Low-cost check control circuit

Abstract

The utility model discloses a low-cost check control circuit, and relates to the technical field of voltage detection, the low-cost check control circuit comprises a voltage stabilization module and a control module, the voltage stabilization module realizes voltage stabilization through a plurality of voltage stabilization devices connected in series, and the control module realizes control of a load circuit by using a triode and related resistor elements. The multi-stage voltage stabilizer has the advantages that the multi-stage voltage stabilizer is combined to set an accurate threshold value, voltage drop is detected in real time, a power supply is cut off, device damage is avoided, a rear-end circuit is accurately protected, when the input voltage rises to a safe value, power supply of the circuit is automatically recovered, manual intervention is not needed, and continuous operation reliability of equipment is guaranteed; a voltage stabilizer, a triode and a small number of resistors are adopted to replace a high-cost IC or MCU, the hardware cost is remarkably reduced, and a budget sensitive design is adapted.

Description

Technical Field

[0001] This application relates to the field of power electronic control technology, and in particular to a low-cost inspection control circuit. Background Technology

[0002] In long-distance wiring scenarios, due to the existence of line impedance, the power supply voltage decreases significantly with the increase of transmission distance, causing back-end electronic components (such as sensors, controllers, LED modules, etc.) to malfunction due to insufficient input voltage, and even causing overheating, performance degradation or permanent damage due to long-term undervoltage operation.

[0003] Existing solutions have significant drawbacks: ICs with undervoltage protection can trigger protection through preset thresholds, but dedicated ICs are expensive, and some solutions require manual restart after voltage recovery, lacking self-recovery capability and making them difficult to adapt to frequently fluctuating power supply environments; MCU voltage detection requires additional configuration of ADC modules, comparators, and control circuits, further increasing hardware complexity and cost, and relying on software programming results in long development cycles and poor compatibility.

[0004] None of the above solutions can balance the requirements of low cost and high reliability. Traditional IC solutions are limited by hardware costs, while MCU solutions are driven up by complex peripheral circuits. At the same time, both have insufficient dynamic response capability to voltage fluctuations, making it difficult to meet the dual requirements of economy and stability in industrial long-distance power supply scenarios. Utility Model Content

[0005] In order to achieve this, this application provides a low-cost inspection control circuit.

[0006] This application provides a low-cost inspection control circuit, which adopts the following technical solution:

[0007] Check the input voltage of the load circuit to the control circuit. The control circuit includes a voltage regulator module and a control module. The input terminal of the voltage regulator module receives the load voltage. The voltage regulator module has at least two voltage regulator devices that are electrically connected in series. The control module is connected to the output terminal of the voltage regulator module. The output terminal of the control module outputs a control signal to control the load circuit. The control module includes switching devices and resistive elements.

[0008] By adopting the above technical solution, the voltage regulator module outputs a precise control voltage. After the control voltage is transmitted to the control module, the control module outputs a turn-off and turn-on control signal according to the level of the control voltage.

[0009] Optionally, the anode of the first voltage regulator ZD1 is connected to one end of the first resistor R1, a voltage divider node A is set at the connection between the anode of the first voltage regulator ZD1 and the first resistor R1, the cathode of the first voltage regulator ZD1 is connected to the anode of the second voltage regulator ZD2, the cathode of the second voltage regulator ZD2 is connected to the anode of the third voltage regulator ZD3, and the cathode of the third voltage regulator ZD3 is connected to the load voltage.

[0010] By adopting the above technical solution, the voltage regulator is reverse-connected. After the reverse voltage applied across its two ends reaches a certain value, it enters the reverse breakdown state. In the reverse breakdown region, the voltage across the Zener diode remains basically constant and equal to its breakdown voltage. Even if the input voltage changes, as long as the current through the Zener diode changes within the allowable range, the voltage across its two ends can remain relatively stable, thereby achieving the voltage regulation function.

[0011] Optionally, the end of the first resistor R1 furthest from the input terminal of the control module is grounded, the voltage value of the anode of the first voltage regulator ZD1 is the load voltage minus the breakdown voltage of the voltage regulator module, the voltage value of the anode of the first voltage regulator ZD1 is the voltage division value of the first resistor R1, and the voltage division node A is connected to the input terminal of the control module.

[0012] By adopting the above technical solution, once the voltage regulator model is selected, its breakdown voltage is fixed. Subtracting the fixed breakdown voltage from the load voltage will cause the voltage at the output terminal A to change with the input load voltage. At this time, measuring the voltage at the output terminal A can indirectly reflect the change in the load voltage.

[0013] The first resistor R1 provides normal regulated current for the voltage regulator and also acts as a voltage divider. Its voltage value is the control signal of the control module. When the input load voltage drops below the load circuit start-up voltage, the output signal shuts off the load circuit. When the input load voltage rises back to the load circuit start-up voltage, the load circuit operates normally.

[0014] Optionally, the input terminal of the control module is connected to the base of the first transistor Q1, the collector of the first transistor Q1 is grounded, the first resistor R1 is connected in parallel between the base and collector of the first transistor, the emitter of the first transistor Q1 is connected to one end of the second resistor R2, and the other end of the second resistor R2 is connected to the control signal output terminal EN.

[0015] By adopting the above technical solution, the first resistor R1 can provide a current path for the base of the first transistor, so that the base can obtain a suitable bias voltage, thereby ensuring that the first transistor Q1 can work normally. When the temperature changes or other factors cause the parameters of the first transistor Q1 to change, the first resistor R1 can suppress the change of collector current, thereby maintaining the stability of the circuit.

[0016] The second resistor R2 can limit the magnitude of the emitter current, thereby providing some protection for the first transistor Q1 and preventing excessive current from damaging the first transistor Q1.

[0017] Optionally, the control signal output terminal EN is connected to the control pin of the load.

[0018] By adopting the above technical solution, the product works normally when the control pin is at a high level, and stops working when the control pin is at a low level.

[0019] Optionally, the first transistor Q1 is a PNP transistor or a P-channel MOSFET.

[0020] By adopting the above technical solutions, if PNP transistors are used, the cost is relatively low, which is advantageous in some cost-sensitive applications. If P-channel MOSFETs are used, since MOSFETs are voltage-controlled devices, the control mechanism is more direct and efficient, and they have faster switching speeds and lower switching losses.

[0021] In summary, this application includes at least one of the following beneficial effects:

[0022] 1. A fixed threshold is set by connecting multiple Zener diodes in series (e.g., VZD1+VZD2+VZD3), and voltage changes are monitored in real time by voltage divider resistors with an accuracy of ±2%. When the voltage drops to the threshold, the load power supply is immediately cut off to avoid damage to the downstream circuit due to overvoltage or undervoltage.

[0023] 2. When the input voltage rises back to a safe range, the voltage of the voltage divider resistor increases, causing the transistor to automatically turn off, the control pin returns to a high level, and the load circuit is powered on again. No manual intervention is required throughout the process, ensuring the reliability of continuous equipment operation.

[0024] 3. The core circuit is built using Zener diodes (such as Zener diodes), transistors (PNP or P-MOS) and a small number of resistors, eliminating the need to rely on high-cost dedicated ICs or MCUs. This reduces hardware costs by more than 50%, making it suitable for budget-sensitive industrial or consumer electronics scenarios. Attached Figure Description

[0025] Figure 1 This is a structural block diagram of one embodiment of the low-cost inspection control circuit of this application;

[0026] Figure 2 This is a schematic diagram of the specific circuit structure of one embodiment of the low-cost inspection control circuit of this application;

[0027] Figure 3 This is a specific circuit diagram of one embodiment of the low-cost inspection control circuit of this application;

[0028] Explanation of reference numerals in the attached diagram: 1. Inspection control circuit; 2. Load circuit; 3. Voltage regulator module; 4. Control module. Detailed Implementation

[0029] The following is in conjunction with the appendix Figure 1 To the attached Figure 3 This application will be described in further detail.

[0030] With the widespread use of electronic products, long-distance connection cables are becoming increasingly common. Long-distance transmission can lead to voltage drop issues, affecting the operation of downstream electronic components and potentially causing them to overheat or even be damaged due to unstable operation. Therefore, this application primarily employs the following low-cost hardware design scheme, effectively solving the problem of product instability caused by voltage drop during long-distance transmission without increasing additional hardware costs. Figure 1 As shown, this application adds a check control circuit 1 to the load circuit 2. The load input voltage of this check control circuit 1 is the same as that of the load circuit 2. When the check control circuit 1 detects that the load input voltage is lower than the threshold for the normal operation of the load circuit 2, it shuts down the load circuit 2. When it detects that the load input voltage has risen back to the operating voltage value, it automatically restores the load circuit 2. The following is a further detailed description of a low-cost check control circuit of this application.

[0031] Example 1

[0032] like Figure 2 As shown, the low-cost inspection control circuit 1 provided in this embodiment includes a voltage regulator module 3 and a control module 4. The voltage regulator module 3 and the control module 4 work together to achieve low-voltage protection for the load circuit 2, thus stopping the load from operating in a timely manner and preventing damage when the voltage drops. This effect is achieved because the voltage regulator module 3 can stably provide a reference voltage, while the control module 4 controls the load circuit 2 through simple switching logic.

[0033] Specifically, such as Figure 3 As shown, voltage regulator module 3 includes multiple voltage regulator devices connected in series. These voltage regulator devices can be Zener diodes, such as ZD1, ZD2, and ZD3. The main function of the Zener diodes is to provide a stable voltage reference value through their breakdown characteristics. Taking ZD1 as an example, its anode is connected to the input terminal of control module 4 and one end of the first resistor R1, and its cathode is connected to the anode of the second Zener diode ZD2; the cathode of ZD2 is connected to the anode of the third Zener diode ZD3, and the cathode of ZD3 is finally connected to the load voltage input terminal. This series structure allows voltage regulator module 3 to provide a total reference voltage composed of the superposition of the breakdown voltages of multiple Zener diodes. Replaceable features of the Zener diodes include, but are not limited to, Zener diodes, precision voltage regulator chips, etc., and the specific selection depends on the required voltage accuracy and stability.

[0034] Control module 4 includes switching devices and resistive elements. The switching device can be a PNP transistor Q1 or a P-channel MOSFET. Its base (or gate) is connected to the voltage divider output terminal A of the voltage regulator module 3 through a first resistor R1, its collector (or source) is grounded, and its emitter (or drain) is connected to the control signal output terminal EN through a second resistor R2. The function of the first resistor R1 is to limit the current flowing into the base of the switching device, preventing damage due to overcurrent. The second resistor R2 is used to further limit the current at the control signal output terminal EN, ensuring the stability and reliability of the control signal. Replaceable resistive elements include metal film resistors, carbon film resistors, or thin-film resistors of different resistance values; the specific selection depends on the current requirements and power consumption limitations in the actual application.

[0035] The coordination between voltage regulator module 3 and control module 4 is as follows: When the load voltage VDC (a DC voltage) is input to voltage regulator module 3, module 3 provides a fixed reference voltage through a series-connected Zener diode. Based on the Zener diode's breakdown voltage characteristics, when the load voltage drops below the level necessary to maintain the total reference voltage of voltage regulator module 3, the voltage at the voltage divider output terminal A will also decrease. At this time, the base voltage of switching device Q1 is lower than its turn-on threshold voltage, causing Q1 to conduct and pull the control signal output terminal EN low. The control signal output terminal EN is connected to the load's control pin. When the control signal is low, the load circuit 2 stops working, thus preventing component damage due to insufficient voltage.

[0036] The combination logic and combined effect of all the secondary features constituting control module 4 are described in detail below: The first resistor R1 forms a current-limiting loop between the base and collector of the switching device Q1, ensuring the safe operation of the switching device; the second resistor R2 forms a voltage-dividing loop between the emitter of the switching device Q1 and the control signal output terminal EN, ensuring stable output of the control signal. This combination logic enables control module 4 to respond quickly to changes in load voltage and adjust the state of the control signal in a timely manner, thereby achieving low-voltage protection for load circuit 2.

[0037] In addition, the first resistor R2 has two important functions: firstly, it provides normal regulated current to ZD1, ZD2, and ZD3, while preventing them from being damaged due to excessive current; secondly, it acts as a voltage divider, so that changes in the load voltage can be accurately reflected on the voltage divider output terminal A, thereby improving the response sensitivity of the control module 4.

[0038] The implementation principle of this embodiment is as follows: a stable reference voltage is provided by the voltage regulator module 3, and the load circuit 2 is controlled by the switching devices in the control module 4. When the load voltage is normal, the control module 4 outputs a high-level signal, and the load circuit 2 operates normally; when the load voltage drops to a level insufficient to maintain the total reference voltage of the voltage regulator module 3, the control module 4 outputs a low-level signal, and the load circuit 2 stops working. This design not only achieves low-voltage protection but also has self-recovery characteristics. When the load voltage returns to normal, the control module 4 automatically switches back to a high-level signal, allowing the load circuit 2 to restart. Compared with existing technologies, this solution does not rely on complex MCUs or expensive ICs, significantly reducing hardware costs, while simplifying the circuit structure and improving the reliability and stability of the system.

[0039] Example 2

[0040] The difference between this embodiment and the previous embodiment is that the voltage regulator module 3 uses a different combination of voltage regulator devices, and the control module 4 uses a P-channel MOSFET instead of a PNP transistor as the switching device. This improvement aims to further optimize circuit performance, especially in high-frequency switching scenarios.

[0041] Specifically, voltage regulator module 3 still includes multiple voltage regulator devices, but different combinations of these devices can be selected. For example, in addition to Zener diodes, a precision voltage regulator chip (such as the TL431) can be introduced as one of the voltage regulator devices. Precision voltage regulator chips have higher voltage accuracy and lower temperature drift characteristics, making them suitable for applications with high voltage stability requirements. Furthermore, the series structure of voltage regulator module 3 can be flexibly adjusted according to actual needs, such as increasing or decreasing the number of voltage regulator devices to adapt to different voltage ranges.

[0042] The switching device in control module 4 uses a P-channel MOSFET instead of a PNP transistor. P-channel MOSFETs have lower on-resistance and faster switching speeds, making them particularly suitable for high-frequency switching applications. Their gate is connected to the voltage divider output terminal A of voltage regulator module 3 via a first resistor R1, their source is grounded, and their drain is connected to the control signal output terminal EN via a second resistor R2. Compared to PNP transistors, P-channel MOSFETs offer superior switching characteristics, significantly improving circuit response speed and efficiency.

[0043] The implementation principle of this embodiment is as follows: by introducing a precision voltage regulator chip and a P-channel MOSFET, the performance of the circuit is further optimized. The combination of voltage regulator devices in voltage regulator module 3 is more flexible, and it can adapt to a wider range of voltage ranges and application scenarios; the switching device of control module 4 uses a P-channel MOSFET, which improves the response speed and efficiency of the circuit, and is especially suitable for high-frequency switching scenarios. This improvement not only retains the advantage of low cost, but also significantly improves the performance and applicability of the circuit.

[0044] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A low cost check control circuit, characterized by, The utility model relates to a load voltage checking control circuit, comprising: a checking control circuit (1) inputs the input voltage of load circuit (2), and the checking control circuit includes voltage stabilizing module (3) and control module (4); The input end of voltage stabilizing module (3) inputs load voltage, and voltage stabilizing module (3) is at least two voltage stabilizing devices, and the voltage stabilizing devices are electrically connected in series; The output end of control module (4) is connected with the output end of voltage stabilizing module (3), the output end of control module (4) outputs control signal and controls load circuit (2), and control module (4) includes switching device and resistance element.

2. A low cost check control circuit according to claim 1, characterized in that The anode of first voltage stabilizing device ZD1 is connected with one end of first resistance R1, the anode of first voltage stabilizing device ZD1 and the connection of first resistance R1 are provided with voltage division node A, the cathode of first voltage stabilizing device ZD1 is connected with the anode of second voltage stabilizing device ZD2, the cathode of second voltage stabilizing device ZD2 is connected with the anode of third voltage stabilizing device ZD3, and the cathode of third voltage stabilizing device ZD3 inputs load voltage.

3. A low cost check control circuit according to claim 2, characterized in that The one end of first resistance R1 is connected with ground away from the input end of control module (4), the voltage value of the anode of first voltage stabilizing device ZD1 is the load voltage minus the breakdown voltage of voltage stabilizing module (3), the voltage value of the anode of first voltage stabilizing device ZD1 is the voltage division value of first resistance R1, and the voltage division node A is connected with the input end of control module (4).

4. A low cost check control circuit according to claim 2, characterized in that The input end of control module (4) is connected with the base of first triode Q1, the collector of first triode Q1 is connected with ground, first resistance R1 is connected between the base and the collector of first triode Q1 in parallel, the emitter of first triode Q1 is connected with one end of second resistance R2, and the other end of second resistance R2 is connected with control signal output end EN.

5. A low cost check control circuit according to claim 4, characterized in that The control signal output end EN is connected with the control pin of load.

6. A low cost check control circuit according to claim 4, characterized in that The first triode Q1 is PNP type triode, and can be replaced by P channel type MOS tube.

7. A low cost check control circuit according to claim 1, characterized in that The load voltage is direct current voltage.

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