Direct-current voltage control switch with starting protection function

Abstract

The invention discloses a direct-current voltage control switch with a starting protection function. The invention aims to solve the problems that in the prior art, the voltage control precision of a direct-current voltage control switch is insufficient, and the direct-current voltage control switch malfunctions due to the fact that the voltage of an input power supply is unstable in the starting stage and large voltage fluctuation occurs in part of application scenes. The circuit of the switch consists of a voltage detection part and a filtering delay part, when there is an input voltage, the input voltage is subjected to a certain time delay through the filtering time delay part, and then the voltage is detected through the voltage detection part. When the input voltage reaches the set conduction voltage, the direct-current voltage-controlled switch is conducted, and otherwise, the direct-current voltage-controlled switch is closed. By adopting a voltage detection technology, the control precision of the direct-current voltage-controlled switch is improved. And meanwhile, a filtering technology and a delay mechanism are adopted, so that the input voltage has a certain stabilization time, the protection function in the starting stage is realized, and the control precision and reliability of the direct-current voltage control switch are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of power electronics, specifically relating to a DC voltage control switch with start-up protection function. Background Technology

[0002] Existing DC voltage control switches suffer from insufficient voltage control accuracy. In certain application scenarios, the unstable input voltage during startup can cause malfunctions. To address these issues, this invention employs voltage detection technology, improving the control accuracy of the DC voltage control switch. Simultaneously, filtering technology and a delay mechanism are used to allow the input voltage sufficient time to stabilize, thus enabling protection during startup. This invention significantly improves the control accuracy and reliability of the DC voltage control switch. Summary of the Invention

[0003] To address the above-mentioned problems, this invention proposes a DC voltage control switch with start-up protection function.

[0004] The technical solution of this invention is: A DC voltage control switch with start-up protection function includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1, a second capacitor C2, a first MOSFET Q1, a second MOSFET Q2, a Zener diode D1, and a voltage comparator U1. The input voltage is grounded through the first capacitor C1, and then grounded after passing through the first resistor R1 and the second resistor R2. The input voltage passes through the third resistor R3 and the negative terminal of the Zener diode D1, and then grounded from the positive terminal of the Zener diode D1. The non-inverting input of the voltage comparator U1 is connected to the negative terminal of the Zener diode D1, and the inverting input is connected to the junction of the first resistor R1 and the second resistor R2. The voltage terminal of the voltage comparator U1 is connected to the input voltage, and the ground terminal of the voltage comparator U1 is grounded. The input voltage is connected to the output terminal of the voltage comparator U1 and the gate of the second MOSFET Q2 through the fourth resistor R4. The input voltage passes through the parallel fifth resistor R5 and the second capacitor C2, and then grounded through the sixth resistor R6. The gate of the first MOSFET Q1 is connected to the junction of the fifth resistor R5 and the sixth resistor R6. The source of the first MOSFET Q1 is connected to the input voltage, and the drain of the first MOSFET Q1 is connected to the source of the second MOSFET Q2. The drain of the second MOSFET Q2 serves as the output terminal of the entire circuit.

[0005] The beneficial effects of this invention are: This invention integrates voltage detection technology, filtering technology, and delay mechanism. In particular, for specific products with high precision requirements in specific scenarios, it enables precise adjustment of the conduction voltage of the voltage-controlled switch and allows the input voltage to stabilize for a certain period of time, thereby significantly improving the control accuracy and reliability of the DC voltage control switch. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the principle of a DC voltage control switch with start-up protection function according to the present invention.

[0007] Figure 2 This is a comparison chart showing the direct input of power supply voltage and the input voltage after processing by this invention. Detailed Implementation

[0008] The present invention will now be described in detail with reference to the accompanying drawings.

[0009] Since the components used in the circuit diagram of this invention are well known in the art, the following description will downplay the mechanism explanation of these commonly used components and some common-sense circuit principles, so as to highlight the core idea of ​​this invention.

[0010] like Figure 1 As shown, a DC voltage control switch with start-up protection function has a circuit consisting of two parts: a voltage detection part and a filtering and delay part. The circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1, a second capacitor C2, a first MOSFET Q1, a second MOSFET Q2, a Zener diode D1, and a voltage comparator U1. The input voltage is grounded through the first capacitor C1, and then grounded after passing through the first resistor R1 and the second resistor R2. The input voltage then passes through the third resistor R3 and the negative terminal of the Zener diode D1, before being grounded from the positive terminal of the Zener diode D1. The non-inverting input of the voltage comparator U1 is connected to the negative terminal of the Zener diode D1, and the inverting input is connected to the junction of the first resistor R1 and the second resistor R2. The voltage terminal of the voltage comparator U1 is connected to the input voltage, and its ground terminal is grounded. The input voltage is connected to the output terminal of the voltage comparator U1 and the gate of the second MOSFET Q2 through the fourth resistor R4. The input voltage passes through the parallel fifth resistor R5 and the second capacitor C2, and then grounded through the sixth resistor R6. The gate of the first MOSFET Q1 is connected to the junction of the fifth resistor R5 and the sixth resistor R6. The source of the first MOSFET Q1 is connected to the input voltage, and the drain of the first MOSFET Q1 is connected to the source of the second MOSFET Q2. The drain of the second MOSFET Q2 serves as the output terminal of the entire circuit.

[0011] The voltage detection section and the filtering delay section of this invention are specifically implemented as follows: The voltage V1 to be detected is obtained by sampling through R1 and R2: ; The reference voltage V2 is generated by Zener diode D1. When the detected voltage V1 is less than the reference voltage V2, V3 will output a high level under the action of voltage comparator U1 and pull-up resistor R4. When the detected voltage V1 is greater than the reference voltage V2, V3 will output a low level under the action of voltage comparator U1. C1 filters out pulses from the input voltage, while the delay circuit consisting of R5, R6, C2, and Q1 delays the output of the input voltage from the drain of Q1 to the source of Q2. If V3 is high, Q2 will not conduct, and the DC voltage control switch will be off. If V3 is low, Q2 will conduct, and the DC voltage control switch will conduct.

[0012] In practical applications, based on the specific product requirements of a particular scenario, the reference voltage is first adjusted by selecting the voltage regulation parameter of the Zener diode D1. Then, the values ​​of R1 and R2 are adjusted so that V1 is greater than V2 when the switch meets the conduction condition. This results in a high-precision DC voltage control switch. When there is voltage at the input terminal, the voltage value is determined only after a certain filtering and delay. If the input voltage reaches or exceeds the conduction voltage, the DC voltage control switch conducts; otherwise, the DC voltage control switch is closed.

[0013] The filtering delay effect of the present invention is as follows: Figure 2 As shown. In the experiment, the oscilloscope acquired the input voltage, and the power supply input voltage was set to 18V. The waveform of channel 2 represents the voltage waveform directly input without filtering or delay, and the maximum overshoot voltage reaches 22.260V ( Figure 2 The maximum value is 2), with an error of approximately 23.67%. Using the input voltage processed by this invention, i.e., the waveform of channel 1, the maximum overshoot voltage is only 18.848V ( Figure 2 The maximum value is 1), and the error is approximately 4.71%. This indicates that the present invention can reduce the overshoot of a specific power input by about five times, significantly improving the control accuracy of the DC voltage control switch. The control accuracy of the DC voltage control switch is particularly important for specific products requiring high precision in specific scenarios.

Claims

1. A DC voltage control switch with start-up protection function, characterized in that, The circuit of the control switch consists of a voltage detection section and a filtering and delay section. When there is an input voltage, the input voltage is filtered and delayed for a certain period of time before being detected by the voltage detection section. When the input voltage reaches the set conduction voltage, the DC voltage-controlled switch is turned on; otherwise, the DC voltage-controlled switch is turned off.

2. A DC voltage control switch with start-up protection function according to claim 1, characterized in that, The circuit for voltage detection and filtering / delay includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1, a second capacitor C2, a first MOSFET Q1, a second MOSFET Q2, a Zener diode D1, and a voltage comparator U1. The input voltage is grounded through the first capacitor C1, and then grounded after passing through the first resistor R1 and the second resistor R2. The input voltage then passes through the third resistor R3 and the negative terminal of the Zener diode D1, and finally grounded from the positive terminal of the Zener diode D1. The non-inverting input of the voltage comparator U1 is connected to the negative terminal of the Zener diode D1. The inverting input terminal of the circuit is connected to the junction of the first resistor R1 and the second resistor R2. The voltage terminal of the voltage comparator U1 is connected to the input voltage, and the ground terminal of the voltage comparator U1 is grounded. The input voltage is connected to the output terminal of the voltage comparator U1 and the gate of the second MOSFET Q2 through the fourth resistor R4. The input voltage is then connected to the ground through the fifth resistor R5 and the second capacitor C2 in parallel, and then through the sixth resistor R6. The gate of the first MOSFET Q1 is connected to the junction of the fifth resistor R5 and the sixth resistor R6. The source of the first MOSFET Q1 is connected to the input voltage, and the drain of the first MOSFET Q1 is connected to the source of the second MOSFET Q2. The drain of the second MOSFET Q2 serves as the output terminal of the entire circuit.

3. A DC voltage control switch with start-up protection function according to claim 1 or 2, characterized in that, In the specific implementation process, the detected voltage V1 is obtained by sampling through R1 and R2: ； Wherein, VIN represents the input voltage.

4. A DC voltage control switch with start-up protection function according to claim 1 or 2, characterized in that, The specific implementation process is as follows: The reference voltage V2 is generated by the Zener diode D1; when the detected voltage V1 is less than the reference voltage V2, V3 will output a high level under the action of voltage comparator U1 and pull-up resistor R4; when the detected voltage V1 is greater than the reference voltage V2, V3 will output a low level under the action of voltage comparator U1; C1 can filter out pulses from the input voltage, while the delay circuit composed of R5, R6, C2 and Q1 can delay the output of the input voltage from the drain of Q1 to the source input of Q2; if V3 is high, Q2 will not conduct, and the DC voltage-controlled switch will be closed; if V3 is low, Q2 will conduct, and the DC voltage-controlled switch will conduct.

5. A DC voltage control switch with start-up protection function according to claim 1 or 2, characterized in that, In the specific implementation process, according to the needs of specific products in specific scenarios, the reference voltage is first adjusted by selecting the voltage regulation value parameter of the Zener diode D1, and then the values ​​of R1 and R2 are adjusted so that V1 is greater than V2 when the switch meets the conduction condition; that is, a high-precision DC voltage-controlled switch is obtained. When there is voltage at the input terminal, the voltage value is judged only after a certain filtering and delay. If the input voltage reaches or exceeds the conduction voltage, the DC voltage-controlled switch is turned on; otherwise, the DC voltage-controlled switch is turned off.

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