Power supply power output detection and control circuit

Abstract

The utility model belongs to the technical field of power supply detection, and particularly relates to a power supply power output detection and control circuit which comprises a power supply input unit, a DC-DC power supply unit, an LDO power supply unit, a voltage detection unit, a current detection unit, a main control unit, a dummy load circuit control switch unit, a dummy load and a load control switch unit. The input direct-current power supply voltage is detected through the voltage detection unit, the input direct-current power supply current is detected through the current detection unit, and when the direct-current power supply voltage reaches the starting voltage, the dummy load circuit is controlled through the main control unit to control the switch unit to enable access to the dummy load and detect the on-load output voltage and current, so that the on-load power is obtained. When the voltage of the input direct-current power supply is insufficient or the on-load power is insufficient, the power supply to the load is cut off, and when the electric quantity of the power supply system corresponding to the direct-current power supply to be input is recovered to the capacity capable of working normally, the power is supplied to the load again, so that the load is prevented from working in an unstable state.

Description

TECHNICAL FIELD

[0001] The utility model belongs to power supply detection technical field, especially relate to a power supply power output detection and control circuit. BACKGROUND

[0002] Solar power supply system is an important way of renewable energy utilization, which has a wide application in residential, commercial buildings, remote areas power supply and other fields. With the global attention to environmental problems and the increase of energy demand, solar energy as a clean energy, its research and application gradually become the focus of countries. Solar power supply system has the advantages of environmental protection, renewable, distributed, etc., which can effectively reduce pollutant emissions and damage to the environment, promote sustainable energy development, and reduce the pressure of global climate change.

[0003] Although solar power supply system has many advantages, it also has some shortcomings and limitations, such as only generating electricity during the day, not at night; greatly affected by weather, long-term rain, snow, cloudy, foggy days or even changes in cloud cover will seriously affect the power generation state of the system; low conversion efficiency of solar cells; unstable power supply, which may not provide stable power supply when the battery power is low, especially in rainy weather or at night, the power generation of solar panels will be greatly reduced, resulting in insufficient power supply.

[0004] When the power supply system is unstable and the battery power is low, the powered equipment will be in some unstable working state, such as repeated restart of the equipment, unable to communicate, some high-power peripherals cannot work, etc.; this will cause the power of the power supply system to be consumed until exhausted, and the powered equipment in unstable working state is also prone to damage.

[0005] In order to ensure the stable work of the powered equipment, such as camera, Internet of Things gateway, acquisition equipment, control equipment and other outdoor Internet of Things equipment powered by solar energy, it is necessary to research a power supply power output detection and control circuit to avoid unstable working state of the powered equipment due to power supply problems. INVENTION CONTENTS

[0006] In order to solve the above problems, the utility model provides a power supply power output detection and control circuit. The specific technical scheme is as follows:

[0007] A power supply power output detection and control circuit, comprising: a power input unit, a DC-DC power supply unit, an LDO power supply unit, a voltage detection unit, a current detection unit, a main control unit, a false load circuit control switch unit, a false load, a load control switch unit;

[0008] The power input unit, DC-DC power supply unit, LDO power supply unit and main control unit are connected in sequence.

[0009] The voltage detection unit is connected with the power input unit and the main control unit respectively;

[0010] The current detection unit is connected with the power input unit, the main control unit, the dummy load circuit control switch unit and the load control switch unit respectively;

[0011] The main control unit is connected with the dummy load circuit control switch unit and the load control switch unit respectively, and the dummy load circuit control switch unit is connected with the dummy load;

[0012] The power input unit is used for connecting the direct current input power supply;

[0013] The DC-DC power supply unit is used for converting the direct current input power supply into the first direct current voltage, and the LDO power supply unit is used for converting the first direct current voltage into the second direct current voltage suitable for the operation of the main control unit;

[0014] The voltage detection unit is used for detecting the voltage of the direct current input power supply and inputting the detected voltage into the main control unit;

[0015] The current detection unit is used for detecting the current of the direct current input power supply and inputting the detected current into the main control unit, and supplying power for the dummy load circuit control switch unit and the load control switch unit;

[0016] The main control unit is used for controlling the working state of the dummy load circuit control switch unit and the load control switch unit according to the detected voltage and current, so as to realize the power supply for the load when the voltage and power of the direct current input power supply meet the conditions.

[0017] Preferably, the power input unit comprises a power input seat J2, a bidirectional TVS protection tube D4 and a Schottky diode D3; the power input seat J2 is connected with the direct current input power supply and comprises a first connecting end and a second connecting end; the first connecting end is connected with the anode of the Schottky diode D3 and one end of the bidirectional TVS protection tube D4 respectively; the second connecting end and the other end of the bidirectional TVS protection tube D4 are grounded respectively; and the cathode of the Schottky diode D3 is used as a power output end to output the direct current power supply voltage.

[0018] Preferably, the DC-DC power supply unit comprises a first input filter circuit, a power supply chip, a voltage conversion circuit and a first output filter circuit connected in sequence; the first input filter circuit is configured to filter the DC power supply voltage output by the cathode of the Schottky diode D3 and input the filtered DC power supply voltage to the power supply chip; the power supply chip is configured to step down the filtered DC power supply voltage and input the stepped-down DC power supply voltage to the voltage conversion circuit; the voltage conversion circuit is configured to convert the stepped-down DC power supply voltage into a first DC voltage and input the first DC voltage to the first output filter circuit; and the first output filter circuit is configured to filter the first DC voltage and input the filtered first DC voltage to the LDO power supply unit.

[0019] Preferably, the LDO power supply unit comprises a second input filter circuit, a step-down chip and a second output filter circuit connected in sequence; the second input filter circuit is configured to filter the first DC voltage and input the filtered first DC voltage to the step-down chip; the step-down chip is configured to step down the filtered first DC voltage to obtain a second DC voltage and input the second DC voltage to the second output filter circuit; and the second output filter circuit is configured to filter the second DC voltage and input the filtered second DC voltage to the master control unit.

[0020] Preferably, the voltage detection unit comprises a voltage dividing circuit and an RC filter circuit connected in sequence.

[0021] The voltage dividing circuit is configured to divide the DC power supply voltage output by the cathode of the Schottky diode D3 and input the obtained divided voltage to the RC filter circuit.

[0022] The RC filter circuit is configured to filter the divided voltage and input the filtered divided voltage to the master control unit.

[0023] Preferably, the current detection unit comprises a current detection chip, a first pin of the current detection chip is connected with the resistor R16, a second pin of the current detection chip and the other end of the resistor R16 are grounded respectively; a third pin of the current detection chip is connected with the first DC voltage and one end of the capacitor C15 respectively, the other end of the capacitor C15 is grounded; a fourth pin of the current detection chip is connected with one end of the resistor R18 and the cathode of the Schottky diode D3 respectively; a fifth pin of the current detection chip is connected with the other end of the resistor R18, the dummy load circuit control switch unit and the load control switch unit respectively; a sixth pin of the current detection chip is connected with one end of the resistor R13, the other end of the resistor R13 is connected with one end of the resistor R12, the cathode of the unidirectional TVS diode and the master control unit respectively; the other end of the resistor R12 and the anode of the unidirectional TVS diode are grounded respectively.

[0024] Preferably, the dummy load circuit control switch unit comprises a first NMOS Q4 and a first PMOS Q3, the G poles of the first NMOS Q4 are connected with the master control unit and one end of a resistor R11 respectively, the other end of the resistor R11 is grounded, the S pole of the first NMOS Q4 is grounded, the D pole of the first NMOS Q4 is connected with one end of a resistor R10, the other end of the resistor R10 is connected with one end of a resistor R9, one end of a capacitor C6 and the G pole of the first PMOS Q3 respectively, the S pole of the first PMOS Q3 is connected with the other end of the resistor R9, the other end of the capacitor C6, one end of a capacitor C5 and the current detection unit respectively, the other end of the capacitor C5 is grounded, the D pole of the first PMOS Q3 is connected with one end of a capacitor C7, one end of a resistor R8 and one end of a dummy load resistor R7 respectively, the other end of the capacitor C7 and the other end of the dummy load resistor R7 are grounded respectively, the other end of the resistor R8 is connected with the anode of a light emitting diode D5, and the cathode of the light emitting diode D5 is grounded.

[0025] Preferably, the load control switch unit comprises a second NMOS Q2 and a second PMOS Q1, the G poles of the second NMOS Q2 are connected with the master control unit and one end of a resistor R6 respectively, the other end of the resistor R6 is grounded, the S pole of the second NMOS Q2 is grounded, the D pole of the second NMOS Q2 is connected with one end of a resistor R4, the other end of the resistor R4 is connected with one end of a resistor R3, one end of a capacitor C2 and the G pole of the second PMOS Q1 respectively, the S pole of the second PMOS Q1 is connected with the other end of the resistor R3, the other end of the capacitor C2, one end of a capacitor C1 and the current detection unit respectively, the other end of the capacitor C1 is grounded, the D pole of the second PMOS Q1 is connected with one end of a capacitor C3, one end of a resistor R1 and one end of a load connecting seat J1 respectively, the other end of the capacitor C3 and the other end of the load connecting seat J1 are grounded respectively, the other end of the resistor R1 is connected with the anode of a light emitting diode D1, and the cathode of the light emitting diode D1 is grounded.

[0026] Compared with the prior art, the utility model has the advantages of the following beneficial effects:

[0027] The utility model provides a kind of power power output detection and control circuit, including power input unit, DC-DC power unit, LDO power unit, voltage detection unit, current detection unit, main control unit, dummy load circuit control switch unit, dummy load, load control switch unit;The input DC power voltage is detected by voltage detection unit, the input DC power current is detected by current detection unit, when DC power voltage reaches starting voltage, dummy load circuit control switch unit is enabled to access dummy load by main control unit control, detects load output voltage and current, to obtain load power, when the input DC power voltage is insufficient or load power is insufficient, then cut off to load power supply, when the power supply system corresponding to the input DC power is restored to the capacity that can normally work, load is powered again, avoid the load work to do in unstable state, and certain electric quantity is reserved for power supply system.

[0028] By the utility model connects between power supply system and load, can protect power supply system, not let power supply system be in serious feeder state. Ensure that load can always work in stable state, avoid load to be repeatedly restarted or be in abnormal state due to insufficient electric quantity. The utility model design is simple, and cost is low. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical scheme of the embodiment of the application, the following will be simply introduced to the drawing needed to be used in embodiment description. In all drawings, similar elements or parts are generally identified by similar reference signs. In the drawings, each element or part is not necessarily drawn according to actual proportion.

[0030] Figure 1 It is the principle schematic diagram of the utility model.

[0031] Figure 2 It is the circuit schematic diagram of power input unit.

[0032] Figure 3 It is the circuit schematic diagram of DC-DC power unit.

[0033] Figure 4 It is the circuit schematic diagram of LDO power unit.

[0034] Figure 5 It is the circuit schematic diagram of main control unit.

[0035] Figure 6 It is the circuit schematic diagram of voltage detection unit.

[0036] Figure 7 It is the circuit schematic diagram of current detection unit.

[0037] Figure 8 It is the circuit schematic diagram of dummy load circuit control switch unit.

[0038] Figure 9 Circuit schematic diagram for load control switch unit. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0040] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "top", "bottom", "top surface", "bottom surface", "inner", "outer", "inner side", "outer side" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0041] In the description of the present application, the meaning of several is one or more, and the meaning of multiple is two or more. Greater than, less than, more than, etc. are understood as not including the number, and above, below, etc. are understood as including the number. If the terms "first", "second", "third" are described, they are only for the purpose of description and distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the sequence of indicated technical features.

[0042] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "setting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. The embodiments will be described below according to the overall structure of the present application.

[0043] As Figure 1As shown, the embodiment provides a power supply power output detection and control circuit, which comprises a power input unit, a DC-DC power supply unit, an LDO power supply unit, a voltage detection unit, a current detection unit, a master control unit, a dummy load circuit control switch unit, a dummy load, and a load control switch unit. The power input unit, the DC-DC power supply unit, the LDO power supply unit, and the master control unit are connected in sequence. The voltage detection unit is connected with the power input unit and the master control unit respectively. The current detection unit is connected with the power input unit, the master control unit, the dummy load circuit control switch unit, and the load control switch unit respectively. The master control unit is connected with the dummy load circuit control switch unit and the load control switch unit respectively. The dummy load circuit control switch unit is connected with the dummy load. The power input unit is connected with a direct current input power supply. The load control switch unit is connected with a load.

[0044] The power input unit is used for connecting a direct current input power supply. The DC-DC power supply unit is used for converting the direct current input power supply into a first direct current voltage. The LDO power supply unit is used for converting the first direct current voltage into a second direct current voltage suitable for the working of the master control unit. The voltage detection unit is used for detecting the voltage of the direct current input power supply and inputting the detected voltage into the master control unit. The current detection unit is used for detecting the current of the direct current input power supply and inputting the detected current into the master control unit and supplying power for the dummy load circuit control switch unit and the load control switch unit. The master control unit is used for controlling the working state of the dummy load circuit control switch unit and the load control switch unit according to the detected voltage and current, so as to realize the power supply for the load when the voltage and power of the direct current input power supply meet the conditions.

[0045] The working principle of the utility model is as follows:

[0046] The power input unit is connected with a direct current input power supply. The DC-DC power supply unit converts the direct current input power supply into a first direct current voltage. The LDO power supply unit converts the first direct current voltage into a second direct current voltage suitable for the working of the master control unit to supply power for the master control unit.

[0047] The voltage detection unit detects the voltage of the direct current input power supply and inputs the detected voltage into the master control unit. The current detection unit detects the current of the direct current input power supply and inputs the detected current into the master control unit and supplies power for the dummy load circuit control switch unit and the load control switch unit.

[0048] The master control unit controls the working state of the switch unit and the load control switch unit according to the detected voltage and current, so as to realize power supply for the load when the voltage and power of the DC input power source meet the conditions. When the voltage detected by the voltage detection unit is lower than the set starting voltage, the DC input power source enters dormancy, the load control switch unit is controlled to cut off the connection between the DC input power source and the load, and the load is not powered. When the voltage detected by the voltage detection unit is greater than or equal to the set starting voltage, the master control unit controls the switch unit of the dummy load circuit to connect the dummy load, the load power of the DC input power source is detected by the dummy load, when the load power of the DC input power source is insufficient, the DC input power source enters dormancy again; when it is detected that the load power of the DC input power source is sufficient, the master control unit controls the switch unit of the dummy load circuit to cut off the power supply between the dummy load, controls the load control switch unit to connect the circuit between the load, and opens the load power supply, thereby providing stable power supply for the real load.

[0049] As shown in Figure 2 The power input unit includes a power input seat J2, a bidirectional TVS protection tube D4 and a Schottky diode D3. The power input seat J2 is connected with the DC input power source and includes a first connection end and a second connection end. The first connection end is connected with the anode of the Schottky diode D3 and one end of the bidirectional TVS protection tube D4 respectively. The second connection end and the other end of the bidirectional TVS protection tube D4 are grounded respectively. The cathode of the Schottky diode D3 is used as a power output end to output the DC power voltage. The power input seat J2 can receive the DC input power input of 7V-24V. The model of the bidirectional TVS protection tube D4 can be selected according to the actual input power voltage, which is used for voltage protection, absorbs the transient voltage in the circuit when the power is plugged in, and prevents the high voltage from damaging the sensitive elements in the circuit. The model of the Schottky diode D3 is SS54, which is used to prevent the positive and negative poles of the power supply from being connected reversely. When the power supply is connected reversely, the Schottky diode D3 is cut off, thereby protecting the subsequent circuit. In this embodiment, the DC power voltage is taken as an example for description.

[0050] The DC-DC power unit includes a first input filter circuit, a power chip, a voltage conversion circuit and a first output filter circuit connected in sequence. The first input filter circuit is used to filter the DC power voltage output by the cathode of the Schottky diode D3 and input the filtered DC power voltage to the power chip. The power chip is used to step down the filtered DC power voltage and input the stepped-down DC power voltage to the voltage conversion circuit. The voltage conversion circuit is used to convert the stepped-down DC power voltage into a first DC voltage and input the first DC voltage to the first output filter circuit. The first output filter circuit is used to filter the first DC voltage and input the filtered first DC voltage to the LDO power unit.

[0051] As Figure 3 shown, the first input filter circuit includes capacitors C20, C21, and C22, the power supply chip is ME3116AM6G chip U4, the voltage conversion circuit includes resistors R19, R21, and R22, and the first output filter circuit includes capacitors C17, C18, and C19.

[0052] The fourth pin of the power supply chip is connected to one end of resistor R20, the fifth pin of the power supply chip, the other end of resistor R20, one end of capacitor C20, one end of capacitor C21, and one end of capacitor C22 are respectively connected to the cathode of Schottky diode D3, that is, the cathode of Schottky diode D3 outputs the DC power supply voltage. The sixth pin of the power supply chip is respectively connected to the cathode of diode D7, one end of capacitor C14, and one end of inductor L1, the anode of diode D7 is grounded, the other end of capacitor C14 is connected to the first pin of the power supply chip, the other end of inductor L1 is respectively connected to one end of resistor R19, one end of capacitor C16, one end of capacitor C17, one end of capacitor C18, and one end of capacitor C19, and outputs the first DC voltage as the output end of the DC-DC power supply unit, the other end of resistor R19 and the other end of capacitor C16 are respectively connected to the third pin of the power supply chip and one end of resistor R21, the other end of resistor R21 is connected to one end of resistor R22, the other end of resistor R22, the other end of capacitor C17, the other end of capacitor C18, and the other end of capacitor C19 are respectively grounded.

[0053] The ME3116AM6G chip U4 can provide higher power conversion efficiency and greater output power, and the chip has a wide voltage input range of 4.75-40V, which is suitable for use in scenarios with a large input voltage range. Resistor R20 is the starting resistor of the chip, which enables the power supply chip to start working as soon as it is powered on. Capacitor C14 is the Cboot capacitor of the power supply chip, which has the functions of providing driving voltage, improving efficiency, reducing loss, improving stability and response speed, etc. Diode D7 is an anti-parallel diode used for protecting the switching tube and releasing energy. Capacitor C16 is a feedforward capacitor used for improving the transient response or phase margin of the loop. R19 is Ru, and the sum of R21 and R22 is Rd, and the output first DC voltage Vo = 0.8*(Ru+Rd) / Rd, by adjusting the resistance values of Ru and Rd, the output first DC voltage is configured to be 5V, that is, the DC-DC power supply unit converts the 24V DC power supply voltage to the first DC voltage of 5V.

[0054] The LDO power supply unit comprises a second input filter circuit, a step-down chip and a second output filter circuit connected in sequence; the second input filter circuit is configured to filter the first direct current voltage and input the filtered first direct current voltage to the step-down chip; the step-down chip is configured to step down the filtered first direct current voltage to obtain a second direct current voltage and input the second direct current voltage to the second output filter circuit; and the second output filter circuit is configured to filter the second direct current voltage and input the filtered second direct current voltage to the main control unit.

[0055] As shown in Figure 4 , the second input filter circuit comprises capacitors C8 and C9, the step-down chip is an LDO power supply XC6206P332MR chip U2, and the second output filter circuit comprises capacitors C10, C11 and C12.

[0056] The Vin pin of the step-down chip is connected with one end of the capacitor C8, one end of the capacitor C9 and the output end of the DC-DC power supply unit, and a first direct current voltage of 5V is inputted. The Vout pin of the step-down chip is connected with one end of the capacitor C10, one end of the capacitor C11 and one end of the capacitor C12, and serves as an output end of the LDO power supply unit, outputs a second direct current voltage of 3.3V and supplies power to the main control unit. The other end of the capacitor C8, the other end of the capacitor C9, the GND pin of the step-down chip, the other end of the capacitor C10, the other end of the capacitor C11 and the other end of the capacitor C12 are grounded.

[0057] The LDO power supply XC6206P332MR chip U2 has better power supply ripple and lower static current, is configured to step down a 5V power supply to a 3.3V power supply and provide power supply for the main control unit; C8 and C9 are input filter capacitors, and C10, C11 and C12 are output filter capacitors, which are configured to filter high-frequency noise and ripple in the circuit.

[0058] As shown in Figure 5 , the main control unit comprises an STM32G030F6T6 main control chip U1, uses an ADC interface of a pin PA0 and a pin PA1 to collect a detection current of the current detection unit and a detection voltage of the voltage detection unit. A GPIO output function of a pin PA6 and a pin PA7 is configured to control the output of the rear-stage power supply circuit, that is, an EN-PWR-OUT signal output by the pin PA6 controls the working state of the load control switch unit, and an ENRES-OUT signal output by the pin PA7 controls the working state of the dummy load circuit control switch unit.

[0059] The resistor R2 is a pull-down resistor on the pin BOOT0, so that the pin BOOT0 keeps a default pull-down state during power-on. The capacitor C4 is a capacitor on the reset pin NRST, which pulls down the reset pin NRST during power-on and triggers a reset operation.

[0060] One end of the resistor R5 is connected with the pin PA4, and the other end is connected with the anode of the light emitting diode D2, and the cathode of the light emitting diode D2 is grounded. The resistor R5 and the light emitting diode D2 are the running indicator of the master control unit, which shows the running state of the master control unit. The socket J3 is the download port of the master control chip, and the socket J3 has five connection ends, in which three connection ends are connected with the NRST, SWDIO and SWCLK / BOOT0 of the master control chip U1 respectively, which are used for downloading the firmware, and one of the other two connection ends is grounded, and the other connection end is connected with the second direct current voltage. The socket J4 is the debugging port of the master control chip U1, which has five connection ends, in which four connection ends are connected with the NRST, SWCLK / BOOT0, USART1_RX and USART1_TX of the master control chip U1 respectively, and the other connection end is grounded, which is used for viewing the running log of the master control unit.

[0061] The voltage detection unit comprises a voltage dividing circuit and an RC filter circuit connected in sequence; the voltage dividing circuit is used for dividing the direct current power supply voltage output by the cathode of the Schottky diode D3, and inputting the obtained divided voltage to the RC filter circuit; and the RC filter circuit is used for filtering the divided voltage, and inputting the filtered divided voltage to the master control unit.

[0062] As shown in Figure 6 The voltage dividing circuit comprises a resistor R14 and a resistor R17, and the RC filter circuit comprises a resistor R15 and a capacitor C13. One end of the resistor R14 is connected with the cathode of the Schottky diode D3 of the power input unit, and is connected with the direct current power supply voltage, and the other end of the resistor R14 is connected with one end of the resistor R17 and one end of the resistor R15 respectively, the other end of the resistor R17 is grounded, and the other end of the resistor R15 is connected with one end of the capacitor C13 and the pin PA1 of the master control chip respectively, and the other end of the capacitor C13 is grounded. The resistor R14 and the resistor R17 are the voltage dividing resistors of the input voltage, and after voltage division, the voltage is input to the pin PA1 of the master control chip U1 through the RC filter circuit of the resistor R15 and the capacitor C13 for analog voltage sampling.

[0063] As shown in Figure 7As shown, the current detection unit includes a current detection chip, the first pin of the current detection chip is connected with the resistor R16, the second pin of the current detection chip and the other end of the resistor R16 are grounded respectively; the third pin of the current detection chip is connected with the first direct current voltage and one end of the capacitor C15 respectively, the other end of the capacitor C15 is grounded; the fourth pin of the current detection chip is connected with one end of the resistor R18 and the cathode of the Schottky diode D3 respectively; the fifth pin of the current detection chip is connected with the other end of the resistor R18, the false load circuit control switch unit and the load control switch unit respectively; the sixth pin of the current detection chip is connected with one end of the resistor R13, the other end of the resistor R13 is connected with one end of the resistor R12, the cathode of the unidirectional TVS diode and the main control unit respectively; the other end of the resistor R12 and the anode of the unidirectional TVS diode are grounded respectively.

[0064] The current detection chip is INA199A1DCKR chip U3. The input voltage is input from the fourth pin of U3, and the fifth pin is output. The resistor R18 is a sampling resistor. The current of the direct current power supply voltage VCC-24V passes through the sampling resistor R18, and a pressure difference is generated at both ends of the sampling resistor R18. The pressure difference is output through the sixth pin of the U3 chip. After being divided by the resistors R13 and R12, the analog voltage sampling is output to the pin PA0 of the main control chip U1. D6 is a TVS diode, which protects the input voltage from exceeding the voltage that the pin of the chip U3 can withstand. The reference voltage of the chip U3 is grounded through the resistor R16, and the capacitor C15 is an input filter capacitor.

[0065] As shown in Figure 8 The false load circuit control switch unit includes a first NMOS tube Q4 and a first PMOS tube Q3. The G pole of the first NMOS tube Q4 is connected with the main control unit and one end of the resistor R11 respectively, and the other end of the resistor R11 is grounded. The S pole of the first NMOS tube Q4 is grounded. The D pole of the first NMOS tube Q4 is connected with one end of the resistor R10, and the other end of the resistor R10 is connected with one end of the resistor R9, one end of the capacitor C6 and the G pole of the first PMOS tube Q3 respectively. The S pole of the first PMOS tube Q3 is connected with the other end of the resistor R9, the other end of the capacitor C6, one end of the capacitor C5 and the current detection unit respectively, and the other end of the capacitor C5 is grounded. The D pole of the first PMOS tube Q3 is connected with one end of the capacitor C7, one end of the resistor R8 and one end of the false load resistor R7 respectively, and the other end of the capacitor C7 and the other end of the false load resistor R7 are grounded respectively. The other end of the resistor R8 is connected with the anode of the light emitting diode D5, and the cathode of the light emitting diode D5 is grounded.

[0066] The first NMOS tube Q4 is an NMOS tube 2N7002K, the G terminal of the first NMOS tube Q4 is connected with the pin PA7 of the main control chip U1, and a default pull-down state is provided for the G terminal of the first NMOS tube Q4 by using the resistor R11, so that the G terminal of the first NMOS tube Q4 is not in a floating state. The first PMOS tube Q3 is a high-power PMOS tube AO4407, and the VCC-24-OUT voltage signal output by the 5th pin of the current detection chip is directly connected with the S terminal of the first PMOS tube Q3. The G terminal and the S terminal of the first PMOS tube Q3 are connected through the resistor R9, so that the default voltage of the Vgs of the first PMOS tube Q3 is close to 0, and the first PMOS tube Q3 is in a default state of non-conduction. The resistor R10 is connected between the G terminal of the first PMOS tube Q3 and the D terminal of the first NMOS tube Q4, when the EN-RES-OUT signal output by the pin PA7 of the main control chip U1 is at a high level, the first NMOS tube Q4 is turned on, the resistor R10 is equivalent to being connected with the ground, the voltage signal VCC-24-OUT output by the 5th pin of the current detection chip is divided by the resistor R9 and the resistor R10, and a voltage difference is generated between the Vgs of the first PMOS tube Q3, so that the first PMOS tube Q3 is turned on, and the dummy load resistor R7 is powered. When the EN-RES-OUT signal output by the pin PA7 of the main control chip U1 is at a low level, the first NMOS tube Q4 is turned off, and the voltage signal VCC-24-OUT output by the 5th pin of the current detection chip cannot power the dummy load resistor R7. The resistor R8 and the light-emitting diode D5 are a power indicator lamp of the dummy load resistor; the capacitors C5 and C7 are filter capacitors.

[0067] As shown in Figure 9 The load control switch unit includes a second NMOS tube Q2 and a second PMOS tube Q1. The G terminal of the second NMOS tube Q2 is connected with the main control unit and one end of the resistor R6, respectively, and the other end of the resistor R6 is grounded. The S terminal of the second NMOS tube Q2 is grounded. The D terminal of the second NMOS tube Q2 is connected with one end of the resistor R4, and the other end of the resistor R4 is connected with one end of the resistor R3, one end of the capacitor C2 and the G terminal of the second PMOS tube Q1, respectively. The S terminal of the second PMOS tube Q1 is connected with the other end of the resistor R3, the other end of the capacitor C2, one end of the capacitor C1 and the current detection unit, respectively, and the other end of the capacitor C1 is grounded. The D terminal of the second PMOS tube Q1 is connected with one end of the capacitor C3, one end of the resistor R1 and one end of the load connection seat J1, respectively, and the other end of the capacitor C3 and the other end of the load connection seat J1 are grounded, respectively. The other end of the resistor R1 is connected with the anode of the light-emitting diode D1, and the cathode of the light-emitting diode D1 is grounded.

[0068] The second NMOS tube Q2 is an NMOS tube 2N7002K, the G level of the second NMOS tube Q2 is connected with the pin PA6 of the main control chip U1, and a default pull-down state is given to the G level of the second NMOS tube Q2 by using the resistor R6, so that the G level of the second NMOS tube Q2 is not in a floating state. The second PMOS tube Q1 is a high-power PMOS tube AO4407, and the VCC-24-OUT voltage signal output by the 5th pin of the current detection chip is directly connected with the S level of the second PMOS tube Q1. The G level of the second PMOS tube Q1 is connected with the S level of the second PMOS tube Q1 through the resistor R3, so that the default voltage of the Vgs of the second PMOS tube Q1 is close to 0, and the second PMOS tube Q1 is in a default state of non-conduction. The resistor R4 is connected between the G level of the second PMOS tube Q1 and the D level of the second NMOS tube Q2, when the EN-PWR-OUT signal output by the pin PA6 of the main control chip U1 is at a high level, the second NMOS tube Q2 is turned on, the resistor R4 is equivalent to being connected with the ground, the resistor R3 and the resistor R4 divide the VCC-24-OUT voltage signal output by the 5th pin of the current detection chip, and a voltage difference is generated between the Vgs of the second PMOS tube Q1, so that the second PMOS tube Q1 is turned on. When the EN-PWR-OUT signal output by the pin PA6 of the main control chip U1 is at a low level, the second NMOS tube Q2 is turned off, so that the VCC-24-OUT voltage signal output by the 5th pin of the current detection chip is disconnected from the direct electrical connection of the load. The load connection seat J1 is a load output port, and is used for being connected with the load, so as to supply power to the load. The resistor R1 and the light emitting diode D1 are load power indicator lamps. The capacitors C1 and C3 are filter capacitors.

[0069] The specific working principle of the utility model is that:

[0070] The utility model is connected between the direct current input power supply and the load, when the utility model is connected with the direct current input power supply, the EN-PWR-OUT and EN-RES-OUT signals output by the pin PA6 and pin PA7 of the main control chip U1 are at a low level by default, and the false load circuit control switch unit and the load control switch unit are disconnected.

[0071] The voltage detection unit detects the voltage of the direct current input power supply, when the voltage of the direct current input power supply is less than the starting voltage, then the utility model enters dormancy, the direct current input power supply does not supply power to the load, when the voltage of the direct current input power supply is greater than or equal to the starting voltage, the pin PA7 of the main control chip U1 outputs the EN-RES-OUT signal as high level, so that the dummy load circuit control switch unit connects the power supply of the dummy load, and the voltage detection unit continuously detects the voltage of the direct current input power supply, the current detection unit detects the current of the direct current input power supply, and the main control chip measures the input voltage and load current through ADC_IN0 and ADC_IN1, and obtains the load power of the direct current input power supply.When the load power of the direct current input power supply is insufficient, the utility model reenters dormancy; when the main control chip U1 detects that the load power of the direct current input power supply is greater than or equal to the set power threshold, then the main control chip U1 outputs the EN-RES-OUT signal as low level through the pin PA7, and the dummy load power supply is turned off, at the same time, the main control chip U1 outputs the EN-PWR-OUT signal as high level through the pin PA6, so that the load control switch unit connects the direct current input power supply and the load, the load power supply circuit is turned on, and the real load is provided with stable power supply.

[0072] The solar power supply system using 12V lithium battery is taken as an example, when the measured input voltage is lower than 10V, it can be determined that the voltage of the lithium battery is insufficient, the utility model enters dormancy, and the utility model is woken up after a period of time, and the power supply voltage is read again, when the power supply voltage meets the power supply condition, the cement resistor is used again to act as a dummy load to detect the load power of the circuit, when the load power is insufficient, the utility model reenters dormancy; when it is detected that the load power is sufficient, then the dummy load power supply is turned off, the load power supply circuit is turned on, and the real load is provided with stable power supply.

[0073] The foregoing description of the specific exemplary embodiments of the present application is for the purpose of illustrating and describing, rather than limiting the application, and it will be apparent to those of ordinary skill in the art that many changes and modifications can be made to the embodiments with the foregoing teaching, notwithstanding what can be suggested above and although only a few of the exemplary embodiments of the present application have been described. Although the embodiments of the present application have been described, the specific embodiments are merely illustrative of the present application and are not intended to limit the present application, and the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner, and the exemplary embodiments are selected and described for the purpose of explaining the specific principles of the present application and its practical application, so that those skilled in the art can make modifications, replacements, variations and various different selections and changes to the embodiments without creative contribution after reading the specification, as long as they are within the scope of the claims of the present application.

Claims

1. A power supply power output detection and control circuit, characterized by, The application relates to a power supply input unit, a DC-DC power supply unit, an LDO power supply unit, a voltage detection unit, a current detection unit, a master control unit, a dummy load circuit control switch unit, a dummy load and a load control switch unit. The power supply input unit, the DC-DC power supply unit, the LDO power supply unit and the master control unit are sequentially connected. The voltage detection unit is connected with the power supply input unit and the master control unit. The current detection unit is connected with the power supply input unit, the master control unit, the dummy load circuit control switch unit and the load control switch unit. The master control unit is connected with the dummy load circuit control switch unit and the load control switch unit. The power supply input unit is used for connecting a direct-current input power supply. The DC-DC power supply unit is used for converting the direct-current input power supply into a first direct-current voltage; and the LDO power supply unit is used for converting the first direct-current voltage into a second direct-current voltage suitable for the working of the master control unit. The voltage detection unit is used for detecting the voltage of the direct-current input power supply and inputting the detected voltage into the master control unit. The current detection unit is used for detecting the current of the direct-current input power supply and inputting the detected current into the master control unit and supplying power for the dummy load circuit control switch unit and the load control switch unit. The master control unit is used for controlling the working state of the dummy load circuit control switch unit and the load control switch unit according to the detected voltage and current, so as to realize the power supply for the load when the voltage and power of the direct-current input power supply meet the conditions. The power supply input unit comprises a power supply input seat J2, a bidirectional TVS protection tube D4 and a Schottky diode D3; the power supply input seat J2 is connected with a direct-current input power supply and comprises a first connecting end and a second connecting end; the first connecting end is connected with the anode of the Schottky diode D3 and one end of the bidirectional TVS protection tube D4 respectively; the second connecting end and the other end of the bidirectional TVS protection tube D4 are grounded respectively; and the cathode of the Schottky diode D3 is used as a power supply output end to output a direct-current power supply voltage.

2. A power supply power output detection and control circuit according to claim 1, characterised in that, The DC-DC power supply unit comprises a first input filter circuit, a power supply chip, a voltage conversion circuit and a first output filter circuit which are sequentially connected; the first input filter circuit is used for filtering the direct-current power supply voltage output by the cathode of the Schottky diode D3 and inputting the filtered direct-current power supply voltage into the power supply chip; the power supply chip is used for reducing the voltage of the filtered direct-current power supply voltage and inputting the reduced direct-current power supply voltage into the voltage conversion circuit; the voltage conversion circuit is used for converting the reduced direct-current power supply voltage into a first direct-current voltage and inputting the first direct-current voltage into the first output filter circuit; and the first output filter circuit is used for filtering the first direct-current voltage and inputting the filtered first direct-current voltage into the LDO power supply unit.

3. A power supply power output detection and control circuit according to claim 2, characterised in that, ​ 4. A power supply power output detection and control circuit according to claim 1, wherein, The LDO power supply unit comprises a second input filter circuit, a step-down chip and a second output filter circuit connected in sequence; the second input filter circuit is configured to filter the first direct current voltage and input the filtered first direct current voltage to the step-down chip; the step-down chip is configured to step down the filtered first direct current voltage to obtain a second direct current voltage and input the second direct current voltage to the second output filter circuit; and the second output filter circuit is configured to filter the second direct current voltage and input the filtered second direct current voltage to the master control unit.

5. A power supply power output detection and control circuit according to claim 2, wherein, The voltage detection unit comprises a voltage dividing circuit and an RC filter circuit connected in sequence. The voltage dividing circuit is configured to divide the direct current supply voltage output by the cathode of the Schottky diode D3 and input the obtained divided voltage to the RC filter circuit. The RC filter circuit is configured to filter the divided voltage and input the filtered divided voltage to the master control unit.

6. A power supply power output detection and control circuit according to claim 2, wherein, The current detection unit comprises a current detection chip; the first pin of the current detection chip is connected with the resistor R16; the second pin of the current detection chip and the other end of the resistor R16 are grounded; the third pin of the current detection chip is connected with the first direct current voltage and one end of the capacitor C15 respectively; the other end of the capacitor C15 is grounded; the fourth pin of the current detection chip is connected with one end of the resistor R18 and the cathode of the Schottky diode D3 respectively; the fifth pin of the current detection chip is connected with the other end of the resistor R18, the false load circuit control switch unit and the load control switch unit respectively; the sixth pin of the current detection chip is connected with one end of the resistor R13; the other end of the resistor R13 is connected with one end of the resistor R12, the cathode of the unidirectional TVS diode and the master control unit respectively; the other end of the resistor R12 and the anode of the unidirectional TVS diode are grounded.

7. A power supply power output detection and control circuit according to claim 1, wherein, The false load circuit control switch unit comprises a first NMOS tube Q4 and a first PMOS tube Q3; the G pole of the first NMOS tube Q4 is connected with the master control unit and one end of the resistor R11 respectively; the other end of the resistor R11 is grounded; the S pole of the first NMOS tube Q4 is grounded; the D pole of the first NMOS tube Q4 is connected with one end of the resistor R10; the other end of the resistor R10 is connected with one end of the resistor R9, one end of the capacitor C6 and the G pole of the first PMOS tube Q3 respectively; the S pole of the first PMOS tube Q3 is connected with the other end of the resistor R9, the other end of the capacitor C6, one end of the capacitor C5 and the current detection unit respectively; the other end of the capacitor C5 is grounded; the D pole of the first PMOS tube Q3 is connected with one end of the capacitor C7, one end of the resistor R8 and one end of the false load resistor R7 respectively; the other end of the capacitor C7 and the other end of the false load resistor R7 are grounded respectively; the other end of the resistor R8 is connected with the anode of the light-emitting diode D5; the cathode of the light-emitting diode D5 is grounded.

8. A power supply power output detection and control circuit according to claim 1, wherein, The load control switch unit comprises a second NMOS tube Q2 and a second PMOS tube Q1; the G poles of the second NMOS tube Q2 are connected with a master control unit and one end of a resistor R6 respectively, and the other end of the resistor R6 is grounded; the S pole of the second NMOS tube Q2 is grounded; the D pole of the second NMOS tube Q2 is connected with one end of a resistor R4, and the other end of the resistor R4 is connected with one end of a resistor R3, one end of a capacitor C2 and the G pole of the second PMOS tube Q1 respectively; the S pole of the second PMOS tube Q1 is connected with the other end of the resistor R3, the other end of the capacitor C2, one end of a capacitor C1 and a current detection unit respectively, and the other end of the capacitor C1 is grounded; the D pole of the second PMOS tube Q1 is connected with one end of a capacitor C3, one end of a resistor R1 and one end of a load connection seat J1 respectively, the other end of the capacitor C3 and the other end of the load connection seat J1 are grounded respectively, the other end of the resistor R1 is connected with the anode of a light emitting diode D1, and the cathode of the light emitting diode D1 is grounded.

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