A solid-liquid density meter power switching circuit

Abstract

The utility model provides a kind of solid-liquid densimeter power switching circuit, belong to densimeter power switching field, including power management circuit and power supply switching circuit, the power management circuit includes charging management module, the charging management module is connected with power input filter module and battery power output module respectively, the battery power output module is also connected with battery voltage detection module;The power supply switching circuit includes power supply switching module, the power supply switching module side is connected with the input protection module for overload protection, the other side is respectively connected with enable control module, state indicating module and reference voltage stabilizing module, wherein state indicating module and reference voltage stabilizing module are also interconnected;The present power switching circuit can solve the problem of frequent charging and discharging of battery when using the existing solid-liquid densimeter.

Description

Technical Field

[0001] This utility model belongs to the field of power switching for densitometers, and specifically relates to a power switching circuit for a solid-liquid densitometer. Background Technology

[0002] In many industries, it's common to use both DC power supplies and batteries to power equipment. In traditional DC power supply scenarios, the battery is constantly charging and discharging during DC power supply, which directly impacts battery life. Furthermore, it's impossible to charge the battery during DC power supply. Therefore, traditional power switching systems perform poorly when high-standard DC power supplies and batteries are used simultaneously.

[0003] Current solid-liquid density meters suffer from the problem of frequent charging and discharging of the battery when powered by both DC power and a battery simultaneously. Utility Model Content

[0004] In view of this, this utility model proposes a power switching circuit for a solid-liquid density meter, which can solve the problem of frequent charging and discharging of the power supply battery when the existing solid-liquid density meter is powered by both DC power and battery, thereby improving the battery life.

[0005] This utility model is implemented as follows:

[0006] This utility model proposes a power switching circuit for a solid-liquid density meter, specifically including a power management circuit and a power supply switching circuit. The power management circuit includes a charging management module, which is connected to a power input filtering module and a battery power output module. The battery power output module is also connected to a battery voltage detection module. The power supply switching circuit includes a power supply switching module, which is connected to an input protection module for overload protection on one side and to an enable control module, a status indication module, and a reference voltage regulator module on the other side. The status indication module and the reference voltage regulator module are also interconnected.

[0007] The power supply switching module includes a relay J1. One end of the normally open contact of the relay J1 is connected to both the input protection module and the 12V power supply, and the other end is connected to the enable control module. The normally closed contact of the relay J1 is connected to the positive terminal of the battery. One end of the control contact of the relay J1 is connected to both the status indicator module and the 12V power supply, and the other end is connected to the reference voltage regulator module.

[0008] The charging management module includes a power management chip IC1. The LX pin of the power management chip IC1 is connected to the battery power output module through an inductor L1. The VIN pin of the power management chip IC1 is connected to a 12V power supply. The VINSEN pin of the power management chip IC1 is connected to the IO port of the MCU and is also connected to the power input filtering module through a resistor R2.

[0009] Furthermore, the enable control module includes a P-type field-effect transistor Q1, the drain of which is connected to an analog power supply; the source and gate of the P-type field-effect transistor Q1 are connected in series through a resistor R13; the gate of the P-type field-effect transistor Q1 is connected to the collector of a transistor Q2 through a resistor R43, and the emitter of the transistor Q2 is grounded; the gate of the P-type field-effect transistor Q1 is also connected to one end of a switch S1, and the other end of the switch S1 is grounded; the base and emitter of the transistor Q2 are connected in series through a resistor R17, and the base of the transistor Q2 is connected to the IO control port of the MCU through a resistor R15;

[0010] The gate of the P-type field-effect transistor Q1 is connected to a 3.3V power supply via a series diode D4 and a resistor R42; both diode D4 and resistor R42 are connected to the IO control port of the MCU.

[0011] Furthermore, the reference voltage regulator module includes a voltage regulator IC2, a resistor R16, and a resistor R18. The cathode of the voltage regulator IC2 is connected to the relay J1, the anode of the voltage regulator IC2 is grounded, and the reference terminal of the voltage regulator IC2 is connected to a 12V power supply through the resistor R16. The reference terminal of the voltage regulator IC2 is also connected in series with the anode of the voltage regulator IC2 through the resistor R18.

[0012] The beneficial effect of adopting the above-mentioned further technical solution is that by utilizing the precise reference characteristics of the voltage regulator IC2 and setting the voltage divider through resistors R16 and R18, a stable reference voltage is output, which, together with other circuits, achieves regulated output.

[0013] Furthermore, the status indication module includes diode D2, light-emitting diode D3, and resistor R14. Resistor R14 is connected in series with light-emitting diode D3. The series circuit formed by resistor R14 and light-emitting diode D3 is connected in parallel with diode D2. The two ends of the parallel circuit formed by diode D2, light-emitting diode D3, and resistor R14 are respectively connected to the two control terminal contacts of relay J1. The cathode of light-emitting diode D3 and the anode of diode D2 are connected to the cathode of voltage regulator IC2.

[0014] Furthermore, the input protection module mainly consists of a fuse F1. One end of the fuse F1 is connected to both the relay J1 and the 12V power supply, while the other end is connected to port 1 of the plug-in P7. Port 2 of the plug-in P7 is grounded.

[0015] The beneficial effect of adopting the above-mentioned further technical solution is that by setting fuse F1, external power input protection can be achieved, avoiding fire caused by circuit breakers.

[0016] Furthermore, the LX pin of the power management chip IC1 is connected to the BST pin of the power management chip IC1 through capacitor C1, and the LX pin of the power management chip IC1 is also connected to the VOUT pin of the power management chip IC1 through inductor L1; the LX pin of the power management chip IC1 is also grounded through resistors R6 and R12; the end of resistor R12 near resistor R6 is also connected to the FB pin of the power management chip IC1.

[0017] Furthermore, the power input filtering module consists of three capacitors C4, C5 and C6 connected in parallel. One end of the parallel circuit formed by capacitors C4, C5 and C6 is connected to a 12V power supply, and the other end is grounded.

[0018] The beneficial effect of adopting the above-mentioned further technical solution is that by setting capacitors C4, C5 and C6 in parallel, the input power supply voltage can be filtered.

[0019] Furthermore, the battery power output module consists of three capacitors C7, C8, and C9 connected in parallel, and a plug-in P1 connected in parallel. One end of the parallel circuit consisting of capacitors C7, C8, and C9 is connected to the positive terminal of the battery power supply, and the other end is grounded. Port 1 of plug-in P1 is grounded, and port 2 is connected to the positive terminal of the battery power supply.

[0020] The beneficial effect of adopting the above-mentioned further technical solution is that by setting capacitors C7, C8 and C9 in parallel, filtering of the stable output voltage can be achieved.

[0021] Furthermore, the battery voltage detection module consists of two resistors connected in series, R1 and R5. Resistor R5 is grounded, and resistor R1 is connected to the positive terminal of the battery power supply. Both resistor R1 and resistor R5 are connected to the ADC port of the MCU.

[0022] Furthermore, the power management chip IC1 has multiple VIN pins, multiple VSYS pins, and also multiple AGND, PGND, and GND pins.

[0023] Compared with the prior art, the beneficial effects of the power switching circuit for a solid-liquid density meter provided by this utility model are: when the device is powered by an external power source, the relay can switch to DC power supply; when the external power source is unplugged, it automatically switches to battery power supply, avoiding the simultaneous supply of power to the device system by the battery and preventing frequent charging and discharging of the battery, which would reduce battery life.

[0024] Meanwhile, the MCU can detect the battery voltage in real time after charging stops and display the detection data.

[0025] Compared to traditional systems that use both external power and battery power, this circuit can effectively improve battery life. Attached Figure Description

[0026] Figure 1 This is a point diagram of the overall switching circuit. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0028] like Figure 1 As shown, this utility model provides a power switching circuit for a solid-liquid density meter. The novel includes a power management circuit and a power switching circuit. The power management circuit manages the 12V charging power supply, and the power switching circuit switches the power supply to the load.

[0029] The power management circuit includes a central charging management module, around which are connected a power input filtering module and a battery-powered output module. The battery-powered output module is also connected to a battery voltage detection module. The power supply switching circuit includes a power supply switching module. One side of the power supply switching module is connected to an input protection module for overload protection, and the other side is connected to an enable control module, a status indicator module, and a reference voltage regulator module. The status indicator module and the reference voltage regulator module are also interconnected.

[0030] The power supply switching module mainly consists of a relay J1. The normally open contact 3 of relay J1 is connected to both the 12V power supply and the input protection module, and the normally open contact 2 is connected to the enable control module. The normally closed contact 4 of relay J1 is connected to the positive terminal VBAT of the battery. The control contact 5 of relay J1 is connected to both the 12V power supply and the status indication module, and the control contact 1 is connected to the reference voltage regulator module.

[0031] The input protection module mainly consists of fuse F1 and plug-in P7 connected in series with fuse F1. One end of fuse F1 is connected to the normally open contact of relay J1, and the other end is connected to contact 1 of plug-in P7. Contact 2 of plug-in P7 is grounded.

[0032] The enable control module mainly consists of a P-type field-effect transistor (FET) Q1, a transistor Q2, a diode, a switch S1, a connector P8, and multiple resistors. The gate of the P-type FET Q1 is connected to the collector of the transistor Q2 via a resistor R43, and the emitter of the transistor Q2 is directly grounded. The gate and source of the P-type FET Q1 are connected in series via a resistor R13, and the drain is connected to the analog circuit power supply VCC. The gate of the P-type FET Q1 is also connected to the 3.3V power supply via a series diode D4 and a resistor R42. Simultaneously, diode D4 and resistor R42 are also connected to the MCU's I / O control contacts.

[0033] The gate of the P-type field-effect transistor Q1 is also connected to one end of the switch S1, and the other end of the switch S1 is grounded. At the same time, a plug-in P8 is connected in parallel at the switch S1. Port 1 of plug-in P8 is connected to the gate of the P-type field-effect transistor Q1, and port 2 is grounded.

[0034] The emitter and base of transistor Q2 are connected in series through resistor R17, and the base of transistor Q2 is also connected to the MCU's IO control contact port through resistor R15.

[0035] The reference voltage regulator module consists of voltage regulator IC2, resistor R16, and resistor R18. The reference terminal of voltage regulator IC2 is connected to the 12V power supply via resistor R16, its anode is grounded, and its cathode is connected to contact 5 of the control contact of relay J1. The anode and reference terminal of voltage regulator IC2 are also connected via resistor R18. Resistors R16 and R18 are primarily used for voltage division of the 12V power supply.

[0036] The status indication module consists of a photodiode D3, a diode D2, and a resistor R14. The photodiode D3 is connected in series with the resistor R14, and the series circuit of the resistor R14 and the photodiode D4 is connected in parallel with the diode D2. The two ends of the parallel circuit are connected to the control contact 1 and the control contact 5 of the relay J1, respectively.

[0037] The power management chip IC1 is the "brain and actuator" of the entire power management circuit. The power management chip is mainly used to coordinate battery charging and power conversion, and also takes into account status monitoring and safety protection, so as to ensure reliable battery charging and stable power supply to the device.

[0038] The power management chip IC1's input voltage detection pin, VINSEN, is connected to the 12V power supply via resistor R2 and also grounded via resistor R8; the charging current setting pin, ICHG, is grounded via resistor R9; the input current limiting setting pin is grounded via resistor R10; the serial data line pin, SDA, is connected to the 5V power supply via resistor R3; the serial clock line pin, SCL, is connected to the 5V power supply via resistor R4; and the lighting control pin, LED, is connected to the positive terminal of LED D1 via resistor R7, with the negative terminal of LED D1 directly grounded. The input voltage detection pin, VINSEN, is also connected to the MCU's I / O port.

[0039] The power management chip IC1 has two PWM output pins LX. The two PWM output pins LX are connected to each other outside the power management chip IC1 and are interconnected with the bootstrap pin BST of the power management chip IC1 through a capacitor C1. The PWM output pin LX is connected to VBAT through an inductor L1 to output to the battery. The PWM output pin LX is also connected to the power output pin VOUT of the power management chip IC1 through an inductor L1.

[0040] Meanwhile, the power management chip IC1 also has a feedback regulation pin FB. The feedback regulation pin FB is connected to the battery via resistor R6 and VBAT, and grounded via resistor R12. The feedback regulation pin FB receives the sampling signal of the output voltage and feeds it back to the chip to ensure the stability of the output voltage.

[0041] The power management chip IC1 also has an NTC pin for connecting an NTC thermistor, which is grounded through resistor R11.

[0042] The power management chip IC1 includes three chip power input pins, VIN22, VIN23 and VIN24, which are all connected to a 12V power supply.

[0043] The power management chip IC1 includes two analog ground pins AGND, two power ground pins PGND, and one general ground pin GND, all of which are grounded. These multiple types of ground pins provide a reference point for the internal circuitry of the chip, maintaining stable battery characteristics while enhancing grounding effectiveness and reducing interference.

[0044] The power management chip IC1 includes three power node pins VSYS, which are grounded through two parallel capacitors C2 and C3.

[0045] The power input filtering module includes three capacitors C4, C5 and C6 connected in parallel. C5 and C6 are polarized capacitors. The positive terminals of C5 and C6 are connected to each other and connected to a 12V power supply. The negative terminals of C5 and C6 are connected to each other and grounded.

[0046] The battery-powered output module includes three capacitors connected in parallel: C7, C8, and C9. Capacitor C9 is a polarized capacitor; its positive terminal is connected to the battery's positive terminal VBAT, and its negative terminal is grounded. These three parallel capacitors filter the output voltage. The battery's positive terminal VBAT is also connected to port 2 of plug-in P1, and port 1 of plug-in P1 is grounded.

[0047] The battery voltage detection module includes two resistors connected in series, R1 and R5. Resistor R5 is grounded, and resistor R1 is connected to the positive terminal VBAT of the battery. Resistors R1 and R5 are also connected to the ADC port of the MCU.

[0048] Optionally, the model number of the P-type field-effect transistor Q1 is NDT456P-VB.

[0049] Optionally, transistor Q2 is model S8050.

[0050] Optionally, diodes D2 and D4 have the same model number, IN4007.

[0051] Optionally, regulator IC2 is an adjustable parallel regulator, model TL431.

[0052] Optionally, LED D1 emits yellow light, and LED D3 emits red light.

[0053] The principle of this utility model is as follows:

[0054] When no external power is connected, relay J1 is not energized, and the battery supplies power to the system through contact 4 of relay J1. When an external power source is connected, relay J1 energizes, and the external power supplies power to the system through contacts 2 and 3 of relay J1. When switch S1 is not pressed, the gate of P-type MOSFET Q1 is pulled high to the system supply voltage of 12V through resistor R13. When switch S1 is pressed, the system power supply supplies power to the MCU through transistor Q2. After the MCU starts up, it pulls the base level of transistor Q2 high, and the gate control contact of P-type MOSFET Q1 is pulled down to GND through transistor Q2, keeping P-type MOSFET Q1 conducting.

[0055] The MCU's I / O port is normally at a high level. When switch S1 is pressed, the I / O port is pulled down to GND by switch S1. When the MCU detects that the I / O port level changes from high to low, it controls transistor Q2 to turn off, P-type MOSFET Q1 to turn off, the system power is disconnected, and the device is powered off.

[0056] The external power supply is connected to the positive terminal VBAT of the battery via the power management chip IC1. After being divided by resistors R2 and R8, the external power supply is connected to the input voltage detection pin VINSEN of the power management chip IC1. At the same time, the input voltage detection pin VINSEN is connected to the MCU's IO port.

[0057] The output of the power management chip IC1 is controlled by adjusting the I / O port level. When an external power source charges the battery through the power management chip IC1, the MCU pulls the I / O port level high. The battery is connected to the MCU's ADC port via resistors R1 and R5, pulling the control pin level of the power management chip IC1 low and stopping the charging chip output. The battery voltage is sampled through the MCU's ADC port. After the sampling is complete, the control pin level of the power management chip IC1 is pulled high to continue charging the battery.

[0058] Thus, the external power supply and the battery can be switched to supply power to the equipment system via relay J1, ensuring that the battery does not frequently charge and discharge when powered externally, thereby improving the battery's lifespan.

[0059] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A power switching circuit for a solid-liquid density meter, characterized in that, The device includes a power management circuit and a power supply switching circuit. The power management circuit includes a charging management module, which is connected to a power input filtering module and a battery power output module. The battery power output module is also connected to a battery voltage detection module. The power supply switching circuit includes a power supply switching module, which is connected to an input protection module for overload protection on one side and to an enable control module, a status indicator module, and a reference voltage regulator module on the other side. The status indicator module and the reference voltage regulator module are also interconnected. The power supply switching module includes a relay J1. One end of the normally open contact of the relay J1 is connected to both the input protection module and the 12V power supply, and the other end is connected to the enable control module. The normally closed contact of the relay J1 is connected to the positive terminal of the battery. One end of the control contact of the relay J1 is connected to both the status indicator module and the 12V power supply, and the other end is connected to the reference voltage regulator module. The charging management module includes a power management chip IC1. The LX pin of the power management chip IC1 is connected to the battery power output module through an inductor L1. The VIN pin of the power management chip IC1 is connected to a 12V power supply. The VINSEN pin of the power management chip IC1 is connected to the IO port of the MCU and is also connected to the power input filtering module through a resistor R2.

2. The power switching circuit for a solid-liquid density meter according to claim 1, characterized in that, The enable control module includes a P-type field-effect transistor Q1, the drain of which is connected to an analog power supply; the source and gate of the P-type field-effect transistor Q1 are connected in series through a resistor R13; the gate of the P-type field-effect transistor Q1 is connected to the collector of a transistor Q2 through a resistor R43, and the emitter of the transistor Q2 is grounded; the gate of the P-type field-effect transistor Q1 is also connected to one end of a switch S1, and the other end of the switch S1 is grounded; the base and emitter of the transistor Q2 are connected in series through a resistor R17, and the base of the transistor Q2 is connected to the IO control port of the MCU through a resistor R15; The gate of the P-type field-effect transistor Q1 is connected to a 3.3V power supply via a series diode D4 and a resistor R42; both diode D4 and resistor R42 are connected to the IO control port of the MCU.

3. The power switching circuit for a solid-liquid density meter according to claim 2, characterized in that, The reference voltage regulator module includes a voltage regulator IC2, a resistor R16, and a resistor R18. The cathode of the voltage regulator IC2 is connected to the relay J1, and the anode of the voltage regulator IC2 is grounded. The reference terminal of the voltage regulator IC2 is connected to a 12V power supply through the resistor R16. The reference terminal of the voltage regulator IC2 is also connected in series with the anode of the voltage regulator IC2 through the resistor R18.

4. The power switching circuit for a solid-liquid density meter according to claim 3, characterized in that, The status indication module includes diode D2, light-emitting diode D3, and resistor R14. Resistor R14 is connected in series with light-emitting diode D3. The series circuit formed by resistor R14 and light-emitting diode D3 is connected in parallel with diode D2. The two ends of the parallel circuit formed by diode D2, light-emitting diode D3, and resistor R14 are respectively connected to the two control terminal contacts of relay J1. The cathode of light-emitting diode D3 and the anode of diode D2 are connected to the cathode of voltage regulator IC2.

5. The power switching circuit for a solid-liquid density meter according to claim 4, characterized in that, The input protection module mainly consists of a fuse F1. One end of the fuse F1 is connected to both the relay J1 and the 12V power supply, while the other end is connected to port 1 of the plug-in P7. Port 2 of the plug-in P7 is grounded.

6. The power switching circuit for a solid-liquid density meter according to claim 5, characterized in that, The LX pin of the power management chip IC1 is connected to the BST pin of the power management chip IC1 through capacitor C1. The LX pin of the power management chip IC1 is also connected to the VOUT pin of the power management chip IC1 through inductor L1. The LX pin of the power management chip IC1 is also grounded through resistors R6 and R12. The end of resistor R12 near resistor R6 is also connected to the FB pin of the power management chip IC1.

7. The power switching circuit for a solid-liquid density meter according to claim 1, characterized in that, The power input filtering module consists of three capacitors C4, C5 and C6 connected in parallel. One end of the parallel circuit formed by capacitors C4, C5 and C6 is connected to a 12V power supply, and the other end is grounded.

8. The power switching circuit for a solid-liquid density meter according to claim 1, characterized in that, The battery power output module consists of three capacitors C7, C8, and C9 connected in parallel, and a plug-in P1 connected in parallel. One end of the parallel circuit formed by capacitors C7, C8, and C9 is connected to the positive terminal of the battery power supply, and the other end is grounded. Port 1 of plug-in P1 is grounded, and port 2 is connected to the positive terminal of the battery power supply.

9. The power switching circuit for a solid-liquid density meter according to claim 1, characterized in that, The battery voltage detection module consists of two resistors connected in series, R1 and R5. Resistor R5 is grounded, and resistor R1 is connected to the positive terminal of the battery power supply. Both resistor R1 and resistor R5 are connected to the ADC port of the MCU.

10. A power switching circuit for a solid-liquid density meter according to claim 1, characterized in that, The power management chip IC1 has multiple VIN pins, multiple VSYS pins, and multiple AGND, PGND, and GND pins.

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