A control board considering the anti-interference performance of charging gun temperature measurement

Abstract

The present invention relates to a control board that takes into account the anti-interference performance of charging gun temperature measurement. The control board comprises a first voltage follower, a second voltage follower, and a filter circuit. The first and second voltage followers are both connected to the filter circuit and the temperature sensor of the charging gun head. The filter circuit is also connected to the data acquisition port of the main control chip. This invention improves measurement accuracy while protecting the control chip from damage.

Description

Technical Field

[0001] The present invention relates to the field of charging piles, and in particular to a control board card that takes into account the temperature measurement and anti-interference performance of a charging gun. Background Art

[0002] The current DC charging pile control board needs to have the function of collecting the temperature of the charging gun head. There is a pt1000 temperature sensor on the gun head. Its resistance change corresponds to the current temperature value. Therefore, the resistance value of pt1000 needs to be collected to obtain the temperature value. The existing solutions are as follows Figure 1 As shown, the voltage is generally divided by two resistors (Rpt1000 and R1) and then transmitted to the control chip for collection. The collected voltage is Vad. The larger the resistance of the connected pt1000, the larger the collected voltage. The resistance value of pt1000 can be obtained by Rpt1000 / (Rpt1000+R1)*5=Vad. However, this solution is susceptible to interference, resulting in inaccurate measurement. Moreover, since the external input signal is directly connected to the collection port of the main control chip, the main control chip is easily damaged when the external input is abnormal. Summary of the Invention

[0003] The purpose of the present invention is to provide a control board card that takes into account the anti-interference performance of temperature measurement of a charging gun, which can improve the measurement accuracy while protecting the control chip from damage.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A control board considering the anti-interference performance of charging gun temperature measurement, comprising:

[0006] A first voltage follower, a second voltage follower and a filter circuit; the first voltage follower and the second voltage follower are both connected to the filter circuit and the temperature sensor of the charging gun head; the filter circuit is also connected to the acquisition port of the main control chip.

[0007] Optionally, the control board considering the anti-interference performance of the charging gun temperature measurement further includes: a balancing bridge circuit; the temperature sensor of the charging gun head is respectively connected to the first voltage follower and the second voltage follower through the balancing bridge circuit.

[0008] Optionally, the control board considering the anti-interference performance of the charging gun temperature measurement further includes: a third voltage follower circuit; the filter circuit and the acquisition port of the main control chip are connected through the third voltage follower circuit.

[0009] Optionally, the control board considering the anti-interference performance of the charging gun temperature measurement further includes: a first conditioning circuit; the third voltage follower circuit and the acquisition port of the main control chip are connected through the first conditioning circuit.

[0010] Optionally, the control board considering the anti-interference performance of the charging gun temperature measurement further includes: a fourth voltage follower; the first conditioning circuit and the acquisition port of the main control chip are connected through the fourth voltage follower.

[0011] Optionally, the control board considering the anti-interference performance of the charging gun temperature measurement further includes: a second conditioning circuit; the fourth voltage follower and the acquisition port of the main control chip are connected through the second conditioning circuit.

[0012] Optionally, the control board considering the anti-interference performance of the charging gun temperature measurement further includes: a clamping diode; the second conditioning circuit and the acquisition port of the main control chip are both connected to the clamping diode.

[0013] Optionally, the balancing bridge circuit includes: resistor No. 160, resistor No. 161 and resistor No. 167; one end of resistor No. 160 is connected to one end of resistor No. 161, and the other end of resistor No. 160 is respectively connected to the temperature sensor of the charging gun head and the base of the second voltage follower; the other end of resistor No. 161 is respectively connected to one end of resistor No. 167 and the base of the first voltage follower; the other end of resistor No. 167 is connected to the temperature sensor of the charging gun head.

[0014] Optionally, the filtering circuit includes: capacitor No. 203, resistor No. 163, resistor No. 164, resistor No. 168 and resistor No. 169; one end of resistor No. 163 is respectively connected to the collector of the first voltage follower and the emitter of the first voltage follower; the other end of resistor No. 163 is respectively connected to one end of capacitor No. 203 and one end of resistor No. 164; one end of resistor No. 168 is respectively connected to the collector of the second voltage follower and the emitter of the second voltage follower, and the other end of resistor No. 168 is respectively connected to the other end of capacitor No. 203 and one end of resistor No. 169; the other end of resistor No. 164 and the other end of resistor No. 169 are both connected to the acquisition port of the main control chip.

[0015] Optionally, the third voltage follower circuit includes: resistor No. 159, resistor No. 170 and a third voltage follower, one end of resistor No. 159 is respectively connected to the collector of the filter circuit and the third voltage follower; the other end of resistor No. 159 is connected to the emitter of the third voltage follower; resistor No. 170 is respectively connected to the base of the filter circuit and the third voltage follower; the emitter of the third voltage follower is connected to the acquisition port of the control chip.

[0016] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: when the external input is abnormal, the present invention can protect the control chip from damage due to the presence of an isolation circuit composed of a first voltage follower and a second voltage follower between the input signal and the acquisition port of the main control chip, and because of the presence of a filter circuit that can filter out interference, the temperature of the charging gun head can be measured more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in 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 any creative work.

[0018] Figure 1 This is the circuit diagram of the existing DC control board;

[0019] Figure 2 A schematic diagram of the structure of a control board card that takes into account the anti-interference performance of temperature measurement of a charging gun provided by an embodiment of the present invention;

[0020] Figure 3 A circuit diagram of module 1 provided in an embodiment of the present invention;

[0021] Figure 4 A circuit diagram of module 2 provided in an embodiment of the present invention;

[0022] Figure 5 A circuit diagram of module three provided in an embodiment of the present invention;

[0023] Figure 6 Circuit diagram of the filter capacitor module used for the positive terminal of the voltage follower;

[0024] Figure 7 Circuit diagram of the filter capacitor module used at the negative terminal of the voltage follower.

[0025] Explanation of symbols:

[0026] R159-159 resistor, R160-160 resistor, R161-161 resistor, R162-162 resistor, R163-163 resistor, R164-164 resistor, R165-165 resistor, R166-166 resistor, R167-167 resistor, R168-168 resistor, R169-169 resistor, R170-170 resistor, C203- Capacitor No. 203, C204-capacitor No. 204, C232-capacitor No. 232, U46A-first voltage follower, U46B-second voltage follower, U48A-third voltage follower, U48B-fourth voltage follower, D52-clamping diode, S_AD_PT1000-output end of the control board considering the anti-interference performance of the charging gun's temperature measurement, pt1000+-positive pole of the temperature sensor of the charging gun head, pt 1000--negative pole of the temperature sensor of the charging gun head. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] This embodiment provides a control board that takes into account the anti-interference performance of the charging gun temperature measurement. Figure 2 As shown, the control board considering the anti-interference performance of the charging gun temperature measurement includes: a first voltage follower U46A, a second voltage follower U46B and a filter circuit; the first voltage follower U46A and the second voltage follower U46B are both connected to the filter circuit and the temperature sensor of the charging gun head; the filter circuit is also connected to the acquisition port of the main control chip.

[0030] As an optional implementation, the control board considering the anti-interference performance of the charging gun temperature measurement also includes: a balancing bridge circuit; the temperature sensor of the charging gun head is respectively connected to the first voltage follower U46A and the second voltage follower U46B through the balancing bridge circuit.

[0031] As an optional implementation, the control board card considering the anti-interference performance of the charging gun temperature measurement further includes: a third voltage follower circuit; the filter circuit and the acquisition port of the main control chip are connected through the third voltage follower circuit.

[0032] As an optional implementation, the control board card considering the anti-interference performance of the charging gun temperature measurement further includes: a first conditioning circuit; the third voltage follower circuit and the acquisition port of the main control chip are connected through the first conditioning circuit.

[0033] As an optional implementation, the control board considering the anti-interference performance of the charging gun temperature measurement further includes: a fourth voltage follower U48B; the first conditioning circuit and the acquisition port of the main control chip are connected through the fourth voltage follower U48B.

[0034] As an optional implementation, the control board considering the anti-interference performance of the charging gun temperature measurement further includes: a second conditioning circuit; the fourth voltage follower U48B and the acquisition port of the main control chip are connected through the second conditioning circuit.

[0035] As an optional implementation, the second conditioning circuit includes: resistor No. 165 R165 and capacitor No. 204 C204; one end of the resistor No. 165 R165 is respectively connected to the collector of the fourth voltage follower U48B and the emitter of the fourth voltage follower U48B; the other end of the resistor No. 165 R165 is connected to one end of the capacitor No. 204 C204 and the acquisition port of the main control chip, and the other end of the capacitor No. 204 C204 is grounded.

[0036] As an optional implementation, the control board considering the anti-interference performance of the charging gun temperature measurement further includes: a clamping diode D52; the second conditioning circuit and the acquisition port of the main control chip are both connected to the clamping diode D52; specifically, the first end of the clamping diode D52 is grounded, the second end of the clamping diode D52 is respectively connected to one end of capacitor C204 No. 204, the other end of resistor R165 No. 165 and the acquisition port of the main control chip, the third end of the clamping diode D52 is connected to the power supply, and the second end of the clamping diode D52, one end of capacitor C204 No. 204 and the other end of resistor R165 No. 165 constitute the output end S_AD_PT1000 of the control board considering the anti-interference performance of the charging gun temperature measurement.

[0037] As an optional implementation, Figure 3As shown, the balancing bridge circuit includes: resistor No. 160 R160, resistor No. 161 R161 and resistor No. 167 R167; one end of the resistor No. 160 R160 is connected to one end of the resistor No. 161 R161, and the other end of the resistor No. 160 R160 is respectively connected to the positive electrode pt1000+ of the temperature sensor of the charging gun head and the base of the second voltage follower U46B; the other end of the resistor No. 161 R161 is respectively connected to one end of the resistor No. 167 R167 and the base of the first voltage follower U46A; the other end of the resistor No. 167 R167 is connected to the negative electrode pt1000- of the temperature sensor of the charging gun head and is grounded.

[0038] As an optional implementation, Figure 4 As shown, the filtering circuit includes: capacitor No. 203 C203, resistor No. 163 R163, resistor No. 164 R164, resistor No. 168 R168 and resistor No. 169 R169; one end of the resistor No. 163 R163 is respectively connected to the collector of the first voltage follower U46A and the emitter of the first voltage follower U46A; the other end of the resistor No. 163 R163 is respectively connected to one end of the capacitor No. 203 C203 and the emitter of the resistor No. 164 One end of the resistor No. 168 is connected; one end of the resistor No. 168 R168 is respectively connected to the collector of the second voltage follower U46B and the emitter of the second voltage follower U46B, and the other end of the resistor No. 168 R168 is respectively connected to the other end of the capacitor No. 203 C203 and one end of the resistor No. 169 R169; the other end of the resistor No. 164 R164 and the other end of the resistor No. 169 R169 are both connected to the acquisition port of the main control chip.

[0039] As an optional embodiment, the third voltage follower circuit includes: resistor No. 159 R159, resistor No. 170 R170 and a third voltage follower U48A, one end of the resistor No. 159 R159 is respectively connected to the collector of the filter circuit and the third voltage follower U48A; the other end of the resistor No. 159 R159 is connected to the emitter of the third voltage follower U48A; the resistor No. 170 R170 is respectively connected to the base of the filter circuit and the third voltage follower U48A; the emitter of the third voltage follower U48A is connected to the acquisition port of the control chip. Specifically, one end of the resistor No. 159 R159 and the collector of the third voltage follower U48A are connected to the other end of the resistor No. 164 R164; one end of the resistor No. 170 R170 and the base of the third voltage follower U48A are connected to the other end of the resistor No. 169 R169; the other end of the resistor No. 170 R170 is grounded.

[0040] As an optional implementation, Figure 5 As shown, the first conditioning circuit includes: resistor No. 166 R166 and capacitor No. 232 C232; one end of the resistor No. 166 R166 is connected to the emitter of the third voltage follower U48A; the other end of the resistor No. 166 R166 is connected to one end of the capacitor No. 232 C232 and the base of the fourth voltage follower U48B; the other end of the capacitor No. 232 C232 is grounded; the collector and emitter of the fourth voltage follower U48B are both connected to the second conditioning circuit.

[0041] As an optional implementation, the control board card considering the anti-interference performance of the charging gun temperature measurement also includes: resistor No. 162 R162, one end of resistor No. 162 is respectively connected to the other end of resistor No. 166 R166, one end of capacitor No. 232 C232 and the base of the fourth voltage follower U48B.

[0042] As an optional implementation, the control board considering the anti-interference performance of the charging gun temperature measurement also includes: eight filter capacitor modules, each filter capacitor module includes two parallel capacitors, the specific structure is as follows Figure 6 and Figure 7 As shown, the capacitors in this part are the filter capacitors at the op amp power supply in the entire circuit, which keep the chips (U46A, U48A, U46B and U48B) in a stable working state. Figure 6 The filter capacitor module shown is used for the positive terminal of the voltage follower. Figure 6 +5V_PT is connected to the positive terminals of U46A, U48A, U46B and U48B. Figure 7 The filter capacitor module shown is used for the negative terminal of the voltage follower. Figure 7 -5V_PT is connected to the negative terminals of U46A, U48A, U46B and U48B.

[0043] The balanced bridge circuit of the present invention, the first voltage follower U46A and the second voltage follower U46B form a module 1, the structure of which is as follows: Figure 3 The filter circuit and the third voltage follower circuit form module 2, and the structure is as follows: Figure 4 The first conditioning circuit, resistor R162, the fourth voltage follower U48B, the second conditioning circuit and the clamping diode D52 form module three, and the structure is as follows. Figure 5 shown.

[0044] The present invention has the following technical effects:

[0045] 1. Module 1: The charging gun tip's temperature sensor and three 1kΩ resistors (R160, R161, and R167) form a balanced bridge. The bridge's two ends are fed into Module 2 via the first and second voltage followers (U46A and U46B). These voltage followers effectively isolate the input from Module 2, providing isolation from the input to the data acquisition side and protecting the main control circuitry. This resolves the existing issue of directly connecting external input signals to the data acquisition port of the main control chip, which can easily damage the control chip if the external input is abnormal.

[0046] 2. Module 2: The two voltage signals output by module 1 are differentially amplified in equal proportion by module 2 and then input into module 3. Module 2 amplifies the voltage difference generated by the balanced bridge and filters out input interference through C203 connected in the middle, thus solving the problem of susceptibility to interference in the existing technology.

[0047] 3. Module three: The voltage input from module two is recorded as Vin. The Vin signal may be a negative voltage. Therefore, the voltage input to the third voltage follower U48A is converted into a positive voltage through the pull-up resistor composed of R166 and R162, recorded as Vout. Then Vout = (Vin + 3.3) / 2. The voltage at this time can be sent to the main control chip for voltage collection through the second conditioning circuit. In addition, a BAV99 clamping diode D52 is added to prevent the voltage signal generated by the circuit from being higher than 3.3V or lower than 0V from entering the main control chip, thereby playing a protective role.

[0048] 4. It has the characteristics of wide temperature measurement range, high sensitivity, good linearity and easy temperature compensation.

[0049] 5. The design cost is low and the overall circuit is stable and durable.

[0050] 6. During the charging process of an electric vehicle, if the collected gun temperature rises instantly, charging should be stopped. Traditional detection circuits are easily affected by the external environment and produce erroneous temperature values, causing charging to stop. The circuit of the present invention collects temperature more stably and will not cause temperature jumps due to external influences, thereby ensuring charging stability.

[0051] 7. The temperature reflected by the circuit of the present invention is more accurate. When the temperature of the charging gun head rises abnormally, it can accurately feed back to the control chip, providing an accurate judgment basis for subsequent abnormal processing and charging stop processing, ensuring the safety of electric vehicle charging.

[0052] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0053] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A control board considering the anti-interference performance of charging gun temperature measurement, characterized in that: include: A balanced bridge circuit, a first voltage follower, a second voltage follower, and a filter circuit; The first voltage follower and the second voltage follower are both connected to the filter circuit and the temperature sensor of the charging gun head; the filter circuit is also connected to the acquisition port of the main control chip; The temperature sensor of the charging gun head is connected to the first voltage follower and the second voltage follower respectively through the balancing bridge circuit; the balancing bridge circuit includes: resistor No. 160, resistor No. 161 and resistor No. 167; one end of the resistor No. 160 is connected to one end of the resistor No. 161, and the other end of the resistor No. 160 is connected to the temperature sensor of the charging gun head and the base of the second voltage follower respectively; the other end of the resistor No. 161 is connected to one end of the resistor No. 167 and the base of the first voltage follower respectively; the other end of the resistor No. 167 is connected to the temperature sensor of the charging gun head; the filtering circuit includes: capacitor No. 203, capacitor No. 16 Resistor No. 3, resistor No. 164, resistor No. 168 and resistor No. 169; one end of resistor No. 163 is respectively connected to the collector of the first voltage follower and the emitter of the first voltage follower; the other end of resistor No. 163 is respectively connected to one end of capacitor No. 203 and one end of resistor No. 164; one end of resistor No. 168 is respectively connected to the collector of the second voltage follower and the emitter of the second voltage follower, and the other end of resistor No. 168 is respectively connected to the other end of capacitor No. 203 and one end of resistor No. 169; the other end of resistor No. 164 and the other end of resistor No. 169 are both connected to the acquisition port of the main control chip.

2. A control board considering the anti-interference performance of charging gun temperature measurement according to claim 1, characterized in that: It also includes: a third voltage follower circuit; the filter circuit and the acquisition port of the main control chip are connected through the third voltage follower circuit.

3. A control board considering the anti-interference performance of charging gun temperature measurement according to claim 2, characterized in that: Also includes: a first conditioning circuit; The third voltage follower circuit and the acquisition port of the main control chip are connected through the first conditioning circuit.

4. A control board considering the anti-interference performance of charging gun temperature measurement according to claim 3, characterized in that: Also includes: A fourth voltage follower; the first conditioning circuit and the acquisition port of the main control chip are connected through the fourth voltage follower.

5. A control board considering the anti-interference performance of charging gun temperature measurement according to claim 4, characterized in that: Also includes: a second conditioning circuit; The fourth voltage follower and the acquisition port of the main control chip are connected through the second conditioning circuit.

6. A control board considering the anti-interference performance of charging gun temperature measurement according to claim 5, characterized in that: Also includes: Clamping diode; the second conditioning circuit and the acquisition port of the main control chip are both connected to the clamping diode.

7. The control board considering the anti-interference performance of charging gun temperature measurement according to claim 2, characterized in that: The third voltage follower circuit includes: resistor No. 159, resistor No. 170 and a third voltage follower, one end of resistor No. 159 is respectively connected to the collector of the filter circuit and the third voltage follower; the other end of resistor No. 159 is connected to the emitter of the third voltage follower; resistor No. 170 is respectively connected to the base of the filter circuit and the third voltage follower; the emitter of the third voltage follower is connected to the acquisition port of the main control chip.

Images