Power supply management circuit of lamp string

Abstract

The utility model relates to the technical field of power supply management, and discloses a power supply management circuit of a light string, comprising an isolation AC-DC circuit which is connected with 220V AC voltage input and outputs 24V DC voltage; the DC-DC circuit is used for converting the input 24V direct current voltage into 5V direct current voltage; the driving circuit is used for controlling PWM signal output and adjusting a load duty ratio to realize light string dimming; according to the utility model, through the design of the isolation AC-DC circuit, 220V alternating current can be converted into 24V direct current, electrical isolation is realized, and safe isolation between power supply input and a subsequent circuit is ensured; through the design of the DC-DC circuit, the stable adjustment of the output voltage is realized, the stable operation of the lamp string is ensured, and the performance reduction or damage of the lamp string caused by voltage fluctuation is avoided; through the design of the driving circuit, the control switch is adopted to control the signal output of the PWM, so that the adjustment of the duty ratio of the load is realized, and the purpose of dimming the lamp string is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply circuits, in particular to the technical field of power supply management circuits for light strings, and specifically to a power supply management circuit for light strings. Background Art

[0002] The power management circuit of the light string mainly includes the input power supply, AC-DC circuit, DC-DC circuit, drive circuit and output load. When designing the power management circuit of the light string, it is necessary to understand the voltage, current requirements and luminous characteristics of the light string, and have sufficient electrical isolation and protection mechanisms to prevent accidents such as electric shock and fire. In summary, the light string power circuit is an important part to ensure the stable operation of the light string. Through reasonable circuit design and component selection, the safety, stability and efficiency of the system can be improved.

[0003] A search revealed patent application number CN200920060274.4, which discloses an LED light string and a power supply correction circuit for the LED light string. The LED light string includes multiple LED luminaires connected in series via wires. The LED light string also includes a power supply correction circuit comprising a bridge rectifier circuit and a filter capacitor. The bridge rectifier circuit includes two input terminals and two output terminals, with the filter capacitor connected in parallel to the two output terminals. The two ends of the wire are connected to the two output terminals, respectively. This utility model can effectively reduce flickering and irregular beating of the LED luminaires, thereby improving the operational stability of the LED light string.

[0004] The current light string power supply circuit lacks electrical isolation protection during the AC to DC conversion process, which can easily cause damage to subsequent circuits or loads, posing a risk of electric shock. In addition, the circuit voltage stability is poor, which reduces the stability of the output voltage and poses a risk of damage to the light string. Therefore, we need to propose a power management circuit for the light string. Utility Model Content

[0005] The purpose of the present utility model is to provide a power management circuit for a light string. Through the design of an isolated AC-DC circuit, 220V alternating current can be converted into 24V direct current, while achieving electrical isolation, ensuring the safe isolation of the power input and subsequent circuits, and reducing the risk of electric shock; through the design of a DC-DC circuit, stable regulation of the output voltage is achieved, which helps to ensure the stable operation of the light string and avoid performance degradation or damage to the light string caused by voltage fluctuations; through the design of a driving circuit, a control switch is used to control the PWM signal output, thereby achieving the adjustment of the load duty cycle, achieving the purpose of dimming the light string, and solving the problems raised in the above background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solutions: a power management circuit for a light string, comprising:

[0007] An isolated AC-DC circuit that receives 220V AC voltage input and outputs 24V DC voltage;

[0008] A DC-DC circuit for converting an input 24V DC voltage into a 5V DC voltage;

[0009] A driving circuit used to control PWM signal output and adjust load duty cycle to achieve light string dimming;

[0010] The isolated AC-DC circuit, DC-DC circuit, and drive circuit are connected in sequence. The isolated AC-DC circuit includes a wiring terminal P1, the DC-DC circuit includes a voltage stabilizing chip U6, and the drive circuit includes a microcontroller U12. Pin 2 of the wiring terminal P1 is electrically connected to pin 7 of the voltage stabilizing chip U6, and pin 1 of the microcontroller U12 is connected to the voltage stabilizing chip U6.

[0011] Preferably, the isolated AC-DC circuit also includes a terminal block U18 connected to a 220V AC voltage and an isolation transformer U17. A fuse U14 and a thermistor R1 are connected between pin 2 of the terminal block U18 and pin 1 of the isolation transformer U17. Pin 1 of the terminal block U18 is connected to pin 2 of the isolation transformer U17. The two ends of the thermistor R1 are respectively connected to a varistor R105 and a capacitor C1. The terminal ends of the varistor R105 and the capacitor C1 are connected between pin 1 of the terminal block U18 and pin 2 of the isolation transformer U17.

[0012] Preferably, capacitors C4 and C5 are connected in parallel between pins 3 and 4 of the isolation transformer U17, one of the terminals of the capacitors C4 and C5 is connected to pin 1 of the terminal P1, and the other terminal of the capacitors C4 and C5 is connected to pin 2 of the terminal P1.

[0013] Preferably, the DC-DC circuit also includes a terminal P2, a capacitor C6 is connected between pins 1 and 8 of the voltage stabilizing chip U6, a resistor R34 is connected to pin 2 of the voltage stabilizing chip U6, and an inductor L3 is connected to pin 8 of the voltage stabilizing chip U6, and the connection terminals of the resistor R34 and the inductor L3 output a 5V DC voltage.

[0014] Preferably, the 4th pin of the voltage stabilizing chip U6 is connected to a capacitor C69 and a resistor R104 arranged in parallel, one terminal of the capacitor C69 and the resistor R104 is connected to a resistor R103, and the other terminal of the capacitor C69 and the resistor R104 is connected to the terminal of the resistor R34 and the inductor L3;

[0015] The connection terminals of the resistor R34 and the inductor L3 are connected to pin 2 of the connection terminal P2, and the grounded capacitor C74 is connected to pin 2 of the connection terminal P2.

[0016] Preferably, a capacitor C75 is connected between pins 6 and 7 of the voltage stabilizing chip U6, pins 5 and 7 of the voltage stabilizing chip U6 are connected, and a capacitor C73 is connected between pins 5 and 6 of the voltage stabilizing chip U6.

[0017] Preferably, pin 1 of the microcontroller U12 is connected to pin 2 of the terminal P2, and pin 3 of the microcontroller U12 is respectively connected to a resistor R13 and a capacitor C14, one end of the resistor R13 is connected to a control switch SW1 and a resistor R14 in sequence, and the resistor R14 is connected to pin 1 of the microcontroller U12.

[0018] Preferably, a resistor R10 and a resistor R11 are connected between pin 1 and pin 4 of the microcontroller U12, and a capacitor C13 and a capacitor C15 arranged in parallel are connected to pin 1 of the microcontroller U12.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] This utility model can convert 220V AC power into 24V DC power through the design of an isolated AC-DC circuit, and at the same time achieve electrical isolation, ensuring the safe isolation of the power input and subsequent circuits, reducing the risk of electric shock; through the design of the DC-DC circuit, stable regulation of the output voltage is achieved, which helps to ensure the stable operation of the light string and avoid performance degradation or damage to the light string caused by voltage fluctuations; through the design of the drive circuit, a control switch is used to control the PWM signal output, thereby realizing the adjustment of the load duty cycle and achieving the purpose of dimming the light string. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a circuit diagram of the isolated AC-DC circuit of the utility model;

[0022] Figure 2 This is a circuit diagram of the DC-DC circuit of the present utility model;

[0023] Figure 3 This is a circuit diagram of the drive circuit of the utility model. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] See also Figure 1-3 The present invention provides a technical solution: a power management circuit for a light string, comprising:

[0026] An isolated AC-DC circuit that receives 220V AC voltage input and outputs 24V DC voltage;

[0027] A DC-DC circuit for converting an input 24V DC voltage into a 5V DC voltage;

[0028] A driving circuit used to control PWM signal output and adjust load duty cycle to achieve light string dimming;

[0029] The isolated AC-DC circuit, DC-DC circuit, and drive circuit are connected in sequence. The isolated AC-DC circuit includes a wiring terminal P1, the DC-DC circuit includes a voltage stabilizing chip U6, and the drive circuit includes a microcontroller U12. Pin 2 of the wiring terminal P1 is electrically connected to pin 7 of the voltage stabilizing chip U6, and pin 1 of the microcontroller U12 is connected to the voltage stabilizing chip U6.

[0030] After the 220V AC voltage is input from the terminal block U18, it is processed by the isolated AC-DC circuit and converted into a 24V DC voltage, which is output from pin 2 of the terminal block P1 to pin 7 of the voltage regulator chip U6. The 24V DC voltage is then converted into a 5V DC voltage through the DC-DC circuit, and the 5V DC voltage is then output to the drive circuit. The output of the PWM signal is controlled by the control switch SW1 to adjust the duty cycle of the load (light string) to achieve the purpose of dimming.

[0031] The isolated AC-DC circuit also includes a terminal block U18 connected to a 220V AC voltage and an isolation transformer U17. A fuse U14 and a thermistor R1 are connected between pin 2 of the terminal block U18 and pin 1 of the isolation transformer U17. Pin 1 of the terminal block U18 is connected to pin 2 of the isolation transformer U17. The two ends of the thermistor R1 are respectively connected to a varistor R105 and a capacitor C1. The terminal ends of the varistor R105 and the capacitor C1 are connected between pin 1 of the terminal block U18 and pin 2 of the isolation transformer U17.

[0032] Pin 1 of terminal block U18 is connected to the L line, and pin 2 of terminal block U18 is connected to the N line. Fuse U14 can prevent components in the circuit from burning out.

[0033] Capacitors C4 and C5 are connected in parallel between pins 3 and 4 of the isolation transformer U17. One of the terminals of the capacitors C4 and C5 is connected to pin 1 of the terminal P1, and the other terminal of the capacitors C4 and C5 is connected to pin 2 of the terminal P1.

[0034] Pin 1 of the wiring terminal P1 is grounded, and pin 2 of the wiring terminal P1 outputs a 24V DC voltage.

[0035] The DC-DC circuit also includes a terminal P2, a capacitor C6 is connected between pins 1 and 8 of the voltage regulator chip U6, a resistor R34 is connected to pin 2 of the voltage regulator chip U6, and an inductor L3 is connected to pin 8 of the voltage regulator chip U6. The connection terminals of the resistor R34 and the inductor L3 output a 5V DC voltage.

[0036] Pin 8 of the voltage regulator chip U6 is connected to a grounded diode D1.

[0037] Pin 4 of the voltage stabilizing chip U6 is connected to a capacitor C69 and a resistor R104 connected in parallel. One terminal of the capacitor C69 and the resistor R104 is connected to a resistor R103. The other terminal of the capacitor C69 and the resistor R104 is connected to the terminal of the resistor R34 and the inductor L3.

[0038] The connection terminals of the resistor R34 and the inductor L3 are connected to pin 2 of the connection terminal P2, and the grounded capacitor C74 is connected to pin 2 of the connection terminal P2.

[0039] A capacitor C75 is connected between pins 6 and 7 of the voltage stabilizing chip U6, pins 5 and 7 of the voltage stabilizing chip U6 are connected, and a capacitor C73 is connected between pins 5 and 6 of the voltage stabilizing chip U6.

[0040] Pin 1 of the microcontroller U12 is connected to pin 2 of the terminal P2, and pin 3 of the microcontroller U12 is respectively connected to a resistor R13 and a capacitor C14. One end of the resistor R13 is connected to a control switch SW1 and a resistor R14 in sequence, and the resistor R14 is connected to pin 1 of the microcontroller U12.

[0041] The resistor R14 is connected to pin 1 of the control switch SW1 , the resistor R13 is connected to pin 2 of the control switch SW1 , and pins 3 and 4 of the control switch SW1 are grounded.

[0042] Resistors R10 and R11 are connected between pins 1 and 4 of the microcontroller U12. Capacitors C13 and C15, arranged in parallel, are connected to pin 1 of the microcontroller U12. The terminals of capacitors C13 and C15 are grounded. Resistor R15 is connected to pin 5 of the microcontroller U12. Resistor R12 is connected to pin 7 of the microcontroller U12.

[0043] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A power management circuit for a light string, characterized in that: include: An isolated AC-DC circuit that receives 220V AC voltage input and outputs 24V DC voltage; A DC-DC circuit for converting an input 24V DC voltage into a 5V DC voltage; A driving circuit used to control PWM signal output and adjust load duty cycle to achieve light string dimming; The isolated AC-DC circuit, DC-DC circuit, and drive circuit are connected in sequence. The isolated AC-DC circuit includes a wiring terminal P1, the DC-DC circuit includes a voltage stabilizing chip U6, and the drive circuit includes a microcontroller U12. Pin 2 of the wiring terminal P1 is electrically connected to pin 7 of the voltage stabilizing chip U6, and pin 1 of the microcontroller U12 is connected to the voltage stabilizing chip U6.

2. The power management circuit for a light string according to claim 1, characterized in that: The isolated AC-DC circuit also includes a terminal block U18 connected to a 220V AC voltage and an isolation transformer U17. A fuse U14 and a thermistor R1 are connected between pin 2 of the terminal block U18 and pin 1 of the isolation transformer U17. Pin 1 of the terminal block U18 is connected to pin 2 of the isolation transformer U17. The two ends of the thermistor R1 are respectively connected to a varistor R105 and a capacitor C1. The terminal ends of the varistor R105 and the capacitor C1 are connected between pin 1 of the terminal block U18 and pin 2 of the isolation transformer U17.

3. The power management circuit for a light string according to claim 2, wherein: Capacitors C4 and C5 are connected in parallel between pins 3 and 4 of the isolation transformer U17. One of the terminals of the capacitors C4 and C5 is connected to pin 1 of the terminal P1, and the other terminal of the capacitors C4 and C5 is connected to pin 2 of the terminal P1.

4. The power management circuit for a light string according to claim 1, wherein: The DC-DC circuit also includes a terminal P2, a capacitor C6 is connected between pins 1 and 8 of the voltage regulator chip U6, a resistor R34 is connected to pin 2 of the voltage regulator chip U6, and an inductor L3 is connected to pin 8 of the voltage regulator chip U6. The connection terminals of the resistor R34 and the inductor L3 output a 5V DC voltage.

5. The power management circuit for a light string according to claim 4, characterized in that: Pin 4 of the voltage stabilizing chip U6 is connected to a capacitor C69 and a resistor R104 connected in parallel. One terminal of the capacitor C69 and the resistor R104 is connected to a resistor R103. The other terminal of the capacitor C69 and the resistor R104 is connected to the terminal of the resistor R34 and the inductor L3. The connection terminals of the resistor R34 and the inductor L3 are connected to pin 2 of the connection terminal P2, and the grounded capacitor C74 is connected to pin 2 of the connection terminal P2.

6. The power management circuit for a light string according to claim 5, characterized in that: A capacitor C75 is connected between pins 6 and 7 of the voltage stabilizing chip U6, pins 5 and 7 of the voltage stabilizing chip U6 are connected, and a capacitor C73 is connected between pins 5 and 6 of the voltage stabilizing chip U6.

7. The power management circuit for a light string according to claim 6, characterized in that: Pin 1 of the microcontroller U12 is connected to pin 2 of the terminal P2, and pin 3 of the microcontroller U12 is respectively connected to a resistor R13 and a capacitor C14. One end of the resistor R13 is connected to a control switch SW1 and a resistor R14 in sequence, and the resistor R14 is connected to pin 1 of the microcontroller U12.

8. The power management circuit for a light string according to claim 7, characterized in that: Resistors R10 and R11 are connected between pins 1 and 4 of the microcontroller U12 , and capacitors C13 and C15 arranged in parallel are connected to pin 1 of the microcontroller U12 .

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