Novel open circuit detection circuit applied to D4I non-isolated power supply

Abstract

The utility model discloses a novel open circuit detection circuit applied to a D4I non-isolated power supply. The novel open circuit detection circuit comprises a power supply management module, a detection module and an MCU control module. The power supply management module is connected between an external power supply and the lamp and is used for controlling voltage output to the lamp; the detection module is connected between the MCU control module and the power management module, and is used for outputting a first signal to the MCU control module when detecting that the power management module is open-circuited, or outputting a second signal to the MCU control module when detecting that the power management module is not open-circuited; the output end of the MCU control module is connected to the power management module, and can judge open circuit when receiving the first signal, judge not open circuit when receiving the second signal and feed back to the power management module; by means of the structure, open circuit detection can be achieved, the current reading precision is effectively improved, and very good practicability is achieved.

Description

Technical Field

[0001] The utility model relates to the field of power supply circuits and controller circuits, and in particular to a novel open circuit detection circuit applied to a D4I non-isolated power supply. Background Art

[0002] With the development of science and technology, switching power supplies have flourished in the electronics industry, and non-isolated D4I switching power supplies are emerging in an endless stream; open circuit detection of D4I switching power supplies is an issue that all D4I products must strictly control and pay attention to; if the D4I switching power supply does not have open circuit detection, it will not meet the D4I certification requirements. The open circuit detection function of D4I currently used in the industry basically reports an open circuit when no current is detected on the current transformer. The method of using current transformers for open circuit detection has a large deviation in reading current. Considering the accuracy of reading current, the PWM duty cycle can be used to read the current without a large deviation, but there is a problem of open circuit detection; therefore, there is an urgent need for a new open circuit detection circuit applied to D4I non-isolated power supplies to solve the above problems. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a novel open circuit detection circuit applied to a D4I non-isolated power supply.

[0004] The technical solution adopted by an embodiment of the utility model to solve the technical problem is: a new open circuit detection circuit applied to a D4I non-isolated power supply, including a power management module, a detection module and an MCU control module;

[0005] The power management module is connected between the external power supply and the lamp, and is used to control the voltage output to the lamp;

[0006] The detection module is connected between the MCU control module and the power management module, and is used to output a first signal to the MCU control module when it is detected that the power management module is open-circuited, or output a second signal to the MCU control module when it is detected that the power management module is not open-circuited;

[0007] The output end of the MCU control module is connected to the power management module, and can be judged as an open circuit when receiving a first signal, and judged as a non-open circuit when receiving a second signal and fed back to the power management module.

[0008] As one of the preferred embodiments of the utility model, the power management module includes a rectifier bridge BD1, capacitors EC1-EC3, resistors R1-4, MOS tube Q1, diode D1, transformer T1 and power chip U1, the input ends of the rectifier bridge DB1 are respectively connected to L and N of the external power supply, the output end of the rectifier bridge DB1 is respectively connected to the first end of the capacitor EC1, the first end of the resistor R1, the first end of the diode D1, the first end of the capacitor EC3 and one end of the lamp, the second end of the resistor R1 is connected to the first pin of the power chip U1, the second end of the diode D1 is respectively connected to the drain of the MOS tube Q1 and the first end of the transformer T1, and the transformer T The second end of MOS tube Q1 is connected to the second end of capacitor EC3 and the other end of the lamp, the first end of resistor R3 is connected to the third end of transformer T1, the second end of resistor R3 and the first end of resistor R4 are connected to the fourth end of power chip U1, the gate of MOS tube Q1 is connected to the eighth end of power chip U1, the source of MOS tube Q1 is respectively connected to the first end of resistor R2 and the seventh end of power chip U1, the second end of capacitor EC1, the second end of capacitor EC2, the fourth end of transformer T1, the sixth end of power chip U1, the second end of resistor R4, and the second end of resistor R2 are connected to GND terminal together.

[0009] As one of the preferred embodiments of the utility model, the detection module includes resistors R5-6, a diode D2 and a capacitor EC4, the first end of the diode D2 is connected to the third end of the transformer T1 and the first end of the resistor R3, the second end of the diode D2 is connected to the first end of EC4 and the first end of the resistor R5, the second end of the resistor R5 and the first end of the resistor R6 are connected to the MCU control module, and the second end of the capacitor EC4 and the second end of the resistor R6 are connected to the GND end.

[0010] The beneficial effects of the utility model are as follows: a novel open circuit detection circuit applied to a D4I non-isolated power supply comprises a power management module, a detection module and an MCU control module; the power management module is connected between an external power supply and a lamp, and is used to control the voltage output to the lamp; the detection module is connected between the MCU control module and the power management module, and is used to output a first signal to the MCU control module when an open circuit is detected in the power management module, or to output a second signal to the MCU control module when an open circuit is detected in the power management module; the output end of the MCU control module is connected to the power management module, and can judge as an open circuit when a first signal is received, and judge as not an open circuit when a second signal is received and feed back to the power management module; the above structure can realize open circuit detection, and effectively improve the accuracy of reading current, and has very good practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0012] Figure 1 This is a block diagram of a new open circuit detection circuit used in D4I non-isolated power supply;

[0013] Figure 2 The schematic diagram of a new open circuit detection circuit used in D4I non-isolated power supply. DETAILED DESCRIPTION

[0014] This section will describe in detail the specific embodiments of the utility model. The preferred embodiments of the utility model are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the utility model, but it cannot be understood as a limitation on the protection scope of the utility model.

[0015] In the description of the present utility model, the meaning of "more than" is more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0016] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0017] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0018] Reference Figure 1 to Figure 2In the present utility model, the open circuit detection circuit is applied in the D4I non-isolated power supply, and the specific circuit of the D4I non-isolated power supply is not described in detail; the open circuit detection circuit includes a power management module 10, a detection module 20 and an MCU control module 30; the power management module 10 is connected between the external power supply and the lamp, and is used to control the voltage output to the lamp; the detection module 20 is connected between the MCU control module 30 and the power management module 10, and is used to output a first signal to the MCU control module 30 when it is detected that the power management module 10 is open-circuited, or output a second signal to the MCU control module 30 when it is detected that the power management module 10 is not open-circuited; the output end of the MCU control module 30 is connected to the power management module 10, and can be judged as an open circuit when the first signal is received, and judged as not open circuit when the second signal is received and fed back to the power management module 10.

[0019] As a preferred embodiment of the power management module 10, the power management module 10 includes a rectifier bridge BD1, capacitors EC1-EC3, resistors R1-4, MOS tube Q1, diode D1, transformer T1 and power chip U1. The input ends of the rectifier bridge DB1 are respectively connected to L and N of the external power supply. The rectifier bridge DB The output end of 1 is respectively connected to the first end of the capacitor EC1, the first end of the resistor R1, the first end of the diode D1, the first end of the capacitor EC3 and one end of the lamp, the second end of the resistor R1 is connected to the first pin of the power chip U1, the second end of the diode D1 is respectively connected to the drain of the MOS tube Q1 and the first end of the transformer T1, the second end of the transformer T1 is connected to the second end of the capacitor EC3 and the other end of the lamp, the first end of the resistor R3 is connected to the third end of the T1 transformer, the second end of the resistor R3 and the first end of the resistor R4 are connected to the fourth end of the power chip U1, the gate of the MOS tube Q1 is connected to the eighth end of the power chip U1, the source of the MOS tube Q1 is respectively connected to the first end of the resistor R2 and the seventh end of the power chip U1, the second end of the capacitor EC1, the second end of the capacitor EC2, the fourth end of the transformer T1, the sixth end of the power chip U1, the second end of the resistor R4, and the second end of the resistor R2 are commonly connected to the GND end.

[0020] In one embodiment, the detection module 20 includes resistors R5-6, a diode D2 and a capacitor EC4, the first end of the diode D2 is connected to the third end of the transformer T1 and the first end of the resistor R3, the second end of the diode D2 is connected to the first end of EC4 and the first end of the resistor R5, the second end of the resistor R5 and the first end of the resistor R6 are connected to the MCU control module 30, and the second end of the capacitor EC4 and the second end of the resistor R6 are connected to the GND end.

[0021] After the system is powered on and works normally, if the system output is not open at this time, the third end of the transformer T1 outputs a continuous high level, which is then rectified by the diode D2, filtered by the capacitor EC4, and divided by the resistors R5 and R6. When the MCU control module 30 detects a high level (second signal) that lasts for 100ms, it reports that it is not open; if the system output is open at this time, the third end of the transformer T1 outputs intermittent high and low levels, which are then rectified by the diode D2, filtered by the capacitor EC4, and divided by the resistors R5 and R6. When the MCU control module 30 detects a low level (first signal) that lasts for 100ms, it reports that it is open; the advantage of the utility model is that the above structure can not only realize open circuit detection, but also effectively improve the accuracy of reading current, and it has very good practicality.

[0022] Of course, the present invention is not limited to the above-mentioned embodiments, and technicians familiar with the field may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications and substitutions are all included in the scope defined by the claims of this application.

Claims

1. A novel open circuit detection circuit for D4I non-isolated power supply, characterized in that: It comprises a power management module (10), a detection module (20) and an MCU control module (30); The power management module (10) is connected between the external power supply and the lamp, and is used to control the voltage output to the lamp; The detection module (20) is connected between the MCU control module (30) and the power management module (10), and is used to output a first signal to the MCU control module (30) when it is detected that the power management module (10) is open-circuited, or to output a second signal to the MCU control module (30) when it is detected that the power management module (10) is not open-circuited; The output end of the MCU control module (30) is connected to the power management module (10), and can be judged as an open circuit when receiving the first signal, and judged as a non-open circuit when receiving the second signal, and fed back to the power management module (10).

2. According to claim 1, a novel open circuit detection circuit applied to a D4I non-isolated power supply is characterized in that: The power management module (10) comprises a rectifier bridge BD1, capacitors EC1-EC3, resistors R1-4, a MOS tube Q1, a diode D1, a transformer T1 and a power chip U1. The input ends of the rectifier bridge DB1 are respectively connected to L and N of an external power supply. The output end of 1 is respectively connected to the first end of the capacitor EC1, the first end of the resistor R1, the first end of the diode D1, the first end of the capacitor EC3 and one end of the lamp, the second end of the resistor R1 is connected to the first pin of the power chip U1, the second end of the diode D1 is respectively connected to the drain of the MOS tube Q1 and the first end of the transformer T1, the second end of the transformer T1 is connected to the second end of the capacitor EC3 and the other end of the lamp, the first end of the resistor R3 is connected to the third end of the T1 transformer, the second end of the resistor R3 and the first end of the resistor R4 are connected to the fourth end of the power chip U1, the gate of the MOS tube Q1 is connected to the eighth end of the power chip U1, the source of the MOS tube Q1 is respectively connected to the first end of the resistor R2 and the seventh end of the power chip U1, the second end of the capacitor EC1, the second end of the capacitor EC2, the fourth end of the transformer T1, the sixth end of the power chip U1, the second end of the resistor R4, and the second end of the resistor R2 are commonly connected to the GND end.

3. According to claim 2, a novel open circuit detection circuit applied to a D4I non-isolated power supply is characterized in that: The detection module (20) comprises resistors R5-6, a diode D2 and a capacitor EC4, wherein a first end of the diode D2 is connected to a third end of the transformer T1 and a first end of the resistor R3, a second end of the diode D2 is connected to a first end of EC4 and a first end of the resistor R5, a second end of the resistor R5 and a first end of the resistor R6 are connected to the MCU control module (30), and a second end of the capacitor EC4 and a second end of the resistor R6 are connected to a GND end.

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