CN110783905A - Discharge protection circuit, filter circuit, rectifier, control system and tacking machine - Google Patents

Abstract

The invention provides a discharge protection circuit, a filter circuit, a rectifier device, a control system and a tacking machine. By setting a protection resistor, a discharge switch, a start protection switch, a first circuit input end and a second circuit input end; The first end of the protection resistor is electrically connected to the input end of the first circuit, the second end of the protection resistor is electrically connected to one end of the bleeder switch, and the other end of the bleeder switch is electrically connected to one end of the filter capacitor and the input end of the second circuit respectively; The first end of the protection switch is electrically connected to the other end of the filter capacitor, the second end of the start-up protection switch is electrically connected to the first end of the protection resistor, and the third end of the start-up protection switch is electrically connected to the second end of the protection resistor, so that the Only one protection resistor in the discharge protection circuit can realize the start-up protection and discharge protection of the filter capacitor, which reduces the number of protection resistors in the circuit. Therefore, the space inside the device is saved, and the production and manufacturing costs are reduced.

Description

Discharge protection circuit, filter circuit, rectifier, control system and tacking machine

technical field

The invention relates to the technical field of sewing/sewing, in particular to a discharge protection circuit, a filter circuit, a rectifying device, a control system and a bar tacking machine.

Background technique

When the control device or control system is just connected to the power supply, a large current surge will occur, which may cause damage to the circuit system. Therefore, in the design of the control system, protection measures are usually set in the circuit. Similarly, when there is energy In the feedback circuit, in order to prevent the power feedback from causing losses to the circuit system, corresponding protection measures will also be set.

In the field of sewing/sewing technology, it is a common technical means to apply start-up protection and over-voltage protection to the control system. The usual practice is to set a protection resistor for start-up protection and a protection resistor for discharge energy. For example, in the control system of the tacking machine, there are protection resistors for start-up protection and overvoltage protection respectively.

However, as the precision of the control system becomes higher and higher, the internal space of the control system becomes smaller and smaller, and the protection resistor is often large in size and high in power, which results in a waste of the internal space of the equipment and increases the manufacturing and production costs.

SUMMARY OF THE INVENTION

In view of this, the present invention provides a bleeder protection circuit, a filter circuit, a rectifier device, a control system and a tacking machine, so as to solve the problems of waste of internal space of the equipment and increased manufacturing and production costs.

According to a first aspect of the embodiments of the present disclosure, the present invention provides a leakage protection circuit, including:

a protection resistor, a bleeder switch, a start-up protection switch, a first circuit input end and a second circuit input end;

The first end of the protection resistor is electrically connected to the input end of the first circuit, the second end of the protection resistor is electrically connected to one end of the bleeder switch, and the other end of the bleeder switch is respectively connected to one end of the filter capacitor is electrically connected to the input end of the second circuit; the first end of the startup protection switch is electrically connected to the other end of the filter capacitor, the second end of the startup protection switch is electrically connected to the first end of the protection resistor, The third end of the start-up protection switch is electrically connected to the second end of the protection resistor;

the first circuit input end and the second circuit input end are electrically connected to the two poles of the power supply;

The start-up protection switch is used to be set to the first switch state or the second switch state according to the voltage of the filter capacitor; when in the first switch state, the first end of the start-up protection switch and the connection of the start-up protection switch The third end is turned on; when in the second switch state, the first end of the start-up protection switch and the second end of the start-up protection switch are turned on;

The protection resistor is used to connect in series with the filter capacitor when the start-up protection switch is in the first switch state, and when the start-up protection switch is in the second switch state and the voltage of the filter capacitor is greater than the first preset voltage threshold, be connected in series with the bleeder switch, so that the circuit formed by the protection resistor and the bleeder switch is connected in parallel with the filter capacitor;

The bleeder switch is configured to be turned on when the start-up protection switch is in the second switch state and the voltage of the filter capacitor is greater than the first preset voltage threshold.

Optionally, the leakage protection circuit further includes:

a control device, one end of the control device is electrically connected to the filter capacitor, and the other end of the control device is electrically connected to the start-up protection switch;

The control device is configured to obtain the voltage of the filter capacitor, and if the voltage of the filter capacitor is greater than a second preset voltage threshold, send a state switching control instruction to the startup protection switch, and the second preset voltage The threshold is less than the first preset voltage threshold;

The activation protection switch is specifically configured to switch the first switch state to the second switch state according to the state switching control instruction.

Optionally, the startup protection switch includes: a relay, and the state of the relay includes a normally open state and a normally closed state;

The relay is specifically configured to be in a normally open state when the start-up protection switch is in a first switch state; and in a normally-closed state when the start-up protection switch is in a second switch state.

Optionally, the other end of the control device is also electrically connected to the discharge switch;

The control device is further configured to send a closing control instruction to the bleeder switch if the voltage of the filter capacitor is greater than a first preset voltage threshold;

The relief switch is specifically configured to be turned on according to the closing control command.

Optionally, the discharge switch includes: a MOS transistor.

Optionally, the protection resistor is a cement resistor or an aluminum shell resistor.

According to a second aspect of the embodiments of the present disclosure, the present disclosure provides a filter circuit, including: a filter capacitor and the leakage protection circuit according to any one of the first aspects of the embodiments of the present disclosure.

The leakage protection circuit is electrically connected to the filter capacitor.

According to a third aspect of the embodiments of the present disclosure, the present disclosure provides a rectifying device, including: a rectifying circuit and the filter circuit according to the second aspect of the embodiments of the present disclosure.

The input end of the rectifier circuit is connected to the AC power supply, and the output end of the rectifier circuit is electrically connected to the first circuit input end and the second circuit input end of the filter circuit respectively.

The rectifier circuit is used for rectifying the input AC power and outputting the DC power.

According to a fourth aspect of the embodiments of the present disclosure, the present disclosure provides a control system, including: an AC power source, a load device, and the rectifying device according to the second aspect of the embodiments of the present disclosure.

The AC power source, the rectifying device, and the load device are electrically connected in sequence.

The AC power supply is used for supplying power to the load device through the rectifying device.

According to a fifth aspect of the embodiments of the present disclosure, the present invention provides a bar tacking machine, including the control system according to the fourth aspect of the embodiments of the present disclosure.

The bleeder protection circuit, filter circuit, rectifier device, control system and tacking machine provided by the present invention are provided by setting a protection resistor, a bleeder switch, a start-up protection switch, a first circuit input end and a second circuit input end; the protection The first end of the resistor is electrically connected to the input end of the first circuit, the second end of the protection resistor is electrically connected to one end of the bleeder switch, and the other end of the bleeder switch is respectively connected to one end and the second end of the filter capacitor. The circuit input end is electrically connected; the first end of the startup protection switch is electrically connected to the other end of the filter capacitor, the second end of the startup protection switch is electrically connected to the first end of the protection resistor, and the startup protection switch is electrically connected to the first end of the protection resistor. The third end of the protection switch is electrically connected to the second end of the protection resistor; the first circuit input end and the second circuit input end are electrically connected to the two poles of the power supply correspondingly; the activation protection switch is used for According to the voltage of the filter capacitor, it is set to the first switch state or the second switch state; when in the first switch state, the first end of the start-up protection switch and the third end of the start-up protection switch are turned on; in the first switch state In two switch states, the first end of the start-up protection switch and the second end of the start-up protection switch are conductive; the protection resistor is used to connect with the filter capacitor when the start-up protection switch is in the first switch state connected in series, when the start-up protection switch is in the second switch state and the voltage of the filter capacitor is greater than the first preset voltage threshold, it is connected in series with the bleeder switch, so that the protection resistor and the bleeder switch form a circuit connected in parallel with the filter capacitor; the bleeder switch is used to conduct when the start-up protection switch is in the second switch state and the voltage of the filter capacitor is greater than the first preset voltage threshold, so that only one protection is passed in the bleeder protection circuit The resistor can realize the start-up protection and discharge protection of the filter capacitor, which reduces the number of protection resistors in the circuit. Therefore, the space inside the device is saved, and the production and manufacturing costs are reduced.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description serve to explain the principles of the disclosure.

FIG. 1 is a schematic structural diagram of a discharge protection circuit provided by an embodiment of the present invention;

2 is a schematic diagram of a connection circuit of a discharge protection circuit in the embodiment shown in FIG. 1 when the start-up protection switch is in a first switch state;

3 is a schematic diagram of the connection circuit of the discharge protection circuit in the embodiment shown in FIG. 1 when the start-up protection switch is in the second switch state and the voltage of the filter capacitor is not greater than the first preset voltage threshold;

4 is a schematic diagram of the connection circuit of the discharge protection circuit in the embodiment shown in FIG. 1 , when the start-up protection switch is in the second switch state and the voltage of the filter capacitor is greater than the first preset voltage threshold;

5 is a schematic structural diagram of a discharge protection circuit provided by another embodiment of the present invention;

6 is a schematic structural diagram of a filter circuit provided by an embodiment of the present invention;

7 is a schematic structural diagram of a rectifier device provided by an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a control system provided by an embodiment of the present invention.

The above-mentioned drawings, having shown clear embodiments of the present disclosure, will hereinafter be described in greater detail, these drawings and written descriptions are not intended to limit the scope of the disclosed concepts in any way, but by reference to specific embodiments The concepts of the present disclosure are explained to those skilled in the art.

Reference number:

1: bleeder protection circuit; 11: start protection switch; 12: protection resistor; 13: bleeder switch; 14: first circuit input; 15: second circuit input; 16: control device;

2: Filter capacitor.

Detailed ways

Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. Where the following description refers to the drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the illustrative examples below are not intended to represent all implementations consistent with this disclosure. Rather, they are merely examples of apparatus and systems consistent with some aspects of the present disclosure as recited in the appended claims.

In the prior art, in order to solve the problems of excessive starting current and energy feedback in the circuit, corresponding starting protection and discharge protection are usually set. and protective resistors for bleed protection. However, the protection resistor in the startup protection circuit only plays a protective role when the circuit is connected to the power supply. With the smooth startup of the circuit, the protection resistor in the startup protection circuit is short-circuited by the relay, so it is always in an idle state, resulting in startup The utilization rate of the protection resistor in the protection circuit is low. At the same time, due to the existence of the protection resistor in the start-up protection, the bleeder protection will not be triggered when the system is just started. Therefore, considering that the start-up protection and the bleeder protection will not be triggered at the same time, the start-up protection and the bleeder protection share one protection resistor, can reduce the number of protection resistors. However, how to implement start-up protection and discharge protection through a protection resistor in the circuit is a problem currently faced.

The technical solutions of the present invention and how the technical solutions of the present application solve the above-mentioned technical problems will be described in detail below with specific examples. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic structural diagram of a bleeder protection circuit provided by an embodiment of the present invention. As shown in FIG. 1 , the bleeder protection circuit 1 provided by this embodiment includes:

A protection resistor 12 , a bleeder switch 13 , a start-up protection switch 11 , a first circuit input end 14 and a second circuit input end 15 .

The first end of the protection resistor 12 is electrically connected to the first circuit input end 14 , the second end of the protection resistor 12 is electrically connected to one end of the bleeder switch 13 , and the other end of the bleeder switch 13 is respectively connected to one end of the filter capacitor 2 and the first end of the bleeder switch 13 . The two circuit input ends 15 are electrically connected; the first end of the startup protection switch 11 is electrically connected to the other end of the filter capacitor 2, the second end of the startup protection switch 11 is electrically connected to the first end of the protection resistor 12, and the startup protection switch 11 is electrically connected to the first end of the protection resistor 12. The third terminal is electrically connected to the second terminal of the protection resistor 12 .

The first circuit input terminal 14 and the second circuit input terminal 15 are electrically connected to the two poles of the power supply; specifically, the first circuit input terminal 14 is connected to the positive pole of the DC power supply, and the second circuit input terminal 15 is connected to the negative pole of the DC power supply. Of course, the first circuit input terminal 14 can also be connected to the negative pole of the DC power supply, the second circuit input terminal 15 can be connected to the positive pole of the DC power supply, and the first circuit input terminal 14 and the second circuit input terminal 15 can be connected to the positive pole of the DC power supply. , The electrical connection method of the negative electrode can be adjusted according to specific needs, which is not specifically limited here.

The protection switch 11 is activated to be set to the first switching state or the second switching state according to the voltage of the filter capacitor 2; when in the first switching state, the first terminal of the protection switch 11 and the third terminal of the protection switch 11 are activated. The terminal is turned on; in the second switch state, the first terminal of the start-up protection switch 11 and the second end of the start-up protection switch 11 are turned on.

The start-up protection switch 11 has at least a first switch state and a second switch state. When the start-up protection switch 11 is in different states, the corresponding connection state of the pressure relief protection circuit changes accordingly, thereby realizing different circuit functions.

The protection resistor 12 is used to connect in series with the filter capacitor 2 when the start-up protection switch 11 is in the first switch state, and when the start-up protection switch 11 is in the second switch state and the voltage of the filter capacitor 2 is greater than the first preset voltage threshold, connect with the filter capacitor 2 The bleeder switch 13 is connected in series, so that the circuit formed by the protection resistor 12 and the bleeder switch 13 is connected in parallel with the filter capacitor 2 .

The bleeder switch 13 is configured to be turned on when the start-up protection switch 11 is in the second switch state and the voltage of the filter capacitor 2 is greater than the first preset voltage threshold.

2 is a schematic diagram of the connection circuit of the discharge protection circuit 1 when the start-up protection switch 11 is in the first switch state. The third end of the switch 11 is turned on, and the discharge switch 13 is turned off. At this time, the connection loop of the pressure relief protection circuit is the first circuit input end 14 , the protection resistor 12 , the filter capacitor 2 , and the second circuit input end 15 in sequence. concatenate. The first circuit input end 14 and the second circuit input end 15 are respectively connected to the positive and negative poles of the DC power supply. Since the protection resistor 12 is connected in series in the connection loop, when the connection loop passes through the first circuit input end 14 and the second circuit input end When 15 is connected to direct current, the protection resistor 12 has a larger resistance value, which will reduce the current of the connection loop, thereby realizing the protection of the filter capacitor 2 .

3 is a schematic diagram of the connection circuit of the bleeder protection circuit 1 when the start-up protection switch 11 is in the second switch state and the voltage of the filter capacitor 2 is not greater than the first preset voltage threshold. As shown in FIG. 3 , when the start-up protection switch 11 is in the second state In the switching state and the voltage of the filter capacitor 2 is not greater than the first preset voltage threshold, the first end of the start-up protection switch 11 and the second end of the start-up protection switch 11 are turned on, and the bleeder switch 13 is turned off. At this time, the pressure is released. The connection loop of the protection circuit is that the first circuit input end 14 , the filter capacitor 2 , and the second circuit input end 15 are connected in series in sequence. The first circuit input end 14 and the second circuit input end 15 are respectively connected to the positive and negative electrodes of the DC power supply. At this time, the protection resistor 12 is equivalent to being short-circuited from the connection loop shown in FIG. 2 , and the filter capacitor 2 is directly connected to the first circuit input end 14 and the second circuit input end 15 .

Specifically, when the discharge protection circuit 1 is just connected to the DC power supply through the first circuit input terminal 14 and the second circuit input terminal 15, there is a problem of excessive current. In order to prevent the excessive current in the circuit from damaging the filter capacitor 2, The protection resistor 12 needs to be set to limit the loop current. Therefore, the initial state of the start-up protection switch 11 is the first switch state, that is, the first end and the third end of the start-up protection switch 11 are in a normally closed state, while the first and second ends of the start-up protection switch 11 are in a normally open state . As the filter capacitor is continuously charged in the connection loop, the voltage of the filter capacitor 2 gradually increases, and the equivalent resistance formed by the filter capacitor 2 gradually increases. When the filter capacitor 2 reaches the second preset voltage, the connection loop Therefore, the protection resistor 12 is short-circuited from the connection loop, so that the filter capacitor 2 is directly connected to the first circuit input end 14 and the second circuit input end 15 to complete the filter capacitor 2 boot protection process.

4 is a schematic diagram of the connection circuit of the bleeder protection circuit 1 when the start-up protection switch 11 is in the second switch state and the voltage of the filter capacitor 2 is greater than the first preset voltage threshold. As shown in FIG. 4 , when the start-up protection switch 11 is in the second switch state When the voltage of the filter capacitor 2 is greater than the first preset voltage threshold, the protection resistor 12 is connected in series with the bleeder switch 13 so that the circuit formed by the protection resistor 12 and the bleeder switch 13 is connected in parallel with the filter capacitor 2 . At this time, since the voltage of the filter capacitor 2 is greater than the first preset voltage threshold, the discharge switch 13 is turned on, and the voltage discharge protection circuit forms two parallel circuits. Specifically, the first parallel circuit is the first circuit input terminal 14 and the filter capacitor. 2. The second circuit input terminals 15 are connected in series in sequence, and the second parallel loop is the first circuit input terminal 14, the protection resistor 12, the bleeder switch 13, and the second circuit input terminal 15 are connected in series in sequence. Among them, since the protection resistor 12 is equivalent to being connected in parallel to both ends of the filter capacitor 2 , it functions as a discharge resistor, and can perform discharge protection on the filter capacitor 2 .

Optionally, the protection resistor 12 is a cement resistor or an aluminum shell resistor.

In this embodiment, by setting the protection resistor 12 , the bleeder switch 13 , the start-up protection switch 11 , the first circuit input end 14 and the second circuit input end 15 ; the first end of the protection resistor 12 is electrically connected to the first circuit input end 14 connected, the second end of the protection resistor 12 is electrically connected to one end of the bleeder switch 13, and the other end of the bleeder switch 13 is electrically connected to one end of the filter capacitor 2 and the second circuit input end 15 respectively; The terminal is electrically connected to the other terminal of the filter capacitor 2, the second terminal of the protection switch 11 is electrically connected to the first terminal of the protection resistor 12, the third terminal of the protection switch 11 is electrically connected to the second terminal of the protection resistor 12; A circuit input end 14 and a second circuit input end 15 are electrically connected to the two poles of the power supply; the protection switch 11 is activated to be set to the first switch state or the second switch state according to the voltage of the filter capacitor 2; In a switch state, the first end of the start-up protection switch 11 and the third end of the start-up protection switch 11 are conductive; in the second switch state, the first end of the start-up protection switch 11 and the second end of the start-up protection switch 11 are conductive The protection resistor 12 is used to connect in series with the filter capacitor 2 when the start-up protection switch 11 is in the first switch state, and when the start-up protection switch 11 is in the second switch state and the voltage of the filter capacitor 2 is greater than the first preset voltage threshold , connected in series with the bleeder switch 13, so that the circuit formed by the protection resistor 12 and the bleeder switch 13 is connected in parallel with the filter capacitor 2; When it is greater than the first preset voltage threshold, it is turned on, so that only one protection resistor 12 in the discharge protection circuit 1 can realize the start-up protection and discharge protection of the filter capacitor 2, which reduces the number of protection resistors 12 in the circuit. Therefore, This saves space inside the device and reduces production and manufacturing costs.

5 is a schematic structural diagram of a schematic structural diagram of a bleeder protection circuit 1 provided by another embodiment of the present invention. As shown in FIG. 5 , the bleeder protection circuit 1 provided in this embodiment is the same as the bleeder protection circuit 1 provided in the embodiment shown in FIG. 1 On the basis of the discharge protection circuit 1, and further refined and expanded, the discharge protection circuit 1 provided in this embodiment further includes:

The control device 16, one end of the control device 16 is electrically connected to the filter capacitor 2, and the other end is electrically connected to the start-up protection switch 11; the control device 16 is used to obtain the voltage of the filter capacitor 2, if the voltage of the filter capacitor 2 is greater than the second preset voltage threshold, then send a state switching control instruction to the activation protection switch 11, and the second preset voltage threshold is smaller than the first preset voltage threshold; activation of the protection switch 11 is specifically used to switch the first switch state to the first switch state according to the state switching control instruction. Two switch states.

The control device 16 is electrically connected to the filter capacitor 2, and can obtain the voltage of the filter capacitor 2. According to the voltage of the filter capacitor 2, it sends a state switching control command to the startup protection switch 11 to change the state of the startup protection switch 11.

Specifically, according to the specific parameters of the filter capacitor 2, when the filter capacitor 2 is charged, the voltage of the filter capacitor 2 gradually increases, and its equivalent resistance also increases gradually. After setting the value, it can be considered that it is safe to directly charge the filter capacitor 2 without causing damage to it, and the preset value is the second preset voltage threshold. Therefore, when the voltage of the capacitor obtained by the control device 16 is greater than the second preset voltage threshold, a state switching control instruction is sent to the start-up protection switch 11 to make it switch to the second switch state, that is, the protection resistor 12 is short-circuited to make the filter The capacitor 2 is directly electrically connected to the first circuit input terminal 14 and the second circuit input terminal 15 .

Wherein, the second preset voltage threshold is smaller than the first preset voltage threshold.

It can be understood that the first preset voltage threshold is a condition for triggering the discharge protection of the filter capacitor 2, that is, if the first preset voltage threshold is exceeded, the filter capacitor 2 may be damaged, such as breakdown, electric shock, etc., Therefore, the first preset voltage threshold is generally higher than the entire working voltage of the filter capacitor 2 . The second preset voltage threshold is the condition for triggering the short circuit of the protection resistor 12, which is used to solve the problem that when the filter capacitor 2 is just connected to the power supply, when the filter capacitor 2 is not charged, the resistance is very small and is easily damaged by a large current. However, as the filter capacitor 2 is charged, the voltage of the filter capacitor 2 will gradually increase to the working voltage. When the filter capacitor 2 reaches the second preset voltage threshold, the protection resistor 12 is short-circuited, which can improve the working efficiency of the circuit. , therefore, it can be determined that the second preset voltage threshold is smaller than the working voltage of the filter capacitor 2 . The first preset voltage threshold and the second preset voltage threshold are threshold parameters set for different purposes, and the second preset voltage threshold is smaller than the first preset voltage threshold.

The specific values of the first preset voltage threshold and the second preset voltage threshold can be designed and selected according to specific requirements, and are not limited here.

Optionally, the start-up protection switch 11 includes: a relay, and the state of the relay includes a normally open state and a normally closed state.

The relay is specifically used when the start-up protection switch 11 is in the first switch state, the relay is in a normally open state; when the start-up protection switch 11 is in the second switch state, the relay is in a normally closed state.

Specifically, the relay has a first connection end, a second connection end and a third connection end, wherein the first connection end is electrically connected to the first end of the pneumatic protection switch, and the second connection end is electrically connected to the second end of the pneumatic protection switch connection, and the third connection end is electrically connected with the third end of the pneumatic protection switch. Since there is a one-to-one correspondence between the three connection terminals of the relay and the three terminals of the start-up protection switch 11, when the pneumatic protection switch is in the first switch state, the relay is in the first connection state, that is, the first connection of the relay When the pneumatic protection switch of the relay is in the second switch state, the relay is in the second connection state, that is, the first connection end and the second connection end of the relay are connected.

The normally open and normally closed states of the relay are relative to the first connection state and the second connection state of the relay, that is, if the relay is in the first connection state when it is not powered on, that is, the first connection of the relay. The first connection state of the relay is in the normally closed state, and the second connection state is in the normally open state; if the relay is in the second connection state when it is not powered on, that is, the relay When the first connection end and the second connection end are conductive, the second connection state of the relay is in a normally closed state, and the first connection state is in a normally open state. The normally closed or normally open states of the first connection state and the second connection state are opposite, and the first connection state and the second connection state cannot be in the normally open state or the normally closed state at the same time.

Optionally, the relay includes normally open control contacts and normally closed control contacts. When the normally open control contact is turned on, the relay is in a normally open state; correspondingly, when the normally closed control contact is turned on, the relay is in a normally closed state. Specifically, when the relay switches the connection state, it is triggered by the pull-in of electric power. For example, the first connection end and the second connection end of the relay are pulled in, so that the relay is in the second connection state. However, after the relay is switched to the second connection state, in order to maintain the stable connection of the relay, the second connection state needs to be set to the normally closed state. Here, by turning on the normally closed contact of the second connection state, the second connection state is The state is set to normally closed.

In a specific embodiment, the relay includes a normally closed contact in a first connection state and a normally closed contact in a second connection state. When the normally closed contact in the first connection state is turned on, the relay sets the first connection state to Normally closed state, the second connection state is set to the normally open state; when the normally closed contact of the second connection state is turned on, the relay sets the second connection state to the normally closed state, and the first connection state is set to the normally open state; When the normally closed contacts in the first connection state and the normally closed contacts in the second connection state are both non-conductive, the normally open state or normally closed state of the previous relay connection state is maintained.

Of course, it can be understood that, in the above-mentioned specific embodiment, the setting of the first connection state or the second connection state can also be realized by disconnecting the normally closed contact in the first connection state or the normally closed contact in the second connection state. In the normally closed state, the implementation process is similar to the implementation process in the above-mentioned embodiment, and details are not repeated here.

In this embodiment, by setting the normally open state and the normally closed state for the first connection state or the second connection state of the relay, the relay is in different connection states, thereby realizing the multiplexing of the protection resistors 12 and making the discharge protection circuit The start-up protection and the discharge protection in 1 can share a protection resistor 12, which reduces the cost and saves the internal space of the device.

Optionally, the other end of the control device 16 is also electrically connected to the bleeder switch 13 .

The control device 16 is further configured to send a closing control instruction to the bleeder switch 13 if the voltage of the filter capacitor 2 is greater than the first preset voltage threshold.

The bleeder switch 13 is specifically used to turn on according to the closing control command.

Specifically, when the voltage of the filter capacitor 2 is greater than the first preset voltage threshold, it means that the voltage of the filter capacitor 2 is too high and exceeds the normal working voltage, which may cause damage to the filter capacitor 2 . At this time, the control device 16 sends a closing control command to the bleeder switch 13 to turn on the bleeder switch 13. After the conduction, the bleeder switch 13 and the protection resistor 12 form a bleeder protection circuit in parallel with the filter capacitor 2, so as to realize the Bleed protection of filter capacitor 2. The specific connection method is similar to the schematic diagram of the connection circuit of the discharge protection circuit 1 shown in FIG. 4 , and will not be repeated here.

Optionally, the bleeder switch 13 includes: a MOS tube, when the MOS tube is turned on, the bleeder switch 13 is turned on, thereby realizing a bleeder protection circuit, and the conduction mode of the MOS tube may be greater than the first preset voltage threshold. , the MOS tube is always in the conduction state, or the MOS tube can be turned on by means of a certain frequency chopping.

FIG. 6 is a schematic structural diagram of a filter circuit provided by an embodiment of the present invention. As shown in FIG. 6 , the filter circuit provided by this embodiment includes: The bleeder protection circuit 1 provided by any of the embodiments.

The discharge protection circuit 1 is electrically connected to the filter capacitor 2, wherein the specific connection method of the discharge protection circuit 1 and the filter capacitor 2 is the same as the connection between the discharge protection circuit 1 and the filter capacitor 2 in the embodiment corresponding to FIG. 1 to FIG. 5 . The connection method is the same and will not be repeated here.

FIG. 7 is a schematic structural diagram of a rectifier device provided by an embodiment of the present invention. As shown in FIG. 7 , the rectifier device provided by this embodiment includes: a rectifier circuit and a filter circuit provided by the embodiment shown in FIG. 6 .

The input end of the rectifier circuit is connected to the AC power supply, and the output end of the rectifier circuit is electrically connected to the first circuit input end 14 and the second circuit input end 15 of the filter circuit, respectively.

The rectifier circuit is used to rectify the input AC power and output the DC power.

FIG. 8 is a schematic structural diagram of a control system provided by an embodiment of the present invention. As shown in FIG. 8 , the control system provided by this embodiment includes: an AC power supply, a load device, and the rectifier device provided by the embodiment shown in FIG. 7 .

The AC power source, the rectifier device, and the load device are electrically connected in sequence.

The AC power supply is used to supply power to the load equipment through the rectifier.

An embodiment of the present invention provides a bar tacking machine, including the control system provided by the embodiment shown in FIG. 8 .

In the several embodiments provided by the present invention, it should be understood that the disclosed apparatus and system may be implemented in other manners. For example, the device embodiments described above are only illustrative. For example, the division of modules is only a logical function division. In actual implementation, there may be other division methods, for example, multiple modules or components may be combined or integrated. to another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or modules, and may be in electrical, mechanical or other forms.

Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention which follow the general principles of the present invention and include common knowledge or conventional techniques in the technical field not disclosed by the present invention . The specification and examples are to be regarded as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

It should be understood that the present invention is not limited to the precise structures described above and illustrated in the accompanying drawings, and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims (10)

1. A bleeder protection circuit, comprising: a protection resistor, a bleeder switch, a start-up protection switch, a first circuit input end and a second circuit input end; The first end of the protection resistor is electrically connected to the input end of the first circuit, the second end of the protection resistor is electrically connected to one end of the bleeder switch, and the other end of the bleeder switch is respectively connected to one end of the filter capacitor and the first end of the bleeder switch. The two circuit input ends are electrically connected; the first end of the startup protection switch is electrically connected to the other end of the filter capacitor, the second end of the startup protection switch is electrically connected to the first end of the protection resistor, and the The third end of the activation protection switch is electrically connected with the second end of the protection resistor; the first circuit input end and the second circuit input end are electrically connected to the two poles of the power supply; The start-up protection switch is used to be set to the first switch state or the second switch state according to the voltage of the filter capacitor; when in the first switch state, the first end of the start-up protection switch and the connection of the start-up protection switch The third end is turned on; when in the second switch state, the first end of the start-up protection switch and the second end of the start-up protection switch are turned on; The protection resistor is used to connect in series with the filter capacitor when the start-up protection switch is in the first switch state, and when the start-up protection switch is in the second switch state and the voltage of the filter capacitor is greater than the first preset voltage threshold, be connected in series with the bleeder switch, so that the circuit formed by the protection resistor and the bleeder switch is connected in parallel with the filter capacitor; The bleeder switch is configured to be turned on when the start-up protection switch is in the second switch state and the voltage of the filter capacitor is greater than the first preset voltage threshold. 2. The circuit of claim 1, further comprising: a control device, one end of the control device is electrically connected to the filter capacitor, and the other end of the control device is electrically connected to the start-up protection switch; The control device is configured to obtain the voltage of the filter capacitor, and if the voltage of the filter capacitor is greater than a second preset voltage threshold, send a state switching control instruction to the startup protection switch, and the second preset voltage The threshold is less than the first preset voltage threshold; The activation protection switch is specifically configured to switch the first switch state to the second switch state according to the state switching control instruction. 3 . The circuit according to claim 2 , wherein the start-up protection switch comprises: a relay, and the states of the relay include a normally open state and a normally closed state; 3 . When the startup protection switch is in the first switch state, the relay is in a normally open state; when the startup protection switch is in the second switch state, the relay is in a normally closed state. 4. The circuit of claim 2, wherein The other end of the control device is also electrically connected to the discharge switch; The control device is further configured to send a closing control instruction to the bleeder switch if the voltage of the filter capacitor is greater than a first preset voltage threshold; The discharge switch is used for conducting according to the closing control command. 5 . The circuit according to claim 1 , wherein the bleeder switch comprises: a MOS transistor. 6 . 6 . The circuit according to claim 1 , wherein the protection resistor is a cement resistor or an aluminum shell resistor. 7 . 7. A filter circuit, characterized in that, comprising: a filter capacitor and the discharge protection circuit according to any one of claims 1-6; The leakage protection circuit is electrically connected to the filter capacitor. 8. A rectifier device, characterized in that, comprising: a rectifier circuit and a filter circuit as claimed in claim 7; The input end of the rectifier circuit is connected to the AC power supply, and the output end of the rectifier circuit is electrically connected to the first circuit input end and the second circuit input end of the filter circuit respectively; The rectifier circuit is used for rectifying the input AC power and outputting the DC power. 9. A control system, characterized in that it comprises: an AC power supply, a load device and the rectifying device according to claim 8; The AC power source, the rectifier device, and the load device are electrically connected in sequence; The AC power supply is used for supplying power to the load device through the rectifying device. 10. A bar tacking machine, characterized by comprising the control system of claim 9.

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