Clamp relay voltage circuit
By using clamp relay circuit in the charger and controlling the voltage across the relay with the voltage divider module and the reverse protection module, the problem of increasing the relay volume and cost of the charger output current and voltage is solved, and a more economical relay selection is achieved.
Patent Information
- Application Number
- CN202421937093.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-09
- Publication Date
- 2025-04-18
- Estimated Expiration
- 2034-08-09
AI Technical Summary
In the existing charger design, as the current and voltage at the charger output increases, the relay needs to withstand large currents and large voltages, thereby increasing the size and cost of the relay.
The clamp relay circuit is adopted. Through the series connection between the voltage divider module and the reverse protection module, the voltage across the relay of the on-off circuit is controlled so that it is smaller than the charging power supply voltage, thereby selecting a relay with a smaller withstand voltage value specification.
The voltage withstand value specification of the relay is reduced, the production cost is reduced, and the excessive increase in the relay volume is avoided.
Smart Images
Figure CN222775975U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of circuits, in particular to a circuit for clamping a relay voltage. Background Art
[0002] When designing a charger, a relay needs to be connected in series at the output end because of the need to control the safety standards for output voltage and current. As the current used by electrical appliances increases, the current at the output end of the charger must also output a large current, so the relay used should also be able to withstand a large current. As the current increases, the corresponding output voltage of the charger will also increase, resulting in the relay being able to withstand a large voltage, and the voltage withstand value of the relay must also be considered. For example, when the voltage of the charging power supply is 80V, the voltage withstand specification of the relay should be greater than 80V, and the increase in the voltage withstand value of the relay is often related to the coil material and the number of turns of the coil of the relay. The more turns, the higher the voltage withstand value. As a result, the increase in the voltage withstand value of the relay will lead to an increase in the number of turns of the coil of the relay, causing the volume of the relay to increase accordingly, which will cause inconvenience during use, and the cost of using the relay will also increase accordingly. Utility Model Content
[0003] In view of the deficiencies of the prior art, the utility model provides a circuit for clamping relay voltage.
[0004] The purpose of the utility model is achieved through the following solutions:
[0005] A circuit for clamping a relay voltage comprises: a charging unit and a rechargeable battery; the charging unit comprises a rectifier module, an LLC module, a clamp circuit and an on-off circuit, the rectifier module is electrically connected to the LLC module, the LLC module is electrically connected to the clamp circuit, the on-off circuit and the rechargeable battery respectively, the clamp circuit is electrically connected to the on-off circuit and the rechargeable battery respectively, and the rechargeable battery is electrically connected to the on-off circuit.
[0006] In one embodiment, the clamping circuit includes a voltage divider module and a first reverse protection module. The voltage divider module is connected in series with the first reverse protection module, and the voltage divider module is connected in series with the first reverse protection module in parallel with the on-off circuit. The voltage divider module is also electrically connected to the rechargeable battery, and the first reverse protection module is also electrically connected to the LLC module.
[0007] In one embodiment, the voltage divider module includes a resistor R30, a resistor R47 and a resistor R48, and the resistor R30, the resistor R47 and the resistor R48 have a terminal 1 and a terminal 2 respectively, and the terminal 1 and the terminal 2 of the resistor R30 are respectively connected in parallel with the LLC module and the on-off circuit; the terminal 1 and the terminal 2 of the resistor R47 and the resistor R48 are connected in parallel, and after the parallel connection, the terminal 1 of the resistor R47 and the resistor R48 is electrically connected to the first reverse protection module, and after the parallel connection, the terminal 2 of the resistor R47 and the resistor R48 is electrically connected to the on-off circuit and the rechargeable battery.
[0008] In one embodiment, the first reverse protection module includes a diode D2, the diode D2 has a terminal 1 and a terminal 2, the terminal 1 of the diode D2 is electrically connected to the voltage divider module; the terminal 2 of the diode D2 is electrically connected to the LLC module, the voltage divider module and the on-off circuit respectively.
[0009] In one embodiment, the on-off circuit includes an input power supply, a relay KI, a second reverse protection module, an overcurrent protection module, a switch module, a voltage limiting module and a filter module; the relay KI has a terminal 1, a terminal 2, a terminal 3 and a terminal 4, the terminal 1 and the terminal 2 of the relay KI are electrically connected to the clamping circuit, the terminal 1 of the relay KI is electrically connected to the LLC module, and the terminal 2 of the relay KI is electrically connected to the filter module and the rechargeable battery respectively;
[0010] The input power supply is electrically connected to terminal 3 of relay KI and the reverse protection module;
[0011] The second reverse protection module is connected in parallel to the terminals 3 and 4 of the relay KI, and is electrically connected to the overcurrent protection module;
[0012] The overcurrent protection module is electrically connected to terminal 4 of the relay KI and the switch module respectively;
[0013] The switch module is electrically connected to the LLC module, the voltage dividing module, the voltage limiting module, the filter module and the rechargeable battery respectively;
[0014] The voltage limiting module is electrically connected to the LLC module, the voltage dividing module, the filter module and the rechargeable battery respectively;
[0015] The filter module is electrically connected to the No. 2 terminal of the relay KI, the LLC module and the voltage divider module respectively, and the filter module is also connected in parallel with the rechargeable battery.
[0016] In one embodiment, the second reverse protection module includes a diode D1 having a terminal 1 and a terminal 2, wherein the terminal 1 of the diode D1 is electrically connected to the terminal 3 of the relay KI and the input power supply; the terminal 2 of the diode D1 is electrically connected to the terminal 4 of the relay KI and the overcurrent protection module, respectively.
[0017] In one embodiment, the overcurrent protection module includes a resistor R34 and a resistor R35, and the resistor R34 and the resistor R35 have a terminal 1 and a terminal 2 respectively. The terminal 1 and the terminal 2 of the resistor R34 are respectively connected in parallel with the terminal 1 and the terminal 2 of the resistor R35, and the terminal 1 of the resistor R34 and the resistor R35 are electrically connected to the terminal 4 of the relay KI, and the terminal 2 of the resistor R34 and the resistor R35 are electrically connected to the switch module.
[0018] In one embodiment, the switch module includes a transistor Q1, which has a base B, a collector C and an emitter E. The base B of the transistor Q1 is electrically connected to the voltage limiting module, the collector C of the transistor Q1 is electrically connected to the overcurrent protection module, and the emitter E of the transistor Q1 is electrically connected to the LLC module, the voltage divider module, the voltage limiting module, the filter module and the rechargeable battery respectively.
[0019] In one embodiment, the voltage limiting module includes a resistor R36 and a resistor R37, and the resistor R36 and the resistor R37 have a terminal 1 and a terminal 2 respectively. The terminals 1 of the resistor R36 and the resistor R37 are respectively electrically connected to the base B of the transistor Q1, and the terminal 2 of the resistor R36 is externally connected to the signal P1 input, and the terminal 2 of the resistor R37 is respectively electrically connected to the LLC module, the voltage divider module, the filter module and the rechargeable battery.
[0020] In one embodiment, the filtering module includes a capacitor C20, which has a terminal 1 and a terminal 2. The terminal 1 of the capacitor C20 is electrically connected to the terminal 2 of the relay KI, and the terminal 2 is electrically connected to the LLC module, the voltage divider module and the voltage limiting module respectively. The filtering module is also connected in parallel with the rechargeable battery.
[0021] Compared with the prior art, the utility model has at least the following advantages:
[0022] The utility model adopts a clamping circuit as a voltage limiting circuit to control the voltage at both ends of the relay of the on-off circuit through the principle of series voltage division, so that the withstand voltage specification of the relay can be lower than the power supply voltage. When the output voltage of the charger is high, a relay with a smaller withstand voltage specification can be used, thereby reducing the production cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:
[0024] Figure 1 This is a circuit structure diagram of the utility model;
[0025] Among them, the figure markings are, 1. a circuit for clamping relay voltage; 10. charging unit; 110. rectifier module; 120. LLC module; 130. clamping circuit; 131. voltage divider module; 132. first reverse protection module; 140. on-off circuit; 141 input power supply; 142 relay KI; 143. second reverse protection module; 144. overcurrent protection module; 145. switch module; 146. voltage limiting module; 147. filter module; 20. rechargeable battery. DETAILED DESCRIPTION
[0026] The following will disclose multiple embodiments of the present invention with drawings. For the purpose of clear description, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present invention. In other words, in some embodiments of the present invention, these practical details are not necessary. In addition, in order to simplify the drawings, some conventional structures and components will be depicted in a simple schematic manner in the drawings.
[0027] It should be noted that all directional indications such as up, down, left, right, front, back... in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture as shown in the accompanying drawings. If the specific posture changes, the directional indication will also change accordingly.
[0028] In addition, in the present utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present utility model. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.
[0029] In order to further understand the content, features and effects of the utility model, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:
[0030] like Figure 1 As shown, a circuit 1 for clamping a relay voltage includes: a charging unit 10 and a rechargeable battery 20 . The charging unit 10 is electrically connected to the rechargeable battery 20 , and the charging unit 10 charges the rechargeable battery 20 .
[0031] refer to Figure 1The charging unit 10 includes a rectifier module 110, an LLC module 120, a clamping circuit 130 and an on-off circuit 140. The rectifier module 110 is electrically connected to the LLC module 120. The LLC module 120 is electrically connected to the clamping circuit 130, the on-off circuit 140 and the rechargeable battery 20 respectively. The clamping circuit 130 is electrically connected to the on-off circuit 140 and the rechargeable battery 20 respectively. The rechargeable battery 20 is electrically connected to the on-off circuit 140.
[0032] When the circuit of the clamping relay voltage is working, the mains inputs electric energy into the rectifier module 110, and the rectifier module 110 converts the AC power of the mains into DC power and outputs it to the LLC module 120. The rectifier module 110 has a PFC module, which is a power factor corrector. When used, it can improve the conversion rate of the AC power of the mains into DC power. The LLC module 120 is a resonant converter, which can tune the DC power output by the rectifier module 110, reduce the ripple of the output DC power, and improve the stability of the DC power. The DC power is then output by the LLC module 120 to the on-off circuit 140, and finally the electric energy is transmitted to the rechargeable battery 20, thereby completing the charging of the rechargeable battery 20.
[0033] Further, refer to Figure 1 The clamp circuit 130 includes a voltage divider module 131 and a reverse protection module 132. The voltage divider module 131 is connected in series with the first reverse protection module 132, and the voltage divider module and the reverse protection module are connected in series and then connected in parallel with the on-off circuit 140. The voltage divider module 131 is also electrically connected to the rechargeable battery 20, and the reverse protection module 132 is also electrically connected to the LLC module 120. The voltage divider module can be used to limit the voltage of the part of the clamp circuit connected to the on-off circuit, and the first reverse protection module 132 prevents the current of the LLC module 120 from flowing directly from the clamp circuit 130 through the rechargeable battery 20 to prevent the clamp voltage from failing.
[0034] Specifically, the voltage divider module 131 includes a resistor R30, a resistor R47, and a resistor R48. The resistor R30, the resistor R47, and the resistor R48 have a terminal 1 and a terminal 2, respectively. The terminal 1 and the terminal 2 of the resistor R30 are electrically connected to the LLC module 120 and the on-off circuit 140, respectively; the terminal 1 and the terminal 2 of the resistor R47 and the resistor R48 are connected in parallel, and the terminal 1 is electrically connected to the first reverse protection module 132 after the parallel connection, and the terminal 2 is electrically connected to the on-off circuit 140 and the rechargeable battery 20 after the parallel connection;
[0035] The first reverse protection module 132 includes a diode D2 having a terminal 1 and a terminal 2. The terminal 1 of the diode D2 is electrically connected to the voltage divider module 131 ; the terminal 2 of the diode D2 is electrically connected to the LLC module 120 , the voltage divider module 131 and the on-off circuit 140 , respectively.
[0036] Among them, the No. 1 and No. 2 ends of the resistor R30 are electrically connected to the LLC module 120 and the on-off circuit 140 respectively; the No. 1 and No. 2 ends of the resistor R47 and the resistor R48 are connected in parallel, and the No. 1 end after parallel connection is electrically connected to the No. 1 end of the diode D2, and the No. 2 end after parallel connection is electrically connected to the on-off circuit 140 and the rechargeable battery 20; the No. 1 end of the diode D1 is electrically connected to the No. 1 end of the resistor R47 and the resistor R48, and the No. 2 end of the diode D1 is electrically connected to the LLC module 120, the resistor R30 and the on-off circuit 140 respectively. It should be noted that the resistor R30, the resistor R47 and the resistor R48 act as a voltage divider, and the resistor R47 and the resistor R48 are connected in parallel, so that the voltage of the A end and the B end is less than the voltage of the No. 1 end and the No. 2 end of the resistor R30; the diode D2 prevents the current of the LLC module 120 from flowing directly from the clamping circuit to the rechargeable battery to prevent the clamping voltage from failing.
[0037] Further, refer to Figure 1 The on-off circuit 140 includes an input power supply 141, a relay KI 142, a second reverse protection module 143, an overcurrent protection module 144, a switch module 145, a voltage limiting module 146 and a filter module 147. The relay KI 142 has a terminal 1, a terminal 2, a terminal 3 and a terminal 4. The terminal 1 and the terminal 2 of the relay KI 142 are electrically connected to the clamping circuit 130, the terminal 1 of the relay KI 142 is electrically connected to the LLC module 120, and the terminal 2 of the relay KI 142 is electrically connected to the filter module 147 and the rechargeable battery 20 respectively.
[0038] Specifically, refer to Figure 1 , the input power supply 141 is electrically connected to the No. 3 terminal of the relay KI142 and the second reverse protection module 143. The second reverse protection module 143 is connected in parallel to the No. 3 terminal and the No. 4 terminal of the relay KI142, and is electrically connected to the overcurrent protection module 144; the overcurrent protection module 144 is electrically connected to the No. 4 terminal of the relay KI142 and the switch module 145 respectively; the switch module 145 is electrically connected to the LLC module 120, the voltage dividing module 131, the voltage limiting module 146, the filter module 147 and the rechargeable battery 20 respectively; the voltage limiting module 146 is electrically connected to the LLC module 120, the voltage dividing module 131, the filter module 147 and the rechargeable battery 20 respectively; the filter module 147 is electrically connected to the No. 2 terminal of the relay KI142, the LLC module 120 and the voltage dividing module 131 respectively, and the filter module 147 is also connected in parallel to the rechargeable battery 20.
[0039] Among them, the input power supply 141 provides power for the relay KI142 to control the contact or disconnection of the relay KI142; the relay KI142 controls the process of the LLC module 120 charging the rechargeable battery 20; the second reverse protection module 143 prevents the self-inductance current generated by the coil on the relay KI142 from reversely impacting the input power supply 141; the overcurrent protection module 144 shunts the current of the input power supply 141 to prevent the large current from impacting the switch module 145; the switch module 145 is used to control the on and off of the on-off circuit 140; the voltage limiting module 146 is used to keep the switch module 145 at a level; the filter module 146 is used to reduce the ripple of the output voltage of the LLC module 120 and reduce the interference to the rechargeable battery 20.
[0040] Specifically, refer to Figure 1 The second reverse protection module 143 includes a diode D1 having a terminal 1 and a terminal 2. Terminal 1 of the diode D1 is electrically connected to terminal 3 of the relay KI142 and the input power supply 141; terminal 2 of the diode D1 is electrically connected to terminal 4 of the relay KI142 and the overcurrent protection module 144 respectively.
[0041] Specifically, the overcurrent protection module 144 includes a resistor R34 and a resistor R35, and the resistor R34 and the resistor R35 have a terminal 1 and a terminal 2 respectively. The terminal 1 and the terminal 2 of the resistor R34 are respectively connected in parallel with the terminal 1 and the terminal 2 of the resistor R35, and the terminal 1 after parallel connection is electrically connected to the terminal 4 of the relay KI 142, and the terminal 2 after parallel connection is electrically connected to the switch module 145.
[0042] Specifically, the switch module 145 includes a transistor Q1, which has a base B, a collector C and an emitter E. The base B of the transistor Q1 is electrically connected to the voltage limiting module 146, the collector C of the transistor Q1 is electrically connected to the overcurrent protection module 144, and the emitter E of the transistor Q1 is electrically connected to the LLC module 120, the voltage dividing module 131, the voltage limiting module 146, the voltage limiting module 146 and the rechargeable battery 20 respectively;
[0043] Specifically, the voltage limiting module 146 includes a resistor R36 and a resistor R37, and the resistor R36 and the resistor R37 have a terminal 1 and a terminal 2 respectively. The terminals 1 of the resistor R36 and the resistor R37 are respectively electrically connected to the base B of the transistor Q1, the terminal 2 of the resistor R36 is externally connected to the signal P1 input, and the terminal 2 of the resistor R37 is respectively electrically connected to the LLC module 120, the voltage divider module 131, the filter module 147 and the rechargeable battery 20.
[0044] Specifically, the filter module 147 includes a capacitor C20 having a terminal 1 and a terminal 2. The terminal 1 of the capacitor C20 is electrically connected to the terminal 2 of the relay KI 142, and the terminal 2 is electrically connected to the LLC module 120, the voltage divider module 131 and the voltage limiting module 146 respectively. The filter module 147 is also connected in parallel with the rechargeable battery 20.
[0045] The input power source 141 is electrically connected to the terminal 1 of the relay KI 142 and the terminal 1 of the diode D1; the terminal 1 of the diode D1 is electrically connected to the terminal 3 of the relay KI 142 and the input power source 141, the terminal 2 of the diode D1 is electrically connected to the terminal 4 of the relay KI 142 and the terminals 1 of the resistors R34 and R35 respectively; the terminals 1 and 2 of the resistor R34 are connected in parallel with the terminals 1 and 2 of the resistor R35 respectively, and the terminal 1 after parallel connection is connected to the relay KI The No. 4 terminal of 142 and the No. 2 terminal of the diode D1 are electrically connected respectively, and the No. 2 terminal after parallel connection is electrically connected to the collector C of the transistor Q1; the collector C of the transistor Q1 is electrically connected to the No. 1 terminals of the resistors R34 and R35, the base B of the transistor Q1 is electrically connected to the No. 1 terminals of the resistors R36 and R37, the emitter E of the transistor Q1 is electrically connected to the LLC module 120, the No. 2 terminal of the resistor R30, the No. 2 terminal of the resistor R37, the No. 2 terminal of the capacitor C20 and the rechargeable battery 20 respectively; the No. 1 terminals of the resistors R36 and R37 are electrically connected to the collector B of the transistor Q1, the No. 2 terminal of the resistor R36 is externally connected to the signal P1 input, the No. 2 terminal of the resistor R37 is electrically connected to the LLC module 120, the resistor R30 Terminal 2 of the relay, the emitter E of the transistor Q1, terminal 2 of the capacitor C20 and the rechargeable battery 20 are electrically connected respectively; terminal 1 of the capacitor C20 is electrically connected to terminal 2 of the relay, terminal 2 of the capacitor C20 is electrically connected to the LLC module 120 and terminal 2 of the resistor R30, and the capacitor C20 is also connected in parallel with the rechargeable battery 20.
[0046] It should be noted that the input power supply 141 provides power to the relay KI 142 to control the closing or disconnection of the relay KI 142; the relay KI 142 is used to control the process of the LLC module 120 charging the rechargeable battery 20; the diode D1 can prevent the induced current generated by the coil on the relay KI 142 from flowing out from the No. 3 terminal of the relay KI 142 in the reverse direction, thereby preventing the transistor Q1 from being affected; the resistor R34 and the resistor R35 resistor R34 shunts the current output from the No. 4 terminal of the relay KI 142 to prevent the large current from impacting the transistor Q1; the transistor Q1 is used to control the on and off of the on-off circuit 140; the resistor R37 is used as a pull-down resistor to clamp the input signal to a high potential, and the resistor R36 is used to prevent the input level voltage from being too large to prevent damage to the base B of the transistor Q1; the capacitor C20 is used to reduce the interference of the ripple on the output voltage to prevent the charging process of the rechargeable battery. In this embodiment, the on and off of the input power source 141 is controlled by the MCU inside the charging unit 10 , and the input signal P1 is output by the MCU inside the charging unit 10 .
[0047] In summary, during the specific implementation of this embodiment, when the rechargeable battery 20 is connected to the charging unit 10, some weak current will be released from the rechargeable battery 20. When this part of the current flows from the positive electrode of the rechargeable battery 20 into the resistor R47 and the No. 2 terminal of the resistor R48 of the clamp circuit 130, it flows into the anode P2 of the diode D2 through the No. 1 terminal of the resistor R47 and the resistor R48, and then flows out from the cathode N2 of the diode D2 to the No. 1 terminal of the resistor R30, and finally returns to the negative electrode of the rechargeable battery 20 through the No. 2 terminal of the resistor R30. Through the voltage division principle of the series circuit, the voltages at the No. 1 and No. 2 terminals of the resistor R30 are greater than the voltages at the two terminals AB. At this time, the voltages at the two terminals of the relay KI142 are the voltages at the two terminals AB, so the voltages at the two terminals of the relay KI142 are limited by the clamp. At this time, the MCU inside the charging unit 10 detects the connection of the rechargeable battery 20, inputs the driving signal P1 to the base B of the transistor Q1, and controls the input power supply 141 to output current to flow into the terminal 3 of the relay KI 142, and flow out from the terminal 4 through the terminals 1 of the resistors R34 and R35, and finally flow out from the terminals 2 of the resistors R34 and R35 to the collector C of the transistor Q1. The driving signal P1 is input to the base B of the transistor Q1 through the terminal 1 of the resistor R36, so that the voltage of the collector C is greater than the driving signal level of the base B, and the driving signal level of the base B is greater than the voltage of the emitter E, so that the transistor Q1 is turned on, and the input power supply 141 inputs current from the terminal 3 of the relay KI 142 and flows out from the terminal 4 of the relay KI 142. At this time, the coil in the relay KI 142 is energized, and the switches at the terminals 1 and 2 of the relay KI 142 are attracted. As a result, the on-off circuit 140 is turned on, and the AC power can be input into the rectifier module 110 for rectification and output as DC power. The DC power then flows into the A terminal from the terminal 1 of the relay KI142 through the LLC module 120, and flows out from the terminal 2 of the relay KI 142 to the positive electrode of the rechargeable battery 20, and finally flows back from the negative electrode of the rechargeable battery 20 to the LLC module 130, so as to complete the charging process of the rechargeable battery 20.
[0048] When the MCU detects that the rechargeable battery 20 is fully charged, it will not send a driving signal to the transistor Q1. At this time, the MCU also controls the input power supply 141 to stop providing power to the relay KI 142. Therefore, no current flows through the terminals 3 and 4 of the relay KI 142. The internal coils of the terminals 3 and 4 of the relay KI 142 are not energized, and the switches of the terminals 1 and 2 of the relay KI 142 cannot be attracted. That is, the switches of the terminals 1 and 2 are disconnected, so that the power of the LLC module 130 cannot be transmitted to the rechargeable battery 20, and the charging unit 10 will no longer charge the rechargeable battery 20.
[0049] In this embodiment, the voltage of the rechargeable battery 20 is 80V, the charging current is 50A, and the specification of the relay used needs to be greater than 80V / 50A. Through external voltage sampling, it is obtained that the conduction voltage drop of the diode D2 is 1.5V, the resistance of the resistor R47 and the resistor R48 in parallel is 1Ω, and the resistance of the resistor R30 is 9Ω, which is greater than the resistance of the resistor R47 and the resistor R48 in parallel. According to Kirchhoff's voltage law, the voltage at the 1st and 2nd terminals of the resistor R47 and the resistor R48 in parallel is , so the voltages at the A and B terminals are 7.85V+1.5V=9.35V. At this time, the voltage at both ends of the relay KI 152 is limited to 9.35V, and the voltage withstand value of the relay voltage specification only needs to be greater than 9.35V. Therefore, the clamping circuit 140 is used as a voltage limiting circuit to control the voltage at both ends of the relay KI 152, and then when the charging power supply voltage is high, the relay voltage withstand value specification can be selected to be lower than the power supply voltage. When the charging power supply voltage is high, a relay with a smaller voltage withstand value specification is used, thereby reducing the production cost.
[0050] The above is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.
Claims
1. A circuit for clamping a relay voltage, characterized in that: include: A charging unit (10) and a rechargeable battery (20); the charging unit (10) comprises a rectifier module (110), an LLC module (120), a clamping circuit (130) and an on-off circuit (140); the rectifier module (110) is electrically connected to the LLC module (120); the LLC module (120) is electrically connected to the clamping circuit (130), the on-off circuit (140) and the rechargeable battery (20); the clamping circuit (130) is electrically connected to the on-off circuit (140) and the rechargeable battery (20); and the rechargeable battery (20) is electrically connected to the on-off circuit (140).
2. A circuit for clamping relay voltage according to claim 1, characterized in that: The clamping circuit (130) comprises a voltage dividing module (131) and a first reverse protection module (132); the voltage dividing module (131) and the first reverse protection module (132) are connected in series, and the voltage dividing module (131) and the first reverse protection module (132) are connected in series and then connected in parallel to the on-off circuit (140); the voltage dividing module (131) is also electrically connected to the rechargeable battery (20); and the first reverse protection module (132) is also electrically connected to the LLC module (120).
3. A circuit for clamping relay voltage according to claim 2, characterized in that: The voltage dividing module (131) comprises a resistor R30, a resistor R47 and a resistor R48, wherein the resistor R30, the resistor R47 and the resistor R48 respectively have a terminal 1 and a terminal 2, and the terminal 1 and the terminal 2 of the resistor R30 are respectively connected in parallel with the LLC module (120) and the on-off circuit (140); the terminal 1 and the terminal 2 of the resistor R47 and the resistor R48 are connected in parallel, and after the parallel connection, the terminal 1 of the resistor R47 and the resistor R48 are electrically connected to the first reverse protection module (132), and after the parallel connection, the terminal 2 of the resistor R47 and the resistor R48 are electrically connected to the on-off circuit (140) and the rechargeable battery (20).
4. A circuit for clamping relay voltage according to claim 2, characterized in that: The first reverse protection module (132) comprises a diode D2, the diode D2 having a terminal 1 and a terminal 2, the terminal 1 of the diode D2 being electrically connected to the voltage divider module (131); the terminal 2 of the diode D2 being electrically connected to the LLC module (120), the voltage divider module (131) and the on-off circuit (140), respectively.
5. A circuit for clamping relay voltage according to claim 1, characterized in that: The on-off circuit (140) comprises an input power supply (141), a relay KI (142), a second reverse protection module (143), an overcurrent protection module (144), a switch module (145), a voltage limiting module (146) and a filter module (147); the relay KI (142) has a terminal 1, a terminal 2, a terminal 3 and a terminal 4; the terminal 1 and the terminal 2 of the relay KI (142) are electrically connected to the clamping circuit (130); the terminal 1 of the relay KI (142) is electrically connected to the LLC module (120); the terminal 2 of the relay KI (142) is electrically connected to the filter module (147) and the rechargeable battery (20), respectively; The input power supply (141) is electrically connected to terminal No. 3 of the relay KI (142) and the reverse protection module (143); The second reverse protection module (143) is connected in parallel to terminals 3 and 4 of the relay KI (142), and is electrically connected to the overcurrent protection module (144); The overcurrent protection module (144) is electrically connected to terminal No. 4 of the relay KI (142) and the switch module (145) respectively; The switch module (145) is electrically connected to the LLC module (120), the voltage dividing module (131), the voltage limiting module (146), the filter module (147) and the rechargeable battery (20) respectively; The voltage limiting module (146) is electrically connected to the LLC module (120), the voltage dividing module (131), the filtering module (147) and the rechargeable battery (20) respectively; The filter module (147) is electrically connected to terminal No. 2 of the relay KI (142), the LLC module (120) and the voltage divider module (131) respectively, and the filter module (147) is also connected in parallel to the rechargeable battery (20).
6. A circuit for clamping relay voltage according to claim 5, characterized in that: The second reverse protection module (143) comprises a diode D1 having a terminal 1 and a terminal 2, wherein the terminal 1 of the diode D1 is electrically connected to the terminal 3 of the relay KI (142) and the input power supply (141); and the terminal 2 of the diode D1 is electrically connected to the terminal 4 of the relay KI (142) and the overcurrent protection module (144), respectively.
7. A circuit for clamping relay voltage according to claim 5, characterized in that: The overcurrent protection module (144) comprises a resistor R34 and a resistor R35, wherein the resistor R34 and the resistor R35 respectively have a terminal 1 and a terminal 2, wherein the terminal 1 and the terminal 2 of the resistor R34 are respectively connected in parallel with the terminal 1 and the terminal 2 of the resistor R35, and the terminal 1 of the resistor R34 and the resistor R35 are electrically connected to the terminal 4 of the relay KI, and the terminal 2 of the resistor R34 and the resistor R35 are electrically connected to the switch module (145).
8. A circuit for clamping relay voltage according to claim 5, characterized in that: The switch module (145) comprises a transistor Q1 having a base B, a collector C and an emitter E; the base B of the transistor Q1 is electrically connected to the voltage limiting module (146); the collector C of the transistor Q1 is electrically connected to the overcurrent protection module (144); and the emitter E of the transistor Q1 is electrically connected to the LLC module (120), the voltage dividing module (131), the voltage limiting module (146), the filter module (147) and the rechargeable battery (20), respectively.
9. A circuit for clamping relay voltage according to claim 5, characterized in that: The voltage limiting module (146) comprises a resistor R36 and a resistor R37, the resistor R36 and the resistor R37 respectively having a terminal 1 and a terminal 2, the terminals 1 of the resistor R36 and the resistor R37 respectively being electrically connected to a base B of a transistor Q1, the terminal 2 of the resistor R36 being externally connected to a signal P1 input, and the terminal 2 of the resistor R37 being electrically connected to an LLC module (120), a voltage dividing module (131), a filtering module (147) and a rechargeable battery (20) respectively.
10. A circuit for clamping relay voltage according to claim 5, characterized in that: The filter module (147) comprises a capacitor C20 having a terminal 1 and a terminal 2. The terminal 1 of the capacitor C20 is electrically connected to the terminal 2 of the relay KI (142), and the terminal 2 is electrically connected to the LLC module (120), the voltage dividing module (131) and the voltage limiting module (146), respectively. The filter module (147) is also connected in parallel to the rechargeable battery (20).