Temperature protection power supply circuit and power supply system

Abstract

The invention belongs to the technical field of power supplies, and relates to a temperature protection power supply circuit and a power supply system.The temperature protection power supply circuit comprises an input filtering module, a switch module, a voltage stabilizing module and an output filtering module which are electrically connected, and the input filtering module is used for filtering input voltage; the switch module is used for converting input voltage into output voltage and outputting the output voltage; the voltage stabilizing module is used for maintaining the voltage stabilizing state of the output voltage according to the device temperature change; and the output filtering module is used for filtering the output voltage. According to the technical scheme, the circuit can be simplified, the product cost can be reduced, the influence of temperature change on the circuit is small, the output voltage is stabilized, and normal work of the product is ensured.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and more specifically, to a temperature protection power supply circuit and a power supply system. Background Art

[0002] With the development of science and technology, the use of electronic devices has become very common. Many electronic products, such as outdoor speakers and outdoor lighting, are required to be used both indoors and outdoors. The indoor space is small, and the temperature difference between day and night is not large; the outdoor space is open, and the temperature difference between day and night varies greatly, especially at night, when the temperature may drop below zero. When the internal power supply components of the product cause a large change in output power due to temperature changes, the product may work abnormally.

[0003] Currently, temperature protection of the power supply is performed through some dedicated power management chips. The dedicated power management chips have built-in reference voltages and high precision, but are relatively expensive and have relatively complex circuits. Summary of the invention

[0004] The technical problem to be solved by the embodiments of the present application is that in the related art, circuit temperature protection is performed through a dedicated power management chip, which makes the circuit complex and costly.

[0005] In order to solve the above technical problems, the embodiment of the present application provides a temperature protection power supply circuit, which adopts the following technical solution:

[0006] It includes an input filter module, a switch module, a voltage stabilizing module and an output filter module, wherein the input filter module, the switch module, the voltage stabilizing module and the output filter module are electrically connected;

[0007] The input filter module is used to filter the input voltage; the switch module is used to convert the input voltage into an output voltage output; the voltage stabilization module is used to maintain the voltage stabilization state of the output voltage according to the temperature change of the device; the output filter module is used to filter the output voltage.

[0008] Furthermore, the voltage stabilizing module includes a first voltage stabilizing diode with a positive temperature coefficient and a second voltage stabilizing diode with a negative temperature coefficient connected in series;

[0009] The anode of the first zener diode is grounded, the cathode of the first zener diode is connected to the anode of the second zener diode; and the cathode of the second zener diode is connected to the switch module.

[0010] Furthermore, the voltage stabilizing module further includes a first capacitor, a first end of the first capacitor is connected to the cathode of the second voltage stabilizing diode, and a second end of the first capacitor is grounded.

[0011] Furthermore, the switch module includes a transistor and a voltage-dividing resistor;

[0012] The collector of the transistor is respectively connected to the input voltage, the input filter module and the first end of the voltage-dividing resistor, the base of the transistor is respectively connected to the second end of the voltage-dividing resistor and the cathode of the second voltage-stabilizing diode, and the emitter of the transistor is respectively connected to the output voltage and the output filter module.

[0013] Further, the input filter module includes a second capacitor and a third capacitor connected in parallel;

[0014] A common connection point of the first end of the second capacitor and the first end of the third capacitor is connected to the input voltage and the first end of the switch module respectively;

[0015] The second end of the second capacitor and the second end of the third capacitor are grounded respectively.

[0016] Further, the output filter module includes a fourth capacitor and a fifth capacitor connected in parallel;

[0017] A common connection point of the first end of the fourth capacitor and the first end of the fifth capacitor is connected to the output voltage and the second end of the switch module respectively;

[0018] The second end of the fourth capacitor and the second end of the fifth capacitor are grounded respectively.

[0019] Furthermore, a voltage regulation value of the first voltage regulator diode is greater than 6V, and a voltage regulation value of the second voltage regulator diode is less than 4V.

[0020] Furthermore, the transistor is an NPN transistor or a PNP transistor.

[0021] Furthermore, the resistance value of the voltage-dividing resistor is 2.2±1% kΩ.

[0022] In order to solve the above technical problems, an embodiment of the present application further provides a power supply system, including the temperature protection power supply circuit as described above.

[0023] Compared with the prior art, this application has the following beneficial effects:

[0024] The present application provides a temperature protection power supply circuit, including an input filter module, a switch module, a voltage stabilizing module and an output filter module that are electrically connected. The voltage stabilizing module maintains the voltage stabilizing state of the output voltage according to the temperature change of the device, and the input filter module and the output filter module filter the input voltage and the output voltage respectively, so as to further maintain the stability of the power supply circuit. The simple device of the present application simplifies the circuit, saves space on the circuit board, and reduces the cost, and is suitable for working in different temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the scheme in the present application, a brief introduction is given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 It is a structural block diagram of an embodiment of the temperature protection power supply circuit provided by the present application;

[0027] Figure 2 This is a circuit schematic diagram of an embodiment of a temperature protection power supply circuit provided in the present application. DETAILED DESCRIPTION

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0031] The present application embodiment provides a temperature protection power supply circuit, see Figure 1 As shown, the power supply circuit includes an input filter module 10, a switch module 20, a voltage stabilizing module 30 and an output filter module 40, and the input filter module 10, the switch module 20, the voltage stabilizing module 30 and the output filter module 40 are electrically connected.

[0032] The input filter module 10 is used to filter the input voltage VIN; the switch module 20 is used to convert the input voltage VIN into an output voltage VOUT; the voltage regulator module 30 is used to maintain the voltage regulation state of the output voltage VOUT according to the temperature change of the device; the output filter module 40 is used to filter the output voltage.

[0033] In some embodiments, see Figure 2 As shown, the voltage stabilizing module 30 includes a first voltage stabilizing diode Z1 with a positive temperature coefficient and a second voltage stabilizing diode Z2 with a negative temperature coefficient connected in series; wherein the anode of the first voltage stabilizing diode Z1 is grounded, and the cathode of the first voltage stabilizing diode Z1 is connected to the anode of the second voltage stabilizing diode Z2; and the cathode of the second voltage stabilizing diode Z2 is connected to the switch module 20.

[0034] The temperature coefficient of the first voltage stabilizing diode Z1 is positive, and it operates as an avalanche breakdown. The temperature coefficient of the second voltage stabilizing diode Z2 is negative, and it operates as a Zener breakdown. The two are connected in series, and can perform temperature compensation to provide a reference power supply for the system.

[0035] In some embodiments, the voltage stabilizing module 30 further includes a first capacitor C1 , a first end of the first capacitor C1 is connected to the cathode of the second voltage stabilizing diode Z2 , and a second end of the first capacitor C1 is grounded.

[0036] The first capacitor C1 is used to filter out interference signals and maintain the stability of the circuit voltage.

[0037] In some embodiments, the switch module 20 includes a transistor Q1 and a voltage-dividing resistor R1 .

[0038] The collector of the transistor Q1 is respectively connected to the input voltage VIN, the input filter module 10 and the first end of the voltage-dividing resistor R1, the base of the transistor Q1 is respectively connected to the second end of the voltage-dividing resistor R1 and the cathode of the second voltage-stabilizing diode Z2, and the emitter of the transistor Q1 is respectively connected to the output voltage VOUT and the output filter module 40.

[0039] After power is turned on, the input voltage VIN of the power supply is divided by the voltage divider resistor R1, and a positive current is applied to the base of the transistor Q1, so that the transistor Q1 is turned on, and the input voltage VIN is output through the transistor Q1.

[0040] Among them, the common connection point of the collector of the transistor Q1 and the first end of the voltage-dividing resistor R1 is the first end of the switch module 20, the emitter of the transistor Q1 is the second end of the switch module 20, and the common connection point of the base of the transistor Q1 and the second end of the voltage-dividing resistor R1 is the third end of the switch module 20.

[0041] In some embodiments, the transistor Q1 can be an NPN transistor or a PNP transistor, which can be selected according to actual needs and is not limited here.

[0042] In this embodiment, a common connection point between the first end of the first capacitor C1 and the cathode of the second voltage stabilizing diode Z2 is connected to the third end of the switch module 20 , and the first capacitor C1 can maintain the stability of the base voltage of the transistor Q1 .

[0043] In some embodiments, the input filter module 10 includes a second capacitor C2 and a third capacitor C3 connected in parallel. A common connection point of a first end of the second capacitor C2 and a first end of the third capacitor C3 is connected to an input voltage VIN and a first end of the switch module 20, respectively; and a second end of the second capacitor C2 and a second end of the third capacitor C3 are grounded, respectively.

[0044] The capacitance value of the second capacitor C2 is much greater than that of the third capacitor C3, and the two capacitors connected in parallel can filter the input voltage VIN. For example, the capacitance parameter of the second capacitor C2 is 10μF / 25V; the capacitance parameter of the third capacitor C3 is 0.1μF / 25V.

[0045] In some embodiments, the output filter module 40 includes a fourth capacitor C4 and a fifth capacitor C5 connected in parallel. A common connection point of a first end of the fourth capacitor C4 and a first end of the fifth capacitor C5 is connected to the output voltage VOUT and a second end of the switch module 20, respectively; a second end of the fourth capacitor C4 and a second end of the fifth capacitor C5 are grounded, respectively.

[0046] The capacitance value of the fourth capacitor C4 is much greater than that of the fifth capacitor C5, and the two capacitors connected in parallel can filter the output voltage VOUT. For example, the capacitance parameter of the fourth capacitor C4 is 10μF / 25V; the capacitance parameter of the fifth capacitor C5 is 0.1μF / 25V.

[0047] It should be understood that the capacitance values ​​of the second capacitor C2 and the fourth capacitor C4 can be the same or different. Similarly, the capacitance values ​​of the third capacitor C3 and the fifth capacitor C5 can be the same or different. The selection is made according to actual needs and is not limited here.

[0048] The working principle of the temperature protection power supply circuit of the present application in electronic products is as follows:

[0049] When the product is working, the temperature rises, the second Zener diode Z2 is a negative temperature coefficient device, and the voltage regulation value decreases; the first Zener diode Z1 is a positive temperature coefficient device, and the voltage regulation value increases. The two are connected in series, and the overall voltage regulation value remains almost unchanged, and the power supply output is stable, thereby reducing the impact of temperature rise on the power supply output accuracy.

[0050] When the product is working, the temperature decreases, the first Zener diode Z1 is a positive temperature coefficient device, and the voltage regulation value decreases; the second Zener diode Z2 is a negative temperature coefficient device, and the voltage regulation value increases. The two are connected in series, and the overall voltage regulation value remains almost unchanged, and the power supply output is stable, thereby reducing the impact of temperature rise on the power supply output accuracy;

[0051] When the product is working, the temperature remains unchanged, the voltage stabilization values ​​of the first voltage stabilizing diode Z1 and the second voltage stabilizing diode Z2 remain unchanged, and the power supply output is stable.

[0052] In some embodiments, the voltage regulation value of the first Zener diode is greater than 6 V, and the voltage regulation value of the second Zener diode is less than 4 V. As a specific example, the voltage regulation value of the first Zener diode is 12 V, and the voltage regulation value of the second Zener diode is 3.6 V.

[0053] In some embodiments, the resistance value of the voltage dividing resistor R1 is 2.2±1% kΩ.

[0054] In some embodiments, the capacitance parameter of the first capacitor C1 is 4.7 μF / 25V.

[0055] The temperature protection power supply circuit formed by the coordination of capacitors, resistors, positive and negative temperature coefficient Zener diodes and transistors in the present application has a simple circuit structure. Compared with some higher-priced power management chips, it uses common components, which can significantly reduce product costs. At the same time, the circuit is less affected by temperature changes, can stabilize the output voltage, and ensure the normal operation of the product, safety and reliability.

[0056] The present application also provides a power supply system, which includes the temperature protection power supply circuit as described above, and is capable of operating in a working environment with large temperature changes, and is particularly suitable for products with strict cost requirements.

[0057] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to perform equivalent replacement of some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. A temperature protection power supply circuit, characterized in that: include: An input filter module, a switch module, a voltage stabilizing module and an output filter module, wherein the input filter module, the switch module, the voltage stabilizing module and the output filter module are electrically connected; The input filter module is used to filter the input voltage; the switch module is used to convert the input voltage into an output voltage output; the voltage stabilization module is used to maintain the voltage stabilization state of the output voltage according to the temperature change of the device; the output filter module is used to filter the output voltage.

2. The temperature protection power supply circuit according to claim 1, characterized in that: The voltage stabilizing module comprises a first voltage stabilizing diode with a positive temperature coefficient and a second voltage stabilizing diode with a negative temperature coefficient connected in series; The anode of the first zener diode is grounded, the cathode of the first zener diode is connected to the anode of the second zener diode; and the cathode of the second zener diode is connected to the switch module.

3. The temperature protection power supply circuit according to claim 2, characterized in that: The voltage stabilizing module further includes a first capacitor, a first end of the first capacitor is connected to the cathode of the second voltage stabilizing diode, and a second end of the first capacitor is grounded.

4. The temperature protection power supply circuit according to claim 2, characterized in that: The switch module includes a triode and a voltage dividing resistor; The collector of the transistor is respectively connected to the input voltage, the input filter module and the first end of the voltage-dividing resistor, the base of the transistor is respectively connected to the second end of the voltage-dividing resistor and the cathode of the second voltage-stabilizing diode, and the emitter of the transistor is respectively connected to the output voltage and the output filter module.

5. The temperature protection power supply circuit according to claim 1, characterized in that: The input filter module includes a second capacitor and a third capacitor connected in parallel; A common connection point of the first end of the second capacitor and the first end of the third capacitor is connected to the input voltage and the first end of the switch module respectively; The second end of the second capacitor and the second end of the third capacitor are grounded respectively.

6. The temperature protection power supply circuit according to claim 1, characterized in that: The output filter module includes a fourth capacitor and a fifth capacitor connected in parallel; A common connection point of the first end of the fourth capacitor and the first end of the fifth capacitor is connected to the output voltage and the second end of the switch module respectively; The second end of the fourth capacitor and the second end of the fifth capacitor are grounded respectively.

7. The temperature protection power supply circuit according to claim 2, characterized in that: The voltage regulation value of the first voltage regulator diode is greater than 6V, and the voltage regulation value of the second voltage regulator diode is less than 4V.

8. The temperature protection power supply circuit according to claim 4, characterized in that: The transistor is an NPN transistor or a PNP transistor.

9. The temperature protection power supply circuit according to claim 4, characterized in that: The resistance value of the voltage-dividing resistor is 2.2±1% kΩ.

10. A power supply system, characterized in that: Comprising a temperature protection power supply circuit as claimed in any one of claims 1 to 9.

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