Super capacitor discharge circuit and device for non-discharge control acquisition terminal

Abstract

The utility model relates to a super capacitor discharge circuit and device for a non-discharge control acquisition terminal, which comprises a reference voltage generation circuit, a triangular wave generation circuit, a PWM (Pulse Width Modulation) generation circuit and an adjustable voltage generation circuit, and the output ends of the reference voltage generation circuit and the triangular wave generation circuit are connected with the input end of the PWM generation circuit. The output end of the PWM generation circuit is connected with the input end of the adjustable voltage generation circuit; and the adjustable voltage generation circuit is connected with the acquisition terminal and is used for starting the acquisition terminal and starting the super capacitor to discharge by adjusting an output signal of the PWM generation circuit. By simulating main power supply and gradually regulating voltage, the power consumption of the capacitor is directly utilized, the operation process is simplified, and the discharge efficiency is improved; through circuit design, a wide power supply voltage range can be covered, voltage specifications of different super capacitors can be flexibly matched, and the problem of low discharge efficiency caused by load mismatching in a traditional scheme is avoided.

Description

Technical Field

[0001] This utility model relates to the field of capacitor discharge technology, specifically to a supercapacitor discharge circuit and device for a discharge-free control acquisition terminal. Background Technology

[0002] Data acquisition terminals typically use power-down detection chips to monitor whether the main power supply is disconnected. When the main power supply is disconnected, the terminal's supply voltage will slowly decrease due to the effect of the capacitor on the main power supply output side. When it drops to a certain value, the power-down detection chip starts to activate, changing the level signal on the output side. When the main chip detects the signal change, it controls the supercapacitor backup power circuit to start. However, after the supercapacitor stops backup power, the supercapacitor backup power system is difficult to start without a main power supply, and the terminal itself cannot release the remaining energy of the supercapacitor. Therefore, when the terminal has debugging or low-voltage start-up requirements, it is necessary to use external equipment to dissipate the supercapacitor's energy. However, different types of terminals have different external AC power amplitudes, and the method of restoring power supply and then disconnecting it to dissipate the supercapacitor's energy is not suitable for all scenarios. At the same time, AC power supplies and transformers are bulky and difficult to carry. Currently, a more typical method is to use an external load to dissipate the supercapacitor's voltage to a lower level, but the disadvantage of this solution is that it is difficult to select a suitable load and difficult to control the supercapacitor's discharge time. Utility Model Content

[0003] To address the aforementioned problems, this utility model provides a supercapacitor discharge circuit for a discharge-free control acquisition terminal, comprising a reference voltage generation circuit, a triangular wave generation circuit, a PWM generation circuit, and an adjustable voltage generation circuit. The output terminals of the reference voltage generation circuit and the triangular wave generation circuit are connected to the input terminal of the PWM generation circuit, and the output terminal of the PWM generation circuit is connected to the input terminal of the adjustable voltage generation circuit. The adjustable voltage generation circuit is connected to the acquisition terminal and is used to start the acquisition terminal by adjusting the output signal of the PWM generation circuit to initiate supercapacitor discharge.

[0004] Based on the above scheme, a power supply is also included. The power supply is connected to a reference voltage generation circuit. The reference voltage generation circuit includes a transistor, a first rheostat, and an electrolytic capacitor. When the power supply is turned on, the transistor operates in the amplification region. Adjusting the resistance value of the first rheostat changes the base voltage and emitter voltage of the transistor. The electrolytic capacitor is connected between the collector and emitter of the transistor. The emitter of the transistor outputs a reference voltage.

[0005] Preferably, the triangular wave generating circuit includes a first comparator, a first capacitor, and a second rheostat. The inverting input terminal of the first comparator is connected to the first terminal of the first capacitor, and the first terminal of the first capacitor is also connected to the second rheostat. One end of the second rheostat is connected to the output terminal of the first comparator, and the other end of the second rheostat is connected to the inverting input terminal of the first comparator. The inverting input terminal of the first comparator outputs a triangular wave voltage.

[0006] Preferably, the PWM generation circuit includes a second comparator, a first current-limiting resistor, and a second current-limiting resistor. The reference voltage is connected to the positive input terminal of the second comparator via the first current-limiting resistor, and the triangular wave voltage is connected to the inverting input terminal of the second comparator via the second current-limiting resistor. The output of the second comparator is a PWM voltage. The first variable resistor is adjusted to change the duty cycle of the PWM voltage, and the second variable resistor is adjusted to change the frequency of the PWM voltage.

[0007] Preferably, the adjustable voltage generation circuit includes an operational amplifier, a first diode, and a second diode. The PWM voltage is connected to the input terminal of the operational amplifier after being filtered by an RC filter. The first diode is used to start the operational amplifier, and the second diode is used to limit the maximum output value of the circuit. The operational amplifier outputs a terminal power supply voltage.

[0008] Based on the above scheme, the power supply is connected in parallel with a single-phase TVS diode and then connected to the reference voltage generation circuit, the triangular wave generation circuit, the PWM generation circuit, and the adjustable voltage generation circuit.

[0009] On the other hand, this application also provides a supercapacitor discharge device for a discharge-free control acquisition terminal, for connecting the acquisition terminal, including the supercapacitor discharge circuit as described above.

[0010] Furthermore, this application also provides a data acquisition terminal, including the supercapacitor discharge circuit described above.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0012] 1. By simulating main power supply and gradually adjusting the voltage, the terminal directly consumes the capacitor's power by its own power consumption, simplifying the operation process and improving discharge efficiency;

[0013] 2. Through circuit design, it can cover a wide range of power supply voltages and flexibly match the voltage specifications of different supercapacitors, avoiding the problem of low discharge efficiency caused by load mismatch in traditional solutions;

[0014] 3. A Zener diode is introduced to limit the maximum output voltage, effectively preventing damage to downstream circuits due to overvoltage; at the same time, the optimized filtering design ensures minimal voltage fluctuations during voltage regulation, guaranteeing stable operation of the terminal equipment during discharge. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the supercapacitor discharge structure of the control terminal of this utility model;

[0016] Figure 2 This is a circuit diagram of the power supply section of this utility model;

[0017] Figure 3 This is a circuit diagram for generating the reference voltage of this utility model;

[0018] Figure 4 This is a circuit diagram for generating a triangular wave according to this utility model;

[0019] Figure 5 This is a circuit diagram for generating PWM waves according to this utility model;

[0020] Figure 6 This is a circuit diagram of the adjustable voltage generation circuit of this utility model. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings:

[0022] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] Data acquisition terminals may face power outages during field use, thus requiring backup power. Supercapacitors are commonly used in terminal circuit design to meet these backup power requirements. The backup power circuit design typically includes a dedicated button to terminate the backup power. During terminal debugging, there may be situations where it's necessary to deplete the supercapacitor's power; some terminals lack this feature.

[0024] To address the aforementioned issues, the terminal's backup power can be activated again, utilizing the terminal's own power consumption to power the supercapacitor. However, without main power, the capacitor backup power system cannot be restarted. Therefore, an adjustable voltage circuit can be designed to provide the terminal with a main power source, and then adjust the voltage value to activate the capacitor backup power system, thereby consuming the capacitor voltage.

[0025] like Figure 1 and Figure 2 As shown, the circuit includes a power supply, a reference voltage generation circuit, a triangular wave generation circuit, a PWM generation circuit, and an adjustable voltage generation circuit. A single-phase TVS diode D1 is connected in parallel with the power supply BT1 to serve as the circuit's power supply VCC. The function of D1 is to prevent surge voltage or static electricity from affecting the circuit.

[0026] like Figure 3 As shown, the reference voltage generation circuit includes a transistor QU1, a first variable resistor QR1, and an electrolytic capacitor E1. QR1 is connected between the base and collector of QU1, and E1 is connected between the collector and emitter of QU1. QU1 is a P-type transistor. When the power is on, the emitter voltage Ve > base voltage Vb > collector voltage Vc. At this time, QU1 operates in the amplification region, and the Veb voltage is clamped. The clamping voltage is measured to be 0.5V. Adjusting the resistance of QR1 will change Vb accordingly. Since the voltage at Ve is always 0.5V higher than the voltage at Vb, Ve will also change with the change of the variable resistor QR1. Because E1 can smooth voltage fluctuations, adjusting QR1 allows Vb to change slowly. Ve is the reference voltage VR_OUT input to the PWM generation circuit.

[0027] In this scenario, the electrolytic capacitor E1 acts as a buffer, ensuring that when the circuit parameters change due to the adjustment of the variable resistor QR1, the reference voltage does not change abruptly, but gradually transitions to a new stable state, preventing rapid voltage fluctuations from adversely affecting the circuit.

[0028] like Figure 4 As shown, the triangular wave generation circuit includes a first comparator U1, a first capacitor C2, and a second variable resistor QR2. The inverting input of U1 is connected to the first terminal of C2, which in turn is connected to QR2. One end of QR2 is connected to the output of U1, and the other end is connected to the inverting input of U1. When the circuit is powered on, the voltage at the non-inverting input of U1 is the voltage after voltage division by resistors R3 and R4. Since the resistances of R3 and R4 are equal, the voltage at the non-inverting input of U1 is VCC / 2. This voltage is greater than the voltage at the inverting input, causing the comparator to output a high level. This high level at the output pulls the potential at the non-inverting input high, simultaneously charging C2. The voltage at the inverting input of the comparator also continues to increase, reaching a maximum value of: When the voltage at the inverting input of the comparator increases to a level greater than that at the non-inverting input, the comparator outputs a low level. This low level at the output pulls down the potential at the non-inverting input, and simultaneously, C2 discharges through QR2, causing the voltage at the inverting input to continuously decrease. The minimum voltage value is: When the voltage at the inverting input of the comparator drops below that at the non-inverting input, the next cycle begins. Therefore, the voltage VT_OUT at the inverting input is a continuously fluctuating triangular waveform.

[0029] like Figure 5 As shown, the PWM generation circuit includes a second comparator U2, a first current-limiting resistor R7, and a second current-limiting resistor R8. VR_OUT is connected to the positive input terminal of U2 via R7, and VT_OUT is connected to the inverting input terminal of U2 via R8. When the reference voltage VR_OUT is higher than the triangular wave voltage VT_OUT, U2 outputs a high level; when the reference voltage VR_OUT is lower than the triangular wave voltage VT_OUT, U2 outputs a low level. Therefore, the output of U2 is the PWM voltage V_PWM, with a high level of VCC and a low level of 0. The duty cycle of the PWM voltage is changed by adjusting the first variable resistor QR1, and the frequency of the PWM voltage is changed by adjusting the second variable resistor QR2.

[0030] like Figure 6 As shown, the adjustable voltage generation circuit includes an operational amplifier U3, a first diode D2, and a second diode D3. The PWM voltage, after being filtered by an RC filter, is connected to the input terminal of the operational amplifier. The PWM wave ripple is significantly reduced after RC filtering, and further isolation by the voltage follower function of the operational amplifier U3 reduces the influence of the primary voltage. The anode of D2 is connected to the output terminal of U3, and the cathode of D2 is connected to VCC, used to start the operational amplifier and ensure its normal output voltage value. The anode of D3 is grounded, and the cathode is connected to the output terminal of U3, and is connected in parallel with C10. The maximum output value of the circuit can be limited by adjusting D3 to prevent damage to subsequent circuits. The output voltage V_OUT of the operational amplifier U3 is supplied to the terminal. For example, when the terminal power supply requires 12V, a 12V Zener diode D3 can be used.

[0031] By introducing a Zener diode to limit the maximum output voltage, the downstream circuitry is effectively prevented from being damaged by overvoltage. At the same time, the optimized filtering design ensures that the voltage fluctuation is minimal during voltage regulation, guaranteeing the stable operation of the terminal equipment during discharge.

[0032] The power supply BT1 is connected in parallel with a single-phase TVS diode D1, and then connected to the aforementioned reference voltage generation circuit, triangular wave generation circuit, PWM generation circuit, and adjustable voltage generation circuit. This application has relatively lenient requirements on the power supply range, but it is important to note that the power supply voltage VCC must be greater than the output voltage V_OUT to maintain the stability and reliability of the circuit.

[0033] In operation, the circuit of this application first generates an adjustable reference voltage by a reference voltage generation circuit and an adjustable triangular wave voltage signal by a triangular wave generation circuit. These two voltage waveforms are then input to the comparator input of the PWM generation circuit, outputting a PWM wave. After passing through an RC filter circuit, a stable output voltage is obtained. The output voltage can be adjusted by changing the duty cycle of the PWM waveform. Increasing the output voltage to meet the power requirements of the terminal system allows the terminal to start. Then, decreasing the duty cycle of the PWM waveform lowers the output voltage. The power-down detection chip within the terminal detects the power change and adjusts its output level. The core board detects the level change and controls the supercapacitor to discharge.

[0034] The circuit described above provides analog main power to the terminal and gradually lowers the voltage, directly utilizing the terminal's own power consumption to power the supercapacitor, simplifying the operation process and improving discharge efficiency.

[0035] Based on the same inventive concept, this application also provides a supercapacitor discharge device for a discharge-free control acquisition terminal, used to connect to the acquisition terminal, including the supercapacitor discharge circuit as described above. It is adaptable to various field application scenarios, requires no fixed discharge equipment or complex operation, and is especially suitable for rapid deployment under conditions without mains power, meeting the discharge needs of different terminals.

[0036] On the other hand, this application also provides a data acquisition terminal, including the supercapacitor discharge circuit as described above; the supercapacitor discharge circuit serves as an external discharge module for supercapacitor management in the backup power system of the data acquisition terminal.

[0037] The foregoing has shown and described the basic principles and main features of this utility model. It is obvious to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments. Therefore, the embodiments should be regarded as exemplary and non-limiting. The scope of this utility model is defined by the appended claims rather than the foregoing description. Therefore, it is intended to include all changes that fall within the meaning and scope of the equivalents of the claims within this utility model.

[0038] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A supercapacitor discharge circuit for a discharge-free control acquisition terminal, characterized in that, It includes a reference voltage generation circuit, a triangular wave generation circuit, a PWM generation circuit, and an adjustable voltage generation circuit. The output terminals of the reference voltage generation circuit and the triangular wave generation circuit are connected to the input terminal of the PWM generation circuit, and the output terminal of the PWM generation circuit is connected to the input terminal of the adjustable voltage generation circuit. The adjustable voltage generation circuit is connected to the acquisition terminal and is used to start the acquisition terminal and enable the supercapacitor to discharge by adjusting the output signal of the PWM generation circuit.

2. The supercapacitor discharge circuit for a discharge-free control acquisition terminal according to claim 1, characterized in that, It also includes a power supply, which is connected to a reference voltage generation circuit. The reference voltage generation circuit includes a transistor, a first rheostat, and an electrolytic capacitor. When the power supply is turned on, the transistor operates in the amplification region. Adjusting the resistance of the first rheostat changes the base voltage and emitter voltage of the transistor. The electrolytic capacitor is connected between the collector and emitter of the transistor. The emitter of the transistor outputs a reference voltage.

3. The supercapacitor discharge circuit for a discharge-free control acquisition terminal according to claim 2, characterized in that, The triangular wave generating circuit includes a first comparator, a first capacitor, and a second rheostat. The inverting input terminal of the first comparator is connected to the first terminal of the first capacitor, and the first terminal of the first capacitor is also connected to the second rheostat. One end of the second rheostat is connected to the output terminal of the first comparator, and the other end of the second rheostat is connected to the inverting input terminal of the first comparator. The inverting input terminal of the first comparator outputs a triangular wave voltage.

4. The supercapacitor discharge circuit for a discharge-free control acquisition terminal according to claim 3, characterized in that, The PWM generation circuit includes a second comparator, a first current-limiting resistor, and a second current-limiting resistor. The reference voltage is connected to the positive input terminal of the second comparator via the first current-limiting resistor, and the triangular wave voltage is connected to the inverting input terminal of the second comparator via the second current-limiting resistor. The output of the second comparator is the PWM voltage. Adjusting the first variable resistor is used to change the duty cycle of the PWM voltage, and adjusting the second variable resistor is used to change the frequency of the PWM voltage.

5. A supercapacitor discharge circuit for a discharge-free control acquisition terminal according to claim 4, characterized in that, The adjustable voltage generation circuit includes an operational amplifier, a first diode, and a second diode. The PWM voltage is connected to the input terminal of the operational amplifier after being filtered by an RC filter. The first diode is used to start the operational amplifier, and the second diode is used to limit the maximum output value of the circuit. The operational amplifier outputs a terminal power supply voltage.

6. A supercapacitor discharge circuit for a discharge-free control acquisition terminal according to claim 2, characterized in that, The power supply is connected in parallel with a single-phase TVS diode and then connected to the reference voltage generation circuit, the triangular wave generation circuit, the PWM generation circuit, and the adjustable voltage generation circuit.

7. A supercapacitor discharge device for a discharge-free control acquisition terminal, characterized in that, For connecting to the acquisition terminal, including the supercapacitor discharge circuit as described in any one of claims 1-6.

8. A data acquisition terminal, characterized in that, Includes the supercapacitor discharge circuit as described in any one of claims 1-6.

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