CN204928578U - A DC power supply automatic adjustment circuit and a DC power supply automatic adjustment device - Google Patents

Abstract

The utility model is suitable for an electron field provides a DC power supply auto -adjusting circuit and DC power supply automatic regulating apparatus, and this circuit includes: the power switching over unit, its input is connected with DC power supply, the main control unit, its feeder ear and power switching over unit connection are held in the operation controls that has the regulating command of a plurality of receipt user, the power output unit, its input is connected with the output of main control unit, the protected location, its input is connected with the output of power output unit, and its output is connected with the feedback end of main control unit, the current -limiting resistor of connection between protected location and circuit output. The utility model discloses a key formula triggers the power and realizes stepping up / stepping down the regulation automatically to the automatic shutdown power is adjusted after detecting the executive signal of load, has saved the human cost, and it is high that it adjusts precision, adjusts evenly, quick, and stabilization of output has improved production efficiency, quality, and the regulation that can halt has the overcurrent protection function.

Description

A DC power supply automatic adjustment circuit and a DC power supply automatic adjustment device

technical field

The utility model belongs to the field of electronics, in particular to a direct current power supply automatic adjustment circuit and a direct current power supply automatic adjustment device.

Background technique

At present, electronic products are full of people's clothing, food, housing and transportation. In recent years, some vehicle-mounted electronic products, such as vehicle-mounted refrigerators, have been highly praised by people. These vehicle-mounted electronic products are generally powered by vehicle-mounted power supplies (car batteries). After a period of power supply, the power may be too low. At this time, the vehicle electronic product needs to cut off the power supply between the vehicle power supply and the vehicle power supply through the built-in power monitoring control board, that is, when the external power supply voltage is lower than the shutdown threshold, the vehicle electronic product is controlled to shut down. , when the external power supply voltage returns to the startup threshold, control the on-board electronic products to start up.

In the production process of these vehicle-mounted electronic products, it is necessary to perform performance tests on the power monitoring control board to ensure product quality, that is, to verify the power-on threshold and shutdown threshold points by outputting fluctuating power supply voltages to the power-monitoring control board of vehicle-mounted electronic products. Whether the power monitoring control board can realize the corresponding power-on and power-off control.

However, at present, the fluctuating power supply voltage output to the power monitoring control board of vehicle electronic products is usually realized by manually adjusting the DC power supply. First, the rhythm of adjustment cannot be grasped, and the test time is long, which affects production efficiency; second, the resolution of manual adjustment is low. , it is difficult to achieve high-precision detection; the third is that the workload is heavy, and a lot of labor costs are required.

Utility model content

The purpose of the embodiment of the utility model is to provide an automatic DC power adjustment circuit, aiming to solve the existing problems of low efficiency, poor accuracy and high labor cost caused by manually adjusting the DC power to verify the performance of vehicle-mounted products.

The embodiment of the utility model is achieved in this way, a direct current power supply automatic adjustment circuit, the circuit includes:

a power conversion unit that converts the DC power supply into an internal power supply voltage, the input terminal of the power conversion unit is connected to the output terminal of the DC power supply;

After receiving the trigger control signal, the main control unit generates the corresponding PWM voltage adjustment signal according to the user's adjustment instruction. The PWM voltage adjustment signal changes regularly or remains unchanged according to the preset step size. The power supply of the main control power supply terminal is connected to the output terminal of the power conversion unit, the trigger control terminal of the main control unit receives the trigger control signal, and the main control unit has a plurality of operation control terminals for receiving user adjustment instructions;

A power output unit for correspondingly adjusting the output power supply voltage according to the PWM voltage adjustment signal, the input end of the power output unit is connected to the output end of the main control unit;

A protection unit that controls the main control unit to perform overcurrent protection when an excessive output current is detected, the input end of the protection unit is connected to the output end of the power output unit, and the output end of the protection unit is connected to the main control unit The feedback terminal connection of the control unit;

A current limiting resistor, one end of the current limiting resistor is connected to the output end of the power output unit and the input end of the protection unit at the same time, and the other end of the current limiting resistor is the output end of the DC power automatic adjustment circuit Connect with the detection terminal of the protection unit.

Further, the operation control terminal includes: a boost regulation terminal, a step-down regulation terminal and a default value restoration terminal;

The regulation instructions include: boost regulation, step-down regulation and default value restoration.

Further, the circuit also includes:

A display unit that displays the current adjustment state in real time through a prompt light, the power supply terminal of the display unit is connected to the output terminal of the power conversion unit, and at least one driving terminal of the display unit is connected to the display output terminal of the main control unit , at least one drive terminal of the display unit is connected to the output terminal of the DC power automatic adjustment circuit.

Further, the power conversion unit includes:

Diode D1, capacitor C1, capacitor C2, capacitor E1, capacitor E2 and DC-DC power chip;

The anode of the diode D1 is the input end of the power conversion unit, the cathode of the diode D1 is connected to one end of the capacitor E2 and the capacitor C1 at the same time, and the other end of the capacitor E2 and the capacitor C1 is simultaneously Grounded, the cathode of the diode D1 is also connected to the input pin (IN) of the DC-DC power chip, the ground pin (GND) of the DC-DC power chip is grounded, the DC-DC power chip The output pin (OUT) is the output end of the power conversion unit connected to one end of the capacitor E1 and the capacitor C2 at the same time, and the other end of the capacitor E1 and the capacitor C2 are grounded at the same time.

Furthermore, the power conversion unit further includes an interface, and the input end of the power conversion unit is plugged into the DC power supply through the interface.

Further, the main control unit includes:

Resistor R1, resistor R2, resistor R3, resistor R4, resistor R10, resistor R13, resistor R14, resistor R15, resistor R19, resistor R21, resistor R22, capacitor C3, capacitor C4, first switching tube, crystal oscillator, first controllable a switch, a second controllable switch, a third controllable switch and a processor;

One end of the resistor R3 is the trigger control end of the main control unit, and the other end of the resistor R3 is connected to the control end of the first switch tube and one end of the resistor R4 at the same time, and the first switch tube The output end of the first switching tube is connected to the other end of the resistor R4 at the same time, the input end of the first switch tube is connected to one end of the resistor R1 and one end of the resistor R2 at the same time, and the other end of the resistor R1 is the Main control unit power supply end, the other end of the resistor R2 is grounded through the capacitor C2, the other end of the resistor R2 is also connected to the trigger pin (P0.0/ADC0/INT0) of the processor, the The detection pin (P0.1/ADC1/INT1) of the processor is the feedback terminal of the main control unit, and the power supply pin (VDD) of the processor is the power supply terminal of the main control unit through the capacitor C4 is grounded, the clock input terminal (XIN/P1.0) of the processor is connected to one pole of the crystal oscillator, and the clock output terminal (XOUT/P1.1) of the processor is connected to the other pole of the crystal oscillator connected, the base terminal of the crystal oscillator is grounded, the reset terminal (RESET/P1.2) of the processor is grounded through the resistor R10, and the multiple data output pins (P2.2, P2.3) of the processor ) is a plurality of display output ends of the main control unit, one end of the resistance R13, the resistance R14, and the resistance R15 is simultaneously the power supply end of the main control unit, and the resistance R13, the resistance R14 , the other end of the resistor R15 is respectively connected to one end of the resistor R19, the resistor R21, and the resistor R22, and the other end of the resistor R19, the resistor R21, and the resistor R22 is respectively connected to the processing The first, second and third control input pins (P0.5/ADC5, P0.7/ADC7, P2.6/ADC8/CLO) of the device are connected, the resistor R13, the resistor R14, the resistor The other end of R15 is also respectively connected to one conduction end of the first, second and third controllable switches, the other conduction end of the first, second and third controllable switches is grounded, and the The control terminals of the first, second and third controllable switches are multiple operation control terminals of the main control unit, and the PWM output pin (P0.6/ADC6/PWM) of the processor is the control terminal of the main control unit. output of the unit.

Further, the power output unit includes:

Resistor R11, resistor R16, resistor R23, resistor R24, variable resistor R20, capacitor C5, capacitor C6, capacitor C7, capacitor C8, first operational amplifier and power output chip;

One end of the resistor R23 is the input end of the power output unit, the other end of the resistor R23 is connected to one end of the capacitor C6 and one end of the resistor R24 at the same time, and the other end of the capacitor C6 is grounded, so The other end of the resistor R24 is grounded through the capacitor C8, the other end of the resistor R24 is also connected to the positive input of the first operational amplifier, and the negative input of the first operational amplifier is simultaneously connected to the One end of the variable resistor R20 is connected to one end of the resistor R16, the other end of the variable resistor R20 is grounded, and the adjusting end of the variable resistor R20 is connected to the inverting input end of the first operational amplifier, so The other end of the resistor R16 is connected to the reference voltage pin (ADJ) of the power output chip, the output end of the first operational amplifier is grounded through the capacitor C7, and the output end of the first operational amplifier is also connected to the The reference voltage pin (ADJ) of the power output chip is connected, the power supply pin of the first operational amplifier is connected with the input pin (VIN) of the power output chip, and the output pin (VOUT) of the power output chip is connected. ) is that the output end of the power output unit is simultaneously connected to one end of the resistor R11 and the capacitor C5, and the other end of the resistor R11 and the capacitor C5 is simultaneously connected to the output end of the first operational amplifier.

Further, the protection unit includes:

Resistor R6, resistor R7, resistor R8, resistor R9 and a second operational amplifier;

One end of the resistance R6 is the input end of the protection unit, the other end of the resistance R6 is connected to the positive input end of the second operational amplifier, and one end of the resistance R9 is the detection end of the protection unit , the other end of the resistor R9 is simultaneously connected to the inverting input end of the second operational amplifier and one end of the resistor R8, and the other end of the resistor R8 is simultaneously connected to the output end of the second operational amplifier and the One end of the resistor R7 is connected, and the other end of the resistor R7 is the output end of the protection unit.

Furthermore, the display unit includes:

Resistor R17, resistor R18, resistor R23, light emitting diode LED1, light emitting diode LED2 and light emitting diode LED3;

One end of the resistor R17 and the resistor R18 is simultaneously the power supply terminal of the display unit, and the other end of the resistor R17 and the resistor R18 are respectively connected to the anodes of the light emitting diode LED1 and the light emitting diode LED2, The cathodes of the light emitting diode LED1 and the light emitting diode LED2 are respectively the first and second driving ends of the display unit, the anode of the light emitting diode LED3 is the third driving end of the display unit, and the light emitting diode The cathode of LED3 is grounded through the resistor R23.

Another object of the embodiment of the present utility model is to provide an automatic DC power adjustment device using the above-mentioned DC power automatic adjustment circuit.

The embodiment of the utility model automatically realizes step-up/step-down adjustment by lightly touching the trigger power supply, and automatically stops power supply adjustment after detecting the action execution signal of the circuit under test, realizing one-button automatic voltage output adjustment, which greatly saves manpower cost, its adjustment accuracy is high, the adjustment is uniform and fast, and the output voltage is stable, which greatly improves the production efficiency and quality. Stream protection and other functions are convenient for users to operate and record.

Description of drawings

Fig. 1 is the structural diagram of the DC power supply automatic adjustment circuit that the utility model embodiment provides;

Fig. 2 is an example circuit structure diagram of the DC power supply automatic adjustment circuit provided by the embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute conflicts with each other.

The embodiment of the utility model adopts a one-button trigger power supply to automatically realize the step-up/step-down adjustment, and automatically stops the power supply adjustment after detecting the execution signal of the load, which saves labor costs. Its adjustment accuracy is high, the adjustment is uniform and fast, and the output The voltage is stable, which improves production efficiency and quality, and can suspend regulation and realize overcurrent protection.

Below in conjunction with specific embodiment the realization of the utility model is described in detail:

Fig. 1 shows the structure of the DC power supply automatic adjustment circuit provided by the embodiment of the present invention. For the convenience of description, only the parts related to the present invention are shown.

As an embodiment of the present invention, the input terminal Vin+ of the direct current power supply automatic adjustment circuit is connected to the direct current power supply DC, and the output terminal is connected to the control circuit of the electronic product, which is used to verify whether the electronic product can effectively operate in the environment where the power supply voltage changes. Realize the preset protection function. Especially for vehicle-mounted electronic products, such as vehicle-mounted refrigerators, the output terminal of the DC power supply automatic adjustment circuit is connected to the power monitoring control board of the vehicle-mounted refrigerator to simulate the voltage change of the car battery during charging and discharging, and verify that the power monitoring control board is in the preset state. Whether the shutdown threshold and startup threshold can effectively control the car refrigerator to be turned on or off, so as to stop the power consumption of the car battery when the power supply voltage is too low, and automatically start the car refrigerator when the car battery is charged to the startup threshold.

The DC power automatic adjustment circuit can be applied to any DC power automatic adjustment device, including:

A power conversion unit 11 that converts the DC power supply into an internal power supply voltage, and the input end of the power conversion unit 11 is connected to the output end of the DC power supply DC;

In the embodiment of the present utility model, the power conversion unit 11 converts the external DC power into a lower stable DC power as the working voltage of the internal circuit, and the working voltage is generally set to the most commonly used +5V or +12V output of the circuit.

After receiving the trigger control signal, the main control unit 12 generates the corresponding PWM voltage adjustment signal according to the user's adjustment instruction, and the PWM voltage adjustment signal changes regularly or remains unchanged according to the preset step size. The output terminal of the conversion unit 11 is connected, the trigger control terminal TESTpoint2 of the main control unit 12 receives the trigger control signal, and the main control unit 12 has a plurality of operation control terminals for receiving user adjustment instructions;

As a preferred embodiment of the present invention, the operation control terminal includes: a voltage boost regulation terminal, a voltage drop regulation terminal, and a default value recovery terminal; the regulation instruction includes: voltage boost regulation, voltage drop regulation, and default value recovery.

In the embodiment of the present utility model, through an external circuit or user control, a trigger control signal is sent to the main control unit 12 as a start instruction, and the main control unit 12 searches for an adjustment instruction after receiving the trigger control signal, and the adjustment instruction is passed by the user. The button operation is issued, which can include step-up regulation, step-down regulation, and default value restoration.

After the main control unit 12 receives the step-down adjustment instruction, the main control unit 12 controls the output voltage to gradually increase according to the preset step size, for example, to increase by 0.1V after each clock cycle;

After the main control unit 12 receives the step-up adjustment instruction, the main control unit 12 controls the output voltage to gradually decrease according to the preset step size, for example, decrease by 0.1V after each clock cycle;

The preset step size is the adjustment accuracy of the DC power automatic adjustment circuit, the smaller the preset step size, the higher the adjustment accuracy, and the adjustment accuracy of the embodiment of the utility model can reach 0.05V.

After the main control unit 12 receives the adjustment command to restore the default value, the main control unit 12 controls the output voltage to return to the default value unchanged, and the default value is generally a voltage value between the power-on threshold and the power-off threshold.

Here, the main control unit 12 controls the change of the output voltage through the outputted PWM voltage adjustment signal, and the purpose of controlling the change of the output voltage can be achieved by changing the duty ratio of the PWM voltage adjustment signal by operating the key on the control terminal.

In the process of voltage automatic adjustment, you can also press the adjustment button again to pause and stop the adjustment at the target voltage point, and then press the same adjustment button again to start again and continue to adjust the output voltage.

According to the PWM voltage adjustment signal, the power output unit 13 correspondingly adjusts the output power supply voltage, and the input end of the power output unit 13 is connected to the output end of the main control unit 12;

In the embodiment of the present invention, the power output unit 13 filters, op-amps, and stabilizes the PWM voltage adjustment signal as a power output, and outputs a changed power supply voltage according to the change of the PWM voltage adjustment signal.

When it is detected that the output current is too large, the protection unit 14 that controls the main control unit 12 to perform overcurrent protection, the input terminal of the protection unit 14 is connected to the output terminal of the power output unit 13, and the output terminal of the protection unit 14 is connected to the feedback of the main control unit 12. terminal connection;

In the embodiment of the present utility model, the protection unit 14 determines whether the current exceeds the range of the safe current that it can carry by detecting the output current, and generates an overcurrent protection after exceeding the range of the safe current (preset current protection threshold) The control command is fed back to the main control unit 12, and the main control unit 12 controls the output voltage to stop increasing according to the over-current protection control command and controls the corresponding over-current protection device to realize over-current protection.

After the protection unit 14 also monitors that the control circuit of the electronic product (the power supply monitoring control board of the car refrigerator) has an action signal feedback, it reports to the main control unit 12, and the main control unit 12 controls to stop the boost/down regulation function (output voltage Stop increasing/decreasing), at this time, the protection unit 14 detects the working voltage on the power monitoring control board or suspends the working voltage.

Current limiting resistor R5, one end of the current limiting resistor R5 is connected to the output end of the power output unit 13 and the input end of the protection unit 14 at the same time, and the other end of the current limiting resistor R5 is the output end VOUT of the DC power automatic adjustment circuit and the protection unit 14 The detection terminal connection.

In the embodiment of the utility model, the default output voltage of the DC power supply automatic adjustment circuit is the preset default value voltage after power-on. At this time, you can press the boost adjustment button to trigger the boost adjustment function, or press the step-down adjustment button. Press the button to trigger the step-down regulation function. After triggering the boost regulation function, the output voltage automatically increases according to the preset step size. After triggering the boost regulation function, the output voltage automatically decreases according to the preset step size until it passes through the output After detecting that the control circuit of the electronic product (the power monitoring control board of the car refrigerator) has an action signal feedback, for example, the power monitoring control board outputs a signal to control the startup/shutdown of the car refrigerator after the output power reaches the startup/shutdown threshold, and then stops the boost / Buck regulation function (the output voltage stops increasing/decreasing), and detects the working voltage on the power monitoring control board or suspends the working voltage. That is, after the load under test completes the corresponding operation after setting the power supply value (complete the function verification), the output voltage adjustment can be stopped. At this time, the default value recovery button can be pressed to trigger the output voltage to return to the default value for the next step. Item function verification.

The embodiment of the utility model automatically realizes step-up/step-down adjustment by lightly touching the trigger power supply, and automatically stops power supply adjustment after detecting the action execution signal of the circuit under test, realizing one-button automatic voltage output adjustment, which greatly saves manpower cost, its adjustment accuracy is high, the adjustment is uniform and fast, and the output voltage is stable, which greatly improves the production efficiency and quality. Stream protection and other functions are convenient for users to operate and record.

Fig. 2 shows an example circuit structure of the DC power supply automatic adjustment circuit provided by the embodiment of the present invention. For the convenience of description, only the parts related to the present invention are shown.

As an embodiment of the present invention, the DC power supply automatic adjustment circuit may also include:

The display unit 15 that displays the current adjustment state in real time through the prompt light, the power supply terminal of the display unit 15 is connected with the output terminal of the power conversion unit 11, at least one drive terminal of the display unit 15 is connected with the display output terminal of the main control unit 12, and the display unit At least one driving end of 15 is connected with the output end of the DC power automatic adjustment circuit.

In the embodiment of the present utility model, the functions of step-up regulation, step-down regulation and default value recovery can be displayed through a plurality of LED lights of different colors. The output voltage is rising continuously. When the yellow LED stops flashing and stays bright, it means that the boost regulation is over and the output voltage stops rising; when the green LED lights flashes, it means that the step-down regulation function is in progress, and the output voltage is falling continuously. When the green LED light stops flashing and remains bright, it means that the step-down regulation is over, and the output voltage stops decreasing; when the red LED is bright, it means that the function of restoring the default value is in progress, and the output voltage remains unchanged at the default value.

As a preferred embodiment of the present invention, the power conversion unit 11 includes:

Diode D1, capacitor C1, capacitor C2, capacitor E1, capacitor E2 and DC-DC power chip U1;

The anode of the diode D1 is the input end of the power conversion unit 11, the cathode of the diode D1 is connected to one end of the capacitor E2 and the capacitor C1 at the same time, the other end of the capacitor E2 and the capacitor C1 are connected to the ground at the same time, and the cathode of the diode D1 is also connected to the DC-DC power supply chip The input pin (IN) of U1 is connected, the ground pin (GND) of the DC-DC power supply chip U1 is grounded, and the output pin (OUT) of the DC-DC power supply chip U1 is the output terminal of the power conversion unit 11 and is connected with the capacitor E1 at the same time. , one end of the capacitor C2 is connected, and the other ends of the capacitor E1 and the capacitor C2 are grounded at the same time.

Preferably, for the convenience of plugging, the power conversion unit 11 may further include an interface CN1, and the input end of the power conversion unit 11 is plugged with the direct current power supply DC through the interface CN1.

As a preferred embodiment of the present invention, the main control unit 12 includes:

Resistor R1, resistor R2, resistor R3, resistor R4, resistor R10, resistor R13, resistor R14, resistor R15, resistor R19, resistor R21, resistor R22, capacitor C3, capacitor C4, first switching tube Q1, crystal oscillator Y1, first A controllable switch SW1, a second controllable switch SW2, a third controllable switch SW3 and a processor U3;

One end of the resistor R3 is the trigger control end of the main control unit 12, the other end of the resistor R3 is connected to the control end of the first switch tube Q1 and one end of the resistor R4 at the same time, and the output end of the first switch tube Q1 is connected to the other end of the resistor R4 Grounded at the same time, the input end of the first switch tube Q1 is connected to one end of the resistor R1 and one end of the resistor R2 at the same time, the other end of the resistor R1 is the power supply end of the main control unit 12, the other end of the resistor R2 is grounded through the capacitor C2, and the resistor R2 The other end is also connected with the trigger pin (P0.0/ADC0/INT0) of the processor U3, the detection pin (P0.1/ADC1/INT1) of the processor U3 is the feedback end of the main control unit 12, and the processor U3 At the same time, the power supply pin (VDD) of the main control unit 12 is grounded through the capacitor C4, the clock input terminal (XIN/P1.0) of the processor U3 is connected to one pole of the crystal oscillator Y1, and the clock output terminal of the processor U3 (XOUT/P1.1) is connected to the other pole of the crystal oscillator Y1, the base terminal of the crystal oscillator Y1 is grounded, the reset terminal (RESET/P1.2) of the processor U3 is grounded through the resistor R10, and the multiple data output pins of the processor U3 Pins (P2.2, P2.3) are multiple display output terminals of the main control unit 12, one end of the resistance R13, resistance R14, and resistance R15 is simultaneously the power supply end of the main control unit 12, and the resistance R13, resistance R14, and resistance R15 are The other end of the resistor R19, the resistor R21, and one end of the resistor R22 are respectively connected to each other, and the other end of the resistor R19, the resistor R21, and the resistor R22 are respectively connected to the first, second, and third control input pins (P0.5 /ADC5, P0.7/ADC7, P2.6/ADC8/CLO), the other end of resistor R13, resistor R14, and resistor R15 are connected to the first controllable switch SW1, the second controllable switch SW2, and the third controllable switch SW1 respectively. One conducting end of the controllable switch SW3 is connected, the other conducting end of the first controllable switch SW1, the second controllable switch SW2, and the third controllable switch SW3 are grounded, the first controllable switch SW1, the second controllable switch The control terminals of SW2 and the third controllable switch SW3 are multiple operation control terminals of the main control unit 12 , and the PWM output pin (P0.6/ADC6/PWM) of the processor U3 is the output terminal of the main control unit 12 .

Preferably, a key switch or a touch switch can be selected as the controllable switch, and the user inputs a corresponding adjustment instruction by lightly touching the key.

As a preferred embodiment of the present invention, the power output unit 13 includes:

Resistor R11, resistor R16, resistor R23, resistor R24, variable resistor R20, capacitor C5, capacitor C6, capacitor C7, capacitor C8, first operational amplifier U2A and power output chip U4;

One end of the resistor R23 is the input end of the power output unit 13, the other end of the resistor R23 is connected to one end of the capacitor C6 and one end of the resistor R24 at the same time, the other end of the capacitor C6 is grounded, the other end of the resistor R24 is grounded through the capacitor C8, and the resistor R24 The other end of the first operational amplifier U2A is also connected to the positive input end of the first operational amplifier U2A, and the negative input end of the first operational amplifier U2A is connected to one end of the variable resistor R20 and one end of the resistor R16 at the same time, and the other end of the variable resistor R20 is grounded , the adjustment terminal of the variable resistor R20 is connected with the inverting input terminal of the first operational amplifier U2A, the other end of the resistor R16 is connected with the reference voltage pin (ADJ) of the power output chip U4, and the output terminal of the first operational amplifier U2A is passed through The capacitor C7 is grounded, the output terminal of the first operational amplifier U2A is also connected to the reference voltage pin (ADJ) of the power output chip U4, and the power supply pin of the first operational amplifier U2A is connected to the input pin (VIN) of the power output chip U4 , the output pin (VOUT) of the power output chip U4 is connected to the output end of the power output unit 13 and one end of the resistor R11 and the capacitor C5 at the same time, and the other end of the resistor R11 and the capacitor C5 is connected to the output end of the first operational amplifier U2A at the same time .

Preferably, the power output chip U4 may be a LM317L power output chip.

In the embodiment of the utility model, the PWM voltage regulation signal is initially stabilized by a two-stage high-pass filter, then amplified by an operational amplifier, and then output by an ADJ voltage regulator (power output chip).

As a preferred embodiment of the present invention, the protection unit 14 includes:

Resistor R6, resistor R7, resistor R8, resistor R9 and second operational amplifier U2B;

One end of the resistor R6 is the input end of the protection unit 14, the other end of the resistor R6 is connected to the positive input end of the second operational amplifier U2B, one end of the resistor R9 is the detection end of the protection unit 14, and the other end of the resistor R9 is simultaneously connected to the second operational amplifier U2B. The inverting input terminal of the second operational amplifier U2B is connected to one end of the resistor R8, and the other end of the resistor R8 is connected to the output terminal of the second operational amplifier U2B and one end of the resistor R7 at the same time, and the other end of the resistor R7 is the output terminal of the protection unit 14 .

As a preferred embodiment of the present invention, the display unit 15 includes:

Resistor R17, resistor R18, resistor R23, light emitting diode LED1, light emitting diode LED2 and light emitting diode LED3;

One end of the resistor R17 and the resistor R18 is the power supply terminal of the display unit 15 at the same time, the other ends of the resistor R17 and the resistor R18 are respectively connected to the anodes of the light-emitting diode LED1 and the light-emitting diode LED2, and the cathodes of the light-emitting diode LED1 and the light-emitting diode LED2 are respectively the display unit The first and second driving ends of 15, the anode of the light emitting diode LED3 is the third driving end of the display unit 15, and the cathode of the light emitting diode LED3 is grounded through the resistor R23.

Function Description:

The default output voltage of the DC power supply automatic adjustment circuit provided by the embodiment of the utility model is the preset default value voltage after power-on. At this time, press the boost adjustment button to trigger the boost adjustment function, and the output voltage will automatically follow the preset step length. Regularity rises until the control circuit of the electronic product (the power monitoring control board of the car refrigerator) has an action signal feedback through the output terminal. For example, the power monitoring control board outputs a signal to control the start of the car refrigerator after the output power reaches the start-up threshold. , stop the boost regulation function (the output voltage stops rising), and detect the working voltage on the power monitoring control board;

If you press the step-down adjustment button after power-on, the step-down adjustment function will be triggered, and the output voltage will automatically decrease according to the preset step size until the control circuit of the electronic product (the power monitoring control board of the car refrigerator) is monitored through the output terminal. ) After the action signal is fed back, for example, the power monitoring control board outputs a signal to control the shutdown of the car refrigerator after the output power reaches the shutdown threshold, then the step-down regulation function is stopped (the output voltage stops falling), and the power monitoring control board is detected to suspend work Voltage;

That is to say, when the load under test has performed the corresponding operation at the set power supply value, the function verification is completed. At this time, the output voltage adjustment can be stopped to end the verification. At this time, the default value can be restored by pressing Press the button to trigger the output voltage to return to the default value, and proceed to the next function verification.

Another object of the embodiment of the present utility model is to provide an automatic DC power adjustment device using the above-mentioned DC power automatic adjustment circuit.

The embodiment of the utility model automatically realizes step-up/step-down adjustment by lightly touching the trigger power supply, and automatically stops power supply adjustment after detecting the action execution signal of the circuit under test, realizing one-button automatic voltage output adjustment, which greatly saves manpower cost, its adjustment accuracy is high, the adjustment is uniform and fast, and the output voltage is stable, which greatly improves the production efficiency and quality. Stream protection and other functions are convenient for users to operate and record.

The above are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model should be included in the utility model. within the scope of protection.

Claims (10)

1. a DC power supply auto-adjusting circuit, is connected with DC power supply, it is characterized in that, described circuit comprises:

DC power supply is converted to the power conversion unit of internal supply voltage, the input of described power conversion unit is connected with the output of described DC power supply;

Generate the main control unit of corresponding PWM regulated voltage signal according to the regulating command of user after receiving Trig control signal, described PWM regulated voltage signal is according to the change of default step-length regularity or remain unchanged, the feeder ear of described master control power supply is connected with the output of described power conversion unit, the trigger control end of described main control unit receives Trig control signal, and described main control unit has the operation control end of multiple reception user regulating command;

According to the power stage unit of the corresponding regulation output supply voltage of described PWM regulated voltage signal, the input of described power stage unit is connected with the output of described main control unit;

Control the protected location that described main control unit carries out overcurrent protection when detecting that output current is excessive, the input of described protected location is connected with the output of described power stage unit, and the output of described protected location is connected with the feedback end of described main control unit;

Current-limiting resistance; one end of described current-limiting resistance is connected with the output of described power stage unit and the input of described protected location simultaneously, and the other end of described current-limiting resistance is that the output of described DC power supply auto-adjusting circuit is connected with the test side of described protected location.

2. circuit as claimed in claim 1, it is characterized in that, described operation control end comprises: boosting adjustable side, reduction regulation end and default value reset terminal;

Described regulating command comprises: boosting adjustment, reduction regulation and default value recover.

3. circuit as claimed in claim 1, it is characterized in that, described circuit also comprises:

The display unit of current adjustment state is shown in real time by prompting light, the power end of described display unit is connected with the output of described power conversion unit, at least one drive end of described display unit is connected with the display translation end of described main control unit, and at least one drive end of described display unit is connected with the output of described DC power supply auto-adjusting circuit.

4. circuit as claimed in claim 1, it is characterized in that, described power conversion unit comprises:

Diode D1, electric capacity C1, electric capacity C2, electric capacity E1, electric capacity E2 and DC-DC power source chip;

The anode of described diode D1 is the input of described power conversion unit, the negative electrode of described diode D1 simultaneously with described electric capacity E2, one end of described electric capacity C1 connects, described electric capacity E2, the other end ground connection simultaneously of described electric capacity C1, the negative electrode of described diode D1 is also connected with the input pin IN of described DC-DC power source chip, the grounding pin GND ground connection of described DC-DC power source chip, with described electric capacity E1 while that the output pin OUT of described DC-DC power source chip being the output of described power conversion unit, one end of described electric capacity C2 connects, described electric capacity E1, the other end ground connection simultaneously of described electric capacity C2.

5. circuit as claimed in claim 4, it is characterized in that, described power conversion unit also comprises an interface, and the input of described power conversion unit is by described interface and described DC power supply grafting.

6. circuit as claimed in claim 1, it is characterized in that, described main control unit comprises:

Resistance R1, resistance R2, resistance R3, resistance R4, resistance R10, resistance R13, resistance R14, resistance R15, resistance R19, resistance R21, resistance R22, electric capacity C3, electric capacity C4, the first switching tube, crystal oscillator, the first gate-controlled switch, the second gate-controlled switch, the 3rd gate-controlled switch and processor;

One end of described resistance R3 is the trigger control end of described main control unit, the other end of described resistance R3 is connected with the control end of described first switching tube and one end of described resistance R4 simultaneously, the output of described first switching tube and the other end of described resistance R4 ground connection simultaneously, the input of described first switching tube is connected with one end of described resistance R1 and one end of described resistance R2 simultaneously, the other end of described resistance R1 is described main control unit feeder ear, the other end of described resistance R2 is by described electric capacity C2 ground connection, the other end of described resistance R2 is also connected with the trigger pin P0.0/ADC0/INT0 of described processor, the detection pin P0.1/ADC1/INT1 of described processor is the feedback end of described main control unit, the power pins VDD of described processor is that the power end of described main control unit is by described electric capacity C4 ground connection simultaneously, the input end of clock XIN/P1.0 of described processor is connected with a pole of described crystal oscillator, the output terminal of clock XOUT/P1.1 of described processor is connected with another pole of described crystal oscillator, the base end ground connection of described crystal oscillator, the reset terminal RESET/P1.2 of described processor is by described resistance R10 ground connection, multiple data output pins P2.2 of described processor, P2.3 is multiple display translation ends of described main control unit, described resistance R13, described resistance R14, one end of described resistance R15 is the feeder ear of described main control unit simultaneously, described resistance R13, described resistance R14, the other end of described resistance R15 respectively with described resistance R19, described resistance R21, one end of described resistance R22 connects, described resistance R19, described resistance R21, the other end of described resistance R22 respectively with first of described processor, second, 3rd control inputs pin P0.5/ADC5, P0.7/ADC7, P2.6/ADC8/CLO connects, described resistance R13, described resistance R14, the other end of described resistance R15 is also respectively with described first, second, one conduction terminal of the 3rd gate-controlled switch connects, described first, second, another conduction terminal ground connection of 3rd gate-controlled switch, described first, second, the control end of the 3rd gate-controlled switch is multiple operation control ends of described main control unit, the PWM output pin P0.6/ADC6/PWM of described processor is the output of described main control unit.

7. circuit as claimed in claim 1, it is characterized in that, described power stage unit comprises:

Resistance R11, resistance R16, resistance R23, resistance R24, variable resistor R20, electric capacity C5, electric capacity C6, electric capacity C7, electric capacity C8, the first operational amplifier and motor driving IC;

One end of described resistance R23 is the input of described power stage unit, the other end of described resistance R23 is connected with one end of described electric capacity C6 and one end of described resistance R24 simultaneously, the other end ground connection of described electric capacity C6, the other end of described resistance R24 is by described electric capacity C8 ground connection, the other end of described resistance R24 is also connected with the positive input of described first operational amplifier, the reverse input end of described first operational amplifier is connected with one end of described variable resistor R20 and one end of described resistance R16 simultaneously, the other end ground connection of described variable resistor R20, the adjustable side of described variable resistor R20 is connected with the reverse input end of described first operational amplifier, the other end of described resistance R16 is connected with the reference voltage pin ADJ of described motor driving IC, the output of described first operational amplifier is by described electric capacity C7 ground connection, the output of described first operational amplifier is also connected with the reference voltage pin ADJ of described motor driving IC, the power pins of described first operational amplifier is connected with the input pin VIN of described motor driving IC, the output pin VOUT of described motor driving IC is connected with one end of described resistance R11 and described electric capacity C5 while of being the output of described power stage unit, described resistance R11 is connected with the output of described first operational amplifier with the other end of described electric capacity C5 simultaneously.

8. circuit as claimed in claim 1, it is characterized in that, described protected location comprises:

Resistance R6, resistance R7, resistance R8, resistance R9 and the second operational amplifier;

One end of described resistance R6 is the input of described protected location; the other end of described resistance R6 is connected with the positive input of described second operational amplifier; one end of described resistance R9 is the test side of described protected location; the other end of described resistance R9 is connected with the reverse input end of described second operational amplifier and one end of described resistance R8 simultaneously; the other end of described resistance R8 is connected with the output of described second operational amplifier and one end of described resistance R7 simultaneously, and the other end of described resistance R7 is the output of described protected location.

9. circuit as claimed in claim 3, it is characterized in that, described display unit comprises:

Resistance R17, resistance R18, resistance R23, LED 1, LED 2 and LED 3;

One end of described resistance R17, described resistance R18 is the power end of described display unit simultaneously, the other end of described resistance R17, described resistance R18 is connected with the anode of described LED 1, described LED 2 respectively, the negative electrode of described LED 1, described LED 2 is respectively first, second drive end of described display unit, the anode of described LED 3 is the 3rd drive end of described display unit, and the negative electrode of described LED 3 is by described resistance R23 ground connection.

10. a DC power supply automatic regulating equipment, is characterized in that, described device comprises the DC power supply auto-adjusting circuit as described in any one of claim 1 to 9.