Temperature-adjustable automatic control switch circuit

Abstract

The utility model discloses a temperature-adjustable automatic control switch circuit, which belongs to the technical field of control circuits and comprises a power supply module connected with a temperature acquisition module used for acquiring external temperature information and a second switch device used for conducting the circuit. The temperature acquisition module is connected with a first switching device used for conducting a circuit, the first switching device is connected with a second switching device, and the first switching device and the second switching device are both connected with a load. Through the mode, the adjustable resistor is used for adjusting the temperature threshold value corresponding to the NTC thermistor, the cost is low, the structure is simple, the temperature adjusting range is 25-150 DEG C, and the experimental conditions required by most common electronic components and circuit boards are met; therefore, the use efficiency of the scheme and the working efficiency of personnel are improved, and the circuit cost and the product research and development cost are further reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of automatic control circuits, in particular to an automatic control switch circuit with adjustable temperature. Background Art

[0002] When screening circuit boards or individual electronic components according to GJB7243-2011 and other standards, the automatic control circuit can strictly control the time required for the test according to the test requirements. After setting the relevant parameters, the input end is connected to an external voltage-stabilized power supply, and the output end is connected to the components or products under test, and the components or products can be automatically powered on and off in conjunction with the environmental test chamber.

[0003] The existing solution is generally a temperature-controlled switch. The input voltage range and temperature threshold cannot be adjusted at the same time. There are the following problems: different types of components or products cannot meet the experimental requirements. For example, using different temperature-controlled switches according to different models will increase the experimental cost.

[0004] Based on this, the utility model designs an adjustable temperature automatic control switch circuit to solve the above problems. Utility Model Content

[0005] In view of the above-mentioned shortcomings of the prior art, the utility model provides an automatic control switch circuit with adjustable temperature.

[0006] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] A temperature-adjustable automatic control switch circuit comprises a power module, the power module is connected to a temperature acquisition module for collecting external temperature information and a second switch device for conducting the circuit, the temperature acquisition module is connected to a first switch device for conducting the circuit, the first switch device is connected to the second switch device, and both the first switch device and the second switch device are connected to a load.

[0008] Furthermore, the power supply module is an external power supply V1.

[0009] Furthermore, the temperature acquisition module includes a first resistor and an NTC thermistor RX.

[0010] Furthermore, the first switch device includes a fifth resistor R5, a first transistor Q1, a second capacitor C2, a second resistor R2, a sixth resistor R6, a third capacitor C3 and a first capacitor C1.

[0011] Furthermore, the second switching device includes a third resistor R3, an eighth resistor R8 and a second transistor Q2.

[0012] Furthermore, one end of the external power supply V1 is electrically connected to one end of the first resistor, one end of the third resistor R3, and the collector of the second transistor Q2, and the other end of the external power supply V1 is electrically connected to one end of the NTC thermistor RX, one end of the second capacitor C2, one end of the second resistor, one end of the third capacitor C3, one end of the first capacitor C1, and one end of the load 5.

[0013] Furthermore, the other end of the first resistor is electrically connected to the other end of the NTC thermistor RX, one end of the fifth resistor R5, and the other end of the second capacitor C2; the other end of the fifth resistor R5 is electrically connected to the base of the first transistor Q1; the emitter of the first transistor Q1 is electrically connected to the other end of the second resistor, the other end of the third capacitor C3, and one end of the sixth resistor R6.

[0014] Furthermore, the collector of the first transistor Q1 is electrically connected to the other end of the third resistor R3 and one end of the eighth resistor R8, the other end of the eighth resistor R8 is electrically connected to the base of the second transistor Q2, and the emitter of the second transistor Q2 is electrically connected to the other end of the sixth resistor R6, the other end of the first capacitor C1, and the other end of the load 5.

[0015] Furthermore, the first resistor is a common resistor R11 or an adjustable resistor R21.

[0016] Furthermore, the second resistor is a common resistor R12 or an adjustable resistor R22.

[0017] Compared with the prior art, the utility model has the following beneficial effects: 1. The input voltage range is between 5V and 50V, and the transistor can be selected according to the demand, and the appropriate collector-emitter voltage can be selected to further increase the input voltage range of the circuit;

[0018] 2. Use adjustable resistors to adjust the temperature threshold corresponding to the NTC thermistor to meet the experimental requirements of different components and products at different ambient temperatures;

[0019] 3. Low cost, simple structure, temperature adjustment range is 25℃-150℃, meeting the experimental conditions required by most commonly used electronic components and circuit boards;

[0020] 4. When this solution is modularly integrated through printed circuit boards, it can support batch parallel application of multiple components or products of the same model, thereby improving the use efficiency of this solution and the work efficiency of personnel, and further reducing circuit costs and product research and development costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 This is a block diagram of an adjustable temperature automatic control switch circuit of the utility model;

[0023] Figure 2 This is a circuit diagram of an adjustable temperature automatic control switch circuit according to the first embodiment of the utility model;

[0024] Figure 3 This is a circuit diagram of an adjustable temperature automatic control switch circuit according to the second embodiment of the utility model.

[0025] The numbers in the figure represent:

[0026] 1. Power module; 2. Temperature acquisition module; 3. First switch device; 4. Second switch device; 5. Load. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] Embodiment 1: In some embodiments, please refer to the drawings of the specification Figure 1-Figure 2 , including a power module 1, the power module 1 is connected to a temperature acquisition module 2 for collecting external temperature information and a second switch device 4 for conducting the circuit, the temperature acquisition module 2 is connected to a first switch device 3 for conducting the circuit, the first switch device 3 is connected to the second switch device 4, and the first switch device 3 and the second switch device 4 are both connected to a load 5.

[0029] The power supply module 1 is an external power supply V1.

[0030] The temperature acquisition module 2 includes a common resistor R11 and an NTC (Negative Temperature Coefficient) thermistor RX;

[0031] The first switch device 3 includes a resistor R5, a transistor Q1, a capacitor C2, an adjustable resistor R12, a resistor R6, a capacitor C3 and a capacitor C1;

[0032] The second switching device 4 includes a resistor R3, a resistor R8 and a transistor Q2;

[0033] One end of the external power supply V1 is electrically connected to one end of the resistor R1, one end of the resistor R3, and the collector of the transistor Q2, and the other end of the external power supply V1 is electrically connected to one end of the NTC thermistor RX, one end of the capacitor C2, one end of the adjustable resistor R12, one end of the capacitor C3, one end of the capacitor C1, and one end of the load 5;

[0034] The other end of the common resistor R11 is electrically connected to the other end of the NTC thermistor RX, one end of the resistor R5, and the other end of the capacitor C2; the other end of the resistor R5 is electrically connected to the base of the transistor Q1; the emitter of the transistor Q1 is electrically connected to the other end of the adjustable resistor R12, the other end of the capacitor C3, and one end of the resistor R6;

[0035] The collector of transistor Q1 is electrically connected to the other end of resistor R3 and one end of resistor R8. The other end of resistor R8 is electrically connected to the base of transistor Q2. The emitter of transistor Q2 is electrically connected to the other end of resistor R6, the other end of capacitor C1 and the other end of load 5.

[0036] Figure 1 The circuit block diagram is shown below. Figure 2 The circuit shown is a circuit structure that uses an NTC thermistor RX to sample the ambient temperature.

[0037] At room temperature 25℃, after voltage division with resistor R1, the voltage after voltage division is from the base to the emitter of transistor Q1, thereby turning on transistor Q1. After transistor Q1 is turned on, the base voltage of transistor Q2 will be pulled down to make it in the cut-off state. At this time, the emitter of transistor Q2 has no output voltage;

[0038] When the temperature rises to a preset threshold, the resistance of the NTC thermistor RX will decrease due to the increase in ambient temperature, and the voltage at the resistor R1 and the NTC thermistor RX will also decrease accordingly. At this time, the base voltage of the transistor Q1 is less than the emitter voltage, and the transistor Q1 is in the cut-off state. The power supply V1 voltage will increase the base voltage of the transistor Q2 through the resistor R3 and turn on the transistor Q2. At this time, the voltage of the power supply V1 will be output to the load 5 through the collector to the emitter of the transistor Q2.

[0039] The emitter of transistor Q2 is connected to resistor R6 and adjustable resistor R12, and the voltage divider between resistor R6 and adjustable resistor R12 is connected to the emitter of transistor Q1. The adjustable resistor R12 can be used to adjust the voltage value at the emitter of transistor Q1, so that the emitter voltage of transistor Q1 is stabilized to a certain value, which is equivalent to increasing the voltage value required for the base of transistor Q1 to turn on. Because the base voltage of transistor Q1 is obtained by the voltage divider of resistor R1 and NTC thermistor RX, when the resistance value of NTC thermistor RX decreases, the voltage at the voltage divider between resistor R1 and NTC thermistor RX will increase, which can further control the temperature threshold corresponding to NTC thermistor RX. Avoid the situation where transistor Q1 is mis-conducted and the output of the emitter of transistor Q2 is turned off.

[0040] In this embodiment, the resistance adjustment amount of the adjustable resistor R12 is higher, and needs to be adjusted from 1KΩ to several tens of KΩ.

[0041] This solution is mainly used to improve the method of conducting electrical aging experiments on components or products. According to the experimental requirements, different types of transistors can be selected for improvement in the input voltage range, and the temperature threshold corresponding to the NTC thermistor can be adjusted using an adjustable resistor to meet the experimental requirements of different components under different ambient temperatures and voltage values, so as to expose various potential defects hidden inside the components as early as possible, thereby achieving the purpose of eliminating early failure products.

[0042] Embodiment 2: In some embodiments, Figure 1 and Figure 3 As shown, as a preferred embodiment of the utility model, it includes a power supply module 1, the power supply module 1 is connected to a temperature acquisition module 2 for collecting external temperature information and a second switch device 4 for conducting the circuit, the temperature acquisition module 2 is connected to a first switch device 3 for conducting the circuit, the first switch device 3 is connected to the second switch device 4, and the first switch device 3 and the second switch device 4 are both connected to a load 5.

[0043] The power supply module 1 is an external power supply V1.

[0044] The temperature acquisition module 2 includes an adjustable resistor R21 and an NTC thermistor RX;

[0045] The first switch device 3 includes a resistor R5, a transistor Q1, a capacitor C2, a common resistor R22, a resistor R6, a capacitor C3 and a capacitor C1;

[0046] The second switch device 4 includes a resistor R3, a resistor R8 and a transistor Q2;

[0047] One end of the external power supply V1 is electrically connected to one end of the adjustable resistor R21, one end of the resistor R3, and the collector of the transistor Q2, and the other end of the external power supply V1 is electrically connected to one end of the NTC thermistor RX, one end of the capacitor C2, one end of the common resistor R22, one end of the capacitor C3, one end of the capacitor C1, and one end of the load 5;

[0048] The other end of the adjustable resistor R21 is electrically connected to the other end of the NTC thermistor RX, one end of the resistor R5, and the other end of the capacitor C2. The other end of the resistor R5 is electrically connected to the base of the transistor Q1. The emitter of the transistor Q1 is electrically connected to the other end of the common resistor R22, the other end of the capacitor C3, and one end of the resistor R6.

[0049] The collector of transistor Q1 is electrically connected to the other end of resistor R3 and one end of resistor R8. The other end of resistor R8 is electrically connected to the base of transistor Q2. The emitter of transistor Q2 is electrically connected to the other end of resistor R6, the other end of capacitor C1 and the other end of load 5.

[0050] Figure 1 The circuit block diagram is shown below. Figure 3 The circuit shown is a circuit structure that uses an NTC thermistor RX to sample the ambient temperature.

[0051] At room temperature 25℃, after voltage division with adjustable resistor R21, the voltage after voltage division is from base to emitter of transistor Q1, thus turning on transistor Q1. After transistor Q1 is turned on, the base voltage of transistor Q2 will be pulled down to make it in cut-off state. At this time, the emitter of transistor Q2 has no output voltage.

[0052] When the temperature rises to a preset threshold, the resistance of the NTC thermistor RX will decrease due to the increase in ambient temperature, and the voltage at the adjustable resistor R21 and the NTC thermistor RX will also decrease accordingly. At this time, the base voltage of the transistor Q1 is less than the emitter voltage, and the transistor Q1 is in the cut-off state. The power supply V1 voltage will increase the base voltage of the transistor Q2 through the resistor R3 and turn on the transistor Q2. At this time, the voltage of the power supply V1 will be output to the load 5 through the collector to the emitter of the transistor Q2.

[0053] The emitter of transistor Q2 is connected to resistor R6 and ordinary resistor R22, and the voltage division point of resistor R6 and ordinary resistor R22 is connected to the emitter of transistor Q1. The voltage value at the base of transistor Q1 can be adjusted by using adjustable resistor R21, which is equivalent to increasing the voltage value required for the base of transistor Q1 to be turned on, so that the emitter voltage of transistor Q1 is stabilized to a certain value. Because the base voltage of transistor Q1 is obtained by the voltage division of adjustable resistor R21 and NTC thermistor RX, when the resistance value of NTC thermistor RX decreases, the voltage at the voltage division point of adjustable resistor R21 and NTC thermistor RX will increase, which can further control the temperature threshold corresponding to NTC thermistor RX. Avoid the situation where transistor Q1 is mis-conducted and the output of the emitter of transistor Q2 is turned off.

[0054] Compared with the first embodiment, the resistance adjustment range of the common resistor R22 in this embodiment is smaller, and only needs to be adjusted within the range of 25Ω-5KΩ.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adjustable temperature automatic control switch circuit, comprising a power module (1), characterized in that: The power supply module (1) is connected to a temperature acquisition module (2) for acquiring external temperature information and a second switch device (4) for conducting a circuit; the temperature acquisition module (2) is connected to a first switch device (3) for conducting a circuit; the first switch device (3) is connected to the second switch device (4); and the first switch device (3) and the second switch device (4) are both connected to a load (5).

2. The temperature-adjustable automatic control switch circuit according to claim 1, characterized in that: The power supply module (1) is an external power supply (V1).

3. The temperature-adjustable automatic control switch circuit according to claim 2 is characterized in that: The temperature acquisition module (2) comprises a first resistor and an NTC thermistor (RX).

4. The temperature-adjustable automatic control switch circuit according to claim 3 is characterized in that: The first switch device (3) comprises a fifth resistor (R5), a first transistor (Q1), a second capacitor (C2), a second resistor (R2), a sixth resistor (R6), a third capacitor (C3) and a first capacitor (C1).

5. The temperature-adjustable automatic control switch circuit according to claim 4, characterized in that: The second switch device (4) comprises a third resistor (R3), an eighth resistor (R8) and a second transistor (Q2).

6. The temperature-adjustable automatic control switch circuit according to claim 5, characterized in that: One end of the external power supply (V1) is electrically connected to one end of the first resistor, one end of the third resistor (R3), and the collector of the second transistor (Q2); the other end of the external power supply (V1) is electrically connected to one end of the NTC thermistor (RX), one end of the second capacitor (C2), one end of the second resistor, one end of the third capacitor (C3), one end of the first capacitor (C1), and one end of the load (5).

7. The temperature-adjustable automatic control switch circuit according to claim 6, characterized in that: The other end of the first resistor is electrically connected to the other end of the NTC thermistor (RX), one end of the fifth resistor (R5), and the other end of the second capacitor (C2); the other end of the fifth resistor (R5) is electrically connected to the base of the first transistor (Q1); the emitter of the first transistor (Q1) is electrically connected to the other end of the second resistor, the other end of the third capacitor (C3), and one end of the sixth resistor (R6).

8. The temperature-adjustable automatic control switch circuit according to claim 7, characterized in that: The collector of the first triode (Q1) is electrically connected to the other end of the third resistor (R3) and one end of the eighth resistor (R8); the other end of the eighth resistor (R8) is electrically connected to the base of the second triode (Q2); and the emitter of the second triode (Q2) is electrically connected to the other end of the sixth resistor (R6), the other end of the first capacitor (C1), and the other end of the load (5).

9. The temperature-adjustable automatic control switch circuit according to claim 8, characterized in that: The first resistor is a common resistor (R11) or an adjustable resistor (R21).

10. The temperature-adjustable automatic control switch circuit according to claim 9, characterized in that: The second resistor is a common resistor (R12) or an adjustable resistor (R22).

Images