Voltage threshold detection device built using transistors and Zener diodes

Abstract

This invention provides a voltage threshold detection device built using transistors and Zener diodes, comprising: a housing, a detection unit, an LED indicator cover, and a wiring harness; the housing includes an upper housing and a lower housing; the detection unit is fixed to the lower housing; the detection unit is connected to one end of the wiring harness; the LED indicator cover is fixed to the upper housing; the upper and lower housings are tightly connected by screws; the wiring harness includes four signals: power supply, ground, logic level output, and the voltage to be monitored. This invention implements a voltage threshold detection module built using transistors and Zener diodes. When the voltage to be monitored exceeds the voltage threshold, the LED will light up to indicate this. The detection voltage threshold can be changed by altering the cutoff voltage parameter of the Zener diode. The logic level output voltage parameter can be changed by altering the power supply signal voltage value. The brightness of the LED indicator can be adjusted by adjusting the current-limiting resistor.

Description

Technical Field

[0001] This utility model relates to the technical field of voltage threshold detection devices, and more particularly to a voltage threshold detection device constructed using transistors and Zener diodes. Background Technology

[0002] In modern automotive electronics, industrial automation, and smart home appliance systems, it is often necessary to monitor the threshold of a certain analog voltage signal in real time so that when the signal reaches or exceeds a certain set value (such as 4.7 V), subsequent control logic or protection actions are immediately triggered. Typical scenarios include: monitoring battery overvoltage / undervoltage in automotive ECUs, alarm judgment of 0-10 V signals from sensors in industrial PLCs, and power failure detection of the DC bus voltage after mains rectification in home appliance MCUs.

[0003] The current mainstream solution in the industry is a three-stage architecture of "analog front-end + ADC + digital comparison". Specifically: Analog front end: The original voltage signal is filtered, scaled, and impedance matched by an operational amplifier or dedicated buffer to meet the input range requirements of the subsequent ADC.

[0004] ADC (Analog-to-Digital Converter): Discretizes continuous analog voltages, typically with a resolution of 10-bit, 12-bit, or higher. Sampling frequencies range from a few kilosps per second (kSPS) to milliseconds per second (MSPS), depending on the system's real-time requirements.

[0005] Digital threshold comparison: Implement the "digital quantity ≥ threshold" judgment in software or hardware logic in MCU, DSP or FPGA, and output the corresponding high / low level or interrupt signal.

[0006] The advantages of this scheme lie in its high accuracy, programmable threshold, and ease of software calibration for errors such as temperature drift and device tolerances; it also leverages digital filtering algorithms to suppress glitches and noise. However, its disadvantages are also quite obvious: a) High system complexity: Multiple chips (op-amps, ADCs, MCUs) need to work together, which significantly increases PCB area, BOM quantity and wiring difficulty.

[0007] b) High cost pressure: Taking a 12-bit ADC + Cortex-M0 MCU as an example, the cost of a single-channel detection chip is often between 0.3 and 0.5 USD; if multi-channel redundancy or functional safety level is required, the cost will increase several times.

[0008] c) Real-time limitations: The latency of the entire ADC sampling-conversion-bus transmission-software comparison link is typically in the tens of microseconds to milliseconds, which is difficult to meet the stringent requirements of overvoltage protection response time <1 µs.

[0009] d) Power consumption and reliability: Multi-chip architecture means higher quiescent current, and failure of any stage (op-amp saturation, ADC communication interruption, MCU crash) will lead to loss of detection function, requiring additional monitoring or watchdog timers, further increasing cost and complexity.

[0010] Therefore, there has always been a demand in the industry to "replace the three-stage architecture with a simple, low-cost, pure hardware device" in order to significantly reduce system complexity, shorten response time and reduce overall cost while maintaining acceptable detection accuracy. Utility Model Content

[0011] In response to the technical problems mentioned in the background section above, a voltage threshold detection device based on transistors and Zener diodes is provided.

[0012] The technical means adopted in this utility model are as follows: A voltage threshold detection device built using transistors and Zener diodes includes: a housing, a detection unit, an LED indicator cover, and a wiring harness; The housing includes an upper housing and a lower housing; the detection unit is fixed on the lower housing. The detection unit is connected to one end of the wire harness; the LED indicator cover is fixed on the upper outer casing. The upper and lower outer shells are tightly connected by screws; the wiring harness includes four signals: power supply, ground, logic level output, and voltage to be monitored.

[0013] Furthermore, the detection unit includes: resistors R1, R2, R3, R4, R5, R6, R7, R8, and R9; capacitors C1 and C2; transistors Q1 and Q2; diodes D1, D2, and D3. One end of resistor R1 is connected to the voltage to be monitored, and the other end is connected in series with the cathode of diode D1; the anode of diode D1 is connected in series with the base of transistor Q1; the emitter of transistor Q1 is grounded, and the collector of transistor Q1 is connected to the base of transistor Q2 through resistor R5; the emitter of transistor Q2 is connected to the positive terminal of the power supply, and the collector of transistor Q2 is connected in series with diode D3 and resistor R9 and then grounded, and a logic level output node is brought out.

[0014] Furthermore, the diode D1 is a Zener diode; the cutoff voltage of the diode D1 is 4.3V.

[0015] Furthermore, resistor R1 is a signal series resistor, resistor R2 is a pull-down resistor that provides a current path to ground for the voltage signal to be monitored, and capacitor C1 is a filter capacitor.

[0016] Furthermore, the diode D3 is a light-emitting diode, and the brightness of the diode D3 is adjusted by the parameters of the resistor R9.

[0017] Furthermore, transistor Q1 is an NPN transistor; transistor Q2 is a PNP transistor.

[0018] Compared with the prior art, the present invention has the following advantages: This invention implements a voltage threshold detection module built using transistors and Zener diodes. When the voltage to be monitored exceeds the voltage threshold, an LED will light up to indicate this. The detection voltage threshold can be changed by changing the cutoff voltage parameter of the Zener diode. The logic level voltage parameter can be changed by changing the voltage value of the power supply signal. The brightness of the LED indicator can be adjusted by adjusting the current limiting resistor.

[0019] Compared with solutions implemented using chips, the cost of this invention is significantly reduced. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall device of this utility model.

[0022] Figure 2 This is a schematic diagram of the circuit connection of this utility model.

[0023] In the picture: 1. Outer casing; 2. LED indicator cover; 3. Wiring harness. Detailed Implementation

[0024] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this utility model or its application or use. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0027] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0028] In the description of this utility model, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0029] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0030] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0031] like Figure 1-2 As shown, this utility model provides a voltage threshold detection device built using a transistor and a Zener diode, including: a housing 1, a detection unit (not shown in the figure), an LED indicator cover 2, and a wiring harness 3; The outer casing 1 includes an upper outer casing and a lower outer casing; the detection unit is fixed on the lower outer casing. The detection unit is connected to one end of the wiring harness 3; the LED indicator cover is fixed on the upper outer casing; The upper and lower outer shells are tightly connected by screws; the wiring harness includes four signals: power supply, ground, logic level output, and voltage to be monitored.

[0032] In a preferred embodiment, the detection unit in this application includes: resistors R1, R2, R3, R4, R5, R6, R7, R8, and R9; capacitors C1 and C2; transistors Q1 and Q2; and diodes D1, D2, and D3. One end of resistor R1 is connected to the voltage to be monitored, and the other end is connected in series with the cathode of diode D1; the anode of diode D1 is connected in series with the base of transistor Q1; the emitter of transistor Q1 is grounded, and the collector of transistor Q1 is connected to the base of transistor Q2 through resistor R5; the emitter of transistor Q2 is connected to the positive terminal of the power supply, and the collector of transistor Q2 is connected in series with diode D3 and resistor R9 and then grounded, and a logic level output node is brought out.

[0033] In this application, diode D1 is a Zener diode; the cutoff voltage of diode D1 is 4.3V. Resistor R1 is a signal series resistor, resistor R2 is a pull-down resistor providing a current path to ground for the voltage signal to be monitored, and capacitor C1 is a filter capacitor. Diode D3 is a light-emitting diode, and the brightness of diode D3 is adjusted by the parameters of resistor R9. Transistor Q1 is an NPN transistor; transistor Q2 is a PNP transistor.

[0034] When the monitored voltage signal is higher than 4.7 volts, the logic level output is a high level of 3.3 volts. At this time, the cutoff voltage parameter of Zener diode D1 is selected as 4.3V. When the monitored voltage signal is 5 volts, the cathode of Zener diode D1 is 5 volts, R3 is the signal series resistor, and R4 provides the VBE turn-on voltage for transistor Q1. The VBE of transistor Q1 is 0.6 volts, plus the cutoff voltage of Zener diode D1 of 4.3 volts. 0.6 volts + 4.3 volts equals 4.9 volts. The monitored voltage signal is 5 volts, which is greater than 4.9 volts. At this moment, Zener diode D1 reaches the avalanche state and begins to conduct in reverse. The series resistor R3 has voltage. The base voltage of transistor Q1 is calculated as follows: the monitored voltage of 5 volts minus the reverse voltage drop of Zener diode D1 of 4.3 volts equals 0.7 volts. The base of transistor Q1 has voltage, and VBE also has voltage. At this time, transistor Q1 meets the turn-on condition and turns on. Switching diode D2 is a protection diode that prevents transient negative current from flowing back through it when a negative electrostatic voltage or negative pulse enters the circuit through the monitored voltage signal. This prevents the transient negative current from flowing through transistor Q1, thus preventing the PN junction of transistor Q1 from conducting in reverse and burning out. When transistor Q1 is turned on, the base voltage of PNP transistor Q2 is equal to 0 volts, and Q2's VBE also has a conduction voltage, meeting the conduction condition and turning on. If the power supply signal is 3.3 volts, the 3.3 volts voltage reaches resistors R7 and R8 through transistor Q2. The pull-down resistor R7 provides a current path to ground for the 3.3 volts, and the series resistor R8 provides a signal path. C2 is a filter capacitor, and the logic level output is 3.3 volts. With 3.3 volts at the upper end of resistor R9, LED D3 has a turn-on voltage and illuminates. The detection threshold voltage of this circuit can be adjusted by adjusting the cutoff voltage parameter of the Zener diode, and the logic level voltage parameter can be changed by changing the value of the power supply signal.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A voltage threshold detection device constructed using a transistor and a Zener diode, characterized in that, include: Housing, detection unit, LED indicator cover, and wiring harness; The housing includes an upper housing and a lower housing; the detection unit is fixed on the lower housing. The detection unit is connected to one end of the wire harness; the LED indicator cover is fixed on the upper outer casing. The upper and lower outer shells are tightly connected by screws; the wiring harness includes four signals: power supply, ground, logic level output, and voltage to be monitored.

2. The voltage threshold detection device constructed using a transistor and a Zener diode according to claim 1, characterized in that, The detection unit includes: resistors R1, R2, R3, R4, R5, R6, R7, R8, and R9; capacitors C1 and C2; transistors Q1 and Q2; diodes D1, D2, and D3. One end of resistor R1 is connected to the voltage to be monitored, and the other end is connected in series with the cathode of diode D1; the anode of diode D1 is connected in series with the base of transistor Q1; the emitter of transistor Q1 is grounded, and the collector of transistor Q1 is connected to the base of transistor Q2 through resistor R5; the emitter of transistor Q2 is connected to the positive terminal of the power supply, and the collector of transistor Q2 is connected in series with diode D3 and resistor R9 and then grounded, and a logic level output node is brought out.

3. The voltage threshold detection device constructed using a transistor and a Zener diode according to claim 2, characterized in that, The diode D1 is a Zener diode; the cutoff voltage of the diode D1 is 4.3V.

4. The voltage threshold detection device constructed using a transistor and a Zener diode according to claim 2, characterized in that, The resistor R1 is a signal series resistor, the resistor R2 is a pull-down resistor that provides a current path to ground for the voltage signal to be monitored, and the capacitor C1 is a filter capacitor.

5. The voltage threshold detection device constructed using a transistor and a Zener diode according to claim 2, characterized in that, The diode D3 is a light-emitting diode, and the brightness of the diode D3 is adjusted by the parameters of the resistor R9.

6. The voltage threshold detection device constructed using a transistor and a Zener diode according to claim 2, characterized in that, Transistor Q1 is an NPN transistor; transistor Q2 is a PNP transistor.

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