Control circuit of heat dissipation equipment and heat dissipation equipment

By designing a heat dissipation equipment control circuit using temperature-sensitive diode modules and switch modules, the problems of high cost and complex structure of the heat dissipation equipment in the prior art are solved, and a simple and reliable control method and the effect of extending the service life of the equipment are achieved.

CN222532077UActive Publication Date: 2025-02-25AISWEI NEW ENERGY TECHNOLOGY (YANGZHONG) CO LTD
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Patent Information

Application Number
CN202421236531.6
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-05-31
Publication Date
2025-02-25
Estimated Expiration
2034-05-31

AI Technical Summary

Technical Problem

Existing heat dissipation equipment relies on processor chips and complex software control algorithms, resulting in high costs and complex structures.

Method used

A control circuit for a heat dissipation device is designed, through series connection of the temperature-sensitive diode module, the signal sampling and conditioning module, the comparator module, the first switch module and the second switch module, the characteristics of the temperature-sensitive diode conduction voltage drop change with temperature , controls the on or off of the heat dissipation component.

Benefits of technology

It realizes a simple and reliable structure without processor units and software control algorithms, reduces costs, and avoids repeated switching between current critical points through the hysteresis function, extending the service life of the equipment.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model discloses a control circuit of heat dissipation equipment and the heat dissipation equipment. The control circuit comprises a temperature-sensitive diode module, a signal sampling and conditioning module, a comparator module, a first switch module and a second switch module which are sequentially connected in series. The temperature-sensitive diode module comprises a plurality of temperature-sensitive diodes which are connected in series. The first switch module comprises a first triode, the second switch module comprises a second triode, and the first triode and the second triode are switched off or switched on in response to an output signal of the comparator module; when the heat dissipation assembly is in a non-working state, the first triode is closed, and the second triode is disconnected; when the heat dissipation assembly is in a working state, the first triode is disconnected and the second triode is closed. According to the control circuit of the heat dissipation device, the characteristic that the conduction voltage drop of the temperature-sensitive diode changes along with the temperature is utilized, so that the voltage output by the temperature-sensitive diode module changes along with the change of the temperature, and then the heat dissipation assembly is controlled to be turned on or turned off.
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Description

Technical Field

[0001] The utility model belongs to the technical field of heat dissipation equipment manufacturing, and in particular relates to a control circuit of heat dissipation equipment and heat dissipation equipment. Background Art

[0002] Heat dissipation equipment is a common device, mainly used to prevent the main equipment from overheating and affecting the working efficiency or causing equipment damage. For example, it can be used in photovoltaic inverters or converters, and has a wide range of applications. Most existing heat dissipation equipment relies on processor chips, and the software control algorithm is complex, has high requirements, and is costly. Summary of the invention

[0003] In view of the above technical problems, the utility model provides an improved control circuit of a heat dissipation device and a heat dissipation device.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A control circuit of a heat dissipation device, used for controlling a heat dissipation component to be in a working state or a non-working state, the control circuit comprising:

[0006] A temperature-sensitive diode module, comprising a plurality of temperature-sensitive diodes connected in series, wherein the voltage output by the temperature-sensitive diode module varies with temperature;

[0007] A signal sampling and conditioning module, used for adjusting the magnitude of the voltage signal output by the temperature-sensitive diode module, wherein the signal sampling and conditioning module and the temperature-sensitive diode module are connected in series;

[0008] A comparator module, comprising a comparator, one of the input terminals of the comparator is connected in series with the signal sampling and conditioning module, and the other input terminal of the comparator is connected to a reference voltage;

[0009] A first switch module, comprising a first transistor, wherein the first switch module and an output end of the comparator are connected in series;

[0010] A second switch module, comprising a second triode, wherein the second switch module is connected in series with the first switch module;

[0011] The first transistor and the second transistor are opened or closed in response to the output signal of the comparator module;

[0012] The heat dissipation device includes a heat dissipation module, the heat dissipation module and the second switch module are connected in series, and the heat dissipation module includes the heat dissipation component; when the heat dissipation component is in a non-working state, the first transistor is closed and the second transistor is disconnected; when the heat dissipation component is in a working state, the first transistor is disconnected and the second transistor is closed.

[0013] Preferably, the temperature sensitive diode module comprises:

[0014] A temperature-sensitive diode string, which is formed by connecting a plurality of negative temperature coefficient diodes in series, and the temperature-sensitive diode string is also connected to the first power supply terminal;

[0015] a first resistor, one end of the first resistor being connected to the temperature sensitive diode string, and the other end of the first resistor being connected to the signal sampling and conditioning module;

[0016] A first capacitor is connected in parallel with the first resistor.

[0017] Preferably, the temperature sensitive diode module comprises:

[0018] A temperature sensitive diode string, which is formed by connecting a plurality of positive temperature coefficient diodes in series;

[0019] a first resistor, one end of the first resistor being connected to the temperature sensitive diode string, and the other end of the first resistor being connected to a first power supply terminal;

[0020] A first capacitor is connected in parallel with the first resistor.

[0021] Preferably, the signal sampling and conditioning module comprises:

[0022] Operational amplifier;

[0023] a second resistor, one end of the second resistor being connected to the temperature-sensitive diode module, and the other end of the second resistor being connected to the inverting input end of the operational amplifier;

[0024] a third resistor, one end of the third resistor being connected to the temperature-sensitive diode module, and the other end of the third resistor being connected to the non-inverting input end of the operational amplifier;

[0025] a fourth resistor, one end of the fourth resistor being connected to a connection point between the third resistor and the non-inverting input terminal of the operational amplifier, and the other end of the fourth resistor being connected to a ground terminal;

[0026] a second capacitor, wherein the second capacitor and the fourth resistor are connected in parallel, one end of the second capacitor is connected to a connection point between the third resistor and the fourth resistor, and the other end of the second capacitor is connected to a connection point between the fourth resistor and a ground terminal;

[0027] a fifth resistor, one end of the fifth resistor being connected to a connection point between the second resistor and the inverting input terminal of the operational amplifier, and the other end of the fifth resistor being connected to an output terminal of the operational amplifier;

[0028] a third capacitor, wherein the third capacitor is connected in parallel with the fifth resistor, one end of the third capacitor is connected to a connection point between the second resistor and the inverting input terminal of the operational amplifier, and the other end of the third capacitor is connected to an output terminal of the operational amplifier;

[0029] a sixth resistor, one end of the sixth resistor being connected to the output end of the operational amplifier, and the other end of the sixth resistor being connected to the comparator module;

[0030] A fourth capacitor, one end of which is connected to the comparator module, and the other end of which is connected to a connection point between the fourth resistor and a ground terminal.

[0031] Furthermore, the comparator module further includes:

[0032] a seventh resistor, one end of the seventh resistor being connected to the sixth resistor, and the other end of the seventh resistor being connected to the inverting input end of the comparator;

[0033] A fifth capacitor, one end of the fifth capacitor is connected to the second power supply terminal, and the other end of the fifth capacitor is connected to the ground terminal;

[0034] an eighth resistor, one end of the eighth resistor being connected to a connection point between the fifth capacitor and the second power supply terminal, and the other end of the eighth resistor being connected to a non-inverting input terminal of the comparator;

[0035] a first diode, wherein a cathode of the first diode is connected to the eighth resistor, and an anode of the first diode is connected to a connection point between an output terminal of the comparator and the first switch module;

[0036] a ninth resistor, one end of which is connected to the anode of the first diode, and the other end of which is connected to the output end of the comparator and a connection point of the first switch module;

[0037] A tenth resistor, one end of which is connected to the ninth resistor, and the other end of which is connected to the third power supply terminal.

[0038] Furthermore, the first switch module further includes:

[0039] an eleventh resistor, one end of the eleventh resistor being connected to the output end of the comparator, and the other end of the eleventh resistor being connected to the base of the first transistor;

[0040] a twelfth resistor, one end of the twelfth resistor being connected to a connection point between the eleventh resistor and the base of the first transistor, the other end of the twelfth resistor being connected to the emitter of the first transistor, and the other end of the twelfth resistor being further connected to a ground terminal;

[0041] a sixth capacitor, wherein the sixth capacitor and the twelfth resistor are connected in parallel, one end of the sixth capacitor is connected to a connection point between the eleventh resistor and the base of the first transistor, and the other end of the sixth capacitor is connected to a connection point between the twelfth resistor and a ground terminal;

[0042] A thirteenth resistor, one end of the thirteenth resistor is connected to the collector of the first transistor, and the other end of the thirteenth resistor is connected to the fourth power supply terminal.

[0043] Furthermore, the second switch module further includes:

[0044] a fourteenth resistor, one end of the fourteenth resistor being connected to a connection point between the thirteenth resistor and the collector of the first transistor, and the other end of the fourteenth resistor being connected to a base of the second transistor;

[0045] a fifteenth resistor, one end of the fifteenth resistor being connected to a connection point between the fourteenth resistor and the base of the second transistor, the other end of the fifteenth resistor being connected to the emitter of the second transistor, and the other end of the fifteenth resistor being further connected to a ground terminal;

[0046] A sixteenth resistor, one end of the sixteenth resistor is connected to the collector of the second transistor, and the other end of the sixteenth resistor is connected to the heat dissipation module.

[0047] Furthermore, the heat dissipation module includes:

[0048] a third triode connected to the fifth power terminal; the third triode is configured to be disconnected when the operating current of the heat dissipation component exceeds the rated operating current;

[0049] a second diode and a third diode, the second diode and the third diode are connected in series, the cathode of the second diode is connected to the sixteenth resistor, the anode of the second diode is connected to the third diode; the cathode of the third diode is connected to the second diode, the anode of the third diode is connected to the connection point of the fifth power supply terminal and the emitter of the third transistor; the second diode and the third diode are bias diodes;

[0050] One end of the heat dissipation component is connected to the collector of the third transistor, and the other end of the heat dissipation component is connected to the emitter of the second transistor;

[0051] A seventh capacitor, one end of the seventh capacitor is connected to the collector of the third transistor, and the other end of the seventh capacitor is connected to the emitter of the second transistor and the connection point of the heat dissipation component.

[0052] Furthermore, the heat dissipation module further includes:

[0053] A seventeenth resistor, one end of the seventeenth resistor is connected to the emitter of the third transistor, and the other end of the seventeenth resistor is connected to the fifth power supply terminal; the anode of the third diode is connected to the connection point between the fifth power supply terminal and the seventeenth resistor.

[0054] Furthermore, the first transistor, the second transistor and the third transistor are bipolar junction transistors or MOS transistors.

[0055] A heat dissipation device comprises the control circuit of the heat dissipation device as described above, the heat dissipation device further comprises a heat dissipation module, the heat dissipation module comprises a heat dissipation component, and the heat dissipation module and the second switch module are connected in series.

[0056] The utility model adopts the above solution, which has the following advantages compared with the prior art:

[0057] The control circuit of the heat dissipation device in the utility model is provided with a temperature-sensitive diode module, a signal sampling and conditioning module, a comparator module, a first switch module and a second switch module connected in series in sequence, and the second switch module is connected to the heat dissipation module of the heat dissipation device, and the characteristic that the conduction voltage drop of the temperature-sensitive diode changes with the temperature is utilized, so that the voltage output by the temperature-sensitive diode module changes with the temperature, thereby controlling the opening or closing of the heat dissipation component. The modules cooperate with each other, and there is no need to set up an additional processor unit, nor is there a need to develop an additional software control algorithm. The structure is simple and reliable, and the cost is low.

[0058] In a further preferred solution, the heat dissipation module is further provided with a third transistor, which can be turned on and off according to the real-time current of the heat dissipation component to prevent the heat dissipation component from overcurrent. The entire control circuit has a hysteresis function, which prevents the heat dissipation component from repeatedly switching between the working state and the non-working state at the current critical point, thereby extending the service life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0060] Figure 1 This is a schematic diagram of the connection between the control circuit and the heat dissipation module in the first embodiment of the utility model;

[0061] Figure 2This is a connection diagram of the control circuit and the heat dissipation module in the second embodiment of the present utility model. DETAILED DESCRIPTION

[0062] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. 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 conflict with each other.

[0063] The control circuit and heat dissipation device in the following embodiments may be applied to a photovoltaic inverter or a converter.

[0064] Embodiment 1

[0065] like Figure 1 As described, this embodiment includes a control circuit of a heat dissipation device, which is used to control the heat dissipation component to be in a working state or a non-working state. The control circuit includes a temperature-sensitive diode module 1, a signal sampling and conditioning module 2, a comparator module 3, a first switch module 4 and a second switch module 5 connected in series in sequence. Among them, the temperature-sensitive diode module 1 includes a plurality of temperature-sensitive diodes (Dt1 to Dtn) connected in series, and the voltage output by the temperature-sensitive diode module changes with the change of temperature. The signal sampling and conditioning module 2 is used to adjust the size of the voltage signal output by the temperature-sensitive diode module 1, and the signal sampling and conditioning module 2 and the temperature-sensitive diode module 1 are connected in series. The comparator module 3 includes a comparator U2, one of the input ends of the comparator U2 is connected in series with the signal sampling and conditioning module 2, and the other input end of the comparator U2 is connected to the reference voltage. In this embodiment, the inverting input end of the comparator U2 is connected in series with the signal sampling and conditioning module 2, the non-inverting input end of the comparator U2 is connected to the reference voltage Vref, and the output end of the comparator U2 is connected in series with the first switch module 4. The first switch module 4 includes a first transistor Q1, and the first switch module 4 is connected in series with the output end of the comparator U2. The second switch module 5 includes a second transistor Q2, and the second switch module 5 is connected in series with the first switch module 4. The first transistor Q1 and the second transistor Q2 are opened or closed in response to the output signal of the comparator module 3.

[0066] The heat dissipation device includes a heat dissipation module 6, and the heat dissipation module 6 is connected in series with the second switch module 5. The heat dissipation module 6 includes a heat dissipation component. When the heat dissipation component is in a non-working state, the first transistor Q1 is closed and the second transistor Q2 is disconnected; when the heat dissipation component is in a working state, the first transistor Q1 is disconnected and the second transistor Q2 is closed.

[0067] The following combination Figure 1 The specific structure of each module in the control circuit is introduced:

[0068] In this embodiment, the temperature-sensitive diode module 1 includes a temperature-sensitive diode string (Dt1 to Dtn), a first resistor R1 and a first capacitor C1. The temperature-sensitive diode string is formed by connecting a plurality of negative temperature coefficient diodes in series, and the temperature-sensitive diode string is also connected to the first power supply terminal Vcc1. Specifically, Figure 1 As shown, the anode of the first temperature-sensitive diode Dt1 in the temperature-sensitive diode string is connected to the first power supply terminal Vcc1. One end of the first resistor R1 is connected to the temperature-sensitive diode string, and the other end of the first resistor R1 is connected to the signal sampling and conditioning module. The first capacitor C1 is connected in parallel to both ends of the first resistor R1. When the temperature rises, the total voltage drop of the temperature-sensitive diode string will decrease, and the voltage across the first resistor R1 will increase as the temperature rises.

[0069] The signal sampling and conditioning module 2 includes an operational amplifier U1, a second resistor R2, a third resistor R3, a fourth resistor R4, a second capacitor C2, a fifth resistor R5, a third capacitor C3, a sixth resistor R6 and a fourth capacitor C4. Among them, one end of the second resistor R2 is connected to the temperature-sensitive diode module 1, and the other end of the second resistor R2 is connected to the inverting input terminal of the operational amplifier U1. One end of the third resistor R3 is connected to the temperature-sensitive diode module 1, and the other end of the third resistor R3 is connected to the non-inverting input terminal of the operational amplifier U1. Specifically, in combination with Figure 1 As shown, the third resistor R3 is connected to the connection point between one end of the first resistor R1 and the temperature-sensitive diode string, and the second resistor R2 is connected to the other end of the first resistor R1. One end of the fourth resistor R4 is connected to the connection point between the third resistor R3 and the in-phase input terminal of the operational amplifier U1, and the other end of the fourth resistor R4 is connected to the ground terminal GND. The second capacitor C2 and the fourth resistor R4 are connected in parallel, one end of the second capacitor C2 is connected to the connection point between the third resistor R3 and the fourth resistor R4, and the other end of the second capacitor C2 is connected to the connection point between the fourth resistor R4 and the ground terminal GND. One end of the fifth resistor R5 is connected to the connection point between the second resistor R2 and the inverting input terminal of the operational amplifier U1, and the other end of the fifth resistor R5 is connected to the output terminal of the operational amplifier U1. The third capacitor C3 and the fifth resistor R5 are connected in parallel, one end of the third capacitor C3 is connected to the connection point between the second resistor R2 and the inverting input terminal of the operational amplifier U1, and the other end of the third capacitor C3 is connected to the output terminal of the operational amplifier U1. One end of the sixth resistor R6 is connected to the output terminal of the operational amplifier U1, and the other end of the sixth resistor R6 is connected to the comparator module 1. One end of the fourth capacitor C4 is connected to the comparator module 1 , and the other end of the fourth capacitor C4 is connected to a connection point between the fourth resistor R4 and the ground terminal GND.

[0070] Among them, the second resistor R2, the third resistor R3 and the fourth resistor R4 are the line resistors of the operational amplifier U1, which are mainly used to cooperate with the operational amplifier U1 for signal conditioning. The second capacitor C2 and the third capacitor C3 are the line bypass filter and compensation capacitors of the operational amplifier U1. The sixth resistor R6 and the fourth capacitor C4 constitute the filter resistance and capacitance of the output end of the operational amplifier U1. In this embodiment, the signal sampling and conditioning module 2 is composed of a differential sampling circuit, which can effectively avoid the temperature-sensitive diode module 1 from being directly connected to the rear-end comparator module 3, and the second resistor R2, the third resistor R3, the fourth resistor R4 and the fifth resistor R5 are all adjustable, which is convenient for line debugging.

[0071] The comparator module 3 includes a seventh resistor R7, a fifth capacitor C5, an eighth resistor R8, a first diode D1, a ninth resistor R9 and a tenth resistor R10. Specifically, one end of the seventh resistor R7 is connected to the sixth resistor R6, and the other end of the seventh resistor R7 is connected to the reverse input terminal of the comparator U2. One end of the fourth capacitor C4 is connected to the connection point between the sixth resistor R6 and the seventh resistor R7. One end of the fifth capacitor C5 is connected to the second power supply terminal Vcc2, and the other end of the fifth capacitor C5 is connected to the ground terminal GND. One end of the eighth resistor R8 is connected to the connection point between the fifth capacitor C5 and the second power supply terminal Vcc2, and the other end of the eighth resistor R8 is connected to the in-phase input terminal of the comparator U2. The cathode of the first diode D1 is connected to the eighth resistor R8, and the anode of the first diode D1 is connected to the output terminal of the comparator U2 and the connection point of the first switch module 4. One end of the ninth resistor R9 is connected to the anode of the first diode D1, and the other end of the ninth resistor R9 is connected to the output terminal of the comparator U2 and the connection point of the first switch module 4. One end of the tenth resistor R10 is connected to the ninth resistor R9 , and the other end of the tenth resistor R10 is connected to the third power supply terminal Vcc3 .

[0072] The seventh resistor R7 constitutes a current limiting resistor at the inverting input terminal of the comparator U2. The eighth resistor R8, the ninth resistor R9 and the first diode D1 constitute a hysteresis circuit of the comparator U2, which increases the reference voltage at the inverting input terminal of U2 when U2 outputs a high level. The tenth resistor R10 is a pull-up resistor at the output terminal of the comparator U2.

[0073] The first switch module 4 includes an eleventh resistor R11, a twelfth resistor R12, a sixth capacitor C6 and a thirteenth resistor R13. Among them, one end of the eleventh resistor R11 is connected to the output end of the comparator U2, and the other end of the eleventh resistor R11 is connected to the base of the first transistor Q1. One end of the twelfth resistor R12 is connected to the connection point of the eleventh resistor R11 and the base of the first transistor Q1, the other end of the twelfth resistor R12 is connected to the emitter of the first transistor Q1, and the other end of the twelfth resistor R12 is also connected to the ground terminal GND. The sixth capacitor C6 is connected in parallel with the twelfth resistor R12, one end of the sixth capacitor C6 is connected to the connection point of the eleventh resistor R11 and the base of the first transistor Q1, and the other end of the sixth capacitor C6 is connected to the connection point of the twelfth resistor R12 and the ground terminal GND. One end of the thirteenth resistor R13 is connected to the collector of the first transistor Q1, and the other end of the thirteenth resistor R13 is connected to the fourth power supply terminal Vcc4.

[0074] In this embodiment, the first switch module 4 is mainly used for logic conversion to ensure that the heat dissipation component is turned on when the comparator U2 outputs a low level. This logic is consistent with the protection logic habits in the inverter field, that is, a high level to a low level trigger is enabled. In some other embodiments, the first switch module 4 may not be set, and it is necessary to further adjust the modules and components in the control circuit.

[0075] The eleventh resistor R11 is a base current limiting resistor of the first transistor Q1, the twelfth resistor R12 is a base pull-down resistor of the first transistor Q1, and the sixth capacitor C6 is a base bypass capacitor of the first transistor Q1. The first transistor Q1 is a bipolar junction transistor (BJT) or a metal-oxide-semiconductor field-effect transistor (MOSFET), referred to as a MOS transistor.

[0076] The second switch module 5 includes a fourteenth resistor R14, a fifteenth resistor R15 and a sixteenth resistor R16. Among them, one end of the fourteenth resistor R14 is connected to the connection point of the thirteenth resistor R13 and the collector of the first transistor Q1, and the other end of the fourteenth resistor R14 is connected to the base of the second transistor Q2. One end of the fifteenth resistor R15 is connected to the connection point of the fourteenth resistor R14 and the base of the second transistor Q2, the other end of the fifteenth resistor R15 is connected to the emitter of the second transistor Q2, and the other end of the fifteenth resistor R15 is also connected to the ground terminal GND. One end of the sixteenth resistor R16 is connected to the collector of the second transistor Q2, and the other end of the sixteenth resistor R16 is connected to the heat dissipation module 6. The fourteenth resistor R14 is the base current limiting resistor of the second transistor Q2, the fifteenth resistor R15 is the base pull-down resistor of the second transistor Q2, and the sixteenth resistor R1 is the collector current limiting resistor of the second transistor Q2. Among them, the second transistor Q2 can also be a BJT tube or a MOS tube.

[0077] The heat dissipation module 6 includes a third triode Q3, a second diode D2, a third diode D3, a seventh capacitor C7 and a seventeenth resistor R17. Among them, the third triode Q3 is connected to the fifth power supply terminal Vcc5, and the third triode Q3 is configured to be disconnected when the operating current of the heat dissipation component exceeds the rated operating current. The second diode D2 and the third diode D3 are connected in series, the cathode of the second diode D2 is connected to the sixteenth resistor R16, and the anode of the second diode D2 is connected to the third diode D3. The cathode of the third diode D3 is connected to the second diode D2, and the anode of the third diode D3 is connected to the connection point of the fifth power supply terminal Vcc5 and the emitter of the third triode Q3. The heat dissipation component can be specifically a fan, one end of the heat dissipation component is connected to the collector of the third triode Q3, and the other end of the heat dissipation component is connected to the emitter of the second triode Q2. One end of the seventh capacitor C7 is connected to the collector of the third triode Q3, and the other end of the seventh capacitor C7 is connected to the emitter of the second triode Q2 and the connection point of the heat dissipation component. One end of the seventeenth resistor R17 is connected to the emitter of the third triode Q3, the other end of the seventeenth resistor R17 is connected to the fifth power supply terminal Vcc5, and the anode of the third diode D3 is connected to the connection point of the fifth power supply terminal Vcc5 and the seventeenth resistor R17. The second diode D2 and the third diode D3 can be bias diodes, which are mainly used to set the working state of the third triode Q3. The seventeenth resistor R17 is a current limiting resistor of the emitter of the third triode Q3. The maximum operating current of the heat dissipation component can be set by adjusting the seventeenth resistor R17. The third triode Q3 can be a BJT tube or a MOS tube. The seventh capacitor C7 is a support capacitor of the heat dissipation component and also provides a freewheeling circuit of the heat dissipation component.

[0078] In this embodiment, the emitter of the third transistor Q3 is preferably connected to the seventeenth resistor R17. When the heat dissipation component is abnormally overloaded, the current flowing through the seventeenth resistor R17 and the third transistor Q3 will increase. When the voltage across the seventeenth resistor R17 plus the voltage of the third transistor Q3 is equal to the sum of the voltages of the second diode D2 and the third diode D3, the third transistor Q3 will be disconnected, and the heat dissipation component stops running, thereby protecting the heat dissipation component. In some other embodiments, the seventeenth resistor R17 may not be provided, and the specifics are not limited here.

[0079] In this embodiment, the second power terminal Vcc2, the third power terminal Vcc3 and the fourth power terminal Vcc4 can be the same power terminal. In practical applications, it is necessary to determine whether the power terminals are shared or used separately according to actual conditions. Further, the first power terminal Vcc1 and the fifth power terminal Vcc5 are independent power terminals, the first power terminal Vcc1 is the power supply voltage of the temperature sampling circuit, and the fifth power terminal Vcc5 is mainly used as a driving power supply for driving the heat dissipation component to work.

[0080] This embodiment also includes a heat dissipation device, which includes the above-mentioned control circuit. The heat dissipation device also includes a heat dissipation module 6, which will not be described in detail here.

[0081] Combine the following Figure 1 The operation process of the control circuit in this embodiment is specifically introduced:

[0082] When the temperature rises to a certain level, the total voltage drop of the temperature-sensitive diode string will decrease, and the voltage across the first resistor R1 will increase with the temperature. The voltage V_sense at the inverting input of the comparator U2 is greater than the reference voltage Vref1 at the inverting input of the comparator U2, and the comparator U2 outputs a low level. The reference voltage at the inverting input of the comparator U2 is then reduced to Vref2, Vref2<Vref1, and when V_sense is less than Vref2, the output of the comparator U2 can be turned to a high level, realizing the hysteresis protection function.

[0083] When the comparator U2 outputs a low level, the first transistor Q1 is disconnected, and the second transistor Q2 is closed. The specifications of the second transistor Q2, the third transistor Q3, the heat sink component and the seventeenth resistor R17 are selected so that the second transistor Q2 and the third transistor Q3 can work in a saturated state and continuously drive the heat sink component to work. Since the heat sink component is selected according to the specific application scenario, the rated working voltage and rated working current of different heat sink components are also different. Therefore, the requirements for the second transistor Q2 and the third transistor Q3 will be different. For example, the larger the rated working voltage and rated working current of the heat sink component, the greater the low-voltage current that the third transistor Q3 can withstand, the higher the voltage and current specifications when selecting it, and the higher the current during overload protection, and the power and resistance requirements of the seventeenth resistor R17 are naturally different. The current flowing through the collector of the second transistor Q2 is the sum of the base current of the third transistor Q3 and the currents of the second diode D2 and the third diode D3. Therefore, these parameters should be appropriately adjusted according to the model and specifications of the heat dissipation component in the specific application scenario.

[0084] When the heat dissipation component exceeds the rated working current and an abnormality occurs, the current of the emitter of the third transistor Q3 will increase. When the current increases to a certain level, the third transistor Q3 will be disconnected, thereby achieving overload protection for the heat dissipation component.

[0085] Embodiment 2

[0086] The second embodiment is basically the same as the first embodiment, except that: Figure 2 As shown, the temperature sensitive diode module 1 includes a temperature sensitive diode string (Dt1 to Dtn), a first resistor R1 and a first capacitor C1. The temperature sensitive diode string is formed by connecting a plurality of positive temperature coefficient diodes in series. Figure 2 As shown, the anode of the first temperature-sensitive diode Dt1 in the temperature-sensitive diode string is connected to the first resistor R1, and the other end of the first resistor R1 is connected to the first power supply terminal Vcc1. The first capacitor C1 is connected in parallel with the first resistor R1. One end of the third resistor R3 is connected to the connection point between the anode of the temperature-sensitive diode Dt1 and the first resistor R1, and one end of the second resistor R2 is connected to the cathode of the nth temperature-sensitive diode Dtn in the temperature-sensitive diode string. When the temperature rises, the total voltage drop of the temperature-sensitive diode string will increase, and the voltage across the first resistor R1 will decrease as the temperature rises.

[0087] In summary, the control circuit and heat dissipation device in this embodiment have at least the following advantages:

[0088] 1. By setting a temperature-sensitive diode module, a signal sampling and conditioning module, a comparator module, a first switch module and a second switch module connected in series in sequence, the second switch module is connected to the heat dissipation module of the heat dissipation device, and the characteristic that the conduction voltage drop of the temperature-sensitive diode changes with the temperature is utilized, so that the voltage output by the temperature-sensitive diode module changes with the temperature, thereby controlling the opening or closing of the heat dissipation component;

[0089] 2. The modules cooperate with each other, and there is no need to set up additional processor units or develop additional software control algorithms. The structure is simple, reliable and low-cost;

[0090] 3. The heat dissipation module is also equipped with a third transistor, which can control the on and off according to the real-time current of the heat dissipation component to prevent the heat dissipation component from overcurrent. The entire control circuit has a hysteresis function, which avoids the heat dissipation component repeatedly switching between the working state and the non-working state at the current critical point, thus extending the service life of the equipment.

[0091] As shown in this specification and claims, the terms "comprises" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list, and the method or device may also include other steps or elements. The term "and / or" as used herein includes any combination of one or more of the relevant listed items.

[0092] It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or it can be indirectly fixed or connected to the other feature. In addition, the descriptions of up, down, left, right, etc. used in the present invention are only relative to the relative positional relationship of the components of the present invention in the accompanying drawings.

[0093] The above embodiment is only for illustrating the technical concept and features of the utility model, and is a preferred embodiment. Its purpose is to enable people familiar with the technology to understand the content of the utility model and implement it accordingly, and it cannot be used to limit the protection scope of the utility model. Any equivalent transformation or modification made according to the principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A control circuit for a heat dissipation device, characterized in that: Used to control the heat dissipation component to be in a working state or a non-working state, the control circuit includes: A temperature-sensitive diode module, comprising a plurality of temperature-sensitive diodes connected in series, wherein the voltage output by the temperature-sensitive diode module varies with temperature; A signal sampling and conditioning module, used for adjusting the magnitude of the voltage signal output by the temperature-sensitive diode module, wherein the signal sampling and conditioning module and the temperature-sensitive diode module are connected in series; A comparator module, comprising a comparator, one of the input terminals of the comparator is connected in series with the signal sampling and conditioning module, and the other input terminal of the comparator is connected to a reference voltage; A first switch module, comprising a first transistor, wherein the first switch module and an output end of the comparator are connected in series; A second switch module, comprising a second triode, wherein the second switch module is connected in series with the first switch module; The first transistor and the second transistor are opened or closed in response to the output signal of the comparator module; The heat dissipation device includes a heat dissipation module, the heat dissipation module and the second switch module are connected in series, and the heat dissipation module includes the heat dissipation component; when the heat dissipation component is in a non-working state, the first transistor is closed and the second transistor is disconnected; when the heat dissipation component is in a working state, the first transistor is disconnected and the second transistor is closed.

2. The control circuit of the heat dissipation device according to claim 1, characterized in that: The temperature sensitive diode module comprises: A temperature-sensitive diode string, which is formed by connecting a plurality of negative temperature coefficient diodes in series, and the temperature-sensitive diode string is also connected to the first power supply terminal; a first resistor, one end of the first resistor being connected to the temperature sensitive diode string, and the other end of the first resistor being connected to the signal sampling and conditioning module; A first capacitor is connected in parallel with the first resistor.

3. The control circuit of the heat dissipation device according to claim 1, characterized in that: The temperature sensitive diode module comprises: A temperature sensitive diode string, which is formed by connecting a plurality of positive temperature coefficient diodes in series; a first resistor, one end of the first resistor being connected to the temperature sensitive diode string, and the other end of the first resistor being connected to a first power supply terminal; A first capacitor is connected in parallel with the first resistor.

4. The control circuit of the heat dissipation device according to claim 1, characterized in that: The signal sampling and conditioning module comprises: Operational amplifier; a second resistor, one end of the second resistor being connected to the temperature-sensitive diode module, and the other end of the second resistor being connected to the inverting input end of the operational amplifier; a third resistor, one end of the third resistor being connected to the temperature-sensitive diode module, and the other end of the third resistor being connected to the non-inverting input end of the operational amplifier; a fourth resistor, one end of the fourth resistor being connected to a connection point between the third resistor and the non-inverting input terminal of the operational amplifier, and the other end of the fourth resistor being connected to a ground terminal; a second capacitor, wherein the second capacitor and the fourth resistor are connected in parallel, one end of the second capacitor is connected to a connection point between the third resistor and the fourth resistor, and the other end of the second capacitor is connected to a connection point between the fourth resistor and a ground terminal; a fifth resistor, one end of the fifth resistor being connected to a connection point between the second resistor and the inverting input terminal of the operational amplifier, and the other end of the fifth resistor being connected to an output terminal of the operational amplifier; a third capacitor, wherein the third capacitor is connected in parallel with the fifth resistor, one end of the third capacitor is connected to a connection point between the second resistor and the inverting input terminal of the operational amplifier, and the other end of the third capacitor is connected to an output terminal of the operational amplifier; a sixth resistor, one end of the sixth resistor being connected to the output end of the operational amplifier, and the other end of the sixth resistor being connected to the comparator module; A fourth capacitor, one end of which is connected to the comparator module, and the other end of which is connected to a connection point between the fourth resistor and a ground terminal.

5. The control circuit of the heat dissipation device according to claim 4, characterized in that: The comparator module further comprises: a seventh resistor, one end of the seventh resistor being connected to the sixth resistor, and the other end of the seventh resistor being connected to the inverting input end of the comparator; A fifth capacitor, one end of the fifth capacitor is connected to the second power supply terminal, and the other end of the fifth capacitor is connected to the ground terminal; an eighth resistor, one end of the eighth resistor being connected to a connection point between the fifth capacitor and the second power supply terminal, and the other end of the eighth resistor being connected to a non-inverting input terminal of the comparator; a first diode, wherein a cathode of the first diode is connected to the eighth resistor, and an anode of the first diode is connected to a connection point between an output terminal of the comparator and the first switch module; a ninth resistor, one end of which is connected to the anode of the first diode, and the other end of which is connected to the output end of the comparator and a connection point of the first switch module; A tenth resistor, one end of which is connected to the ninth resistor, and the other end of which is connected to the third power supply terminal.

6. The control circuit of the heat dissipation device according to claim 5, characterized in that: The first switch module further includes: an eleventh resistor, one end of the eleventh resistor being connected to the output end of the comparator, and the other end of the eleventh resistor being connected to the base of the first transistor; a twelfth resistor, one end of the twelfth resistor being connected to a connection point between the eleventh resistor and the base of the first transistor, the other end of the twelfth resistor being connected to the emitter of the first transistor, and the other end of the twelfth resistor being further connected to a ground terminal; a sixth capacitor, wherein the sixth capacitor and the twelfth resistor are connected in parallel, one end of the sixth capacitor is connected to a connection point between the eleventh resistor and the base of the first transistor, and the other end of the sixth capacitor is connected to a connection point between the twelfth resistor and a ground terminal; A thirteenth resistor, one end of the thirteenth resistor is connected to the collector of the first transistor, and the other end of the thirteenth resistor is connected to the fourth power supply terminal.

7. The control circuit of the heat dissipation device according to claim 6, characterized in that: The second switch module further includes: a fourteenth resistor, one end of the fourteenth resistor being connected to a connection point between the thirteenth resistor and the collector of the first transistor, and the other end of the fourteenth resistor being connected to a base of the second transistor; a fifteenth resistor, one end of the fifteenth resistor being connected to a connection point between the fourteenth resistor and the base of the second transistor, the other end of the fifteenth resistor being connected to the emitter of the second transistor, and the other end of the fifteenth resistor being further connected to a ground terminal; A sixteenth resistor, one end of the sixteenth resistor is connected to the collector of the second transistor, and the other end of the sixteenth resistor is connected to the heat dissipation module.

8. The control circuit of the heat dissipation device according to claim 7, characterized in that: The heat dissipation module comprises: a third triode connected to the fifth power terminal; the third triode is configured to be disconnected when the operating current of the heat dissipation component exceeds the rated operating current; a second diode and a third diode, the second diode and the third diode are connected in series, the cathode of the second diode is connected to the sixteenth resistor, the anode of the second diode is connected to the third diode; the cathode of the third diode is connected to the second diode, the anode of the third diode is connected to the connection point of the fifth power supply terminal and the emitter of the third transistor; the second diode and the third diode are bias diodes; One end of the heat dissipation component is connected to the collector of the third transistor, and the other end of the heat dissipation component is connected to the emitter of the second transistor; A seventh capacitor, one end of the seventh capacitor is connected to the collector of the third transistor, and the other end of the seventh capacitor is connected to the emitter of the second transistor and the connection point of the heat dissipation component.

9. The control circuit of the heat dissipation device according to claim 8, characterized in that: The heat dissipation module also includes: A seventeenth resistor, one end of the seventeenth resistor is connected to the emitter of the third transistor, and the other end of the seventeenth resistor is connected to the fifth power supply terminal; the anode of the third diode is connected to the connection point between the fifth power supply terminal and the seventeenth resistor.

10. The control circuit of the heat dissipation device according to claim 9, characterized in that: The first transistor, the second transistor and the third transistor are bipolar junction transistors or MOS transistors.

11. A heat dissipation device, characterized in that: The heat dissipation device comprises the control circuit of the heat dissipation device according to any one of claims 1 to 10, the heat dissipation device further comprises a heat dissipation module, the heat dissipation module comprises a heat dissipation component, and the heat dissipation module and the second switch module are connected in series.