Automatic start-stop circuit

Abstract

The utility model discloses an automatic start-stop circuit, which comprises a temperature sampling loop, a sampling amplification loop, a return difference control loop and a switch control loop which are sequentially connected end to end, and the temperature sampling loop, the sampling amplification loop, the return difference control loop and the switch control loop are connected end to end. And the output signal of any one stage of loop is used as the input signal of the adjacent next stage of loop. In the embodiment of the utility model, the temperature sampling circuit is used for collecting a temperature signal, the sampling amplification loop is used for amplifying the input temperature signal, and the return difference control loop is used for setting a return difference value so as to accurately control the on-off of the switch control loop according to the amplified temperature signal. According to the embodiment of the utility model, temperature analysis and start-stop logic control on the main circuit can be realized without using a microprocessor and occupying computing power resources, so that the resource utilization rate can be effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to temperature control technical field especially relates to a kind of automatic start-stop circuit. BACKGROUND

[0002] With the rapid development of new energy industry, more and more new energy power conversion equipment is vigorously researched and put into field grid-connected operation, such as wind power converter, photovoltaic inverter, high-power energy storage PCS and static var generator. With the increasing demand for performance of equipment, how to ensure performance while meeting the miniaturization of product and improving the utilization rate of power devices is a great challenge.

[0003] In power electronic products / equipment, if a heat source needs to be cooled, the commonly used solution with low cost is air cooling, that is, using a fan to transport low-temperature air to the heat source to carry away heat. However, the operation of the fan will inevitably increase power consumption and cause noise problems, and the device does not need to start the fan when operating in a small power range. The existing solution is to analyze the temperature and control the start-stop logic through a microprocessor combined with software code. However, this solution occupies chip resources and computing power, affecting the software performance of the product.

[0004] Therefore, the existing start-stop control scheme has the problem of occupying computing resources. UTILITY MODEL

[0005] The utility model provides a kind of automatic start-stop circuit, to solve the problem of existing start-stop control scheme with occupying computing resources.

[0006] To solve the above technical problems, the utility model provides an automatic start-stop circuit, which includes a temperature sampling circuit, a sampling amplification circuit, a back difference control circuit and a switch control circuit. The temperature sampling circuit, the sampling amplification circuit, the back difference control circuit and the switch control circuit are connected in sequence, and the output signal of any one-stage circuit is used as the input signal of the next-stage circuit adjacent to it.

[0007] Further, the first end of the temperature sampling circuit is connected to the first end of the sampling amplification circuit, and the second end of the temperature sampling circuit is connected to the second end of the sampling amplification circuit, the third end of the back difference control circuit and the second end of the switch control circuit and grounded simultaneously. The third end of the sampling amplification circuit is connected to the first end and the second end of the back difference control circuit respectively, and the fourth end of the back difference control circuit is connected to the first end of the switch control circuit.

[0008] Further, the return difference control circuit comprises a Zener diode, a triode, a tenth resistor and a first MOS tube, the emitter of the triode is the first end of the return difference control circuit, the negative terminal of the Zener diode is the second end of the return difference control circuit, the positive terminal of the Zener diode is connected with the collector of the triode, the gate of the first MOS tube and the first end of the tenth resistor, the base of the triode is connected with the drain of the first MOS tube, the seventh connection point formed is the fourth end of the return difference control circuit, the second end of the tenth resistor is connected with the source of the first MOS tube, the ninth connection point formed is the third end of the return difference control circuit.

[0009] Further, the temperature sampling circuit comprises a first resistor, a second resistor, a third resistor and a thermistor;

[0010] The second end of the third resistor is connected with the first end of the second resistor and the first end of the thermistor, the second end of the second resistor is connected with the second end of the thermistor, the second connection point formed is the first end of the temperature sampling circuit, the second connection point is connected with the first end of the first resistor, the second end of the first resistor is the second end of the temperature sampling circuit.

[0011] Further, the thermistor is a negative temperature characteristic sensitive resistor.

[0012] Further, the automatic start-stop circuit further comprises a first power supply module, the power output end of the first power supply module is connected with the power input end of the temperature sampling circuit; wherein the first end of the third resistor is the power input end of the temperature sampling circuit.

[0013] Further, the sampling amplification circuit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first operational amplifier and a second operational amplifier; wherein the first end of the fourth resistor is the first end of the sampling amplification circuit, the second end of the sixth resistor is the second end of the sampling amplification circuit;

[0014] The second end of the fourth resistor is connected with the non-inverting input end of the first operational amplifier, the second end of the fifth resistor is connected with the first end of the sixth resistor, the third connection point formed is connected with the non-inverting input end of the second operational amplifier, the output end of the second operational amplifier is connected with the first end of the eighth resistor, the tenth connection point formed is connected with the inverting input end of the second operational amplifier, the second end of the eighth resistor is connected with the first end of the seventh resistor, the fourth connection point formed is connected with the inverting input end of the first operational amplifier, the second end of the seventh resistor is connected with the output end of the first operational amplifier, the fifth connection point formed is the third end of the sampling amplification circuit.

[0015] Further, the automatic start-stop circuit further comprises a second power supply module, a power output end of the second power supply module is connected with a power input end of the sampling amplification circuit, and the first end of the fifth resistor serves as the power input end of the sampling amplification circuit.

[0016] Further, the switch control circuit comprises a ninth resistor, a second MOS tube and a switch.

[0017] The second end of the ninth resistor is connected with the gate of the second MOS tube, a connecting point thereof serves as a first end of the switch control circuit, the drain of the second MOS tube is connected with the first end of the switch, and the second end of the switch serves as a second end of the switch control circuit.

[0018] Further, the automatic start-stop circuit further comprises a third power supply module, a power output end of the third power supply module is connected with a power input end of the switch control circuit, and the ninth resistor is connected with the source of the second MOS tube, and an eighth connecting point formed thereby serves as the power input end of the switch control circuit.

[0019] The utility model discloses an automatic start-stop circuit, the automatic start-stop circuit includes temperature sampling circuit, sampling amplification circuit, back difference control circuit and switch control circuit, temperature sampling circuit, sampling amplification circuit, back difference control circuit and switch control circuit are connected in proper order, and the output signal of arbitrary first stage circuit is as the input signal of the next stage circuit adjacent thereto, in the utility model embodiment, temperature sampling circuit is used to gather temperature signal, sampling amplification circuit is used to amplify the input temperature signal, back difference control circuit is used to set back difference value to realize accurate control to the on-off of switch control circuit according to the temperature signal after amplification, and the utility model embodiment does not need to use microprocessor, does not need to occupy the resource of algorithm power, can realize temperature resolution and start-stop logic control to main circuit, can effectively improve resource utilization. ACCURACY

[0020] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment description, and obviously, the drawings in the following description are some embodiments of the utility model, and for the ordinary skilled in the art, other drawings can also be obtained according to these drawings without creative labor.

[0021] Figure 1 It is the schematic diagram of the automatic start-stop circuit provided by an embodiment of the utility model;

[0022] Figure 2Circuit principle diagram of automatic start-stop circuit is provided by the utility model one embodiment;

[0023] In the drawing, various reference signs are as follows:

[0024] 10, automatic start-stop circuit; 11, temperature sampling circuit; R1, first resistor; R2, second resistor; R3, third resistor; Rntc, thermistor; 12, sampling amplification circuit; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; U1, first operational amplifier;

[0025] U2, second operational amplifier; 13, back difference control circuit; D1, stabilizing diode; T3, triode; R10, tenth resistor; T2, first MOS tube; 14, switch control circuit; R9, ninth resistor; T4, second MOS tube; M1, switch. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0027] It should be understood that when used in the specification and the appended claims, the terms "comprise" and "include" indicate the existence of the described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0028] It should also be understood that the terms used in the specification of the utility model are only for the purpose of describing specific embodiments and do not intend to limit the utility model. As used in the specification and the appended claims of the utility model, unless otherwise clearly indicated by the context, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0029] It should be further understood that the term "and / or" used in the specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0030] Please refer to Figure 1 , Figure 1It is the schematic view of automatic start-stop circuit provided by an embodiment of the utility model. The utility model provides an automatic start-stop circuit 10, the automatic start-stop circuit 10 includes temperature sampling circuit 11, sampling amplification circuit 12, return difference control circuit 13 and switch control circuit 14, temperature sampling circuit 11, sampling amplification circuit 12, return difference control circuit 13 and switch control circuit 14 are sequentially connected in a loop, and the output signal of any one stage circuit is used as the input signal of the next stage circuit adjacent to it.

[0031] In the embodiment, the temperature sampling circuit 11 is used for collecting temperature signals, the sampling amplification circuit 12 is used for amplifying the input temperature signals, and the return difference control circuit 13 is used for setting a return difference value to accurately control the on-off of the switch control circuit 14 according to the amplified temperature signals. The utility model embodiment does not need to use a microprocessor and occupy computing resources, can realize temperature analysis and start-stop logic control of the main circuit, and can effectively improve resource utilization.

[0032] Preferably, in the return difference control circuit 13, a voltage stabilizing tube can be used to realize return difference control.

[0033] In an embodiment, as shown in Figure 1 and Figure 2 The first end of the temperature sampling circuit 11 is connected with the first end of the sampling amplification circuit 12, the second end of the temperature sampling circuit 11 is connected with the second end of the sampling amplification circuit 12, the third end of the return difference control circuit 13 and the second end of the switch control circuit 14 and grounded at the same time, the third end of the sampling amplification circuit 12 is connected with the first end and the second end of the return difference control circuit 13 respectively, and the fourth end of the return difference control circuit 13 is connected with the first end of the switch control circuit 14.

[0034] In the embodiment, the first end of the temperature sampling circuit 11 is connected with the first end of the sampling amplification circuit 12, the second end of the temperature sampling circuit 11 is connected with the second end of the sampling amplification circuit 12, the third end of the back difference control circuit 13 and the second end of the switch control circuit 14 and grounded; wherein the temperature sampling circuit 11 is used for collecting temperature signals and transmitting the collected temperature signals to the sampling amplification circuit 12 through the second end of the temperature sampling circuit 11; the third end of the sampling amplification circuit 12 is connected with the first end and the second end of the back difference control circuit 13 respectively; wherein the sampling amplification circuit 12 is used for amplifying the input temperature signals; the fourth end of the back difference control circuit 13 is connected with the first end of the switch control circuit 14; wherein the back difference control circuit 13 is used for setting back difference value to realize accurate control of the on-off of the switch control circuit 14 according to the amplified temperature signals; specifically, when the temperature is low, the switch control circuit 14 is in the off state, when the temperature is high, the switch control circuit 14 is in the on state.

[0035] Preferably, in the back difference control circuit 13, the back difference control can be realized by a voltage stabilizing tube; specifically, when the voltage amplified by the sampling amplification circuit 12 is not greater than the breakdown voltage of the voltage stabilizing tube, the switch control circuit 14 is in the off state.

[0036] In an embodiment, as shown in Figure 1 and Figure 2 The back difference control circuit 13 includes a voltage stabilizing diode D1, a triode T3, a tenth resistor R10 and a first MOS tube T2, the emitter of the triode T3 is the first end of the back difference control circuit 13, the negative end of the voltage stabilizing diode D1 is the second end of the back difference control circuit 13, the positive end of the voltage stabilizing diode D1 is connected with the collector of the triode T3, the gate of the first MOS tube T2 and the first end of the tenth resistor R10, the base of the triode T3 is connected with the drain of the first MOS tube T2, the seventh connection point formed is the fourth end of the back difference control circuit 13, the second end of the tenth resistor R10 is connected with the source of the first MOS tube T2, and the ninth connection point formed is the third end of the back difference control circuit 13.

[0037] In the embodiment, the back difference control circuit 13 comprises a Zener diode D1, a triode T3, a tenth resistor R10 and a first MOS T2; wherein the breakdown voltage of the Zener diode D1 is Vb, the triode T3 is a PNP triode, and the first MOS T2 is an N-type insulated gate transistor; when the temperature is low, the voltage of the sixth connection point relative to GND is 0, the voltage of the third end of the sampling amplification circuit 12 is Vout, and the voltage of the third end of the sampling amplification circuit 12 relative to the sixth connection point is Verr; by setting certain hardware parameters (such as resistance parameters, etc.), the Verr is less than the Vb under the condition of low temperature, at this time, Verr = Vout, the Zener diode D1 is not conductive, Vg6 = 0 (Vg6 is the voltage of the sixth connection point relative to GND), therefore, the triode T3 and the first MOS T2 are not conductive, when the triode T3 and the first MOS T2 are not conductive, the switch control circuit 14 is also not conductive, thereby realizing temperature analysis and start-stop logic control of the main circuit.

[0038] When the temperature rises, the Vout increases, when the Vout is greater than the Vb, the Zener diode D1 is conductive, Verr = Vb, Verr does not change with the increase of Vout, at this time, the voltage of the sixth connection point relative to GND is Vg6 = Vout-Verr, in the process of temperature rise, the Vg6 increases with the increase of the Vout, when the Vg6 exceeds the turn-on threshold of the first MOS T2, the first MOS T2 is conductive, and the switch control circuit 14 is powered on and works.

[0039] In an embodiment, as shown in Figure 1 and Figure 2 The temperature sampling circuit 11 comprises a first resistor R1, a second resistor R2, a third resistor R3 and a thermistor Rntc.

[0040] The second end of the third resistor R3 is connected with the first end of the second resistor R2 and the first end of the thermistor Rntc, the second end of the second resistor R2 is connected with the second end of the thermistor Rntc, the second connection point formed thereby is the first end of the temperature sampling circuit 11, the second connection point is connected with the first end of the first resistor R1, and the second end of the first resistor R1 is the second end of the temperature sampling circuit 11.

[0041] In the embodiment, the temperature sampling circuit 11 is used to convert the temperature change into a voltage analog signal, and the temperature sampling circuit 11 comprises a first resistor R1, a second resistor R2, a third resistor R3 and a thermistor Rntc; wherein the resistance of the thermistor Rntc changes with the temperature, and when the resistance changes, the voltage transmitted by the temperature sampling circuit 11 to the sampling amplification circuit 12 also changes.

[0042] In an embodiment, as shown in Figure 1 and Figure 2 The thermistor Rntc is a negative temperature characteristic sensitive resistor.

[0043] In the embodiment, the thermistor Rntc is a negative temperature characteristic sensitive resistor, and the resistance is higher when the temperature is low and the resistance is lower when the temperature is high; when the temperature is low, the voltage between the second connection point and the GND is low, and since the second end of the third resistor R3 is connected to the first end of the second resistor R2 and the first end of the thermistor Rntc, the second end of the second resistor R2 is connected to the second end of the thermistor Rntc, the first end of the first resistor R1 is connected to the second connection point, and the second end of the first resistor R1 is used as the second end of the temperature sampling circuit 11, the voltage is transmitted to the sampling amplification circuit 12.

[0044] In an embodiment, as shown in Figure 1 and Figure 2 The automatic start-stop circuit 10 further comprises a first power supply module, and a power output end of the first power supply module is connected to a power input end of the temperature sampling circuit 11; wherein the first end of the third resistor R3 is used as the power input end of the temperature sampling circuit 11.

[0045] In the embodiment, the automatic start-stop circuit 10 further comprises a first power supply module, and the first power supply module is used to supply power to the temperature sampling circuit 11; a power output end of the first power supply module is connected to a power input end of the temperature sampling circuit 11; wherein the first end of the third resistor R3 is used as the power input end of the temperature sampling circuit 11.

[0046] In an embodiment, as shown in Figure 1 and Figure 2 The sampling amplification circuit 12 comprises a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first operational amplifier U1 and a second operational amplifier U2; wherein the first end of the fourth resistor R4 is used as the first end of the sampling amplification circuit 12, and the second end of the sixth resistor R6 is used as the second end of the sampling amplification circuit 12.

[0047] The second end of the fourth resistor R4 is connected with the non-inverting input terminal of the first operational amplifier U1, the second end of the fifth resistor R5 is connected with the first end of the sixth resistor R6, the third connection point formed thereby is connected with the non-inverting input terminal of the second operational amplifier U2, the output terminal of the second operational amplifier U2 is connected with the first end of the eighth resistor R8, the tenth connection point formed thereby is connected with the inverting input terminal of the second operational amplifier U2, the second end of the eighth resistor R8 is connected with the first end of the seventh resistor R7, the fourth connection point formed thereby is connected with the inverting input terminal of the first operational amplifier U1, the second end of the seventh resistor R7 is connected with the output terminal of the first operational amplifier U1, and the fifth connection point formed thereby serves as the third end of the sampling amplification loop 12.

[0048] In the embodiment, the first operational amplifier U1 is used to build a negative feedback amplification circuit, and the second operational amplifier U2 is used to build a follower, which plays a role of isolation.

[0049] Specifically, the sampling amplification loop 12 is used to amplify the voltage from the temperature sampling loop 11, so that the voltage value transmitted to the back difference control loop 13 by the sampling amplification loop 12 changes with the resistance value of the thermistor Rntc; the sampling amplification loop 12 transmits the amplified voltage to the back difference control loop 13 through the fifth connection point, the voltage of the fifth connection point is Vout, and the calculation formula of Vout is as follows:

[0050]

[0051] When the temperature is low, the voltage of the sixth connection point relative to GND is 0, and the voltage of Vout relative to the sixth connection point is Verr. By setting certain hardware parameters (such as resistance parameters), Verr is less than Vb under low temperature conditions, at this time, Verr = Vout, the zener diode D1 is not conductive, Vg6 = 0 (Vg6 is the voltage of the sixth connection point relative to GND), therefore, the triode T3 and the first MOS tube T2 are not conductive, when the triode T3 and the first MOS tube T2 are not conductive, the switch control loop 14 is also not conductive, thereby realizing temperature analysis and start-stop logic control of the main circuit.

[0052] When the temperature rises, the Vout increases, when the Vout is greater than the Vb, the voltage stabilizing diode D1 is turned on, Verr=Vb, Verr does not change with the increase of Vout, at this time, the voltage of the sixth connection point relative to GND is Vg6=Vout-Verr, in the process of temperature rise, the Vg6 increases with the increase of the Vout, when the Vg6 exceeds the turn-on threshold of the first MOS tube T2, the first MOS tube T2 is turned on, the switch control loop 14 is powered on to work.

[0053] In an embodiment, as shown in Figure 1 and Figure 2 The automatic start-stop circuit 10 further comprises a second power supply module, a power output end of the second power supply module is connected with a power input end of the sampling amplification loop 12; wherein the first end of the fifth resistor R5 is used as the power input end of the sampling amplification loop 12.

[0054] In the embodiment, the automatic start-stop circuit 10 further comprises a second power supply module, the second power supply module is used for supplying power for the sampling amplification loop 12; a power output end of the second power supply module is connected with a power input end of the sampling amplification loop 12; wherein the first end of the fifth resistor R5 is used as the power input end of the sampling amplification loop 12.

[0055] In an embodiment, as shown in Figure 1 and Figure 2 The switch control loop 14 comprises a ninth resistor R9, a second MOS tube T4 and a switch M1.

[0056] The second end of the ninth resistor R9 is connected with the gate of the second MOS tube T4, a connection point thereof is used as the first end of the switch control loop 14, the drain of the second MOS tube T4 is connected with the first end of the switch M1, and the second end of the switch M1 is used as the second end of the switch control loop 14.

[0057] In the embodiment, the switch control loop 14 comprises a ninth resistor R9, a second MOS tube T4 and a switch M1, the second MOS tube T4 is a P-type insulated gate transistor, the switch M1 is connected with an electronic device to be controlled, the electronic device to be controlled can be a direct current fan, when the switch M1 is turned on, the direct current fan normally works to dissipate heat for a target device, when the temperature of the target device drops to a stop threshold, the switch M1 is controlled to be turned off, and the direct current fan loses power to stop working.

[0058] Specifically, the sampling amplification circuit 12 is configured to amplify the voltage from the temperature sampling circuit 11, so that the voltage value transmitted by the sampling amplification circuit 12 to the back difference control circuit 13 varies with the resistance value of the thermistor Rntc; the sampling amplification circuit 12 transmits the amplified voltage to the back difference control circuit 13 through the fifth connection point, the voltage of the fifth connection point is Vout, and the calculation formula of Vout is as follows:

[0059]

[0060] When the temperature is low, the voltage of the sixth connection point relative to GND is 0, and the voltage of Vout relative to the voltage of the sixth connection point is Verr. By setting certain hardware parameters (such as resistance parameters, etc.), the Verr is less than the Vb under low temperature conditions, at this time, Verr = Vout, the voltage of the sixth connection point relative to GND is Vg6 = 0, so the triode T3 and the first MOS tube T2 are not conductive, when the triode T3 and the first MOS tube T2 are not conductive, the seventh connection point is high, and since the second MOS tube T4 is a P-type insulated gate transistor, the second MOS tube T4 is not conductive, and the switch M1 is closed.

[0061] When the temperature rises, the Vout increases, when the Vout is greater than the Vb, the voltage stabilizing diode D1 is conductive, Verr = Vb, and Verr does not change with the increase of Vout, at this time, the voltage of the sixth connection point relative to GND is Vg6 = Vout-Verr, during the temperature rising process, the Vg6 increases with the increase of Vout, when the Vg6 exceeds the conduction threshold of the first MOS tube T2, the first MOS tube T2 is conductive, when the first MOS tube T2 is conductive, the level of the seventh connection point will be pulled low, since the second MOS tube T4 is a P-type insulated gate transistor, the second MOS tube T4 is conductive, and the switch M1 is powered on.

[0062] The utility model discloses still can through setting up the triode T3, avoid the switch M1 at temperature threshold point repeatedly start -stop, specific, when the seventh connecting point is low level, the triode T3 is conducted and makes the zener diode D1 bypass formation self -locking, when temperature falls to the conduction threshold value, the first MOS pipe T2 also will not shut off, only when temperature continues to reduce, make the Vout continuously reduce to the shut -off threshold value of the first MOS pipe T2, the first MOS pipe T2 will shut off only, the seventh connecting point can only rise to high level, when the seventh connecting point is high level, the triode T3, the second MOS pipe T4 shut off, the switch M1 loses power and stops working, realizes the back difference in certain temperature range.

[0063] In one embodiment, as shown in Figure 1 and Figure 2 The automatic start-stop circuit 10 further comprises a third power supply module, and a power output end of the third power supply module is connected with a power input end of the switch control loop 14; wherein the ninth resistor R9 is connected with the source electrode of the second MOS pipe T4, and an eighth connecting point formed thereby serves as the power input end of the switch control loop 14.

[0064] In the embodiment, the automatic start-stop circuit 10 further comprises a third power supply module, and the third power supply module is used for supplying power to the switch control loop 14; a power output end of the third power supply module is connected with a power input end of the switch control loop 14; wherein the ninth resistor R9 is connected with the source electrode of the second MOS pipe T4, and an eighth connecting point formed thereby serves as the power input end of the switch control loop 14.

[0065] The utility model discloses an automatic start -stop circuit, the automatic start -stop circuit includes temperature sampling loop, sampling amplification loop, back difference control loop and switch control loop, temperature sampling loop, sampling amplification loop, back difference control loop and switch control loop are connected in proper order, and the output signal of arbitrary first stage loop is as the input signal of the next stage loop adjacent thereto, in the utility model embodiment, temperature sampling circuit is used for gathering temperature signal, sampling amplification loop is used for amplifying the temperature signal of input, back difference control loop is used for setting back difference value to realize accurate control to the on -off of switch control loop according to the temperature signal after amplification, the utility model embodiment need not use microprocessor, need not occupy the resource of algorithm power, can realize temperature resolution and start -stop logic control to main circuit, can effectively improve resource utilization.

[0066] The above merely describes a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present application, and these modifications or replacements should be encompassed within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An automatic start-stop circuit, characterized by comprising: The automatic start-stop circuit comprises a temperature sampling circuit, a sampling amplification circuit, a back difference control circuit and a switch control circuit, the temperature sampling circuit, the sampling amplification circuit, the back difference control circuit and the switch control circuit are sequentially connected in a head-to-tail manner, and an output signal of any one stage circuit is used as an input signal of a next stage circuit adjacent to the one stage circuit.

2. The automatic start-stop circuit of claim 1, wherein, The first end of the temperature sampling circuit is connected with the first end of the sampling amplification circuit, the second end of the temperature sampling circuit is connected with the second end of the sampling amplification circuit, the third end of the back difference control circuit and the second end of the switch control circuit and grounded at the same time, the third end of the sampling amplification circuit is connected with the first end and the second end of the back difference control circuit respectively, and the fourth end of the back difference control circuit is connected with the first end of the switch control circuit.

3. The automatic start-stop circuit of claim 2, wherein, The back difference control circuit comprises a stabilizing diode, a triode, a tenth resistor and a first MOS tube, the emitter of the triode is used as the first end of the back difference control circuit, the negative end of the stabilizing diode is used as the second end of the back difference control circuit, the positive end of the stabilizing diode is connected with the collector of the triode, the gate of the first MOS tube and the first end of the tenth resistor at the same time, the base of the triode is connected with the drain of the first MOS tube, a seventh connection point formed thereby is used as the fourth end of the back difference control circuit, the second end of the tenth resistor is connected with the source of the first MOS tube, and a ninth connection point formed thereby is used as the third end of the back difference control circuit.

4. The automatic start-stop circuit of claim 1, wherein, The temperature sampling circuit comprises a first resistor, a second resistor, a third resistor and a thermistor. The second end of the third resistor is connected with the first end of the second resistor and the first end of the thermistor at the same time, the second end of the second resistor is connected with the second end of the thermistor, a second connection point formed thereby is used as the first end of the temperature sampling circuit, the second connection point is connected with the first end of the first resistor, and the second end of the first resistor is used as the second end of the temperature sampling circuit.

5. The automatic start-stop circuit of claim 4, wherein, The thermistor is a negative temperature characteristic sensitive resistor.

6. The automatic start-stop circuit of claim 4, wherein, The automatic start-stop circuit further comprises a first power supply module, a power output end of the first power supply module is connected with a power input end of the temperature sampling circuit, the first end of the third resistor is used as the power input end of the temperature sampling circuit.

7. The automatic start-stop circuit of claim 1, wherein, The sampling amplification circuit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first operational amplifier and a second operational amplifier, the first end of the fourth resistor is used as the first end of the sampling amplification circuit, and the second end of the sixth resistor is used as the second end of the sampling amplification circuit. The second end of the fourth resistor is connected with the non-inverting input terminal of the first operational amplifier, the second end of the fifth resistor is connected with the first end of the sixth resistor, the third connection point formed is connected with the non-inverting input terminal of the second operational amplifier, the output terminal of the second operational amplifier is connected with the first end of the eighth resistor, the tenth connection point formed is connected with the inverting input terminal of the second operational amplifier, the second end of the eighth resistor is connected with the first end of the seventh resistor, the fourth connection point formed is connected with the inverting input terminal of the first operational amplifier, the second end of the seventh resistor is connected with the output terminal of the first operational amplifier, and the fifth connection point formed is used as the third end of the sampling amplification loop.

8. The automatic start-stop circuit of claim 7, wherein, The automatic start-stop circuit further comprises a second power supply module, and a power output terminal of the second power supply module is connected with a power input terminal of the sampling amplification loop; wherein the first end of the fifth resistor is used as the power input terminal of the sampling amplification loop.

9. The automatic start-stop circuit of claim 1, wherein, The switch control loop comprises a ninth resistor, a second MOS transistor and a switch. The second end of the ninth resistor is connected with the gate of the second MOS transistor, and the connection point is used as the first end of the switch control loop; the drain of the second MOS transistor is connected with the first end of the switch, and the second end of the switch is used as the second end of the switch control loop.

10. The automatic start-stop circuit of claim 9, wherein, The automatic start-stop circuit further comprises a third power supply module, and a power output terminal of the third power supply module is connected with a power input terminal of the switch control loop; wherein the ninth resistor is connected with the source of the second MOS transistor, and the eighth connection point formed is used as the power input terminal of the switch control loop.

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