A high-power constant current source system with positive feedback and short-circuit protection function

Abstract

The utility model provides a high-power constant current source system with positive feedback and short-circuit protection function, which belongs to the field of electronic circuit technology, including: a DC power supply unit, a main circuit BUCK regulating circuit unit, a protection cutoff circuit unit, a main control unit, a real-time current sampling circuit unit, and a load unit; the DC power supply unit, the protection cutoff circuit unit, the main control unit, and the real-time current sampling circuit unit are respectively connected to the main circuit BUCK regulating circuit unit, and the real-time current sampling circuit unit is also respectively connected to the protection cutoff circuit unit and the main control unit. The utility model is applied to a high-power battery (lead-acid, various lithium batteries) charging system, and the duty cycle of the main circuit BUCK regulating circuit unit is adjusted by real-time sampling current signals to the main control unit so that the main circuit BUCK regulating circuit unit outputs a constant current to power the load.

Description

Technical Field

[0001] The utility model belongs to the technical field of electronic circuits, and in particular relates to a high-power constant current source system with positive feedback and short-circuit protection functions. Background Art

[0002] Buck regulator circuit usually refers to the entire circuit design of the buck converter, which is a DC-DC step-down converter used to convert a higher input voltage to a lower output voltage. Buck regulator circuits are widely used in the field of power management, especially in situations where high efficiency and adjustable output voltage are required.

[0003] Currently, the existing technology lacks a circuit system with accurate, safe and reliable current control in the battery charging system used in the "emergency lighting centralized power supply". Utility Model Content

[0004] The purpose of the utility model is to provide a fire emergency lamp driving circuit system with fault type detection. The utility model aims to solve the problem in the prior art of lacking real-time adjustment of the duty cycle of the BUCK circuit to achieve constant current and setting a threshold to cut off the BUCK circuit.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A high-power constant current source system with positive feedback and short-circuit protection function, used for supplying power to a constant current load, comprises: a DC power supply unit, a main loop BUCK regulating circuit unit, a protection cut-off circuit unit, a main control unit, a real-time current sampling circuit unit, and a load unit; the DC power supply unit, the protection cut-off circuit unit, the main control unit, and the real-time current sampling circuit unit are respectively connected to the main loop BUCK regulating circuit unit, and the real-time current sampling circuit unit is also respectively connected to the protection cut-off circuit unit and the main control unit;

[0007] The real-time current sampling circuit unit is used to perform current sampling on the regulating current of the main loop BUCK regulating circuit unit, and send the current value of the current sampling to the main control unit;

[0008] The main control unit receives the current signal of the real-time current sampling circuit unit and compares it with the preset current set internally. The main control unit achieves the constant current by reversely adjusting the duty cycle of the BUCK circuit.

[0009] As a preferred solution of the utility model, the protection cutoff circuit unit also receives the current value collected by the real-time current sampling circuit unit. The protection cutoff circuit unit is used to judge the size of the current value collected by the real-time current sampling circuit unit and the maximum threshold value. If the current signal of the real-time current sampling circuit unit is less than the maximum threshold value, the main loop BUCK regulation circuit works normally. If the current signal of the real-time current sampling circuit unit is greater than the maximum threshold value, the protection cutoff circuit unit directly shuts down the main loop BUCK regulation circuit unit through the hardware circuit.

[0010] As a preferred solution of the utility model, the real-time current sampling circuit unit converts the collected current value signal into a voltage signal that can be recognized by the main control unit.

[0011] As a preferred solution of the utility model, the main loop BUCK regulation circuit unit includes a chip U9, a diode VD9, a diode VD10, a diode VD11, a resistor R62, a resistor R60, a parasitic diode M8, a parasitic diode M9, a resistor R61, a capacitor C28, an inductor L4, and a capacitor E14. A diode VD9 is connected between the VCC terminal and the VB terminal of the chip U9, the diode VD11 is connected in parallel with the resistor R62 and connected to the HO terminal of the chip U9, and the diode VD10 is connected in parallel with the resistor R60 and connected to the LO terminal of the chip U9.

[0012] As a preferred solution of the utility model, the G pole of the parasitic diode M8 is electrically connected to the other end of the diode VD11 and the resistor R62 in parallel, the D pole of the parasitic diode M8 is connected to the VS end of the chip U9, and the VS end of the chip U9 is also connected to the positive electrode of the capacitor E14 through the series inductor L4. A resistor R61 is connected in series between the G pole and the D pole of the parasitic diode M9, the D pole of the parasitic diode M9 is grounded GND, and the D pole of the parasitic diode M8 is connected to the S pole of the parasitic diode M9.

[0013] As a preferred solution of the utility model, the real-time current sampling circuit unit is composed of a chip U10, a capacitor C30, a capacitor C31, a resistor R63, a capacitor C32, and a capacitor C29. The capacitor C29 is connected in parallel with the capacitor C30 and then connected to pin 8 of the chip U10. The pin 8 of the chip U10 is also electrically connected to a 5V power supply. The pin 6 of the chip U10 is connected in series with the capacitor C31 and then to ground GND. The pins 1 and 2 of the chip U10 are short-circuited and electrically connected to the positive electrode of the capacitor E14. The pins 3 and 4 of the chip U10 are short-circuited and then connected in series with two diodes VD12 respectively and then connected to the battery end.

[0014] As a preferred solution of the utility model, pin 1 and pin 2 and pin 3 and pin 4 of the chip U10 are short-circuited to serve as the input side of current collection, pin 7 of the chip U10 is connected in series with resistor R63 and capacitor C32 and then grounded to GND, and pin 5 of the chip U10 is grounded to GND.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] By designing a high-power constant current source system with positive feedback and short-circuit protection function, the high current signal is converted into a voltage signal that can be recognized by the main control unit; the main control unit adjusts the duty cycle of the BUCK circuit in real time through an algorithm to achieve constant current; the maximum circuit current threshold is set inside the protection cut-off circuit unit, and the circuit is directly cut off when the threshold is exceeded. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 This is the overall circuit architecture diagram of a high-power constant current source system with positive feedback and short-circuit protection function of the utility model;

[0019] Figure 2 The utility model discloses a circuit diagram of a main loop BUCK regulating circuit unit and a real-time current sampling circuit unit of a high-power constant current source system with positive feedback and short-circuit protection function. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the utility model in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] Example

[0022] See also Figure 1-2 , the utility model provides the following technical solutions:

[0023] A high-power constant current source system with positive feedback and short-circuit protection function is used to supply power to a constant current load, and is characterized in that it includes: a DC power supply unit, a main loop BUCK regulating circuit unit, a protection cutoff circuit unit, a main control unit, a real-time current sampling circuit unit, and a load unit; the DC power supply unit, the protection cutoff circuit unit, the main control unit, and the real-time current sampling circuit unit are respectively connected to the main loop BUCK regulating circuit unit, and the real-time current sampling circuit unit is also respectively connected to the protection cutoff circuit unit and the main control unit; the real-time current sampling circuit unit is used to sample the regulating current of the main loop BUCK regulating circuit unit, and send the current value of the current sampling to the main control unit; the main control unit receives the current signal of the real-time current sampling circuit unit and compares it with the preset current set internally, and the main control unit achieves the constant current by reversely adjusting the duty cycle of the BUCK circuit.

[0024] Specifically, the protection cutoff circuit unit also receives the current value collected by the real-time current sampling circuit unit. The protection cutoff circuit unit is used to determine the magnitude of the current value collected by the real-time current sampling circuit unit and the maximum threshold value. If the current signal of the real-time current sampling circuit unit is less than the maximum threshold value, the main loop BUCK regulating circuit works normally. If the current signal of the real-time current sampling circuit unit is greater than the maximum threshold value, the protection cutoff circuit unit directly shuts down the main loop BUCK regulating circuit unit through the hardware circuit. The real-time current sampling circuit unit converts the collected current value signal into a signal that can be recognized by the main control unit. The voltage signal of the main loop BUCK regulation circuit unit includes chip U9, diode VD9, diode VD10, diode VD11, resistor R62, resistor R60, parasitic diode M8, parasitic diode M9, resistor R61, capacitor C28, inductor L4, capacitor E14, diode VD9 is connected between the VCC terminal and the VB terminal of chip U9, diode VD11 is connected in parallel with resistor R62 and connected to the HO terminal of chip U9, diode VD10 is connected in parallel with resistor R60 and connected to the LO terminal of chip U9, and the G pole of parasitic diode M8 is electrically connected to diode The other end of the tube VD11 is connected in parallel with the resistor R62, the D pole of the parasitic diode M8 is connected to the VS end of the chip U9, and the VS end of the chip U9 is also connected to the positive pole of the capacitor E14 through the series inductor L4. A resistor R61 is connected in series between the G pole and the D pole of the parasitic diode M9, the D pole of the parasitic diode M9 is grounded GND, and the D pole of the parasitic diode M8 is connected to the S pole of the parasitic diode M9. The real-time current sampling circuit unit is composed of the chip U10, the capacitor C30, the capacitor C31, the resistor R63, the capacitor C32, and the capacitor C29. After the capacitor C29 is connected in parallel with the capacitor C30 Connected to pin 8 of chip U10, pin 8 of chip U10 is also electrically connected to a 5V power supply, pin 6 of chip U10 is connected in series with capacitor C31 and then grounded GND, pin 1 and pin 2 of chip U10 are short-circuited and electrically connected to the positive electrode of capacitor E14, pin 3 and pin 4 of chip U10 are short-circuited and two diodes VD12 are connected in series respectively and then connected to the battery end, pin 1 and pin 2 of chip U10 and pin 3 and pin 4 are short-circuited and serve as the input side of current collection, pin 7 of chip U10 is connected in series with resistor R63 and capacitor C32 in sequence and then grounded GND, and pin 5 of chip U10 is grounded GND.

[0025] In specific applications, the main circuit current of this system flows from the left DC power supply through the main circuit BUCK regulating circuit unit to adjust the current size, and then flows to the load through the real-time current sampling circuit unit. The main control unit receives the current size collected by the real-time current sampling circuit unit, and compares it with the preset current, and continuously reverses the duty cycle of the main circuit BUCK regulating circuit unit to achieve constant current. The protection cutoff circuit unit can also collect the current size. When it is found that the current exceeds the preset maximum threshold, the main circuit BUCK regulating circuit unit is directly closed through the hardware circuit for short-circuit protection.

[0026] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A high-power constant current source system with positive feedback and short-circuit protection function, used to supply power to a constant current load, characterized in that: include: A DC power supply unit, a main loop BUCK regulating circuit unit, a protection cut-off circuit unit, a main control unit, a real-time current sampling circuit unit, and a load unit; the DC power supply unit, the protection cut-off circuit unit, the main control unit, and the real-time current sampling circuit unit are respectively connected to the main loop BUCK regulating circuit unit, and the real-time current sampling circuit unit is also respectively connected to the protection cut-off circuit unit and the main control unit; The real-time current sampling circuit unit is used to perform current sampling on the regulating current of the main loop BUCK regulating circuit unit, and send the current value of the current sampling to the main control unit; The main control unit receives the current signal of the real-time current sampling circuit unit and compares it with the preset current set internally. The main control unit achieves the constant current by reversely adjusting the duty cycle of the BUCK circuit.

2. A high-power constant current source system with positive feedback and short-circuit protection function according to claim 1, characterized in that: The protection cutoff circuit unit also receives the current value collected by the real-time current sampling circuit unit. The protection cutoff circuit unit is used to judge the magnitude between the current value collected by the real-time current sampling circuit unit and the maximum threshold value. If the current signal of the real-time current sampling circuit unit is less than the maximum threshold value, the main loop BUCK regulation circuit works normally. If the current signal of the real-time current sampling circuit unit is greater than the maximum threshold value, the protection cutoff circuit unit directly shuts down the main loop BUCK regulation circuit unit through a hardware circuit.

3. A high-power constant current source system with positive feedback and short-circuit protection function according to claim 2, characterized in that: The real-time current sampling circuit unit converts the collected current value signal into a voltage signal that can be identified by the main control unit.

4. A high-power constant current source system with positive feedback and short-circuit protection function according to claim 3, characterized in that: The main loop BUCK regulation circuit unit includes a chip U9, a diode VD9, a diode VD10, a diode VD11, a resistor R62, a resistor R60, a parasitic diode M8, a parasitic diode M9, a resistor R61, a capacitor C28, an inductor L4, and a capacitor E14. A diode VD9 is connected between the VCC terminal and the VB terminal of the chip U9. The diode VD11 is connected in parallel with the resistor R62 and connected to the HO terminal of the chip U9. The diode VD10 is connected in parallel with the resistor R60 and connected to the LO terminal of the chip U9.

5. A high-power constant current source system with positive feedback and short-circuit protection function according to claim 4, characterized in that: The G pole of the parasitic diode M8 is electrically connected to the other end of the diode VD11 and the resistor R62 in parallel, the D pole of the parasitic diode M8 is connected to the VS end of the chip U9, and the VS end of the chip U9 is also connected to the positive electrode of the capacitor E14 through the series inductor L4. A resistor R61 is connected in series between the G pole and the D pole of the parasitic diode M9, the D pole of the parasitic diode M9 is grounded GND, and the D pole of the parasitic diode M8 is connected to the S pole of the parasitic diode M9.

6. A high-power constant current source system with positive feedback and short-circuit protection function according to claim 5, characterized in that: The real-time current sampling circuit unit is composed of a chip U10, a capacitor C30, a capacitor C31, a resistor R63, a capacitor C32, and a capacitor C29. The capacitor C29 is connected in parallel with the capacitor C30 and then connected to pin 8 of the chip U10. The pin 8 of the chip U10 is also electrically connected to a 5V power supply. The pin 6 of the chip U10 is connected in series with the capacitor C31 and then to ground GND. The pins 1 and 2 of the chip U10 are short-circuited and then electrically connected to the positive electrode of the capacitor E14. The pins 3 and 4 of the chip U10 are short-circuited and then connected in series with two diodes VD12 respectively and then connected to the battery terminal.

7. A high-power constant current source system with positive feedback and short-circuit protection function according to claim 6, characterized in that: Pin 1 and pin 2 and pin 3 and pin 4 of the chip U10 are short-circuited to serve as the input side of current collection, pin 7 of the chip U10 is connected in series with resistor R63 and capacitor C32 in sequence and then grounded to GND, and pin 5 of the chip U10 is grounded to GND.

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