CN218240212U - Sampling protection circuit for current overcurrent signal - Google Patents
Sampling protection circuit for current overcurrent signal Download PDFInfo
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- CN218240212U CN218240212U CN202221282219.1U CN202221282219U CN218240212U CN 218240212 U CN218240212 U CN 218240212U CN 202221282219 U CN202221282219 U CN 202221282219U CN 218240212 U CN218240212 U CN 218240212U
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Abstract
The utility model relates to the technical field of overcurrent protection, and discloses a sampling protection circuit for current overcurrent signals, which comprises a current sampling resistance unit and a voltage-to-ground voltage sampling unit, wherein the current sampling resistance unit is used for sampling the voltage-to-ground voltage of the current sampling resistance unit; the current-limiting filtering unit is used for performing current-limiting filtering action on the electric signal output by the current sampling resistance unit; the level conversion unit comprises an NPN type triode Q1, the NPN type triode Q1 is electrically connected with the current sampling resistor unit, and the NPN type triode Q1 is electrically connected with the current limiting filtering unit; high-speed photoelectric isolation opto-coupler unit. The circuit principle is simple and easy to understand. The circuit is simple to apply, and the required components are few. The PN junction characteristic of the triode is ingeniously utilized to combine with the ohm law of the sampling resistor, so that the rapid response signal output can be realized. The current signal is reasonably converted into a level signal.
Description
Technical Field
The utility model belongs to the technical field of overcurrent protection's technique and specifically relates to a be used for electric current overcurrent signal sampling protection circuit.
Background
The servo motor is an engine which controls mechanical elements to operate in a servo system, and is an auxiliary motor indirect speed changing device. The servo motor can control the speed, the position precision is very accurate, and a voltage signal can be converted into torque and rotating speed to drive a control object. The servo motor has rotor speed controlled by the input signal and fast response, and may be used as the executing element in automatic control system, and has the features of small electromechanical time constant, high linearity, etc. the servo motor can convert the received electric signal into angular displacement or angular speed of the motor shaft for output. The servo motor is divided into two categories of direct current servo motors and alternating current servo motors, and is mainly characterized in that when the signal voltage is zero, the signal voltage has no autorotation phenomenon, and the rotating speed is reduced at a constant speed along with the increase of the torque.
When the load end of the servo driver fails, the situation of excessive current or short circuit can be caused. In this case, if there is no overcurrent/short-circuit protection measure, the load terminal and the power supply terminal are continuously heated, the circuit is irreversibly damaged, and even a more dangerous accident such as fire may occur.
At present, most of design schemes for current protection and short-circuit protection of a servo driver still adopt a current sampling resistor, an operational amplifier chip and an isolation optocoupler, response time of the schemes in design is long, and after an overcurrent signal is triggered, devices on a circuit are more, so that timeliness of overcurrent response is seriously influenced. The circuit principle is more complicated, and the cost is higher, the embodiment of the utility model provides a short circuit and overcurrent protection circuit aims at solving above problem to a certain extent at least.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a be used for electric current to overflow signal sampling protection circuit aims at solving the above-mentioned problem that exists among the prior art.
The application provides a be used for current overflow signal sampling protection circuit includes:
the current sampling resistance unit is used for sampling the voltage to ground of the current sampling resistance unit;
the current-limiting filtering unit is used for performing current-limiting filtering action on the electric signal output by the current sampling resistance unit;
the level conversion unit comprises an NPN type triode Q1, the NPN type triode Q1 is electrically connected with the current sampling resistor unit, and the NPN type triode Q1 is electrically connected with the current limiting filtering unit;
high-speed photoelectric isolation opto-coupler unit.
Further, the current sampling resistance unit includes a sampling resistance R4.
Further, the current-limiting filtering unit comprises a current-limiting resistor R3 and a filtering capacitor C3; the first end of the current-limiting resistor R3 is electrically connected with the end part of the sampling resistor R4, and the second end of the current-limiting resistor R3 is electrically connected with the filter capacitor C3.
Further, the NPN-type triode Q1 is connected to the current limiting resistor R3, and the NPN-type triode Q1 is further connected to the filter capacitor C3.
Further, the sampling protection circuit further comprises a current-limiting resistor R2, and the current-limiting resistor R2 is electrically connected with a collector pin of the NPN type triode Q1.
Further, the sampling protection circuit further comprises a filter capacitor C2, and the filter capacitor C2 is electrically connected with a collector pin of the NPN-type triode Q1.
Further, high-speed photoelectric isolation opto-coupler unit includes high-speed photoelectric isolation opto-coupler U1, high-speed photoelectric isolation opto-coupler U1 includes input and output, high-speed photoelectric isolation opto-coupler U1's input with current limiting resistor R2 electricity is connected.
Further, the output end of the high-speed photoelectric isolation optocoupler U1 is electrically connected with a pull-up resistor R1.
Further, the output end of the high-speed photoelectric isolation optocoupler U1 is electrically connected with a filter capacitor C1.
Compared with the prior art, the utility model provides a pair of be used for electric current to overflow signal sampling protection circuit has following advantage: 1. the circuit principle is simple and easy to understand. The circuit is simple to apply, and the required components are few. The PN junction characteristic of the triode is ingeniously utilized to combine with the ohm law of the sampling resistor, and the rapid response signal output can be achieved. The current signal is reasonably converted into a level signal.
Drawings
Fig. 1 is a circuit diagram of a current overflow signal sampling protection circuit according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The same or similar reference numerals in the drawings of the present embodiment correspond to the same or similar components; in the description of the present invention, it should be understood that if there are the terms "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of the description, but it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore the terms describing the positional relationship in the drawings are only for illustrative purposes and are not to be construed as limitations of the present patent, and those skilled in the art can understand the specific meanings of the terms according to specific situations.
The following describes the implementation of the present invention in detail with reference to specific embodiments.
Referring to fig. 1, a preferred embodiment of the present invention is provided.
A sampling protection circuit for a current overflow signal, comprising:
the current sampling resistance unit is used for sampling the voltage to ground of the current sampling resistance unit;
the current-limiting filtering unit is used for performing current-limiting filtering on the electric signal output by the current sampling resistance unit;
the level conversion unit comprises an NPN type triode Q1, the NPN type triode Q1 is electrically connected with the current sampling resistor unit, and the NPN type triode Q1 is electrically connected with the current limiting filtering unit;
high-speed photoelectric isolation opto-coupler unit.
Further, the current sampling resistance unit includes a sampling resistance R4.
Further, the current-limiting filtering unit comprises a current-limiting resistor R3 and a filtering capacitor C3; the first end of the current limiting resistor R3 is electrically connected with the end part of the sampling resistor R4, and the second end of the current limiting resistor R3 is electrically connected with the filter capacitor C3.
Further, the NPN transistor Q1 is connected to the current limiting resistor R3, and the NPN transistor Q1 is further connected to the filter capacitor C3.
Further, the sampling protection circuit further comprises a current-limiting resistor R2, and the current-limiting resistor R2 is electrically connected with a collector pin of the NPN type triode Q1.
Further, the sampling protection circuit further comprises a filter capacitor C2, and the filter capacitor C2 is electrically connected with a collector pin of the NPN-type triode Q1.
Further, the high-speed photoelectric isolation optocoupler unit comprises a high-speed photoelectric isolation optocoupler U1, the high-speed photoelectric isolation optocoupler U1 comprises an input end and an output end, and the input end of the high-speed photoelectric isolation optocoupler U1 is electrically connected with the current limiting resistor R2.
Further, the output end of the high-speed photoelectric isolation optocoupler U1 is electrically connected with a pull-up resistor R1.
Further, the output end of the high-speed photoelectric isolation optocoupler U1 is electrically connected with a filter capacitor C1.
The working principle of the current overcurrent signal sampling protection circuit is as follows:
when current flows through the sampling resistor R4, the voltage difference is generated between the two ends of the sampling resistor R4 and the ground, and the product of the sampling resistor R4 and the current flowing through the sampling resistor R4 is substituted according to ohm's law U = I R formula to obtain the voltage to the ground of the current sampling resistor R4. The voltage to ground of the sampling resistor R4 passes through the current limiting resistor R3 and is filtered and input into the B base electrode of the NPN type triode Q1 through the filter capacitor C3, and the PN junction characteristic of the triode is utilized to achieve the forward voltage drop conduction characteristic of about 0.7V. The NPN type triode Q1 is clamped to be 0.7V by utilizing the characteristics of the NPN type triode Q.
When the voltage of the sampling resistor R4 to the ground is less than 0.7V, the voltage is filtered and input into the B base electrode of the NPN type triode Q1 through the filter capacitor C3, and the NPN type triode Q1 is in a cut-off state. The collector emitter of the NPN transistor Q1 is non-conductive. And the NPN type triode Q1 is connected with the filter capacitor C2 and the current-limiting resistor R2, and the photodiode at the input end of the high-speed photoelectric isolation optocoupler is not conducted. The photosensitive diode at the output end of the high-speed photoelectric isolation optocoupler is not conducted, the NPN type triode at the output end of the high-speed photoelectric isolation optocoupler is in a cut-off state, and the output end of the high-speed photoelectric isolation optocoupler outputs a high level.
When the voltage of the sampling resistor R4 to the ground is larger than 0.7V, the voltage is filtered and input into the B base electrode of the NPN type triode Q1 through the filter capacitor C3, and the NPN type triode Q1 is in an amplification state. The collector and emitter of the NPN transistor Q1 are turned on. And the NPN type triode Q1 is connected with the filter capacitor C2 and the current-limiting resistor R2, and the photodiode at the input end of the high-speed photoelectric isolation optocoupler is conducted to emit light. And a photosensitive diode at the output end of the high-speed photoelectric isolation optocoupler is conducted, an NPN type triode at the output end of the high-speed photoelectric isolation optocoupler is conducted in an amplification state, and the output end of the high-speed photoelectric isolation optocoupler outputs a low level.
The utility model provides a pair of be used for electric current to overflow signal sampling protection circuit has following advantage: the circuit principle is simple and easy to understand. The circuit is simple to apply, and the required components are few. The PN junction characteristic of the triode is ingeniously utilized to combine with the ohm law of the sampling resistor, so that the rapid response signal output can be realized. The current signal is reasonably converted into a level signal.
In the description of the present application, it is to be noted that the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected unless otherwise explicitly stated or limited. Either mechanically or electrically. Either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.
In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact of the first and second features, or may comprise contact of the first and second features not directly but through another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
The above disclosure provides many different embodiments, or examples, for implementing different features of the application. The components and arrangements of specific examples are described above to simplify the present disclosure. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.
In the description herein, references to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like 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 present application. In this specification, schematic representations of the above terms 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.
The above embodiments are only preferred embodiments of the present application, and the scope of the present application is not limited thereto, and any insubstantial changes and substitutions made by those skilled in the art based on the present application are intended to be covered by the present application.
Claims (9)
1. A sampling protection circuit for a current overflow signal, comprising:
the current sampling resistance unit is used for sampling the voltage to ground of the current sampling resistance unit;
the current-limiting filtering unit is used for performing current-limiting filtering on the electric signal output by the current sampling resistance unit;
the level conversion unit comprises an NPN type triode Q1, the NPN type triode Q1 is electrically connected with the current sampling resistor unit, and the NPN type triode Q1 is electrically connected with the current limiting filtering unit;
high-speed photoelectric isolation opto-coupler unit.
2. The sampling protection circuit for the current over-current signal according to claim 1, wherein the current sampling resistor unit comprises a sampling resistor R4.
3. The sampling protection circuit for the current overflow signal of claim 2, wherein the current limiting filter unit comprises a current limiting resistor R3 and a filter capacitor C3; the first end of the current-limiting resistor R3 is electrically connected with the end part of the sampling resistor R4, and the second end of the current-limiting resistor R3 is electrically connected with the filter capacitor C3.
4. The current overflow signal sampling protection circuit according to claim 3, wherein the NPN transistor Q1 is connected to the current limiting resistor R3, and the NPN transistor Q1 is further connected to the filter capacitor C3.
5. The sampling protection circuit for the current overflow signal of claim 4, further comprising a current limiting resistor R2, wherein the current limiting resistor R2 is electrically connected to the collector pin of the NPN transistor Q1.
6. The sampling protection circuit for the current overflow signal of claim 5, further comprising a filter capacitor C2, wherein the filter capacitor C2 is electrically connected to a collector pin of the NPN transistor Q1.
7. The current overcurrent signal sampling protection circuit according to claim 6, wherein the high-speed photoelectric isolation optocoupler unit comprises a high-speed photoelectric isolation optocoupler U1, the high-speed photoelectric isolation optocoupler U1 comprises an input end and an output end, and the input end of the high-speed photoelectric isolation optocoupler U1 is electrically connected with the current limiting resistor R2.
8. The sampling protection circuit for the current overcurrent signal is characterized in that the output end of the high-speed photoelectric isolation optocoupler U1 is electrically connected with a pull-up resistor R1.
9. The current overflow signal sampling protection circuit as claimed in claim 8, wherein the output terminal of the high-speed optoelectronic isolation optocoupler U1 is electrically connected to a filter capacitor C1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221282219.1U CN218240212U (en) | 2022-05-26 | 2022-05-26 | Sampling protection circuit for current overcurrent signal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221282219.1U CN218240212U (en) | 2022-05-26 | 2022-05-26 | Sampling protection circuit for current overcurrent signal |
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| Publication Number | Publication Date |
|---|---|
| CN218240212U true CN218240212U (en) | 2023-01-06 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221282219.1U Active CN218240212U (en) | 2022-05-26 | 2022-05-26 | Sampling protection circuit for current overcurrent signal |
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| Country | Link |
|---|---|
| CN (1) | CN218240212U (en) |
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2022
- 2022-05-26 CN CN202221282219.1U patent/CN218240212U/en active Active
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