the inverting input end is a virtual ground and the current at the amplifier input end is very small, it can be considered that the current flowing through R11 all flows to R12, so Es / R1=IL[Rf / (Rf+R2)], so AI is a constant current source independent of the amplifier parameters, the constant current size can be adjusted by adjusting R12, and when RL changes, AI can stabilize itself.

[0009] Preferably, one end of the ICIA is connected to one end of R8 and one end of VD3 respectively, the other end of VD3 is connected to one end of R10 and one end of VD4 respectively, the other end of R10 is connected to one end of U1, the other end of U1 is grounded, the other end of R8 is connected to one end of C4, two ends of the ICIA are connected to the other end of C4, one end of R3 and one end of R2 respectively, the other end of R2 is connected to one end of N2 and one end of R1 respectively, the other end of N2 is connected to one end of VD2, the other end of VD2 is connected to one end of C2 and one end of L1 respectively, the other end of C2 is connected to the end opposite to N2, and the connection between N2 and C2 is connected to one end of N1. The other end of the L1 is connected to one end of the C3, the other end of the C3 and the other end of the R1 are both grounded, the other end of the R3 is connected to one end of the R4, one end of the U2 and one end of the R5, the other end of the R4 and the other end of the U2 are both grounded, the other end of the VD4 is connected to the 7th pin of the ICIB and one end of the R9, the other end of the R9 is connected to one end of the C5, the connection between the R3 and U2 is connected to one end of the R5, the other end of the C5 and the other end of the R5 are both connected to the 6th pin of the ICIB, the 5th pin of the ICIB is connected to one end of the R6 and one end of the R7, The other end of R7 is grounded, the induced voltage of transformer winding N2 is rectified by VD2, and the π filter circuit composed of C2, L1, and C3 obtains a DC output voltage on C3. The purpose of setting the N1 winding is to ensure that IC1 can work normally when the output is short-circuited to ensure the safety of the circuit; the working principle of the constant voltage circuit, U2, ICIB, R6, R7, VD4, R10, U1 form a voltage control loop, U2 is a precision voltage regulator, the cathode K and the control electrode R are directly short-circuited to form a precise 2.5V reference voltage, R4 is the current limiting resistor of U2, and the 2.5V reference voltage is sent to the inverting input terminal 6 of ICIB by resistor R5; and the non-inverting input terminal 5 is set by the voltage divider ratio of R6 and R7. If the output voltage rises, the UR7 circuit The voltage also rises, and this voltage is compared with the 2.5V reference voltage at the inverting end. The error signal is output at pin 7, and then converted into a current signal through VD4 and RIO, flowing into the LED in the optocoupler, and then the duty cycle of the primary PWM output is controlled through the feedback control network, so that the output voltage works in a constant voltage state; the working principle of the constant current circuit: U2, IC1A, R1, R2, VD3, R10, and U1 form a current control loop. R1 is the output current sampling resistor. The output current generates a voltage drop of R1 / IOUT on R1, which is directly sent to the non-inverting input terminal 3 of ICA, and the 2.5V reference voltage is a voltage divider circuit composed of R2 and R3, and then the divided voltage is sent to the inverting input terminal 2. The voltage drop of the output current on R1 is 2.The 5V reference voltage is divided and compared, and the error signal is output from pin 1, which is then converted into a current signal through VD3 and RIO, changing the current in the optocoupler LED, and then controlling the primary side PWM output duty cycle through the feedback control network, so that the output characteristics present a constant current characteristic diagram. R8, C4, R9, and C5 are phase compensation components of IC1A and ICIB respectively.

[0010] Preferably, the drive circuit includes LED, IC1, IC2, R16, R17, R18 and R19, one end of the IC1 is connected to one end of IC2, the other end of the IC2 is connected to the positive electrode of the LED, the surface of the IC1 is connected in parallel with R16, the surface of the IC2 is connected in parallel with R18, the connection between IC1 and R16 is connected to one end of R17, the other end of R17 is connected to the connection between IC2 and R18, the connection between R18 and IC2 is connected to one end of R19, one IC or multiple ICs are used to distribute the voltage, there are few types of electronic components, the power factor and power efficiency are very high, no electrolytic capacitors are required, the life is long, and the cost is low.

[0011] Compared with the prior art, the beneficial effects of the utility model are as follows: by setting an adjustable constant current control circuit and a constant voltage and constant current control circuit, the constant voltage and constant current control circuit is started after being connected to a DC power supply to control the input voltage and current, and the adjustable constant current control circuit is connected to an AC power supply to set the input and output currents within a certain range, thereby ensuring the voltage stability and current stability of the drive circuit and ensuring the normal operation of the LED drive power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a circuit diagram of the LED driving power supply of the utility model;

[0013] Figure 2 The circuit diagram of the utility model output adjustable constant current control circuit;

[0014] Figure 3 The circuit diagram of the utility model input adjustable constant current control circuit;

[0015] Figure 4 This is a circuit diagram of a constant voltage and constant current control circuit of the utility model;

[0016] Figure 5 The utility model is a circuit diagram of a driving circuit.

[0017] In the figure: 1. LED driving power supply; 2. Output adjustable constant current control circuit; 3. Input adjustable constant current control circuit; 4. Driving circuit; 5. Constant voltage constant current control circuit. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0019] See also Figure 1-5 The utility model provides a new type of LED driving power supply with stable current and voltage, including an LED driving power supply 1, the LED driving power supply 1 includes an output adjustable constant current control circuit 2, an input adjustable constant current control circuit 3, a driving circuit 4 and a constant voltage constant current control circuit 5, the output adjustable constant current control circuit 2, the input adjustable constant current control circuit 3 and the constant voltage constant current control circuit 5 are all connected to the driving circuit 4, the output adjustable constant current control circuit 2 includes CM7805, R14, R15, Ri and Ci, the input adjustable constant current control circuit 3 includes ES, R11, R12, RF, RL, R13 and AI, and the constant voltage constant current control circuit 5 includes N1, N2, VD1, VD2, C2, L1, C1, C3, R1, R2, R3, C4, R8, VD3, R10, U1, VD4, ICIA, ICIB, R4, U2, R5, C5, R9, R6 and R7.

[0020] Pin 1 of CM7805 is connected to one end of Ci, pin 2 of CM7805 is connected to one end of R14, the other end of R14 is connected to one end of R15, the other end of R15 and pin 3 of CM7805 are both connected to one end of Ri, and the other end of Ri is connected to the other end of Ci. A constant current source circuit can be formed by a three-terminal fixed output integrated regulator. At this time, the integrated regulator itself works in a suspended state. The resistor R=R14+R15 connected between the output terminal of the integrated regulator and the common terminal determines the output current IO of the constant current source. As can be seen from the figure, the current IR flowing through the resistor R=Uo1 / R.

[0021] One end of ES is connected to one end of R11, the other end of R11 is connected to one end of R12 and one end of AI respectively, the other end of AI is connected to one end of R13, the other end of R12 is connected to one end of RL and one end of RF respectively, the other end of RF, the other end of R13 and the other end of ES are all grounded. In the circuit, R12 is much larger than Rf. Since the inverting input end is a virtual ground and the current at the amplifier input end is very small, it can be considered that the current flowing through R11 all flows to R12, so Es / R1=IL[Rf / (Rf+R2)]. Therefore, AI is a constant current source independent of the amplifier parameters. The constant current can be adjusted by adjusting R12. When RL changes, AI can stabilize itself.

[0022] The 1-end pin of ICIA is connected to one end of R8 and one end of VD3 respectively, the other end of VD3 is connected to one end of R10 and one end of VD4 respectively, the other end of R10 is connected to one end of U1, the other end of U1 is grounded, the other end of R8 is connected to one end of C4, the 2-end pins of ICIA are connected to the other end of C4, one end of R3 and one end of R2 respectively, the other end of R2 is connected to one end of N2 and one end of R1 respectively, the other end of N2 is connected to one end of VD2, the other end of VD2 is connected to one end of C2 and one end of L1 respectively, the other end of C2 is connected to the end opposite to N2, the connection between N2 and C2 is connected to one end of N1, one end of N1 is connected to one end of VD1 and one end of C1 respectively, C The other end of 1 is grounded, the other end of L1 is connected to one end of C3, the other end of C3 and the other end of R1 are both grounded, the other end of R3 is respectively connected to one end of R4, one end of U2 and one end of R5, the other end of R4 and the other end of U2 are both grounded, the other end of VD4 is respectively connected to the 7th pin of ICIB and one end of R9, the other end of R9 is connected to one end of C5, the connection between R3 and U2 is connected to one end of R5, the other end of C5 and the other end of R5 are both connected to the 6th pin of ICIB, The 5 pins of ICIB are connected to one end of R6 and one end of R7 respectively, and the other end of R7 is grounded. The induced voltage of transformer winding N2 is rectified by VD2, and the π filter circuit composed of C2, L1, and C3 obtains a DC output voltage on C3. The purpose of setting the N1 winding is to ensure that IC1 can work normally when the output is short-circuited to ensure the safety of the circuit; the working principle of the constant voltage circuit, U2, ICIB, R6, R7, VD4, R10, U1 form a voltage control loop, U2 is a precision voltage regulator, and the cathode K and control electrode R are directly short-circuited to form a precise 2.5V reference voltage. R4 is the current limiting resistor of U2. The 2.5V reference voltage is sent to the inverting input terminal 6 of ICIB by resistor R5; and the non-inverting input terminal 5 is set by the voltage divider ratio of R6 and R7. If the output voltage rises, the UR7 voltage also rises. This voltage is compared with the inverting terminal 2.5V reference voltage, and the 7th foot outputs an error signal, which is then converted into a current signal through VD4 and RIO, flows into the LED in the optocoupler, and then controls the primary side through the feedback control network. PWM output duty cycle makes the output voltage work in a constant voltage state; constant current circuit working principle: U2, IC1A, R1, R2, VD3, R10, U1 form a current control loop, R1 is the output current sampling resistor, the output current generates a voltage drop of R1 / IOUT on R1, the voltage is directly sent to the in-phase input terminal 3 of ICA, and the 2.5V reference voltage is composed of a voltage divider circuit composed of R2 and R3, and then the divided voltage is sent to the inverting input terminal 2. The voltage drop of the output current on R1 is 2.The 5V reference voltage is divided and compared, and the error signal is output from pin 1, which is then converted into a current signal through VD3 and RIO, changing the current in the optocoupler LED, and then controlling the primary side PWM output duty cycle through the feedback control network, so that the output characteristics present a constant current characteristic diagram. R8, C4, R9, and C5 are phase compensation components of IC1A and ICIB respectively.

[0023] The driving circuit 4 includes an LED, IC1, IC2, R16, R17, R18 and R19, one end of IC1 is connected to one end of IC2, the other end of IC2 is connected to the positive electrode of the LED, the surface of IC1 is connected in parallel with R16, the surface of IC2 is connected in parallel with R18, the connection between IC1 and R16 is connected to one end of R17, the other end of R17 is connected to the connection between IC2 and R18, and the connection between R18 and IC2 is connected to one end of R19. One IC or multiple ICs are used to distribute the voltage, there are few types of electronic components, the power factor and power efficiency are very high, no electrolytic capacitors are required, the life is long, and the cost is low.

[0024] When the embodiment of the present application is used: one or more ICs are used to distribute the voltage, there are few types of electronic components, the power factor and power efficiency are very high, no electrolytic capacitors are required, the life is long, and the cost is low. The induced voltage of the transformer winding N2 is rectified by VD2, and the π filter circuit composed of C2, L1, and C3 obtains a DC output voltage on C3. The purpose of setting the N1 winding is to ensure that IC1 can also work normally when the output is short-circuited to ensure the safety of the circuit; the working principle of the constant voltage circuit, U2, ICIB, R6, R7, VD4, R10, U1 form a voltage control loop, U2 is a precision voltage regulator, the cathode K and the control electrode R are directly short-circuited to form a precise 2.5V reference voltage, R4 is the current limiting resistor of U2, and the 2.5V reference voltage is sent to the inverting input terminal 6 pin of ICIB by resistor R5; and the in-phase input terminal 5 pin is set by the voltage divider ratio of R6 and R7. If the output voltage rises, the UR7 voltage also rises. This voltage is compared with the inverting terminal 2.5V reference voltage, and the 7-pin outputs an error signal, Then it is converted into a current signal through VD4 and RIO, flows into the LED in the optocoupler, and then controls the primary side PWM output duty cycle through the feedback control network, so that the output voltage works in a constant voltage state; the working principle of the constant current circuit: U2, IC1A, R1, R2, VD3, R10, U1 form a current control loop, R1 is the output current sampling resistor, the output current generates a voltage drop of R1 / IOUT on R1, the voltage is directly sent to the in-phase input terminal 3 of ICA, and the 2.5V reference voltage is composed of a voltage divider circuit composed of R2 and R3, and then the divided voltage is sent to the inverting input terminal 2, the voltage drop of the output current on R1 is compared with the 2.5V reference voltage divided voltage, and the error signal is output at pin 1, which is then converted into a current signal through VD3 and RIO to change the current in the optocoupler LED, and then controls the primary side PWM output duty cycle through the feedback control network, so that the output characteristics present a constant current characteristic diagram, R8, C4, R9, C5 are phase compensation components of IC1A and ICIB respectively.

[0025] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A new type of LED driving power supply with stable current and voltage, comprising an LED driving power supply (1), characterized in that: The LED driving power supply (1) comprises an output adjustable constant current control circuit (2), an input adjustable constant current control circuit (3), a driving circuit (4) and a constant voltage constant current control circuit (5); the output adjustable constant current control circuit (2), the input adjustable constant current control circuit (3) and the constant voltage constant current control circuit (5) are all connected to the driving circuit (4); the output adjustable constant current control circuit (2) comprises CM7805, R14, R15, Ri and Ci; the input adjustable constant current control circuit (3) comprises ES, R11, R12, RF, RL, R13 and AI; and the constant voltage constant current control circuit (5) comprises N1, N2, VD1, VD2, C2, L1, C1, C3, R1, R2, R3, C4, R8, VD3, R10, U1, VD4, ICIA, ICIB, R4, U2, R5, C5, R9, R6 and R7.

2. According to claim 1, a new type of LED driving power supply with stable current and voltage, characterized in that: Pin 1 of the CM7805 is connected to one end of Ci, pin 2 of the CM7805 is connected to one end of R14, the other end of R14 is connected to one end of R15, the other end of R15 and pin 3 of the CM7805 are both connected to one end of Ri, and the other end of Ri is connected to the other end of Ci.

3. The new LED driving power supply with stable current and voltage according to claim 1, characterized in that: One end of the ES is connected to one end of R11, the other end of R11 is respectively connected to one end of R12 and one end of AI, the other end of AI is connected to one end of R13, the other end of R12 is respectively connected to one end of RL and one end of RF, and the other end of RF, the other end of R13 and the other end of ES are all grounded.

4. The new LED driving power supply with stable current and voltage according to claim 1, characterized in that: One end of the ICIA is connected to one end of R8 and one end of VD3 respectively, the other end of VD3 is connected to one end of R10 and one end of VD4 respectively, the other end of R10 is connected to one end of U1, the other end of U1 is grounded, the other end of R8 is connected to one end of C4, two ends of the ICIA are connected to the other end of C4, one end of R3 and one end of R2 respectively, the other end of R2 is connected to one end of N2 and one end of R1 respectively, the other end of N2 is connected to one end of VD2, the other end of VD2 is connected to one end of C2 and one end of L1 respectively, the other end of C2 is connected to the end opposite to N2, the connection between N2 and C2 is connected to one end of N1, and the One end is respectively connected to one end of VD1 and one end of C1, the other end of C1 is grounded, the other end of L1 is connected to one end of C3, the other end of C3 and the other end of R1 are both grounded, the other end of R3 is respectively connected to one end of R4, one end of U2 and one end of R5, the other end of R4 and the other end of U2 are both grounded, the other end of VD4 is respectively connected to the 7th pin of ICIB and one end of R9, the other end of R9 is connected to one end of C5, the connection between R3 and U2 is connected to one end of R5, the other end of C5 and the other end of R5 are both connected to the 6th pin of ICIB, the 5th pin of ICIB is respectively connected to one end of R6 and one end of R7, and the other end of R7 is grounded.

5. The new LED driving power supply with stable current and voltage according to claim 1, characterized in that: The driving circuit (4) comprises an LED, IC1, IC2, R16, R17, R18 and R19, one end of the IC1 is connected to one end of the IC2, the other end of the IC2 is connected to the positive electrode of the LED, the surface of the IC1 is connected in parallel with R16, the surface of the IC2 is connected in parallel with R18, the connection between IC1 and R16 is connected to one end of R17, the other end of R17 is connected to the connection between IC2 and R18, and the connection between R18 and IC2 is connected to one end of R19.

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