CN216121777U - Short-circuit protection circuit and compressor - Google Patents

Abstract

The utility model is suitable for the technical field of circuit protection, and provides a short-circuit protection circuit and a compressor, wherein the short-circuit protection circuit comprises a sampling module, and the sampling module is connected with a load module and used for detecting a load signal of the load module; the comparison module is connected with the sampling module; the adjusting module is connected with the comparing module; the control module is connected with the adjusting module and the comparing module; the control module is used for outputting a pull-up signal or a pull-down signal, the adjusting module adjusts the size of the protection threshold value according to the pull-up signal or the pull-down signal, the comparing module is used for comparing the load signal according to the protection threshold value and outputting the protection signal to the control module, and the control module is used for controlling the working state of the load module according to the protection signal. The adjusting module adjusts the protection threshold according to the signal of the control module, so that different protection thresholds exist in different working stages of the equipment, and the equipment is effectively protected.

Description

Short-circuit protection circuit and compressor

Technical Field

The utility model belongs to the technical field of circuit protection, and particularly relates to a short-circuit protection circuit and a compressor.

Background

With the development of society, equipment such as compressors and water pumps are widely applied to daily life of people. In some devices similar to compressors, water pumps and the like, the starting current in the starting stage is different from the current in the subsequent normal operation stage, the starting current is greater than the normal working current in the operation stage, in order to avoid the damage of the devices caused by the excessive current in the starting stage or the normal operation stage of the devices, a protection threshold value is generally set, and when the current exceeds the threshold value, the load is turned off to protect the devices.

In the related art, the device generally only sets a protection threshold, and in both the starting stage and the subsequent normal operation stage, because the starting current is greater than the normal working current, the protection threshold is generally set to a current value greater than the starting current.

SUMMERY OF THE UTILITY MODEL

The utility model provides a short-circuit protection circuit, which aims to solve the problem that equipment with different working currents at different stages has different protection thresholds.

The present invention is achieved as such, and a short-circuit protection circuit includes:

the input end of the sampling module is used for being connected with a load module and detecting a load signal of the load module;

the input end of the comparison module is connected with the output end of the sampling module;

the adjusting module is connected with the comparing module;

the control module is respectively connected with the adjusting module and the comparing module;

the control module is used for outputting a pull-up signal or a pull-down signal to the adjusting module, the adjusting module adjusts the size of a protection threshold value according to the pull-up signal or the pull-down signal, the comparing module is used for comparing the load signal according to the protection threshold value and outputting the protection signal to the control module, and the control module is used for controlling the working state of the load module according to the protection signal.

Furthermore, the adjusting module comprises at least one first resistor, one end of the first resistor is connected with the control module, and the other end of the first resistor is connected with the input end of the comparing module.

Furthermore, the comparison module comprises a comparator, a second resistor and a third resistor, wherein one end of the second resistor is connected with the first input end of the comparator, the other end of the second resistor is connected with the sampling module, one end of the third resistor is connected with the second input end of the comparator, and the other end of the third resistor is connected with the power supply.

Furthermore, the adjusting module is connected between the first input terminal of the comparator and the second resistor and/or the adjusting module is connected between the second input terminal of the comparator and the third resistor.

Furthermore, the sampling module comprises a sampling resistor, one end of the sampling resistor is connected with the second resistor, the other end of the sampling resistor is connected with the load module, and the other end of the sampling resistor is grounded.

Furthermore, the comparison module further includes a fourth resistor, one end of the fourth resistor is connected between the third resistor and the second input end of the comparator, and the other end of the fourth resistor is grounded.

Furthermore, the comparison module further includes a first capacitor, one end of the first capacitor is connected between the third resistor and the second input terminal of the comparator, and the other end of the first capacitor is grounded.

Furthermore, the short-circuit protection circuit further comprises a fifth resistor, one end of the fifth resistor is connected between the second resistor and the first input end of the comparator, and the other end of the fifth resistor is connected with a power supply.

Furthermore, the short-circuit protection circuit further includes a sixth resistor, one end of the sixth resistor is connected to a connection point between the fifth resistor and the first input terminal of the comparator, and the other end of the sixth resistor is grounded.

Furthermore, the comparison module further comprises a pull-up resistor, one end of the pull-up resistor is connected with the output end of the comparator, and the other end of the pull-up resistor is connected with the power supply.

Furthermore, the control module further comprises a micro control unit, the input end of the adjusting module is connected with the IO port of the micro control unit, the output end of the adjusting module is connected with the input end of the comparing module, and the output end of the comparing module is connected with the IO port of the micro control unit.

Furthermore, the short-circuit protection circuit further comprises a filtering module, and the filtering module is connected between the output end of the comparison module and the control module.

Furthermore, the filtering module comprises a second capacitor and a seventh resistor, the fifth resistor is connected between the output end of the comparing module and the control module, one end of the second capacitor is connected between the seventh resistor and the control module, and the other end of the second capacitor is grounded.

The present invention also provides a compressor comprising:

the short-circuit protection circuit as described above;

and the input end of the load module is connected with the control module, and the output end of the load module is connected with the input end of the sampling module.

According to the short-circuit protection circuit provided by the utility model, the control module can send a pull-up signal or a pull-down signal to the adjusting module according to different working stages of equipment, the adjusting module adjusts a protection threshold value according to the received pull-up signal or pull-down signal, the adjusting module is connected with the comparison module, the comparison module can receive the protection threshold value, the sampling module is connected with the load module, collects a load signal generated by the load module and transmits the load signal to the comparison module, the comparison module compares the difference value of the load signal and the protection threshold value and correspondingly outputs a protection signal, and after receiving the protection signal, the control module controls the load module to be opened and closed according to the protection signal, so that the effect of protecting the load module is achieved. The adjustment module correspondingly adjusts the protection threshold value through the pull-up signal and the pull-down signal, so that different protection threshold values can be obtained in different working stages of the equipment, the equipment can be effectively protected in different working stages, the equipment is prevented from being damaged due to improper setting of the protection threshold value, the service life of the equipment can be prolonged, and the personal threat to users can be avoided.

Drawings

Fig. 1 is a schematic circuit configuration diagram of a compressor of the present invention.

Fig. 2 is a schematic diagram of a short-circuit protection circuit according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a short-circuit protection circuit according to another embodiment of the utility model.

Fig. 4 is a schematic diagram of a short-circuit protection circuit according to another embodiment of the utility model.

Reference numerals:

the short-circuit protection circuit comprises a short-circuit protection circuit 100, a sampling module 110, a sampling resistor R1, a comparison module 120, a comparator 121, a second resistor R2, a third resistor R4, a fourth resistor R5, a first capacitor C1, a pull-up resistor R6, an adjustment module 130, a first resistor R3, a control module 140, a micro-control unit 141, a fifth resistor R7, a sixth resistor R8, a filtering module 170, a second capacitor C2 and a seventh resistor R9;

a load module 200.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further 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 utility model and are not intended to limit the utility model.

Example one

Referring to fig. 1, a short-circuit protection circuit 100 of the present invention includes a sampling module 110, a comparing module 120, an adjusting module 130, and a control module 140.

The input end of the sampling module 110 is used for connecting with the load module 200 and detecting a load signal of the load module 200; the input end of the comparison module 120 is connected with the output end of the sampling module 110; the adjusting module 130 is connected with the comparing module 120; the control module 140 is respectively connected with the adjusting module 130 and the comparing module 120; the control module 140 is configured to output a pull-up signal or a pull-down signal to the adjusting module 130, the adjusting module 130 adjusts a protection threshold according to the pull-up signal or the pull-down signal, the comparing module 120 is configured to compare the load signal according to the protection threshold and output a protection signal to the control module 140, and the control module 140 is configured to control a working state of the load module 200 according to the protection signal.

In this embodiment, the control module 140 further includes a micro control unit 141, an input end of the adjusting module 130 is connected to an IO port of the micro control unit 141, an output end of the adjusting module 130 is connected to an input end of the comparing module 120, and an output end of the comparing module 120 is connected to the IO port of the micro control unit 141. The micro control unit 141, i.e. an mcu (microcontroller unit), an input end of the adjusting module 130 and an output end of the comparing module 120 are respectively connected to different IO ports of the micro control unit 141. Specifically, the micro control unit 141 outputs a pull-up signal or a pull-down signal to the adjusting module 130, the adjusting module 130 adjusts the protection threshold according to the pull-up signal or the pull-down signal, the comparing module 120 outputs a protection signal according to the protection threshold and the load signal, the micro control unit 141 receives the protection signal and performs corresponding measures on the load module 200 according to the protection signal, and turns off the load module 200 to protect the load module 200 or continues to control the load module 200 to normally operate. It is understood that the control module 140 may also adopt a control component such as a single chip microcomputer.

The embodiment of the utility model provides a short-circuit protection circuit 100, a control module 140 of the short-circuit protection circuit 100 can send a pull-up signal or a pull-down signal to an adjustment module 130 according to different working stages of equipment, the adjustment module 130 adjusts a protection threshold according to the received pull-up signal or pull-down signal, the adjustment module 130 is connected with a comparison module 120, the comparison module 120 can receive the protection threshold, a sampling module 110 is connected with a load module 200, collects a load signal generated by the load module 200 and transmits the load signal to the comparison module 120, the comparison module 120 compares the difference between the load signal and the protection threshold and correspondingly outputs a protection signal, and after the control module 140 receives the protection signal, the control module 200 is controlled to be turned on and off according to the protection signal, so that the effect of protecting the load module 200 is achieved. The adjustment module 130 adjusts the protection threshold value correspondingly through the pull-up signal and the pull-down signal, so that different protection threshold values can be provided at different working stages of the equipment, the equipment can be effectively protected at different working stages, the equipment is prevented from being damaged due to improper setting of the protection threshold value, the service life of the equipment can be prolonged, and the personal threat to users can be avoided.

Example two

The adjusting module 130 includes at least one first resistor R3, one end of the first resistor R3 is connected to the control module 140, and the other end of the first resistor R3 is connected to the input terminal of the comparing module 120.

It is understood that the pull-up signal or the control module 140 controls the end of the first resistor R3 connected to the control module 140 to be connected to the power supply, and the pull-down signal or the control module 140 controls the end of the first resistor R3 connected to the control module 140 to be grounded.

Referring to fig. 2, in the present embodiment, the adjusting module 130 includes a first resistor R3. When the number of the first resistors R3 is one, two working states are included, the first one is that one end of the first resistor R3 is connected with the power supply, and the other end is connected with the input end of the comparison module 120; the second is that one end of the first resistor R3 is grounded, and the other end is connected to the input terminal of the comparison module 120. Specifically, when the micro control unit 141 sends a pull-up signal through the IO port, one end of the first resistor R3 connected to the micro control unit 141 is equivalent to being connected to the power supply, the other end of the first resistor R3 is connected to the input end of the comparator module 120, when the micro control unit 141 sends a pull-down signal through the IO port, one end of the first resistor R3 connected to the micro control unit 141 is equivalent to being grounded, and the other end of the first resistor R3 is connected to the input end of the comparator module 120.

Referring to fig. 3, in the present embodiment, the adjusting module 130 includes two first resistors R3, and one end of the two first resistors R3 is connected to the control module 140 for receiving the pull-up signal or the pull-down signal of the control module 140 and adjusting the protection threshold. When the number of the first resistors R3 is two and the resistance values of the first resistors R3 are the same, the three working states are included, the first one is that one end of one first resistor R3 is grounded, one end of the other first resistor R3 is also grounded, and the other ends of the two first resistors R3 are connected to the input end of the comparison module 120; the second one is that one end of one first resistor R3 is connected with the power supply, one end of the other first resistor R3 is grounded, and the other ends of the two first resistors R3 are both connected with the input end of the comparison module 120; in the third method, one end of one first resistor R3 is connected to the power supply, one end of the other first resistor R3 is also connected to the power supply, and the other ends of the two first resistors R3 are connected to the input terminal of the comparing module 120. When the number of the first resistors R3 is two and the resistances are different, there are four cases, respectively, where one end of each of the two first resistors R3 is grounded; or one end of each of the two first resistors R3 is connected with the power supply; or one end of one first resistor R3 is connected with the power supply, and one end of the other first resistor R3 is grounded; or one end of one first resistor R3 is grounded, and one end of the other first resistor R3 is connected with the power supply. Specifically, the two first resistors R3 are respectively connected to different IO ports of the mcu 141, and can respectively output a pull-up signal or a pull-down signal to the first resistor R3. When the mcu 141 outputs the pull-up signal to the first resistor R3, the mcu 141 connects the first resistor R3 to the mcu 141 at a terminal equivalent to the power connection, and when the mcu 141 outputs the pull-down signal to the first resistor R3, the mcu 141 connects the first resistor R3 to the mcu 141 at a terminal equivalent to the ground connection.

When the number of the first resistors R3 is three and the resistances of the first resistors R3 are the same, four situations are included, respectively, where one end of each first resistor R3 is grounded; or one end of each first resistor R3 is connected with a power supply; or one end of one of the first resistors R3 is connected with a power supply, and one ends of the other two first resistors R3 are both grounded; or one end of two first resistors R3 is connected with the power supply, and one end of the remaining first resistor R3 is grounded. In the present embodiment, the resistance values of the first resistors R3 are the same, and it is understood that the first resistors R3 with different resistance values may be adopted, and the number of corresponding cases is changed correspondingly.

It is understood that the number of the first resistors R3 may also be four or five, and the resistance value of the first resistor R3 may be changed according to actual requirements, such as the size of the protection threshold or the type of the load module 200.

In another embodiment, the adjusting module 130 may also be a switching device such as a transistor or a MOS transistor, and the switching device such as the transistor or the MOS transistor is turned on by applying a level through an IO port of the micro control unit 141, and then another power supply is connected to the adjusting module 130.

EXAMPLE III

Referring to fig. 3, the comparing module 120 includes a comparator 121, a second resistor R2 and a third resistor R4, wherein one end of the second resistor R2 is connected to the first input terminal of the comparator 121, the other end of the second resistor R2 is connected to the sampling module 110, one end of the third resistor R4 is connected to the second input terminal of the comparator 121, and the other end of the third resistor R4 is connected to the power supply. The second resistor R2 and the third resistor R4 play a role of isolation and buffering, so that the accessed voltage can be prevented from directly entering the comparator 121, and the comparator 121 is protected. The sampling module 110 inputs the sampled load signal to a first input terminal of the comparator 121, the comparator 121 compares the load signal with a protection threshold, and outputs a protection signal to the control module 140, and the control module 140 takes corresponding measures for the load module 200 according to the protection signal.

In this embodiment, the first input terminal of the comparator 121 is an inverting input terminal, the second input terminal of the comparator 121 is a non-inverting input terminal, the second input terminal of the comparator 121 is connected to the reference voltage Vref, the first input terminal of the comparator 121 is connected to the load voltage, when the load voltage is greater than the reference voltage, the protection signal output by the comparator 121 changes from a low level to a high level, and when the control module 140 receives the protection signal, changes from the low level to the high level, the load module 200 is turned off, and the load module 200 is protected. The first input terminal of the comparator 121 may also be a non-inverting input terminal, and the second input terminal of the comparator 121 is an inverting input terminal, so that the device may have different protection thresholds in different operation stages, and the implementation principle is the same as that of the embodiment in which the first input terminal of the comparator 121 is an inverting input terminal, but the logic is opposite. In the case where the first input terminal of the comparator 121 is a non-inverting input terminal, when the load voltage is greater than the reference voltage, the protection signal output by the comparator 121 changes from a high level to a low level.

Example four

The adjustment module 130 is connected between the first input terminal of the comparator 121 and the second resistor R2 and/or the adjustment module 130 is connected between the second input terminal of the comparator 121 and the third resistor R4. By changing the voltage of the input terminal of the comparator 121 (which may change the reference voltage or the load voltage), the device may have different protection thresholds in different operation stages, the comparator 121 compares the reference voltage with the load voltage and then outputs a protection signal, and the control module 140 controls the load module 200 to perform corresponding operations according to the protection signal.

Specifically, referring to fig. 3, in the present embodiment, the adjusting module 130 is connected between the first input terminal of the comparator 121 and the second resistor R2. It can be understood that the sampling module 110 transmits the sampled voltage signal to a first input terminal of the comparator 121, one input terminal of the comparator 121 is used for collecting the load voltage, the other input terminal inputs the reference voltage, compares the reference voltage with the load voltage and outputs a high level or a low level, i.e. a protection signal, and the control module 140 takes measures corresponding to the load module 200 according to the received high level or low level.

The adjusting module 130 is connected between the first input terminal of the comparator 121 and the second resistor R2, and can adjust an adjusting range of the load voltage and the reference signal, so that the device has different protection thresholds in different operation phases. Specifically, assume that the original reference voltage is set to 1.1V, and when the adjusting module 130 is not added, assume that the load voltage at the first input terminal of the comparator 121 is 1V, and the variation range of the load signal is 0.1V. At this time, when the load signal changes by more than 0.1V, the comparator 121 compares the load voltage with the reference voltage and outputs a protection signal, and the control module 140 controls the load module 200 to stop operating according to the protection signal. When the adjustment module 130 is added, the superimposed voltage is assumed to be 0.05V, and at this time, the load voltage at the first input terminal of the comparator 121 is 1.05V, and the variation range of the load signal is 0.05V. At this time, when the load signal changes by more than 0.05V, the comparator 121 compares the load voltage with the reference voltage and outputs a protection signal, and the control module 140 controls the load module 200 to stop operating according to the protection signal. It can be seen that the variation range of the load signal can be changed by superimposing the voltage through the adjusting module 130 on the basis of the load voltage originally connected to the first input terminal of the comparator 121, so that the device has different protection thresholds at different operation stages. The data in the above examples are only examples, and the utility model is not limited thereto. When the adjusting module 130 is connected between the first input terminal of the comparator 121 and the second resistor R2, changing the protection threshold by the pull-up signal or the pull-down signal actually changes the range of the accessible load signal, i.e. the range of the current threshold of the load module 200 also changes. The comparator 121 correspondingly outputs a protection signal to the control module 140 by comparing the load voltage with the reference voltage, and the control module 140 correspondingly controls the load module 200 to operate according to the protection signal.

It is understood that the adjusting module 130 may also be connected between the second input terminal of the comparator 121 and the third resistor R4, and the purpose of having different protection thresholds in different operation stages can also be achieved by changing the reference voltage, specifically, assuming that the original reference voltage is set to 1.1V, and when the adjusting module 130 is not added, assuming that the load voltage at the first input terminal of the comparator 121 is 1V, the variation range of the load signal is 0.1V. At this time, when the load signal changes by more than 0.1V, the comparator 121 compares the load voltage with the reference voltage and outputs a protection signal, and the control module 140 controls the load module 200 to stop operating according to the protection signal. When the adjustment module 130 is added, it is assumed that the voltage superimposed on the reference voltage is 0.1V, at this time, the reference voltage of the comparator 121 is 1.2V, the load voltage of the first input terminal of the comparator 121 is 1V, and the variation range of the load signal is 0.2V, whereas when the adjustment module 130 is added, so that the reference voltage of the comparator 121 becomes 1.05V, the load voltage of the first input terminal of the comparator 121 is 1V, and the variation range of the load signal is 0.05V. It is likewise possible to realize devices with different protection thresholds in different operating phases. The principle is similar to that when the adjustment module 130 is connected between the first input terminal of the comparator 121 and the second resistor R2, and is not described herein again. In addition, two adjustment modules 130 may be provided, one adjustment module 130 is respectively disposed between the first input end of the comparator 121 and the second resistor R2, and the other adjustment module 130 is disposed between the first input end of the comparator 121 and the second resistor R2.

Example four

Referring to fig. 3, the sampling module 110 includes a sampling resistor R1, one end of the sampling resistor R1 is connected to the second resistor R2, one end of the sampling resistor R1 connected to the second resistor R2 is used for connecting to the load module 200, and the other end of the sampling resistor R1 is grounded.

Referring to fig. 2, the sampling module 110 is connected to the load module 200, and the short-circuit protection circuit 100 forms a loop. When the mcu 141 outputs a pull-up signal, one end of the first resistor R3 is connected to the power source, the other end is connected to the input terminal of the comparison module 120, the current flows from the power source and sequentially passes through the first resistor R3, the second resistor R2 and the sampling resistor R1, assuming that the current flowing from the load module 200 through the sampling resistor R1 is I and Vref is the reference voltage, when the load voltage exceeds the reference voltage, the high-low level conversion occurs, and therefore, the reference voltage and the load voltage are changedThe following relationship exists between voltages:

wherein R1 is a sampling resistor R1, R2 is a second resistor R2, R3 is a first resistor R3, and Vcc is the power source connected to the first resistor R3, since the values of Vref, Vcc, R1 and R2 are known,

when the current flowing through the sampling resistor R1 of the load module 200 is greater than the current I, that is, the current corresponding to the voltage sampled by the sampling resistor R1 is greater than the current I, so that the load voltage exceeds the reference voltage, the output of the comparator 121 changes from a low level to a high level, and when the current exceeds the protection current, measures need to be taken to protect the load module 200. In practice, the current I can be equal to

The time value is regarded as a reference point, the voltage corresponding to the current I is a protection threshold value, and when the current flowing through the sampling resistor R1 exceeds the protection threshold value, protection measures are taken.

When the mcu 141 outputs a pull-down signal, one end of the first resistor R3 is grounded, the other end is connected to the input terminal of the comparison module 120, a part of the current of the load module 200 flows through the sampling resistor R1 (I is the current flowing through the sampling resistor R1), and a part of the current flows through the second resistor R2 and the first resistor R3 to ground, the load voltage at the first input terminal of the comparator 121 is the voltage from the first resistor R3 to ground, and the reference voltage and the load voltage have the following relationship:

wherein, R1 is a sampling resistor R1, R2 is a second resistor R2, I is the current flowing through the sampling resistor R1, R3 is a first resistor R3, therefore,

when the current flowing through the sampling resistor R1 of the load module 200 is larger than the current I, i.e. the current is sampled by the sampling resistor R1When the current corresponding to the voltage is greater than the current I, the load voltage exceeds the reference voltage, the output of the comparator 121 changes from a low level to a high level, and when the current exceeds the protection current, measures need to be taken to protect the load module 200. In practice, the current I can be equal to

The time value is regarded as a reference point, the voltage corresponding to the current I is a protection threshold value, and when the current flowing through the sampling resistor R1 exceeds the protection threshold value, protection measures are taken. It can be seen that the currents flowing through the sampling module 110 under the conditions of the pull-up signal and the pull-down signal are different, which is equivalent to setting different protection thresholds, so that the pull-up signal or the pull-down signal can be correspondingly output according to the operation stage of the device, and the protection thresholds are adjusted, so that the device can have appropriate protection thresholds in different operation stages. In this embodiment, the resistance of the sampling resistor R1 is 2.5m Ω, and the resistance of the sampling resistor R1 is in milliohm. The resistance of the second resistor R2 is 1k omega. The resistance of the first resistor R3 ranges from tens kilo-ohms to hundreds kilo-ohms, and in the embodiment, the resistance of the first resistor R3 is 100k Ω.

Referring to fig. 3, when the number of the first resistors R3 is two, the operation method of the protection threshold is similar to that when the number of the first resistors R3 is one, and will not be described herein again.

EXAMPLE five

Referring to fig. 3, the comparing module 120 further includes a fourth resistor R5, one end of the fourth resistor R5 is connected between the third resistor R4 and the second input terminal of the comparator 121, and the other end of the fourth resistor R5 is grounded. The third resistor R4 plays a role of isolation buffer, so that the connected voltage can be prevented from directly entering the comparator 121, and the comparator 121 is protected. The fourth resistor R5 functions as a voltage divider, and the reference voltage at the second input terminal of the comparator 121 is the voltage across the fourth resistor R5. In the present embodiment, the resistance of the fourth resistor R5 is 1k Ω. The resistance of the fourth resistor R5 can be selected to be adjusted as desired.

EXAMPLE six

Referring to fig. 3, the comparing module 120 further includes a first capacitor C1, one end of the first capacitor C1 is connected between the third resistor R4 and the second input terminal of the comparator 121, and the other end of the first capacitor C1 is grounded. In the present embodiment, the first capacitor C1 is connected in parallel with the fourth resistor R5. The filtering by the first capacitor C1 can reduce interference, so that the input signal is more stable. The accuracy of the comparator 121 comparing the load signal according to the protection threshold is improved, the accuracy of the protection load module 200 can be effectively improved, and the possibility of false alarm is reduced.

EXAMPLE seven

Referring to fig. 3, the comparing module 120 further includes a pull-up resistor R6, one end of the pull-up resistor R6 is connected to the output terminal of the comparator 121, and the other end of the pull-up resistor R6 is connected to the power supply. Depending on the type of comparator 121 selected, the pull-up resistor R6 may be selectively provided or the pull-up resistor R6 may not be provided. Specifically, when the types of the selected comparators 121 are different, some of the comparators 121 internally provided with the relevant structures to connect power sources to form pull-up may not be provided with the pull-up resistor R6, and have a driving capability, and the comparators 121 can output a high level. When the output of the comparator 121 is in the open collector mode, the pull-up resistor R6 needs to be provided so that the comparator 121 has a driving capability and can output a high level. In case the comparator 121 can output a high level or a low level, the control module 140 can control the load module 200 to operate accordingly according to the high level or the low level (i.e. the content of the protection signal output). In the present embodiment, the pull-up resistor R6 has a resistance of 5.1k Ω. The resistance of the pull-up resistor R6 can be selected to be adjusted as desired.

Example eight

Referring to fig. 3, the short-circuit protection circuit 100 further includes a fifth resistor R7, one end of the fifth resistor R7 is connected between the second resistor R2 and the first input terminal of the comparator 121, and the other end of the fifth resistor R7 is connected to the power supply. The fifth resistor R7 is provided to raise the load voltage, so as not to affect the system operation of the whole device, the resistance of the sampling resistor R1 is small, the voltage on the sampling resistor R1 is small, the comparator 121 is difficult to compare the load voltage with the reference voltage, and the situation that the comparison cannot be determined exists. Therefore, the fifth resistor R7 is connected, and the load voltage is raised by the fifth resistor R7, so that the load voltage can be determined by the comparator 121, interference can be effectively reduced, the reliability of the protection signal output by the comparator 121 is higher, and malfunction of the control module 140 can be effectively avoided. In the present embodiment, the resistance of the fifth resistor R7 is 30k Ω. The resistance of the fifth resistor R7 can be selected to be adjusted as desired.

Example nine

Referring to fig. 4, the short-circuit protection circuit 100 further includes a sixth resistor R8, one end of the sixth resistor R8 is connected to the connection point of the fifth resistor R7 and the first input terminal of the comparator 121, and the other end of the sixth resistor R8 is grounded. When the power supply connected with the fifth resistor R7 meets the requirement of the device, one end of the fifth resistor R7 is directly connected between the second resistor R2 and the first input end of the comparator 121. When the power supply connected with the fifth resistor R7 does not meet the requirement of the device, the sixth resistor R8 is arranged to divide the voltage, so that the voltage connected to the first input end of the comparator 121 meets the requirement. Similarly, in order not to affect the system operation of the whole device, the resistance value of the sampling resistor R1 is small, the voltage across the sampling resistor R1 is small, and the comparator 121 may not compare the load voltage with the reference voltage and may not be able to distinguish the load voltage from the reference voltage. Therefore, the fifth resistor R7 is connected, the voltage is divided by the sixth resistor R8, and the fifth resistor R7 raises the load voltage, so that the load voltage can be determined by the comparator 121, interference can be effectively reduced, the reliability of the protection signal output by the comparator 121 is higher, and malfunction of the control module 140 can be effectively avoided.

Example ten

Referring to fig. 3, the short-circuit protection circuit 100 further includes a filtering module 170, and the filtering module 170 is connected between the output end of the comparing module 120 and the control module 140. Specifically, the filtering module 170 includes a second capacitor C2 and a seventh resistor R9, the seventh resistor R9 is connected between the output end of the comparing module 120 and the control module 140, one end of the second capacitor C2 is connected between the seventh resistor R9 and the control module 140, and the other end of the second capacitor C2 is grounded. Interference can be reduced by providing the filtering module 170, so that the input signal is more stable. In the present embodiment, the resistance of the seventh resistor R9 is 100 Ω. The resistance of the seventh resistor R9 can be selected to be adjusted as desired.

EXAMPLE eleven

An embodiment of the present invention further provides a compressor, including: the short-circuit protection circuit 100 and the load module 200 are as described above. The input of the load module 200 is connected to the control module 140, and the output of the load module 200 is connected to the input of the sampling module 110.

In the present embodiment, the load module 200 includes an inverter circuit. The output end of the inverter circuit is connected with one end of the switch tube module, and the input end of the sampling module 110 is connected with the other end of the switch tube module. The load signal of the load module 200 is collected by the sampling module 110. It is understood that when the short-circuit protection circuit 100 of the present invention is applied to other devices, the load module 200 may be other components, not necessarily an inverter circuit.

The embodiment of the utility model provides a compressor, wherein a control module 140 of a short-circuit protection circuit 100 of the compressor can send a pull-up signal or a pull-down signal to an adjusting module 130 according to different working stages of equipment, the adjusting module 130 adjusts a protection threshold according to the received pull-up signal or pull-down signal, the adjusting module 130 is connected with a comparison module 120, the comparison module 120 can receive the protection threshold, a sampling module 110 is connected with a load module 200, collects a load signal generated by the load module 200 and transmits the load signal to the comparison module 120, the comparison module 120 compares the difference value between the load signal and the protection threshold and correspondingly outputs a protection signal, and after receiving the protection signal, the control module 140 controls the load module 200 to be opened and closed according to the protection signal, so as to achieve the effect of protecting the load module 200. The adjustment module 130 adjusts the protection threshold value correspondingly through the pull-up signal and the pull-down signal, so that different protection threshold values can be provided at different working stages of the equipment, the equipment can be effectively protected at different working stages, the equipment is prevented from being damaged due to improper setting of the protection threshold value, the service life of the equipment can be prolonged, and the personal threat to users can be avoided.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (14)

1. A short-circuit protection circuit, comprising:

the input end of the sampling module is used for being connected with a load module and detecting a load signal of the load module;

the input end of the comparison module is connected with the output end of the sampling module;

the adjusting module is connected with the comparing module;

the control module is respectively connected with the adjusting module and the comparing module;

the control module is used for outputting a pull-up signal or a pull-down signal to the adjusting module, the adjusting module adjusts the size of a protection threshold value according to the pull-up signal or the pull-down signal, the comparing module is used for comparing the load signal according to the protection threshold value and outputting the protection signal to the control module, and the control module is used for controlling the working state of the load module according to the protection signal.

2. The short-circuit protection circuit of claim 1, wherein the adjustment module comprises at least one first resistor, one end of the first resistor is connected to the control module, and the other end of the first resistor is connected to the input terminal of the comparison module.

3. The short-circuit protection circuit of claim 1, wherein the comparison module comprises a comparator, a second resistor, and a third resistor, one end of the second resistor is connected to the first input terminal of the comparator, the other end of the second resistor is connected to the sampling module, one end of the third resistor is connected to the second input terminal of the comparator, and the other end of the third resistor is connected to a power supply.

4. A short-circuit protection circuit as claimed in claim 3, characterized in that the adjusting block is connected between the first input of the comparator and the second resistance and/or the adjusting block is connected between the second input of the comparator and the third resistance.

5. The short-circuit protection circuit as claimed in claim 3, wherein the sampling module comprises a sampling resistor, one end of the sampling resistor is connected with the second resistor, one end of the sampling resistor connected with the second resistor is used for being connected with the load module, and the other end of the sampling resistor is grounded.

6. The short-circuit protection circuit of claim 3, wherein the comparison module further comprises a fourth resistor, one end of the fourth resistor is connected between the third resistor and the second input terminal of the comparator, and the other end of the fourth resistor is grounded.

7. The short-circuit protection circuit of claim 3, wherein the comparison module further comprises a first capacitor, one end of the first capacitor is connected between the third resistor and the second input terminal of the comparator, and the other end of the first capacitor is grounded.

8. The short-circuit protection circuit of claim 3, further comprising a fifth resistor, one end of the fifth resistor being connected between the second resistor and the first input terminal of the comparator, the other end of the fifth resistor being connected to a power supply.

9. The short-circuit protection circuit according to claim 8, further comprising a sixth resistor, one end of which is connected to a connection point of the fifth resistor and the first input terminal of the comparator, and the other end of which is grounded.

10. The short-circuit protection circuit of claim 3, wherein the comparison module further comprises a pull-up resistor, one end of the pull-up resistor is connected to the output terminal of the comparator, and the other end of the pull-up resistor is connected to the power supply.

11. The short-circuit protection circuit according to claim 1, wherein the control module further comprises a micro control unit, an input terminal of the adjusting module is connected to an IO port of the micro control unit, an output terminal of the adjusting module is connected to an input terminal of the comparing module, and an output terminal of the comparing module is connected to an IO port of the micro control unit.

12. The short-circuit protection circuit of claim 1, further comprising a filtering module connected between an output of the comparing module and a control module.

13. The short-circuit protection circuit as claimed in claim 12, wherein the filtering module includes a second capacitor and a seventh resistor, the seventh resistor is connected between the output terminal of the comparing module and the control module, one end of the second capacitor is connected between the seventh resistor and the control module, and the other end of the second capacitor is grounded.

14. A compressor, comprising:

the short-circuit protection circuit of any one of claims 1 to 13;

and the input end of the load module is connected with the control module, and the output end of the load module is connected with the input end of the sampling module.

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