A voltage threshold based indicator light extinguishing circuit
Patent Information
- Application Number
- CN202521684127.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-08
- Publication Date
- 2026-10-27
- Estimated Expiration
- 2035-08-08
AI Technical Summary
[0002]开关电源的高压电路中储能元件会存储能量，达至几百伏乃至上千伏，一般都会在高压电路中设计有断电后的自放电电路，断电后经过一段时间放电，这些高压电路的残存电压往往仍超过人体接触的安全电压，现有技术中一般通过采集电路采集高压电路输出电压转换后送给监控单元，再通过控制指示灯或在数码管或显示屏上显示来达到提醒、预警的作用，当系统中没有监控单元时，针对残余电压一般没有指示或显示电路进行预警，在检修操作时可能存在安全隐患
本实用新型提供的一种新型的基于电压阈值的指示灯熄灭电路，实现输入电压高于安全电压阈值时，指示灯持续点亮；当电压下降至低于安全电压阈值时，指示灯熄灭，满足安全监测需求，能降低安全隐患，具有电路简单，成本低优点。
Smart Images
Figure CN224909716U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of switching power supply technology, specifically to an indicator light extinguishing circuit based on a voltage threshold. Background Technology
[0002] In the high-voltage circuit of a switching power supply, energy storage elements store energy, reaching hundreds or even thousands of volts. Generally, a self-discharge circuit is designed in the high-voltage circuit after power failure. After a period of discharge following power failure, the residual voltage in these high-voltage circuits often still exceeds the safe voltage for human contact. In current technology, the output voltage of the high-voltage circuit is collected by a data acquisition circuit, converted, and sent to the monitoring unit. The voltage is then displayed on a control indicator light or digital tube or display screen to provide a reminder or warning. When there is no monitoring unit in the system, there is generally no indicator or display circuit to provide a warning for the residual voltage, which may pose a safety hazard during maintenance operations. Summary of the Invention
[0003] To address the problems existing in the prior art, the purpose of this utility model is to provide an indicator light extinguishing circuit based on a voltage threshold. This circuit eliminates the need for a monitoring unit and can control the indicator light to remain lit when the circuit input voltage is higher than the safe voltage threshold, and to turn off when the voltage drops below the safe voltage threshold, thereby achieving the function of reminder and warning.
[0004] The technical solution of this utility model is: An indicator light extinguishing circuit based on a voltage threshold includes: A voltage threshold detection circuit and an indicator light circuit are included. The voltage threshold detection circuit is used to detect the input voltage and includes a first voltage divider resistor R1, a second voltage divider resistor R2, a third voltage divider resistor R3, a Zener diode V1, and a filter capacitor C1. The first voltage divider resistor R1, the second voltage divider resistor R2, and the third voltage divider resistor R3 are connected in series between the positive terminal of the input voltage and ground. The Zener diode V1 and the filter capacitor C1 are both connected in parallel across the voltage divider circuit formed by the second voltage divider resistor R2 and the third voltage divider resistor R3. The indicator light circuit includes a voltage regulator N1, a current-limiting resistor R4, an indicator light, and an auxiliary power supply. The reference terminal of the voltage regulator N1 is connected to the output terminal of the voltage divider circuit composed of the second voltage divider resistor R2 and the third voltage divider resistor R3, and its anode is grounded. The first terminal of the current-limiting resistor R4 is connected to the auxiliary power supply, and the indicator light is connected between the second terminal of the current-limiting resistor R4 and the cathode of the voltage regulator N1.
[0005] Furthermore, the voltage regulator N1 is a TL431 voltage regulator.
[0006] Furthermore, the indicator light described is a light-emitting diode or LED device.
[0007] Beneficial effects This utility model provides a novel indicator light extinguishing circuit based on a voltage threshold, which enables the indicator light to remain on when the input voltage is higher than the safe voltage threshold, and to turn off when the voltage drops below the safe voltage threshold, thus meeting safety monitoring requirements, reducing safety hazards, and having the advantages of simple circuit and low cost. Attached Figure Description
[0008] Figure 1 This is a circuit schematic diagram of an embodiment of the present invention. Detailed Implementation
[0009] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other. It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.
[0010] The working principle of this utility model will be explained below with reference to the embodiments shown in the accompanying drawings: As shown in Figure 1, an embodiment of the indicator light extinguishing circuit based on a voltage threshold according to this utility model includes a voltage threshold detection circuit and an indicator light circuit. The voltage threshold detection circuit is used to detect the input voltage and includes a first voltage divider resistor R1, a second voltage divider resistor R2, a third voltage divider resistor R3, and a Zener diode V1. The first voltage divider resistor R1, the second voltage divider resistor R2, and the third voltage divider resistor R3 are connected in series and then connected between the positive terminal HV+ of the input voltage and ground. The Zener diode V1 is connected in parallel with the second voltage divider resistor R2 and the third voltage divider resistor R3. The voltage divider circuit consists of a voltage regulator N1 and a filter capacitor C1 connected in parallel across the voltage regulator V1. The indicator light circuit includes a voltage regulator N1, a current-limiting resistor R4, a light-emitting diode V2, and a 12V auxiliary power supply. Pin 1 of the reference terminal of the voltage regulator N1 is connected to the output terminal of the voltage divider circuit composed of the second voltage divider resistor R2 and the third voltage divider resistor R3. Pin 3, the anode of the voltage regulator N1, is grounded. The first end of the current-limiting resistor R4 is connected to the 12V auxiliary power supply. The light-emitting diode V2 is connected between the second end of the current-limiting resistor R4 and pin 3, the cathode of the TL431 voltage regulator N1.
[0011] In this embodiment, some device parameters are as follows: R1=225K ohms, R2=75K ohms, R2=100K ohms, Zener diode V1=5.1V, voltage regulator N1 is TL431; The working principle is as follows: when the input voltage is positive terminal HV+ and the voltage is V... HV+ When the voltage is above 10V, the voltage V divided by the third voltage divider resistor R3 is... R3 =V HV+ The voltage across resistor R3 / (R1+R2+R3) will be higher than 2.5V, and pin 1 of the reference terminal connected to TL431 regulator N1 will also be higher than 2.5V. Since the voltage at pin 1 of TL431 regulator N1 remains higher than 2.5V, TL431 regulator N1 remains on, thus the indicator light circuit is on, current flows through LED V2, and LED V2 remains lit. To prevent damage to TL431 regulator N1 from excessive voltage, a 5.1V Zener diode V1 is connected in parallel across the voltage divider circuit formed by the second and third voltage divider resistors R2 and R3, along with a filter capacitor C1. This clamps the voltage across the filter capacitor C1 and the voltage across the voltage divider circuit formed by the second and third voltage divider resistors R2 and R3 at 5.1V. Thus, when the input voltage is positive (HV) and the voltage is negative (V), the voltage across the input voltage will be higher than 2.5V. HV+ A voltage above 10V prevents the TL431 regulator N1 from being damaged by overvoltage and ensures that the voltage at pin 1 remains above 2.5V, maintaining conduction and thus keeping the indicator light circuit on, causing LED V2 to remain lit. When the HV+ voltage is below 10V, the voltage divided by the third voltage divider resistor R3 is below 2.5V, causing the voltage at pin 1 of the TL431 regulator N1 to fall below 2.5V. Consequently, the TL431 regulator N1 does not conduct, the indicator light circuit is off, and LED V2 is extinguished due to lack of current. In practical applications, the voltage divider value across R3 can be changed, thereby altering the voltage threshold V at the positive terminal HV+ that controls whether LED V2 is lit or extinguished. HV+ .
[0012] This invention features a simple and low-cost circuit that can meet safety monitoring needs, reduce safety hazards, is highly practical, and has strong anti-interference capabilities.
[0013] The above description is only a preferred embodiment of this utility model. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principle of this invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the concept and technical solution of the utility model to other occasions without modification, should all be considered within the protection scope of this utility model.
Claims
1. An indicator light extinguishing circuit based on a voltage threshold, characterized in that, include: A voltage threshold detection circuit and an indicator light circuit are included. The voltage threshold detection circuit is used to detect the input voltage and includes a first voltage divider resistor R1, a second voltage divider resistor R2, a third voltage divider resistor R3, a Zener diode V1, and a filter capacitor C1. The first voltage divider resistor R1, the second voltage divider resistor R2, and the third voltage divider resistor R3 are connected in series between the positive terminal of the input voltage and ground. The Zener diode V1 and the filter capacitor C1 are both connected in parallel across the voltage divider circuit formed by the second voltage divider resistor R2 and the third voltage divider resistor R3. The indicator light circuit includes a voltage regulator N1, a current-limiting resistor R4, an indicator light, and an auxiliary power supply. The reference terminal of the voltage regulator N1 is connected to the output terminal of the voltage divider circuit composed of the second voltage divider resistor R2 and the third voltage divider resistor R3, and its anode is grounded. The first terminal of the current-limiting resistor R4 is connected to the auxiliary power supply, and the indicator light is connected between the second terminal of the current-limiting resistor R4 and the cathode of the voltage regulator N1.
2. The indicator light extinguishing circuit based on a voltage threshold according to claim 1, characterized in that, The voltage regulator N1 is a TL431 voltage regulator.
3. The indicator light extinguishing circuit based on a voltage threshold according to claim 1, characterized in that, The indicator light is a light-emitting diode or LED device.