Power supply circuit

Abstract

The utility model discloses a power supply circuit which comprises a signal conditioning circuit, an operational amplifier circuit, a current sampling circuit and a voltage sampling circuit, the signal conditioning circuit is coupled with the operational amplifier circuit, the output end of the operational amplifier circuit is used for being coupled with a load, and the current sampling circuit is used for collecting current output by the operational amplifier circuit. The voltage sampling circuit is used for collecting the voltage output by the operational amplifier circuit, and the output ends of the current sampling circuit and the voltage sampling circuit are both coupled to the signal conditioning circuit. According to the utility model, based on the feedback current and voltage, the current and voltage can be adjusted through the signal conditioning circuit, the output current and voltage are ensured to be stable, on one hand, the stable voltage can be output under the condition of a variable current type load, and on the other hand, the stable current can be output under the condition of a variable voltage type load; according to the utility model, the dynamic response of the circuit is high, the output can be rapidly adjusted when the load changes, the stability and precision of the output voltage can be ensured, and the stability and precision of the output current can also be ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to power supply circuit control technical field especially relates to a power supply circuit. BACKGROUND

[0002] In the design and application of modern electronic products, power supply technology plays a pivotal role, which is the basis for ensuring the stable operation of various electronic devices and realizing efficient function conversion. With the rapid development of science and technology, from portable consumer electronic products such as smart phones and tablet computers to industrial control devices, data center servers and complex medical electronic systems, the requirements for power supply are increasingly strict. These applications not only require the power supply to provide stable and reliable DC voltage output, but also emphasize high efficiency, low noise (i.e. small ripple), fast response to load changes, and good electromagnetic compatibility (EMC) and other characteristics.

[0003] However, the traditional power supply has certain limitations in efficiency and accuracy, especially when facing load changes, the output voltage may fluctuate, affecting the power supply quality. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of power supply circuit, to solve the certain limitations of traditional power supply in efficiency and accuracy in prior art, especially when facing load changes, the output voltage may fluctuate, affecting the power supply quality.

[0005] To realize one of the above utility model purposes, one embodiment of the utility model provides a kind of power supply circuit, the circuit includes: signal conditioning circuit, operational amplifier circuit, current sampling circuit and voltage sampling circuit, the signal conditioning circuit is coupled with the operational amplifier circuit, the output end of the operational amplifier circuit is used to be coupled with load, the current sampling circuit is used to collect the current output by the operational amplifier circuit, the voltage sampling circuit is used to collect the voltage output by the operational amplifier circuit, the output end of the current sampling circuit and the voltage sampling circuit is all coupled with the signal conditioning circuit;

[0006] The signal conditioning circuit is used to adjust output current and output voltage, wherein the signal conditioning circuit adjusts output current so that output current is constant, or the signal conditioning circuit adjusts output voltage so that output voltage is constant.

[0007] As a further improvement of the utility model, the circuit further includes: first operational amplifier, the first input end of the first operational amplifier receives set current, the second input end of the first operational amplifier receives the output current fed back by the current sampling circuit, and the output end of the first operational amplifier is coupled with the operational amplifier circuit.

[0008] A second operational amplifier, a first input end of the second operational amplifier receives a set voltage, a second input end of the second operational amplifier receives an output voltage fed back by the voltage sampling circuit, and an output end of the second operational amplifier is coupled to the first input end of the first operational amplifier through a first switch branch and a second switch branch arranged in parallel.

[0009] As a further improvement of the utility model, the circuit further comprises: when the output voltage is less than the set voltage in the charging state, the first switch branch is turned on, and the output current is constant as the set current value; when the output voltage is equal to the set voltage, the second switch branch is turned on, and the output voltage is constant as the set voltage value.

[0010] As a further improvement of the utility model, the circuit further comprises: the first switch branch comprises a first diode and a first switch, a cathode of the first diode is coupled to the output end of the second operational amplifier, and an anode of the first diode is coupled to the first input end of the first operational amplifier through the first switch.

[0011] The second switch branch comprises a second diode and a second switch, an anode of the second diode is coupled to the output end of the second operational amplifier, and a cathode of the second diode is coupled to the first input end of the first operational amplifier through the second switch.

[0012] As a further improvement of the utility model, the circuit further comprises: a first resistor and a first capacitor are arranged in series between the second input end and the output end of the second operational amplifier; and a second resistor and a second capacitor are arranged in series between the second input end and the output end of the first operational amplifier.

[0013] As a further improvement of the utility model, the circuit further comprises: the output end of the operational amplifier circuit is connected to the load through a sampling resistor.

[0014] The current sampling circuit comprises a third operational amplifier, a first input end and a second input end of the third operational amplifier are coupled to two ends of the sampling resistor respectively, and an output end of the third operational amplifier is coupled to the signal conditioning circuit to feed back the output current of the operational amplifier circuit.

[0015] As a further improvement of the utility model, the circuit further comprises: a third input end and a fourth input end of the third operational amplifier are coupled together through a third resistor, the first input end of the third operational amplifier is coupled to one end of the sampling resistor through a fourth resistor, the second input end of the third operational amplifier is coupled to the other end of the sampling resistor through a fifth resistor, and the first input end and the second input end of the third operational amplifier are further coupled together through a third capacitor.

[0016] As a further improvement of the utility model, the circuit further comprises: the voltage sampling circuit comprises a fourth operational amplifier, the first input end of the fourth operational amplifier is coupled with the first end of the load, the second end of the load is coupled with a reference ground, the second input end of the fourth operational amplifier is coupled with the output end of the fourth operational amplifier, and the output end of the fourth operational amplifier is further coupled to the signal conditioning circuit to feed back the output voltage of the operational amplifier circuit.

[0017] As a further improvement of the utility model, the circuit further comprises: the operational amplifier circuit comprises a fifth operational amplifier, the first input end of the third operational amplifier is coupled with the signal conditioning circuit, the second input end of the third operational amplifier is coupled with the output end of the third operational amplifier, and the output end of the third operational amplifier is further coupled with the load.

[0018] As a further improvement of the utility model, the circuit further comprises: the signal conditioning circuit and the operational amplifier circuit are connected through a sixth resistance, the operational amplifier circuit is connected with the load through a series connection of a seventh resistance and a sampling resistance, the current sampling circuit is connected with the signal conditioning circuit through an eighth resistance, and the voltage sampling circuit is connected with the signal conditioning circuit through a ninth resistance; the current sampling circuit collects the output current through the sampling resistance.

[0019] Compared with the prior art, the utility model has the following beneficial effects: based on the feedback current and voltage of the current sampling circuit and the voltage sampling circuit, the current voltage can be adjusted through the signal conditioning circuit, the output current and voltage are ensured to be stable, on the one hand, stable voltage can be output under the condition of the changeable current type load, and on the other hand, stable current can be output under the condition of the changeable voltage type load; the utility model circuit has high dynamic response, can quickly adjust the output when the load changes, ensures the stability and precision of the output voltage, and also can ensure the stability and precision of the output current. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is the system schematic diagram of power supply circuit in an embodiment of the utility model.

[0021] Figure 2 It is the circuit structure schematic diagram of power supply circuit in an embodiment of the utility model. DETAILED DESCRIPTION

[0022] The utility model will be described in detail in combination with the specific implementation shown in the drawings. But these implementation does not limit the utility model, the conversion of structure, method or function made by the ordinary skill in the art according to these implementation is included in the protection scope of the utility model.

[0023] The utility model provides a kind of power supply circuit, which is used to power load. In addition, the power supply circuit can also be used to charge or discharge battery to detect battery performance. For example, lithium battery is charged and discharged.

[0024] The power supply circuit provides stable current and voltage to the load and can adjust output current and output voltage in real time when the load changes.

[0025] As shown in Figure 1 The power supply circuit includes signal conditioning circuit 1, operational amplifier circuit 2, current sampling circuit 3 and voltage sampling circuit 4.

[0026] The signal conditioning circuit 1 is coupled to the operational amplifier circuit 2, and the output end of the operational amplifier circuit 2 is used to couple the load.

[0027] The signal conditioning circuit 1 is used to control the output current and voltage, which are amplified by the operational amplifier circuit 2 and supplied to the load.

[0028] In one embodiment, the operational amplifier circuit 2 includes a power operational amplifier.

[0029] The current sampling circuit 3 is used to collect the current output by the operational amplifier circuit 2, and the voltage sampling circuit 4 is used to collect the voltage output by the operational amplifier circuit 2. The output ends of the current sampling circuit 3 and the voltage sampling circuit 4 are both coupled to the signal conditioning circuit 1.

[0030] In this way, the current and voltage output to the load can be detected in real time when the power supply circuit supplies power. The voltage is the load voltage, and the current is the current flowing through the load. The output ends of the current sampling circuit 3 and the voltage sampling circuit 4 are both coupled to the signal conditioning circuit 1, so that the detected current and voltage can be fed back to the signal conditioning circuit 1, which adjusts according to the feedback current and voltage.

[0031] The signal conditioning circuit 1 is used to adjust the output current and output voltage. The signal conditioning circuit 1 adjusts the output current to make it constant, or the signal conditioning circuit 1 adjusts the output voltage to make it constant. Specifically, the output current is the current flowing through the load, and the output voltage is the load voltage.

[0032] On the one hand, the signal conditioning circuit 1 adjusts the output current to make it constant, which is supplied to the load by constant current. When the load is a battery pack, the battery pack is charged by constant current. In this process, the output voltage at the load end gradually increases, and when the output voltage reaches the set value, the signal conditioning circuit 1 supplies power to the load with constant voltage and adjusts the output voltage clock to keep it constant. In this process, the output current gradually decreases.

[0033] Of course, the load end changes can also be adapted by adjusting the current and voltage. When the load changes, the output voltage is kept constant by adjusting the current, or the output current is kept constant by adjusting the voltage, or the current and voltage are adjusted to increase or decrease the current voltage simultaneously. The control mode of the power supply circuit is diversified, and can be flexibly matched.

[0034] The signal conditioning circuit 1 is configured to receive a set current Ia and a set voltage Va, and output corresponding current and voltage according to the set current Ia and the set voltage Va. The output current and the output voltage are related to the set current Ia and the set voltage Va.

[0035] The utility model can change the output current and the output voltage by adjusting the value of the set current Ia and the set voltage Va.

[0036] According to the above embodiment, the current supplied to the load is kept stable output, or the voltage supplied to the load is kept stable output. It can also be quickly detected and adjusted when the load changes.

[0037] In an embodiment, a high-precision, low-temperature-coefficient resistor is connected in series at the output end of the operational amplifier circuit 2, and the current sampling circuit 3 and the voltage sampling circuit 4 both detect the current and voltage through the resistor. The high-precision, low-temperature-coefficient resistor can ensure the accuracy of detection.

[0038] As shown in Figure 2 An embodiment of the utility model discloses a signal conditioning circuit 1 comprising a first operational amplifier 11 and a second operational amplifier 12.

[0039] The first input end of the first operational amplifier 11 receives the set current Ia, the second input end of the first operational amplifier 11 receives the output current fed back by the current sampling circuit 3, and the output end of the first operational amplifier 11 is coupled to the operational amplifier circuit 2.

[0040] The first input end of the second operational amplifier 12 receives the set voltage Va, the second input end of the second operational amplifier 12 receives the output voltage fed back by the voltage sampling circuit 4, and the output end of the second operational amplifier 12 is coupled to the first input end of the first operational amplifier 11 through the parallelly arranged first switch branch and second switch branch.

[0041] In an embodiment, the first input end of the first operational amplifier 11 is a non-inverting input end, and the second input end of the first operational amplifier 11 is an inverting input end.

[0042] In an embodiment, the first input end of the second operational amplifier 12 is a non-inverting input end, and the second input end of the second operational amplifier 12 is an inverting input end.

[0043] Specifically, one end of the first switch branch is coupled to the output of the second operational amplifier 12, and the other end is coupled to the first input of the first operational amplifier 11. One end of the second switch branch is coupled to the output of the second operational amplifier 12, and the other end is coupled to the first input of the first operational amplifier 11.

[0044] The set current Ia and the set voltage Va are externally inputted. For example, the external device can be a DSP processor, a host computer, etc.

[0045] The first operational amplifier 11 is used to eliminate the error of the feedback output current, and the second operational amplifier 12 is used to eliminate the error of the feedback output voltage.

[0046] When the first switch branch is turned on, the output current is constant and equal to the set current value, and when the second switch branch is turned on, the output voltage is constant and equal to the set voltage value. Specifically, when the power supply circuit is in the charging state, the output voltage is less than the set voltage Va, the first switch branch is turned on, and the output voltage is equal to the set voltage Va, and the second switch branch is turned on.

[0047] When the output voltage is less than the set voltage Va, the first switch branch is turned on, and the signal conditioning circuit 1 controls the operational amplifier circuit 2 to output a constant current related to the set current Ia value. When the output voltage reaches the set voltage Va, the second switch branch is turned on, and the signal conditioning circuit 1 controls the operational amplifier circuit 2 to output a constant voltage related to the set voltage Va value.

[0048] In an embodiment, when the output current changes and has an error with the set current Ia, the first operational amplifier 11 adjusts the output current to eliminate the difference between the set current Ia.

[0049] In an embodiment, when the output voltage changes and has an error with the set voltage Va, the second operational amplifier 12 adjusts the output voltage to eliminate the difference between the set voltage Va.

[0050] The first operational amplifier 11 and the second operational amplifier 12 compare the feedback output current and the output voltage with the set current Ia and the set voltage Va, so that the output voltage approaches or is equal to the set voltage Va, and the output current approaches or is equal to the set current Ia. Thus, the power supply circuit can output stable current and voltage.

[0051] In other embodiments, the set current Ia and the set voltage Va in the signal conditioning circuit 1 can also be controlled to change the output current and the output voltage of the power supply circuit, or to change the output current or the output voltage of the power supply circuit alone to adapt to different requirements of the load.

[0052] When the power supply circuit adopts constant voltage power supply mode, if the load change causes the output voltage to change, the signal conditioning circuit 1 adjusts the output current so that the output voltage remains constant. For example, when the output voltage has a decreasing trend, the output current is increased to raise the output voltage. Conversely, the output current is reduced.

[0053] When the power supply circuit adopts constant current power supply mode, if the load change causes the output current to change, the signal conditioning circuit 1 adjusts the output voltage so that the output current remains constant. For example, when the output current has a decreasing trend, the output voltage is raised to increase the output current. Conversely, the output voltage is reduced.

[0054] Specifically, the signal conditioning circuit 1 outputs constant voltage based on the dynamic adjustment of the set current Ia or outputs constant current based on the dynamic adjustment of the set voltage Va.

[0055] On the one hand, the set current Ia or the set voltage Va can be adjusted to control the required and stable current and voltage output by the power supply circuit.

[0056] On the other hand, when constant current output, the current is kept constant by controlling the change of the voltage. The output current fed back by the current sampling circuit 3 is used to control the following change of the voltage when the load changes, so that the operational amplifier circuit 2 outputs stable current. When constant voltage output, the voltage is kept constant by controlling the change of the current. The output current fed back by the voltage sampling circuit 4 is used to control the following change of the current when the load changes, so that the operational amplifier circuit 2 outputs stable voltage.

[0057] Thus, based on the technical solutions of constant current power supply or constant voltage power supply provided by the embodiment, the power supply circuit of the utility model provides flexible power supply mode, which can meet the constant voltage demand of the load and also realize constant current power supply; support accurate charging and discharging control of the battery, which is used for efficiently and accurately detecting the battery performance; enhance the safety and stability of the circuit, and ensure reliable operation under various working conditions.

[0058] In an embodiment of the utility model, the first switch branch includes a first diode D1 and a first switch K1, the cathode of the first diode D1 is coupled to the output end of the second operational amplifier 12, and the anode of the first diode D1 is coupled to the first input end of the first operational amplifier 11 through the first switch K1. The second switch branch includes a second diode D2 and a second switch K2, the anode of the second diode D2 is coupled to the output end of the second operational amplifier 12, and the cathode of the second diode D2 is coupled to the first input end of the first operational amplifier 11 through the second switch K2.

[0059] The power supply circuit is in the initial state, the output voltage is less than the set voltage Va, the first switch K1 is closed, the first switch branch is turned on, the cathode of the first diode D1 is connected with the output terminal of the second operational amplifier 12, the first diode D1 works in reverse blocking, at this time, the output terminal of the second operational amplifier 12 cannot output the voltage of the first operational amplifier 11, the first operational amplifier 11 outputs the current related to the set current Ia, the power supply current outputs the constant current, and is in the constant current mode. In the constant current mode, the output voltage rises, when the output voltage reaches the set voltage Va, the second switch K2 is closed, the second switch branch is turned on, the anode of the second diode D2 is connected with the output terminal of the second operational amplifier 12, the second diode D2 works in forward conduction, at this time, the output terminal of the second operational amplifier 12 outputs the set voltage Va to the first operational amplifier 11, the first operational amplifier 11 outputs the voltage related to the set voltage Va, and the power supply current outputs the constant voltage.

[0060] Therefore, when the signal conditioning circuit 1 is initially operated, the constant current output is maintained, the output voltage is gradually increased, when the output voltage is increased to the set voltage Va, the second switch branch is controlled to be turned on, and the constant voltage output is performed. In this way, the signal conditioning circuit 1 can maintain the stable voltage and current output, and the stable voltage and current are the set voltage and current.

[0061] In an embodiment, during the operation of the signal conditioning circuit 1, the signal conditioning circuit 1 receives the output current and the output voltage collected by the current sampling circuit 3 and the voltage sampling circuit 4 in real time. When the output current and the output voltage change due to the change of the load, the first operational amplifier 11 can adjust the output current according to the difference between the output current and the set current Ia, so that the output current approaches or is the same as the set current Ia; the second operational amplifier 12 can adjust the output voltage according to the difference between the output voltage and the set voltage Va, so that the output voltage approaches or is the same as the set voltage Va.

[0062] Further, the first resistor R1 and the first capacitor C1 are connected in series between the second input terminal and the output terminal of the second operational amplifier 12; the second resistor R2 and the second capacitor C2 are connected in series between the second input terminal and the output terminal of the first operational amplifier 11.

[0063] The first resistor R1 and the first capacitor C1 arranged in series and the second resistor R2 and the second capacitor C2 arranged in series are both used for filtering and eliminating noise and improving gain. The first resistor R1 and the first capacitor C1 arranged in series can also form a negative feedback network, which helps to suppress self-oscillation of the second operational amplifier 12, improves the stability of the circuit, and reduces the non-linear distortion of the amplifier, thereby improving the linearity and accuracy of the output signal. By selecting appropriate resistance and capacitance values, the frequency response characteristics of the second operational amplifier 12 can be adjusted to better meet the application requirements. This helps to reduce the impact of high-frequency noise on the circuit and improve the signal-to-noise ratio of the output signal.

[0064] Similarly, the second resistor R2 and the second capacitor C2 arranged in series have the same effect on the first operational amplifier 11.

[0065] In one embodiment of the present application, the output end of the operational amplifier circuit 2 is connected to the load through a sampling resistor 5. The operational amplifier circuit 2 is used to drive the load and provide sufficient current and power output. The operational amplifier circuit 2 has the characteristics of high gain.

[0066] The current sampling circuit 3 detects the current flowing through the sampling resistor 5 to collect the value of the output current. The current flowing through the load generates a voltage, which is the output voltage and also the load voltage. The voltage sampling circuit 4 collects the output voltage.

[0067] The current sampling circuit 3 includes a third operational amplifier 31, the first input end and the second input end of the third operational amplifier 31 are respectively coupled to the two ends of the sampling resistor 5, and the output end of the third operational amplifier 31 is coupled to the signal conditioning circuit 1 to feedback the output current of the operational amplifier circuit 2. In this way, the current flowing through the sampling resistor 5 can be received. Specifically, the sampling resistor 5 converts the current flowing through it into a voltage for the third operational amplifier 31 to collect. By measuring the voltage drop across the sampling resistor 5, the output current can be monitored in real time. In one embodiment, the third operational amplifier 31 is a high-input-impedance high-gain instrument amplifier that can detect small voltage differences, ensuring the stability and accuracy of the current output.

[0068] The third input end and the fourth input end of the third operational amplifier 31 are coupled together through a third resistor R3, the first input end of the third operational amplifier 31 is coupled to one end of the sampling resistor 5 through a fourth resistor R4, the second input end of the third operational amplifier 31 is coupled to the other end of the sampling resistor 5 through a fifth resistor R5, and the first input end and the second input end of the third operational amplifier 31 are also coupled together through a third capacitor C3. The third resistor R3 is used to configure the gain of the third operational amplifier 31. The third capacitor C3 and the third resistor R also ensure the stability of the current sampling signal.

[0069] In one embodiment, the first input terminal of the third operational amplifier 31 is a non-inverting input terminal, and the second input terminal of the third operational amplifier 31 is an inverting input terminal.

[0070] The voltage sampling circuit 4 comprises a fourth operational amplifier 41, the first input terminal of the fourth operational amplifier 41 is coupled to the first terminal of the load, the second terminal of the load is coupled to a reference ground, and the second input terminal of the fourth operational amplifier 41 is coupled to the output terminal of the fourth operational amplifier 41, and the output terminal of the fourth operational amplifier 41 is further coupled to the signal conditioning circuit 1 to feed back the output voltage of the operational amplifier circuit 2. The fourth operational amplifier 41 is a voltage follower, which mainly provides high input impedance and low output impedance, thereby ensuring that the voltage feedback signal is not affected by the load. In one embodiment, the fourth operational amplifier 41 is a low-temperature-coefficient high-gain operational amplifier.

[0071] The output current flows into the first terminal of the load and flows out of the second terminal of the load to the reference ground, and the fourth operational amplifier 41 collects the voltage of the load. Specifically, the output current flows through the load, and the fourth operational amplifier 41 collects the voltage generated on the load.

[0072] The first terminal of the load is a positive terminal, and the second terminal of the load is a negative terminal. The positive terminal receives the output current, and the negative terminal connects the reference ground to flow out the output current.

[0073] In one embodiment, the first input terminal of the fourth operational amplifier 41 is a non-inverting input terminal, and the second input terminal of the fourth operational amplifier 41 is an inverting input terminal.

[0074] In one embodiment of the utility model, the operational amplifier circuit 2 comprises a fifth operational amplifier 21, the first input terminal of the fifth operational amplifier 21 is coupled to the signal conditioning circuit 1, the second input terminal of the fifth operational amplifier 21 is coupled to the output terminal of the fifth operational amplifier 21, and the output terminal of the fifth operational amplifier 21 is further coupled to the load.

[0075] The fifth operational amplifier 21 is a high-gain power operational amplifier, and the supply voltage thereof is a positive and negative voltage to improve the dynamic range thereof, thereby ensuring that it can output current and also absorb current.

[0076] It should be noted that when the operational amplifier circuit 2 absorbs current (absorbs electric energy, that is, controls the battery pack to discharge), the signal conditioning circuit 1 is converted from constant voltage output to constant current output. That is, according to the set voltage Va, the battery pack is controlled to discharge, and as the output current increases, when the set current Ia is reached, the signal conditioning circuit 1 is switched to constant current output.

[0077] In one embodiment, the first input terminal of the fifth operational amplifier 21 is a non-inverting input terminal, and the second input terminal of the fifth operational amplifier 21 is an inverting input terminal.

[0078] In one embodiment of the utility model, signal conditioning circuit 1 and the sixth resistance R6 between the operational amplifier circuit 2 are connected, the operational amplifier circuit 2 is connected the load through the seventh resistance R7 and sampling resistance 5 in series, the current sampling circuit 3 is connected signal conditioning circuit 1 through the eighth resistance R8, the voltage sampling circuit 4 is connected signal conditioning circuit 1 through the ninth resistance R9;The current sampling circuit 3 is collected the output current through the sampling resistance 5.Eighth resistance R8 and ninth resistance R9 main effect is current limiting, also help to reduce the noise of output signal.

[0079] The first input end of the first operational amplifier 11 receives the set voltage Va through the tenth resistance R10, wherein the sixth resistance R6, the tenth resistance R10, the first operational amplifier 11, the second resistance R2 and the second capacitor C2 constitute a current loop conditioning loop, which can effectively eliminate the static error of voltage feedback and current feedback, can automatically adjust to cope with load variation and temperature drift, can quickly respond to input changes, and keep the stability of output voltage and current.

[0080] In the above embodiment, the resistance values of the sixth resistance R6, the seventh resistance R7, the eighth resistance R8, the ninth resistance R9 and the tenth resistance R10 are selected according to the circuit configuration, which is not limited here. The current limiting resistance is used to limit the current size in the circuit to prevent the current from being too large to damage other elements in the circuit, which can effectively control the current passing through the circuit to keep it within the bearing range of the elements.

[0081] In summary, the utility model provides a power supply circuit to solve the certain limitation of traditional power supply in efficiency and precision in the prior art, especially when facing load variation, the output voltage may fluctuate, which affects the power supply quality. Signal conditioning circuit 1, operational amplifier circuit 2, current sampling circuit 3 and voltage sampling circuit 4 are adopted. Signal conditioning circuit 1 is coupled with operational amplifier circuit 2, and the output end of operational amplifier circuit 2 is used to couple the load. Current sampling circuit 3 is used to collect the current output by operational amplifier circuit 2, and voltage sampling circuit 4 is used to collect the voltage output by operational amplifier circuit 2, and the output ends of current sampling circuit 3 and voltage sampling circuit 4 are both coupled with signal conditioning circuit 1. Signal conditioning circuit 1 receives set current Ia and set voltage Va.

[0082] Through the above configuration, the signal conditioning circuit 1 outputs stable current and voltage based on the set current Ia and the set voltage Va to ensure the output current and the output voltage of the power supply circuit stable, and the signal conditioning circuit 1 also adjusts the output of the current and voltage based on the output current and the output voltage fed back by the current sampling circuit 3 and the voltage sampling circuit 4 to ensure that the output current and the output voltage can be timely reacted and the gap eliminated when the output current and the output voltage change, so that the output current and the output voltage remain constant. The set current Ia and the set voltage Va can also be adjusted so that the current and voltage output by the signal conditioning circuit 1 change, and the control power supply circuit can be adapted to different requirements of the load. And the constant value of the output current and the constant value of the output voltage can also be adjusted based on the change of the set current Ia and the set voltage Va.

[0083] It should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

[0084] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present application, and they are not intended to limit the protection scope of the present application. Any equivalent embodiments or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.

Claims

1. A power supply circuit, characterized by comprising: The application relates to a signal conditioning circuit, an operational amplifier circuit, a current sampling circuit and a voltage sampling circuit, the signal conditioning circuit is coupled with the operational amplifier circuit, the output end of the operational amplifier circuit is used for coupling with a load, the current sampling circuit is used for collecting the output current of the operational amplifier circuit, the voltage sampling circuit is used for collecting the output voltage of the operational amplifier circuit, and the output ends of the current sampling circuit and the voltage sampling circuit are coupled with the signal conditioning circuit. The signal conditioning circuit is used for adjusting the output current and the output voltage, wherein the signal conditioning circuit adjusts the output current so that the output current is constant, or the signal conditioning circuit adjusts the output voltage so that the output voltage is constant. The signal conditioning circuit comprises:

2. The power supply circuit of claim 1, wherein, a first operational amplifier, a first input end of the first operational amplifier receives a set current, a second input end of the first operational amplifier receives the output current fed back by the current sampling circuit, and the output end of the first operational amplifier is coupled with the operational amplifier circuit; a second operational amplifier, a first input end of the second operational amplifier receives a set voltage, a second input end of the second operational amplifier receives the output voltage fed back by the voltage sampling circuit, and the output end of the second operational amplifier is coupled with the first input end of the first operational amplifier through a first switch branch and a second switch branch arranged in parallel. When the output voltage of the power supply circuit is less than the set voltage in the charging state, the first switch branch is turned on, the output current is constant and is equal to the set current value; when the output voltage is equal to the set voltage, the second switch branch is turned on, and the output voltage is constant and is equal to the set voltage value.

3. The power supply circuit of claim 2, wherein, The first switch branch comprises a first diode and a first switch, the cathode of the first diode is coupled with the output end of the second operational amplifier, and the anode of the first diode is coupled with the first input end of the first operational amplifier through the first switch; 4. The power supply circuit of claim 2, wherein, The second switch branch comprises a second diode and a second switch, the anode of the second diode is coupled with the output end of the second operational amplifier, and the cathode of the second diode is coupled with the first input end of the first operational amplifier through the second switch. A first resistor and a first capacitor are arranged in series between the second input end and the output end of the second operational amplifier; a second resistor and a second capacitor are arranged in series between the second input end and the output end of the first operational amplifier.

5. The power supply circuit of claim 2, wherein, The output end of the operational amplifier circuit is connected with the load through a sampling resistor; 6. The power supply circuit of claim 1, wherein, The current sampling circuit comprises a third operational amplifier, the first input end and the second input end of the third operational amplifier are coupled to the two ends of the sampling resistor respectively, and the output end of the third operational amplifier is coupled to the signal conditioning circuit to feed back the output current of the operational amplifier circuit. The third input end and the fourth input end of the third operational amplifier are coupled together through a third resistor, the first input end of the third operational amplifier is coupled to one end of the sampling resistor through a fourth resistor, the second input end of the third operational amplifier is coupled to the other end of the sampling resistor through a fifth resistor, and the first input end and the second input end of the third operational amplifier are further coupled together through a third capacitor.

7. The power supply circuit of claim 6, wherein, ​ 8. The power supply circuit of claim 1, wherein, The voltage sampling circuit comprises a fourth operational amplifier, a first input end of the fourth operational amplifier is coupled to a first end of the load, a second end of the load is coupled to a reference ground, a second input end of the fourth operational amplifier is coupled to an output end of the fourth operational amplifier, and the output end of the fourth operational amplifier is further coupled to the signal conditioning circuit to feedback an output voltage of the operational amplifier circuit.

9. The power supply circuit of claim 6, wherein, The operational amplifier circuit comprises a fifth operational amplifier, a first input end of the third operational amplifier is coupled to the signal conditioning circuit, a second input end of the third operational amplifier is coupled to an output end of the third operational amplifier, and the output end of the third operational amplifier is further coupled to the load.

10. The power supply circuit of claim 1, wherein, The signal conditioning circuit and the operational amplifier circuit are connected through a sixth resistance, the operational amplifier circuit is connected to the load through a series connection of a seventh resistance and a sampling resistance, the current sampling circuit is connected to the signal conditioning circuit through an eighth resistance, and the voltage sampling circuit is connected to the signal conditioning circuit through a ninth resistance. The current sampling circuit collects the output current through the sampling resistance.

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