CN215344400U

CN215344400U - Ultra-low voltage power supply circuit for network monitoring equipment

Info

Publication number: CN215344400U
Application number: CN202121589692.XU
Authority: CN
Inventors: 冯秋忠; 陈飞; 吴少勇; 邹长辉
Original assignee: Fujian Sanmei Guangdiao Electronic Technology Co ltd
Current assignee: Fujian Sanmei Guangdiao Electronic Technology Co ltd
Priority date: 2021-07-13
Filing date: 2021-07-13
Publication date: 2021-12-28
Anticipated expiration: 2031-07-13

Abstract

The utility model discloses an extra-low voltage power supply circuit for network monitoring equipment, which comprises an input rectifying circuit, a drive IC and a voltage stabilizing tube, wherein VSEN and VSEND pins of the drive IC are connected with a VIN pin of the voltage stabilizing tube through a resistor R6 and an inductor L1, and the VSEN and VSEND pins of the drive IC are also provided with a fly-wheel diode D3 and are connected with a power output end; a VDD pin of the driving IC is provided with a fly-wheel diode D2 connected with a VIN pin of a voltage stabilizing tube, voltage feedback sampling pins FB1 and FB2 of the driving IC are respectively connected with resistors R1 and R2 and resistors R3 and R4, a feedback pin of the voltage stabilizing tube is connected with a resistor R8, the output end of the voltage stabilizing tube is connected with an inductor L2 and a fly-wheel diode D4, and the other ends of the inductor L2 and the fly-wheel diode D4 are respectively connected with the output end of a power supply. The utility model can meet the use requirement of the ultra-low voltage input range, thereby ensuring the safety performance of the monitoring power supply circuit and being very suitable for outdoor monitoring equipment which is installed remotely.

Description

Ultra-low voltage power supply circuit for network monitoring equipment

Technical Field

The utility model relates to the technical field of power supply of monitoring equipment, in particular to an extra-low voltage power supply circuit for network monitoring equipment.

Background

The power supply of the existing monitoring equipment is usually supplied by commercial power, the external power supply line is a 220V line, and the outdoor monitoring equipment installed in the open air has certain danger when in use, so that electric leakage and electric shock accidents are easily caused by aging of electricity or electric wires, irregular installation and wiring and the like.

In order to ensure safety, in the prior art, some monitoring devices directly adopt a direct current power supply below 36V for power supply, but when the direct current power supply below 36V is directly adopted for power supply, the direct current power supply is limited by factors such as line resistance and voltage drop, and cannot provide high-power output for a long distance (such as more than 500m), and the input voltage of the monitoring device installed at the tail end of the long-distance line is seriously reduced, and cannot meet the normal working requirement of the monitoring device, so that the monitoring device cannot be put into practical use.

According to the standard, Extra-Low Voltage (ELV) refers to the highest Voltage that exists between two simultaneously accessible electrically conductive parts without risking humans in the worst case. The safe voltage limit in China is defined as follows: the power frequency effective value is limited to 50V, and the direct current voltage is limited to 120V. The ultra-low voltage range is slightly higher than the voltage of a direct current power supply below 36V, and the safety requirement can be met when the direct current power supply is used.

Therefore, when the ultra-low voltage power supply is used in the circuit, the requirement of safe power utilization can be met; however, due to the adoption of ultra-low voltage power supply, a special power supply circuit needs to be developed for matching, so that a stable power supply can be provided for the monitoring equipment more safely and efficiently.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problems, an object of the present invention is to provide an extra-low voltage power supply circuit for a network monitoring device, which can meet the requirement of the extra-low voltage input range, so as to ensure the safety performance of the monitoring power supply circuit, and the power supply circuit has the functions of current compensation, over-temperature protection and short-circuit protection, and is very suitable for being used by outdoor monitoring devices installed remotely.

In order to achieve the purpose, the utility model adopts the following technical scheme:

an extra-low voltage power supply circuit for network monitoring equipment comprises an input rectifying circuit, a driving IC and a voltage stabilizing tube, wherein the input rectifying circuit is used for converting input alternating current and direct current into direct current for output, and one output end of the input rectifying circuit is connected with a VIN pin of the driving IC; VSEN and VSEND pins of the driving IC are connected with VIN pins of the voltage regulator tube through a resistor R6 and an inductor L1, and are also provided with a freewheeling diode D3 to be connected with a power output end; a VDD pin of the driving IC is provided with a freewheeling diode D2 connected with a VIN pin of the voltage stabilizing tube, voltage feedback sampling pins FB1 and FB2 of the driving IC are respectively connected with resistors R1 and R2, resistors R3 and R4, a feedback pin of the voltage stabilizing tube is connected with a resistor R8, the output end of the voltage stabilizing tube is connected with an inductor L2 and a freewheeling diode D4, and the other ends of the inductor L2 and the freewheeling diode D4 are respectively connected with the output end of a power supply.

Further, the model number of the driving IC is SL 3036.

Further, a filter capacitor EC3 is disposed between the two power output terminals respectively connected to the inductor L2 and the freewheeling diode D4.

Further, a filter capacitor EC1 is disposed between the two output ends of the input rectification circuit.

Furthermore, a voltage stabilizing diode DZ, a bypass capacitor C2 and a voltage limiting resistor R5 are connected to the VDD pin of the driving IC.

Further, a VIN pin of the voltage regulator tube is also connected with a resistor R7.

Further, the voltage input range of the input rectifying circuit is 13-100V alternating current or direct current.

Further, the output voltage of the circuit is direct current 12V, and the maximum output current is 3A.

The utility model has the following beneficial effects:

1. the power supply circuit is provided with the input rectifying circuit, the driving IC, the voltage stabilizing tube and the special IC peripheral circuit, and can meet the use requirement of an extra-low voltage input range, so that the safety performance of the monitoring power supply circuit is ensured.

2. The utility model can control the output voltage and current by the resistance value of the external resistor of the drive IC, and the output voltage and current are not influenced by inductance, input voltage and output voltage; after the voltage is filtered and stabilized again through the rear end of the circuit, the output voltage and current are smoother and more stable; the driving IC can not generate peak average error when working, the chip directly detects the load current, loop compensation or high-voltage side current induction is not needed, and the precision can be greatly improved.

3. The driving IC is matched with the voltage-stabilizing tube for use, the input-output conversion efficiency of the power supply circuit reaches more than 95%, the conversion efficiency is high, and the heating loss of the circuit is less.

Drawings

Fig. 1 is a schematic circuit diagram of an extra-low voltage power supply circuit for a network monitoring device according to the present invention.

Description of reference numerals:

1. an input rectification circuit; 2. a driver IC; 3. and a voltage stabilizing tube.

Detailed Description

The utility model is described in further detail below with reference to the following figures and specific examples:

referring to fig. 1, an extra-low voltage power supply circuit for a network monitoring device includes an input rectification circuit 1, a drive IC2 and a voltage regulator tube 3, the voltage regulator tube 3 adopts a five-terminal voltage regulator tube, the input rectification circuit 1 is used for converting input alternating current and direct current into direct current output, and one output end of the input rectification circuit 1 is connected with a VIN pin (an MOS transistor drain electrode built in an IC) of the drive IC 2; VSEN and VSEND pins of the driving IC2 are connected with a VIN pin (a first pin) of the voltage regulator tube 3 through a resistor R6 and an inductor L1, and a freewheeling diode D3 is further arranged on the VSEN (an inductive current detection pin) and the VSEND pin (an IC built-in MOS source electrode) of the driving IC2 and connected with a power output end; a VDD pin of the driver IC2 is provided with a freewheeling diode D2 connected to a VIN pin of the regulator tube 3, voltage feedback sampling pins FB1 and FB2 of the driver IC2 are connected to resistors R1 and R2 and resistors R3 and R4 respectively, resistors R1, R2, R3 and R4 can adjust output voltage of the driver IC2, a feedback pin (a fourth pin) of the regulator tube 3 is connected to a resistor R8, an output end (a second pin) of the regulator tube 3 is connected to an inductor L2 and a freewheeling diode D4, and the other ends of the inductor L2 and the freewheeling diode D4 are connected to a power output end respectively. And the VIN pin of the voltage regulator tube 3 is also connected with a resistor R7. And a filter capacitor EC3 is arranged between the two power output ends respectively connected with the inductor L2 and the freewheeling diode D4.

The model of the driver IC2 is a commercially available SL3036 power chip, and the applicant is developing a specific driver chip based on the principle of model SL 3036.

And a filter capacitor EC1 is arranged between the two output ends of the input rectifying circuit 1.

And the VDD pin of the driving IC2 is also connected with a voltage-stabilizing diode DZ, a bypass capacitor C2 and a voltage-limiting resistor R5. And a VCC pin of the driving IC2 is connected with a bypass capacitor C3.

The voltage input range of the input rectifying circuit 1 is 13-100V alternating current or direct current. The output voltage of the circuit is direct current 12V, and the maximum output current is 3A.

The power supply circuit is a simple and efficient bi-stable voltage low-voltage driving circuit, and is a voltage-reducing type constant-voltage and constant-current driving circuit in a current continuous working mode. The method has the characteristics of extremely low standby power consumption, high efficiency, low ripple, excellent bus voltage regulation rate, excellent load regulation rate and the like. The output constant voltage and output constant current functions are supported, a PWM control mode with fixed frequency is adopted, and the typical switching frequency is 140 KHz.

When the load is light, the driving IC2 will automatically reduce the switching frequency to obtain high conversion efficiency. The driver IC2 integrates soft start and over-temperature protection circuit, output short circuit protection, current limiting protection and other functions, and improves system reliability. The input voltage range of the driving IC2 is 13V-80V, voltage reduction resistance-capacitance is not needed, and external and peripheral components are reduced; the power tube is arranged in the power tube, and the output voltage and the output current are externally adjustable.

The drive IC2 adopts a high-voltage endpoint current detection mode, the output voltage and current of the drive module can be set through an external resistor, the drive IC2 integrates an automatic temperature compensation control circuit, when the temperature inside a chip exceeds 150 ℃, the output current is automatically closed inside, the problem that the output current caused by traditional over-temperature protection is too low is avoided, and the loaded device can be reliably protected.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structural changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to other related technical fields, are included in the scope of the present invention.

Claims

1. An extra-low voltage power supply circuit for network monitoring equipment is characterized in that: the input rectification circuit (1) is used for converting input alternating current and direct current into direct current to be output, and one output end of the input rectification circuit (1) is connected with a VIN pin of the drive IC (2); VSEN and VSEND pins of the driving IC (2) are connected with a VIN pin of the voltage regulator tube (3) through a resistor R6 and an inductor L1, and the VSEN and VSEND pins of the driving IC (2) are also provided with a freewheeling diode D3 to be connected with a power output end; a VDD pin of the driving IC (2) is provided with a freewheeling diode D2 and is connected with a VIN pin of the voltage stabilizing tube (3), voltage feedback sampling pins FB1 and FB2 of the driving IC (2) are respectively connected with resistors R1 and R2, resistors R3 and R4, a feedback pin of the voltage stabilizing tube (3) is connected with a resistor R8, the output end of the voltage stabilizing tube (3) is connected with an inductor L2 and a freewheeling diode D4, and the other ends of the inductor L2 and the freewheeling diode D4 are respectively connected with the output end of a power supply.

2. An extra-low voltage power supply circuit for a network monitoring device according to claim 1, characterized in that: the model of the drive IC (2) is SL 3036.

3. An extra-low voltage power supply circuit for a network monitoring device according to claim 1 or 2, characterized in that: and a filter capacitor EC3 is arranged between the two power output ends respectively connected with the inductor L2 and the freewheeling diode D4.

4. An extra-low voltage power supply circuit for a network monitoring device according to claim 1 or 2, characterized in that: and a filter capacitor EC1 is arranged between the two output ends of the input rectifying circuit (1).

5. An extra-low voltage power supply circuit for a network monitoring device according to claim 1 or 2, characterized in that: and the VDD pin of the driving IC (2) is also connected with a voltage stabilizing diode DZ, a bypass capacitor C2 and a voltage limiting resistor R5.

6. An extra-low voltage power supply circuit for a network monitoring device according to claim 1, characterized in that: and the VIN pin of the voltage regulator tube (3) is also connected with a resistor R7.

7. An extra-low voltage power supply circuit for a network monitoring device according to claim 1, characterized in that: the voltage input range of the input rectifying circuit (1) is 13-100V alternating current or direct current.

8. An extra-low voltage power supply circuit for a network monitoring device according to claim 1, characterized in that: the output voltage of the circuit is direct current 12V, and the maximum output current is 3A.