CN210041312U - Over-voltage and under-voltage protection circuit - Google Patents
Over-voltage and under-voltage protection circuit Download PDFInfo
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- CN210041312U CN210041312U CN201921165107.6U CN201921165107U CN210041312U CN 210041312 U CN210041312 U CN 210041312U CN 201921165107 U CN201921165107 U CN 201921165107U CN 210041312 U CN210041312 U CN 210041312U
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Abstract
The utility model relates to a cross undervoltage protection circuit, include: the detection module, processing module and protection module, detection module's input links to each other with the power of being surveyed, detection module's output links to each other with processing module's input, processing module's output links to each other with protection module's input, protection module's output links to each other with the load, detection module sets up different detection voltage critical values, and detect the voltage value of being surveyed the power, obtain the testing result according to detection voltage critical value and the voltage value of being surveyed the power, processing module if judge that the testing result is unusual, control protection module disconnection is surveyed being connected of power and load. Different voltage critical range values can be set through the detection module, so that the load is not limited to a specific test critical value any more, and the protection of the load is directly realized through the processing module, thereby effectively improving the protection performance in overvoltage and undervoltage.
Description
Technical Field
The utility model relates to a voltage protection technical field, concretely relates to cross undervoltage protection circuit.
Background
In the electronic industry, a direct current power supply is often used for supplying power to the whole circuit, the voltages of different circuits are different, and in some cases, power supply needs to be carried out for a long time, but the direct current power supply may have occasional abnormalities, so that abnormal jump of output voltage is caused, and when the direct current power supply cannot detect and carry out protection actions in time, irreversible damage may be caused to the whole circuit board, and huge loss is brought.
Currently, there are many integrated circuit chips for voltage monitoring, such as: the integrated chip for voltage monitoring dedicated to MAX811 series, TPS383X series, MAX706 series, etc., however, such chip can only monitor a fixed voltage value, and even if an abnormal voltage is detected, the protection function cannot be directly implemented on the target circuit, so that the protection performance is relatively poor.
SUMMERY OF THE UTILITY MODEL
In view of this, an object of the present invention is to provide an overvoltage/undervoltage protection circuit to realize detecting different voltage critical values and improve the performance of voltage protection.
In order to achieve the above purpose, the utility model adopts the following technical scheme:
an over-voltage and under-voltage protection circuit comprising: the device comprises a detection module, a processing module and a protection module;
the input end of the detection module is connected with a power supply to be detected, and the output end of the detection module is connected with the input end of the processing module;
the output end of the processing module is connected with the input end of the protection module, and the output end of the protection module is connected with a load;
the detection module sets different detection voltage critical values, detects the voltage value of the detected power supply and obtains a detection result according to the detection voltage critical values and the voltage value of the detected power supply;
and if the processing module judges that the detection result is abnormal, the processing module controls the protection module to disconnect the connection between the detected power supply and the load.
Optionally, the detection module includes: the device comprises a first voltage regulating unit, a second voltage regulating unit, a first comparing unit and a second comparing unit;
the first voltage regulating unit is connected with the first comparing unit, and the second voltage regulating unit is connected with the second comparing unit;
the first comparison unit and the second comparison unit are both connected with the power supply to be tested;
the first comparison unit and the second comparison unit are also respectively connected with the processing module.
Optionally, the first voltage regulating unit includes: the first sliding rheostat, the second sliding rheostat and the first constant value resistor are arranged on the base;
the second voltage adjusting unit includes: a third slide rheostat, a fourth slide rheostat and a second constant value resistor;
one end of the first constant resistor is connected with a power supply, the other end of the first constant resistor is connected with the third end of the first slide rheostat, the second end of the first slide rheostat is connected with the third end of the second slide rheostat, and the second end of the second slide rheostat is grounded;
one end of the second fixed resistor is connected with a power supply, the other end of the second fixed resistor is connected with the third end of the third slide rheostat, the second end of the third slide rheostat is connected with the third end of the fourth slide rheostat, and the second end of the fourth slide rheostat is grounded.
Optionally, the processing module includes a logic unit and a driving unit;
the detection module is connected with the logic unit, the logic unit is also connected with the driving unit, and the driving unit is connected with the protection module.
Optionally, the protection module includes a start-stop unit;
one end of the start-stop unit is connected with the processing module, and the other end of the start-stop unit is connected with the power supply to be tested;
the start-stop unit is also connected with the load.
Optionally, the start-stop unit includes: a manual key, a self-locking switch and an intermediate relay;
the self-locking switch is correspondingly connected with the intermediate relay; the self-locking switch is also connected with the intermediate relay through the manual key;
the intermediate relay is also respectively connected with the power supply to be tested and the load.
Optionally, the protection module further includes a leakage protection module;
and the electric leakage protection modules are connected with the start, protection and stop unit and the load.
Optionally, the overvoltage and undervoltage protection circuit further includes an overcurrent protection module;
and the overcurrent protection modules are connected with the start, protection and stop unit and the load.
Optionally, the overvoltage/undervoltage protection circuit further includes: upper and lower limit detection ports;
the upper limit detection port and the lower limit detection port are respectively connected with the detection module, the upper limit detection port and the lower limit detection port are connected with an external universal meter, and the universal meter measures the detection voltage critical value of the detection module.
Optionally, the overvoltage and undervoltage protection circuit further includes a voltage stabilizing module;
the voltage stabilizing module is respectively connected with the detection module and the processing module.
The utility model discloses a cross undervoltage protection circuit, include: the detection module, processing module and protection module, detection module's input links to each other with the power of being surveyed, detection module's output links to each other with processing module's input, processing module's output links to each other with protection module's input, protection module's output links to each other with the load, detection module sets up different detection voltage critical values, and detect the voltage value of being surveyed the power, obtain the testing result according to detection voltage critical value and the voltage value of being surveyed the power, processing module if judge that the testing result is unusual, control protection module disconnection is surveyed being connected of power and load. Can set for different voltage critical range values through detection module, make no longer confine to and detect a certain fixed voltage value, and make when detection module detects the abnormal value through processing module and protection module, directly control the protection module work through processing module, can adjust voltage monitoring range effectively, and can be under unmanned on duty's the condition, in the very first time of taking place the undervoltage condition, in time break off being connected of power and load, thereby the components and parts among the protection circuit avoid the impact injury of the power of undervoltage, protect the circuit better.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic circuit diagram of an over-voltage and under-voltage protection circuit provided by an embodiment of the present invention.
Fig. 2 is a circuit pin connection diagram of the first voltage regulating unit in the detection module in fig. 1.
Fig. 3 is a circuit pin connection diagram of a second voltage regulating unit in the detection module in fig. 1.
Fig. 4 is a schematic circuit pin connection diagram of the first comparing unit and the second comparing unit of the detection module in fig. 1.
Fig. 5 is a schematic diagram of the first comparison unit and the second comparison unit chips in fig. 4.
Fig. 6 is a specific circuit pin connection diagram of the logic unit of the processing module in fig. 1.
Fig. 7 is a schematic diagram of a logic chip of the logic cell of fig. 6.
Fig. 8 is a specific circuit pin connection diagram of the driving unit of the processing module in fig. 1.
Fig. 9 is a schematic diagram of a driving chip of the driving unit in fig. 8.
Fig. 10 is a specific circuit pin connection diagram of the start-stop unit of the protection module in fig. 1.
Fig. 11 is a circuit pin connection diagram of the voltage stabilization chip in the voltage stabilization module in fig. 1.
Fig. 12 is a schematic diagram of circuit connections set up for the upper and lower limit detection ports.
Fig. 13 is a schematic circuit connection diagram of the power supply of the overvoltage/undervoltage protection circuit.
Fig. 14 is a circuit connection diagram of the filter capacitor of the overvoltage/undervoltage protection circuit.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
Fig. 1 is a schematic circuit diagram of an over-voltage and under-voltage protection circuit provided by an embodiment of the present invention.
As shown in fig. 1, the under-voltage and over-voltage protection circuit of the present embodiment includes: detection module 1, processing module 2 and protection module 3, wherein, detection module 1's input links to each other with being surveyed power BC, detection module 1's output links to each other with processing module 2's input, processing module 2's output links to each other with protection module 3's input, protection module 3's output links to each other with load FZ, detection module 1 sets up different detection voltage critical values, and detect being surveyed power BC's voltage value, obtain the testing result according to detection voltage critical value and being surveyed power BC's voltage value, processing module 2 if judge that the testing result is unusual, control protection module 3 disconnection is surveyed power BC and load FZ's being connected. The whole circuit is divided into three parts, namely a detection module 1, a processing module 2 and a protection module 3, wherein the detection module 1 is the operation basis of the overvoltage and undervoltage protection circuit, the processing module 2 is the core control brain of the overvoltage and undervoltage protection circuit, and the protection module 3 is the execution mechanism of the overvoltage and undervoltage protection circuit, so that the protection of the load FZ can be effectively completed when the value judged by the processing module 2 or the value detected by the detection module 1 is abnormal.
In order to more clearly understand how the detection module 1 implements setting of the monitoring voltage, as shown in fig. 1, the detection module 1 includes: the device comprises a first voltage adjusting unit 11, a second voltage adjusting unit 12, a first comparing unit 13 and a second comparing unit 14, wherein the first voltage adjusting unit 11 is connected with the first comparing unit 13, the second voltage adjusting unit 12 is connected with the second comparing unit 14, the first comparing unit 13 and the second comparing unit 14 are both connected with a power source BC to be detected, and the first comparing unit 13 and the second comparing unit 14 are also connected with the processing module 2 respectively. The first voltage regulating unit 11 and the second voltage regulating unit 12 can regulate the monitoring voltage critical value, and the upper limit voltage and the lower limit voltage can be regulated according to actual requirements. For example, the voltage set by the first voltage adjusting unit 11 is 16.5V, the voltage set by the second voltage adjusting unit 12 is 0V, which indicates that the protection range of the overvoltage/undervoltage protection circuit is 0-16.5V, when the voltage is greater than 16.5V, the overvoltage state is, when the voltage is less than 0V, the undervoltage state is, when the voltage is 0-16.5V, the qualified voltage is, different from the prior art, the prior art can only set a fixed voltage value and cannot adjust, which results in single use, but the overvoltage/undervoltage protection circuit of the present application can detect voltages under various conditions through the first voltage adjusting unit 11 and the second voltage adjusting unit 12, which ensures the use range of the overvoltage/undervoltage protection circuit, and the protection range of the current is 0-10A.
Fig. 2 is a circuit pin connection diagram of the first voltage regulating unit in the detection module in fig. 1.
Fig. 3 is a circuit pin connection diagram of a second voltage regulating unit in the detection module in fig. 1.
As shown in fig. 2 and 3, the first voltage regulating unit 11 includes: a first slide varistor 111, a second slide varistor 112, and a first constant resistor 113, and the second voltage regulating unit 12 includes: the third sliding rheostat 121, the fourth sliding rheostat 122 and the second fixed resistor 123, one end of the first fixed resistor 113 is connected with a power supply, the other end of the first fixed resistor 113 is connected with the third end of the first sliding rheostat 111, the second end of the first sliding rheostat 111 is connected with the third end of the second sliding rheostat 112, the second end of the second sliding rheostat 112 is grounded, one end of the second fixed resistor 123 is connected with the power supply, the other end of the second fixed resistor 123 is connected with the third end of the third sliding rheostat 121, the second end of the third sliding rheostat 121 is connected with the third end of the fourth sliding rheostat 122, and the second end of the fourth sliding rheostat 122 is grounded. The first voltage regulating unit 11 has a circuit formed by connecting a first constant resistor 113(47K Ω resistor), a first sliding rheostat 111(100K Ω) and a second sliding rheostat 112(4.7K Ω) IN series, and is connected to a 24V power supply, and leads an output signal MAX to an IN + input terminal of the first comparing unit 13; at the moment, the voltage range of MAX is 0-16.5V; the second voltage regulating unit 12 is provided with a circuit which is formed by connecting a second fixed value resistor 123(47K omega resistor), a third slide rheostat 121(100K omega) and a fourth slide rheostat 122(4.7K omega) IN series, is connected to a 24V power supply, and leads an output signal MIN to the input end of a second comparing unit 14 IN-; the voltage range of MIN is 0-16.5V; the first voltage regulating unit 11 and the second voltage regulating unit 12 have the same principle and the same circuit connection, wherein the 100K Ω sliding rheostat is a coarse regulating resistor, the 4.7K Ω sliding rheostat is a fine regulating resistor, and the critical voltage of the overvoltage and undervoltage protection circuit is regulated in a mode of combining coarse regulation and fine regulation, so that the regulation can be more accurate.
Fig. 4 is a schematic circuit pin connection diagram of the first comparing unit and the second comparing unit of the detection module in fig. 1.
Fig. 5 is a schematic diagram of the first comparison unit and the second comparison unit chips in fig. 4.
The first comparing unit 13 and the second comparing unit 14 use the same chip, the first comparing unit 13 is used for comparing the voltage value of the accessed power supply BC to be detected with the voltage value set by the first voltage adjusting unit 11, and outputting the comparison result to the processing module 2, the power supply BC to be detected is respectively connected with the first comparing unit 13 and the second comparing unit 14, similarly, the second comparing unit 14 is used for comparing the voltage value of the power supply BC to be detected with the voltage value set by the second voltage adjusting unit 12, and then outputting the comparison result to the processing module 2, and the comparison process can be understood as: and comparing the voltage value of the tested power supply BC with two critical values in a critical range, comparing the voltage value with the maximum value, and comparing the voltage value with the minimum value to obtain whether the voltage value of the tested power supply BC is in the critical range of the maximum value and the minimum value or not. Since the principle and the circuit connection manner of the first comparing unit 13 and the second comparing unit 14 are the same, only one of them will be explained. As shown in fig. 4 and 5, the circuit pins of the voltage comparing unit chip are schematically connected, the voltage comparing unit is implemented by a chip LM358AN, the operating voltage thereof is 3-32V, and the chip is a dual operational amplifier, so one of the operational amplifiers is used as a first comparing unit 13, the other operational amplifier is used as a second comparing unit 14, wherein the MAX signal of the first voltage adjusting unit 11 is connected to the INB + of the chip LM358AN, and the input signal of the measured power supply BC is connected to the INB + and the INA +; the MIN of the second voltage regulating unit 12 is connected to INA-. Its output signals OUTA and OUTB are connected to input pins a and B, respectively, of the processing module 2.
As shown in fig. 1, the processing module 2 specifically includes a logic unit 21 and a driving unit 22, the detecting module 1 is connected to the logic unit 21, the logic unit 21 is further connected to the driving unit 22, and the driving unit 22 is connected to the protection module 3. The logic unit 21 obtains a comparison result of the first comparison unit 13 and the second comparison unit 14, controls the driving unit 22 to operate according to the comparison result, if the comparison result indicates that the voltage of the power supply BC to be tested is outside the critical range, it indicates that the voltage of the power supply BC to be tested is abnormal, controls the protection module 3 to operate, performs timing protection on the load FZ, and if the comparison result indicates that the voltage of the power supply BC to be tested is within the voltage critical range, it maintains the connection between the power supply BC to be tested and the load FZ.
Fig. 6 is a specific circuit pin connection diagram of the logic unit of the processing module in fig. 1.
Fig. 7 is a schematic diagram of a logic chip of the logic cell of fig. 6.
As shown in fig. 6 and 7, the logic unit 21 is implemented by means of a chip CD4081BF3A, the chip can operate at a voltage ranging from 3V to 18V, the output signals of the first comparing unit 13 and the second comparing unit 14 are respectively connected to A, B of the chip of the logic unit 21, the other unused input pins are grounded, and the output pins are floating.
Fig. 8 is a specific circuit pin connection diagram of the driving unit of the processing module in fig. 1.
Fig. 9 is a schematic diagram of a driving chip of the driving unit in fig. 8.
As shown in fig. 8 and 9, the driver chip can be implemented by IXDN609PI, and the operating voltage of the chip is 4.5V-35V, which is supplied with 24V in the present design. The maximum output current peak value can reach 9A, the working voltage of a relay IN the protection module 3 driven by the protection module is 24V, the driving current value is 30mA, the action voltage and the current of the relay are met, the output signal CONTROL of the logic unit 21 is connected to the input pin IN of the driving chip, the output pin OUT of the driving chip is connected to the VCC pin of the relay IN the protection module 3, the input pin of the CONTROL chip is externally connected with a pull-down resistor, the input is pulled down by default when no input exists, and misoperation is prevented.
As shown in fig. 1, the protection module 3 includes a start-stop unit 31, one end of the start-stop unit 31 is connected to the processing module 2, the other end of the start-stop unit 31 is connected to the power BC to be tested, and the start-stop unit 31 is further connected to the load FZ. Wherein, start-stop unit 31 includes: the device comprises a manual key 311, a self-locking switch 312 and an intermediate relay 313, wherein the self-locking switch 312 is correspondingly connected with the intermediate relay 313, the self-locking switch 312 is further connected with the intermediate relay 313 through the manual key 311, and the intermediate relay 313 is further connected with a power supply BC to be tested and a load FZ respectively.
Fig. 10 is a specific circuit pin connection diagram of the start-stop unit of the protection module in fig. 1.
As shown in fig. 10, the START-STOP/power-off circuit mainly includes a START manual button 311, a STOP self-lock switch 312, and a double-path intermediate relay 313, and the contact of the intermediate relay 313 of the present design can complete switching of voltage switches of 24V and 5A. When the output of the driver chip is high 24V, the START manual button 311 is manually pressed, the intermediate relay 313 is actuated, COM1 and NC1 are connected, COM2 and NC2 are connected, and the STOP manual button 311 is in a pressed state as a default state, that is, NC1 and GND are connected, and when the START button bounces, the relay is still actuated. When the STOP button is pressed, the relay is disconnected, or when the output of the driving chip is low, the relay is automatically disconnected, and when the output of the driving chip is restored to be high, the relay is not closed again, namely, the start-STOP function is realized, the COM2 of the intermediate relay 313 is connected with the tested power supply BC, and the NC2 is connected with the load FZ. The connection between the power BC to be detected and the load FZ can be directly disconnected through the protection circuit when the power BC to be detected is obviously abnormal, so that the damage to the load FZ circuit is further reduced, and the safe operation of the circuit is ensured.
Fig. 11 is a circuit pin connection diagram of the voltage stabilization chip in the voltage stabilization module in fig. 1.
As shown in fig. 11, the voltage regulation chip is implemented by LM7818CT, which has an input of 24V and an output of 18V, and the output is connected to the power supply pins of the first comparing unit 13, the second comparing unit 14 and the logic unit 21, so as to provide a stable 18V power supply voltage. As shown in fig. 11, a detailed connection diagram of each pin of the regulator chip is shown. The voltage of the over-voltage and under-voltage protection circuit is ensured to be kept constant.
An overvoltage and undervoltage protection circuit that this embodiment adopted includes: detection module 1, processing module 2 and protection module 3, detection module 1's input links to each other with being surveyed power BC, detection module 1's output links to each other with processing module 2's input, processing module 2's output links to each other with protection module 3's input, protection module 3's output links to each other with load FZ, detection module 1 sets up different detection voltage critical values, and detect the voltage value of being surveyed power BC, obtain the testing result according to detection voltage critical value and being surveyed power BC's voltage value, processing module 2 if judge that the testing result is unusual, control protection module 3 disconnection is surveyed power BC and load FZ's being connected. Can set for different voltage critical range values through detection module 1, make and not being restricted to and detect a certain fixed voltage value, and make when detection module 1 detects the abnormal value through processing module 2 and protection module 3, directly control protection module 3 work through processing module 2, can adjust voltage monitoring range effectively, and can be under the unmanned circumstances, in the very first time of taking place the under-voltage condition, in time break off by being connected of power BC and load FZ, thereby components and parts among the protection circuit avoid the impact injury of the power of under-voltage, better protect the circuit.
For further ensuring the power utilization safety of the load FZ circuit, the overvoltage/undervoltage protection circuit of this embodiment may further include a leakage protection module 3 and an overcurrent protection module 3, the leakage protection module 3 is connected to the start-stop unit 31 and the load FZ, and the overcurrent protection module 3 is connected to the start-stop unit 31 and the load FZ. The power utilization safety of the load FZ circuit can be better ensured by arranging the leakage protection and the overcurrent protection, and the circuit connection schematic diagram of the leakage protection circuit and the overcurrent protection circuit is not described in detail and can be understood by referring to the prior art.
The main function of the earth leakage protection circuit is the function of detecting and judging the earth leakage, and the earth leakage protection circuit does not have the function of switching off and on the main circuit. The leakage protection relay consists of a zero sequence mutual inductor, a release and an auxiliary contact for outputting signals, can be matched with an automatic switch of large current, and is used for the total protection of a low-voltage power grid or the leakage, grounding or insulation monitoring protection of a main circuit. When the main loop has leakage current, the auxiliary contact is connected in series with the separating release of the main loop switch to form a loop, so that the auxiliary contact is connected with the separating release to cut off the air switch, the AC contactor and the like, so that the air switch, the AC contactor and the like are switched off, the main loop is cut off, and the auxiliary contact can also be connected with an acoustic and optical signal device to send out a leakage alarm signal to reflect the insulation condition of the line. The leakage protection switch is a switching element which can not only switch on or off a main circuit like other circuit breakers, but also has a function of detecting and judging leakage current, and when leakage or insulation damage occurs in the main circuit, the leakage protection switch can switch on or off the main circuit according to a judgment result, and the leakage protection switch can be matched with a fuse and a thermal relay to form a low-voltage switching element with complete functions.
In addition to being able to detect and protect against electrical leakage, overcurrent protection is also important, and electrical equipment must also be equipped with overcurrent protection devices such as circuit breakers or fuses to protect electrical equipment and personnel. When overcurrent protection is used in design, it is necessary to ensure that the rated current of a direct current device meets the system working conditions, especially the maximum output current of a component, and different overcurrent devices are suitable for different system designs and rated powers, which is not described herein again, but a general design principle is: during wiring, a high-fusing resistance wire or a suitable breaker is used for limiting the current below the conductive bottleneck of any point in the circuit so as to avoid overload or short circuit, and an over-current protection device of the storage battery is arranged as close as possible so as to avoid the circuit from igniting and igniting hydrogen gas discharged from the storage battery. Each integrated device circuit should be equipped with an independent overcurrent protection device, all electrical devices and power supply lines must have reliable overcurrent protection, the overcurrent protection includes short-circuit protection, overload protection (overload protection), phase failure protection and the like, and in order to enable the overcurrent protection device to play a due protection role, the rated current of a fuse is reasonably selected, and the action value of a relay is selected and adjusted.
Fig. 12 is a schematic diagram of circuit connections set up for the upper and lower limit detection ports.
In order to be able to better understand the critical value of the regulated voltage and to facilitate the measurement, the integrated circuit board of the protection circuit may further be provided with: the upper limit detection port and the lower limit detection port are respectively connected with the detection module 1, the upper limit detection port and the lower limit detection port are connected with an external universal meter, and the universal meter is used for measuring the detection voltage critical value of the detection module 1. As shown in fig. 12, the schematic diagram of the circuit connection of the pins of the upper and lower limit detection circuits is that the upper limit detection circuit and the lower limit detection circuit are, the upper limit detection circuit is connected to the first voltage adjustment unit 11, the lower limit detection circuit is connected to the second voltage adjustment unit 12, so as to more conveniently grasp the adjustment value of the voltage, real-time measurement can be performed by using a multimeter, and the adjusted voltage value can be more accurately known.
Fig. 13 is a schematic circuit connection diagram of the power supply of the overvoltage/undervoltage protection circuit.
As shown in fig. 13, for the circuit connection diagram of the power supply, the power supply provides a 24V dc voltage supply for the circuit, and the cooperation with the voltage stabilizing module 4 ensures the safe and stable use voltage of the overvoltage/undervoltage protection circuit.
Fig. 14 is a circuit connection diagram of the filter capacitor of the overvoltage/undervoltage protection circuit.
The functional block diagram of the whole circuit is shown in fig. 1, and the working process is roughly as follows: the first voltage regulating unit 11 and the second voltage regulating unit 12 are respectively composed of a 100K Ω sliding rheostat, a 4.7K Ω sliding rheostat and a 47K Ω constant value resistor, so that the voltage values of the upper and lower limits of the two sliding rheostats can be regulated, and the coarse regulation and the fine regulation of the upper and lower limit voltages can be realized by the two sliding rheostats with different resistance values. The tested power supply BC is used as an input signal of the first comparing unit 13 and the second comparing unit 14, and is simultaneously input into the start-up and stop unit 31, the first comparing unit 13 and the second comparing unit 14 are used for comparing an input voltage value of the tested power supply BC with a set upper limit voltage value and a set lower limit voltage value, so as to determine whether the input voltage value is within a set value, outputs of the two voltage comparators are subjected to logical and operation through the logic unit 21CD4073BF3A, when the outputs of the two comparators are both 1, the output of the logic unit 21 is also 1, the driving unit 22 is an IXDN609PI driving chip, and is used for driving the 24V intermediate relay 313 in the start-up and stop unit 31 to work, when the output of the logic unit 21 is 1 and after the start-up and stop unit 31 is manually started, the load FZ is connected with the tested power supply BC, when overvoltage or undervoltage occurs during operation, the output of the logic unit 21 becomes 0, so that the driving unit 22 stops driving the start-up and stop unit 31, load FZ is automatic with surveyed power BC disconnection to even when voltage returns when normal, can not automatic recovery load FZ and surveyed power BC's connection, only after the technical staff investigation circuit, after the circuit was just can switch on again by the manual start-up of once more, load FZ and surveyed power BC, the safe handling of under-voltage protection circuit has been guaranteed to the voltage value in the output monitoring range.
In order to improve the functions of the over-voltage and under-voltage protection circuit, a humidity detection circuit can be arranged, so that the working environment of the over-voltage and under-voltage protection circuit is ensured to be in a moisture-free state, the good working performance of the over-voltage and under-voltage protection circuit is ensured, and the circuit can be prevented from being damaged by humidity.
The utility model discloses a cross undervoltage protection circuit mainly comprises the triplex, and the first part is the bound detection circuitry of voltage, can set up arbitrary 0-16.5V's bound detection window. The second part is logic processing control, and when abnormality is detected, an abnormality signal is sent out in time. The second part is a power-on/power-off circuit, and whether the connection between the detected power supply and the load is disconnected or not can be executed under the control instruction of the second part according to the detection result of the first part, so that the functions of an overvoltage and undervoltage protection circuit in an adjustable voltage monitoring range are realized.
It is understood that the same or similar parts in the above embodiments may be mutually referred to, and the same or similar parts in other embodiments may be referred to for the content which is not described in detail in some embodiments.
It should be noted that, in the description of the present invention, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In addition, in the description of the present invention, "a plurality" means at least two unless otherwise specified.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.
Claims (10)
1. An over-voltage and under-voltage protection circuit, comprising: the device comprises a detection module, a processing module and a protection module;
the input end of the detection module is connected with a power supply to be detected, and the output end of the detection module is connected with the input end of the processing module;
the output end of the processing module is connected with the input end of the protection module, and the output end of the protection module is connected with a load;
the detection module sets different detection voltage critical values, detects the voltage value of the detected power supply and obtains a detection result according to the detection voltage critical values and the voltage value of the detected power supply;
and if the processing module judges that the detection result is abnormal, the processing module controls the protection module to disconnect the connection between the detected power supply and the load.
2. The under-voltage and over-voltage protection circuit of claim 1, wherein the detection module comprises: the device comprises a first voltage regulating unit, a second voltage regulating unit, a first comparing unit and a second comparing unit;
the first voltage regulating unit is connected with the first comparing unit, and the second voltage regulating unit is connected with the second comparing unit;
the first comparison unit and the second comparison unit are both connected with the power supply to be tested;
the first comparison unit and the second comparison unit are also respectively connected with the processing module.
3. The under-voltage and over-voltage protection circuit of claim 2, wherein the first voltage regulating unit comprises: the first sliding rheostat, the second sliding rheostat and the first constant value resistor are arranged on the base;
the second voltage adjusting unit includes: a third slide rheostat, a fourth slide rheostat and a second constant value resistor;
one end of the first constant resistor is connected with a power supply, the other end of the first constant resistor is connected with the third end of the first slide rheostat, the second end of the first slide rheostat is connected with the third end of the second slide rheostat, and the second end of the second slide rheostat is grounded;
one end of the second fixed resistor is connected with a power supply, the other end of the second fixed resistor is connected with the third end of the third slide rheostat, the second end of the third slide rheostat is connected with the third end of the fourth slide rheostat, and the second end of the fourth slide rheostat is grounded.
4. The under-voltage and over-voltage protection circuit according to claim 1, wherein the processing module comprises a logic unit and a driving unit;
the detection module is connected with the logic unit, the logic unit is also connected with the driving unit, and the driving unit is connected with the protection module.
5. The over-voltage and under-voltage protection circuit according to claim 1, wherein the protection module comprises a start-up protection unit;
one end of the start-stop unit is connected with the processing module, and the other end of the start-stop unit is connected with the power supply to be tested;
the start-stop unit is also connected with the load.
6. The undervoltage protection circuit of claim 5, wherein the start-up and shutdown unit comprises: a manual key, a self-locking switch and an intermediate relay;
the self-locking switch is correspondingly connected with the intermediate relay; the self-locking switch is also connected with the intermediate relay through the manual key;
the intermediate relay is also respectively connected with the power supply to be tested and the load.
7. The over-voltage and under-voltage protection circuit according to claim 5, wherein the protection module further comprises a leakage protection module;
and the electric leakage protection modules are connected with the start, protection and stop unit and the load.
8. The over-voltage and under-voltage protection circuit according to claim 5, further comprising an over-current protection module;
and the overcurrent protection modules are connected with the start, protection and stop unit and the load.
9. The under-voltage and over-voltage protection circuit of claim 1, further comprising: upper and lower limit detection ports;
the upper limit detection port and the lower limit detection port are respectively connected with the detection module, the upper limit detection port and the lower limit detection port are connected with an external universal meter, and the universal meter measures the detection voltage critical value of the detection module.
10. The under-voltage and over-voltage protection circuit according to any one of claims 1 to 9, further comprising a voltage stabilization module;
the voltage stabilizing module is respectively connected with the detection module and the processing module.
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| CN201921165107.6U CN210041312U (en) | 2019-07-23 | 2019-07-23 | Over-voltage and under-voltage protection circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111879739A (en) * | 2020-07-06 | 2020-11-03 | 广东环凯生物科技有限公司 | Test light source system of microbial luminescence tester and detection method thereof |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111879739A (en) * | 2020-07-06 | 2020-11-03 | 广东环凯生物科技有限公司 | Test light source system of microbial luminescence tester and detection method thereof |
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