Quick power-off restart circuit and servo drive

Abstract

The present invention provides a fast power-off restart circuit and a servo driver, which include a rectifier filter module and a discharge module; the input end of the rectifier filter module is connected to the power supply, the output end thereof is connected to the power conversion module, and the rectifier filter module includes a first rectifier bridge and a start-up circuit, the start-up circuit includes an electrolytic capacitor, and the electrolytic capacitor is respectively connected to the first rectifier bridge and the power conversion module; one end of the discharge module is connected to the power supply, the other end thereof is connected to the power conversion module, and the discharge module is also connected to the electrolytic capacitor; wherein, when the servo driver is started, the power supply charges the electrolytic capacitor through the first rectifier circuit, and when the power supply is powered off, the discharge module discharges the energy stored in the electrolytic capacitor. The present invention can not only shorten the charging time, but also shorten the discharge time, thereby shortening the power-off restart time of the servo driver.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply control circuits, and in particular to a fast power-off restart circuit and a servo driver. Background Art

[0002] The internal power supply of the servo drive in the servo system usually includes two power supplies: output power supply and auxiliary power supply. The output power supply is used to power the motor, and the auxiliary power supply is the internal control power supply of the servo drive. Both the output power supply and the auxiliary power supply require capacitors for voltage stabilization and filtering. At present, the capacitors in the output power supply need to bear a large current, so large-capacity capacitors are usually used. Large-capacity capacitors will not only cause the servo drive to lose power for a long time during the power-off and restart process, but also increase the charging time, which will lead to a longer power-off and restart time for the servo drive. Summary of the invention

[0003] The present invention provides a fast power-off restart circuit and a servo driver, aiming to solve the problem that the current servo driver needs a long time to restart after power-off.

[0004] In a first aspect, the present invention provides a fast power-off restart circuit, which includes a rectifier and filter module and a discharge module; the input end of the rectifier and filter module is connected to a power supply, and the output end is connected to a power conversion module, and the rectifier and filter module includes a first rectifier bridge and a start-up circuit, and the start-up circuit includes an electrolytic capacitor, and the electrolytic capacitor is respectively connected to the first rectifier bridge and the power conversion module; one end of the discharge module is connected to the power supply, and the other end is connected to the power conversion module, and the discharge module is also connected to the electrolytic capacitor; wherein, when the servo drive is started, the power supply charges the electrolytic capacitor through the first rectifier circuit, and when the power supply is powered off, the discharge module discharges the energy stored in the electrolytic capacitor.

[0005] Furthermore, the startup circuit also includes a current limiting circuit; one end of the current limiting circuit is connected to the electrolytic capacitor, and the other end of the current limiting circuit is connected to the power conversion module.

[0006] Furthermore, the current limiting circuit includes a current limiting resistor and a first relay; one end of the current limiting resistor and the normally open end of the first relay are both connected to the electrolytic capacitor, the other end of the current limiting resistor is grounded, and one end of the coil of the first relay is connected to the first output end of the power conversion module, and the other end of the coil of the first relay is grounded.

[0007] Furthermore, the discharge module includes a light-load rectifier circuit, a DC output circuit, a power-off detection circuit and a switching circuit; the input end of the light-load rectifier circuit is connected to the power supply, the output end of the light-load rectifier circuit is connected to the input end of the DC output circuit, the output end of the DC output circuit is connected to the power-off detection circuit, the power-off detection circuit is respectively connected to the power conversion module and the switching circuit, and the switching circuit is also connected to the electrolytic capacitor.

[0008] Furthermore, the DC output circuit includes a first capacitor, a first resistor, a second resistor and a third resistor; one end of the first capacitor, one end of the first resistor and one end of the second resistor are all connected to the output end of the light-load rectifier circuit, the other end of the second resistor is respectively connected to one end of the third resistor and the power-off detection circuit, and the other end of the first capacitor, the other end of the first resistor and the other end of the third resistor are all grounded.

[0009] Furthermore, the power-off detection circuit comprises a photocoupler, the optical input end of the photocoupler is connected to the output end of the DC output circuit, and the optical output end of the photocoupler is respectively connected to the power conversion module and the switch circuit.

[0010] Furthermore, the switching circuit includes a first switching tube, a second switching tube and a second relay; the first pole of the first switching tube is used to connect to the first output end of the power conversion module, the second pole of the first switching tube is connected to one end of the coil of the second relay, and the controlled pole of the first switching tube is connected to the first pole of the second switching tube; the first pole of the second switching tube is also connected to the second output end of the power conversion module, the second pole of the second switching tube is grounded, and the controlled pole of the second switching tube is connected to the optical output end connected to the photocoupler; the other end of the coil of the second relay is grounded, and the normally open end of the second relay is connected to the starting circuit.

[0011] Furthermore, the switching circuit also includes a first diode and a fifth resistor; the cathode of the first diode is connected to the controlled electrode of the first switching tube, and the anode of the first diode is connected to the first electrode of the second switching tube; one end of the fifth resistor is connected to the optical output end of the photocoupler, and the other end of the fifth resistor is grounded.

[0012] Furthermore, the light load rectifier circuit includes a phase load and a second rectifier bridge; the input end of the phase load is used to connect to the power supply, the output end of the phase load is connected to the input end of the second rectifier bridge, and the output end of the second rectifier bridge is connected to the DC output circuit.

[0013] In a second aspect, the present invention further provides a servo drive, comprising the fast power-off and restart circuit as described in any one of the above items.

[0014] The present invention discloses a fast power-off and restart circuit and a servo driver. The fast power-off and restart circuit includes a rectifier filter module and a discharge module. The rectifier filter module includes a first rectifier bridge and a start-up circuit. The start-up circuit includes an electrolytic capacitor. The electrolytic capacitor is respectively connected to the first rectifier bridge and the power conversion module. The discharge module is respectively connected to the power supply, the power conversion module and the electrolytic capacitor. When power is turned on, the power supply can quickly charge the electrolytic capacitor through the first rectifier bridge, thereby improving the power-on speed. At the same time, the discharge module is connected to the electrolytic capacitor. When the power supply is cut off, the energy of the electrolytic capacitor is quickly discharged through the discharge module, which not only shortens the charging time, but also shortens the discharge time, thereby shortening the entire power-off and restart time of the servo driver. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0016] Figure 1 is a block diagram of a fast power-off and restart circuit provided by a first embodiment of the present invention;

[0017] Figure 2 is a block diagram of a fast power-off and restart circuit provided by a second embodiment of the present invention;

[0018] Figure 3 is a block diagram of a fast power-off and restart circuit provided by a third embodiment of the present invention;

[0019] Figure 4 4 is a circuit diagram of a fast power-off and restart circuit provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, operations, elements, components and / or groups thereof.

[0022] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, the singular forms of "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0023] In addition, the directional terms mentioned in the present invention, such as "upper", "lower", "front", "back", "left", "right", "inner", "outer", "side", etc., are only for reference to the directions of the attached drawings and the use status of the product. Therefore, the directional terms used are used to illustrate and understand the present invention, but not to limit the present invention. In addition, in the drawings, structures with similar or identical structures are represented by the same reference numerals.

[0024] See also Figures 1 to 4 , Figure 1 is a block diagram of a fast power-off and restart circuit 100 provided in a first embodiment of the present invention; Figure 2 is a block diagram of a fast power-off and restart circuit 100 provided in a second embodiment of the present invention; Figure 3 is a block diagram of a fast power-off and restart circuit 100 provided in a third embodiment of the present invention;

[0025] Figure 4 FIG. 1 is a circuit diagram of a fast power-off restart circuit 100 provided in one embodiment of the present invention. Figure 1 As shown, the fast power-off restart circuit 100 includes a rectifier filter module 10 and a discharge module 20; the input end of the rectifier filter module 10 is connected to the power supply 200, and the output end thereof is connected to the power conversion module 300, and the rectifier filter module 10 includes a first rectifier bridge 11 and a start-up circuit 12, and the start-up circuit 12 includes an electrolytic capacitor 121, and the electrolytic capacitor 121 is respectively connected to the first rectifier bridge 11 and the power conversion module 300; one end of the discharge module 20 is connected to the power supply 200, and the other end thereof is connected to the power conversion module 300, and the discharge module 20 is also connected to the electrolytic capacitor 121; wherein, when the power supply 200 is powered off, the discharge module 20 discharges the energy stored in the electrolytic capacitor 121.

[0026] Specifically, the fast power-off restart circuit 100 may include a rectifier and filter module 10 and a discharge module 20. The input end of the rectifier and filter module 10 is connected to a power supply 200, which is used to provide alternating current. The rectifier and filter module 10 is used to rectify the alternating current output by the power supply 200 to obtain direct current. At the same time, the output end of the rectifier and filter module 10 is also connected to a power conversion module 300, so as to output direct current to the power conversion module 300.

[0027] The rectifier and filter module 10 may include a first rectifier bridge 11 and a start-up circuit 12. The input end of the first rectifier bridge 11 is connected to the power supply 200, and the output end of the first rectifier bridge 11 is connected to the electrolytic capacitor 121, which is used to rectify the AC current output by the power supply 200 into a DC current and output it to the electrolytic capacitor 121. That is, when powered on, the power supply 200 charges the electrolytic capacitor 121 through the first rectifier bridge 11. When the electrolytic capacitor 121 is fully charged, the electrolytic capacitor 121 discharges and supplies power to the power conversion module 300. The start-up circuit 12 includes the electrolytic capacitor 121. When charging, the electrolytic capacitor 121 is connected to the first rectifier bridge 11. The power supply 200 charges the electrolytic capacitor 121 through the first rectifier bridge 11. When discharging, the electrolytic capacitor 121 is connected to the power conversion module 300, and the electrolytic capacitor 121 supplies power to the power conversion module 300. At the same time, the electrolytic capacitor 121 is also connected to the discharge module 20. When the power supply 200 is supplying power normally, the electrolytic capacitor 121 is not connected to the discharge module 20. When the power supply 200 is powered off, the discharge module 20 is turned on, and the electrolytic capacitor 121 is connected to the discharge module 20, and the energy in the electrolytic capacitor 121 is quickly discharged through the discharge module 20.

[0028] like Figure 4 As shown, Figure 4 Where C is the electrolytic capacitor 121, M1 is the first rectifier bridge 11, U1 is the controller U1 in the power conversion module 300, and the controller U1 includes a power input terminal VCC, a first output terminal VREF, and a second output terminal COMP. Figure 4 It can be seen that the electrolytic capacitor 121 is connected to the output end of the first rectifier bridge 11 and the power input end of the controller U1 respectively, and at the same time, the electrolytic capacitor 121 is also connected in parallel with the discharge module 20. When the power supply 200 is powered off, the electrolytic capacitor 121 is connected to the discharge module 20, and the energy of the electrolytic capacitor 121 is quickly discharged through the discharge module 20.

[0029] One end of the discharge module 20 is connected to the power supply 200 and is powered by the power supply 200. The other end of the discharge module 20 is connected to the power conversion module 300 to detect whether the power supply 200 is powered off. At the same time, the discharge module 20 is also connected to the electrolytic capacitor 121 to discharge the energy of the electrolytic capacitor 121.

[0030] When the power supply 200 is working normally, the discharge module 20 is not working, and the power supply 200 charges the electrolytic capacitor 121 through the first rectifier bridge 11. After being fully charged, the electrolytic capacitor 121 normally supplies power to the power conversion module 300. When the power supply 200 is powered off, the discharge module 20 can detect that the power supply 200 has been powered off, and the discharge module 20 starts to work normally and connects with the electrolytic capacitor 121. After the discharge module 20 is connected with the electrolytic capacitor 121, the energy of the electrolytic capacitor 121 can be quickly discharged through the discharge module 20 to shorten the discharge time, thereby shortening the restart time of the servo drive.

[0031] See also Figure 2 As one embodiment, the starting circuit 12 further includes a current limiting circuit 121; one end of the current limiting circuit 121 is connected to the electrolytic capacitor 121, and the other end of the current limiting circuit 121 is connected to the power conversion module 300.

[0032] Among them, the starting circuit 12 may include an electrolytic capacitor 121 and a current limiting resistor RS, one end of the electrolytic capacitor 121 is respectively connected to the first rectifier bridge 11 and the power conversion module 300, the other end of the electrolytic capacitor 121 is connected to the current limiting circuit 121, and the current limiting circuit 121 is also connected to the power conversion module 300. When power is turned on, the current limiting circuit 121 is used to suppress the charging current of the electrolytic capacitor 121. When the power conversion module 300 works normally, the current limiting circuit 121 is used to reduce the impedance of the electrolytic capacitor 121 and increase the charging current, so that the charging time of the electrolytic capacitor 121 can be reduced, and then the power-on speed of the servo driver can be improved.

[0033] See also Figure 4 As one embodiment, the current limiting circuit 121 includes a current limiting resistor RS and a first relay K1; one end of the current limiting resistor RS and a normally open end of the first relay K1 are both connected to the electrolytic capacitor 121, the other end of the current limiting resistor RS is grounded, and one end of the coil of the first relay K1 is connected to the first output end of the power conversion module 300, and the other end of the coil of the first relay K1 is grounded.

[0034] Among them, the current limiting circuit 121 may include a current limiting resistor RS and a first relay K1, the current limiting resistor RS is connected in parallel with the first relay K1, and one end of the current limiting resistor RS and the normally open end of the first relay K1 are both connected to the electrolytic capacitor 121, and the other end of the current limiting resistor RS is grounded. When powered on, the normally open end of the first relay K1 is in an open state, and the current limiting resistor RS is used to suppress the charging current of the electrolytic capacitor 121 until the power conversion module 300 works normally. After the power conversion module 300 works normally, the normally open end of the first relay K1 is closed, and the current limiting resistor RS is short-circuited, thereby reducing the impedance of the branch of the electrolytic capacitor 121, and the charging current of the electrolytic capacitor 121 increases, thereby reducing the charging time of the electrolytic capacitor 121.

[0035] like Figure 4 As shown, the coil of the first relay K1 is connected to the first output terminal VREF of the controller U1 of the power conversion module 300, the normally open end of the first relay K1 is connected in parallel with the current limiting resistor RS, and the normally open end of the first relay K1 and the current limiting resistor RS are both connected to the capacitor C. When powered on, the controller U1 outputs a low level, the normally open end of the first relay K1 is in a disconnected state, and the current limiting resistor RS suppresses the charging capacitance of the capacitor C. When the controller U1 works normally, the controller U1 outputs a high level, the normally open end of the first relay K1 is closed, the current limiting resistor RS is short-circuited, and the charging current of the electrolytic capacitor 121 increases.

[0036] As one of the embodiments, the discharge module 20 includes a light-load rectifier circuit 21, a DC output circuit 22, a power-off detection circuit 23 and a switch circuit 24; the input end of the light-load rectifier circuit 21 is connected to the power supply 200, the output end of the light-load rectifier circuit 21 is connected to the input end of the DC output circuit 22, the output end of the DC output circuit 22 is connected to the power-off detection circuit 23, the power-off detection circuit 23 is respectively connected to the power conversion module 300 and the switch circuit 24, and the switch circuit 24 is also connected to the electrolytic capacitor 121.

[0037] Among them, the discharge module 20 may include a light-load rectifier circuit 21, a DC output circuit 22, a power-off detection circuit 23 and a switching circuit 24. The input end of the light-load rectifier circuit 21 is connected to the power supply 200, and is used to rectify the AC current output by the power supply 200 to obtain a DC current. At the same time, it is also used to reduce the current output by the power supply 200 so as to provide a smaller DC current for the DC output circuit 22.

[0038] The DC output circuit 22 is connected to the output end of the light load rectifier circuit 21, and is used to provide a stable DC output for the power failure detection circuit 23. The power failure detection circuit 23 is connected to the power conversion module 300 and the switch circuit 24. The switch circuit 24 is respectively connected to the power conversion module 300 and the electrolytic capacitor 121. The power failure detection circuit 23 is used to detect whether the power supply 200 is powered off through the power conversion module 300. When the power supply 200 is powered off, the switch circuit 24 is turned on and provides a discharge path for the electrolytic capacitor 121. It can be understood that the power-off detection circuit 23 is connected to the power conversion module 300, and is used to detect whether the power supply 200 is powered off through the power conversion module 300. It can be configured that when the power supply 200 is working normally, the power-off detection circuit 23 is turned on, and the switch circuit 24 is not turned on; when the power supply 200 is powered off, the power-off detection circuit 23 is not turned on, and the switch circuit 24 is turned on. It can also be configured that when the power supply 200 is working normally, the power-off detection circuit 23 is not turned on, and the switch circuit 24 is not turned on; when the power supply 200 is powered off, the power-off detection circuit 23 is turned on, and the switch circuit 24 is turned on.

[0039] In actual use, when powered on, the power supply 200 provides AC current to the first rectifier bridge 11 and the light-load rectifier circuit 21 respectively. The first rectifier bridge 11 rectifies the AC current to charge the electrolytic capacitor 121. The light-load rectifier circuit 21 rectifies the AC current and reduces the current output by the power supply 200 to provide a smaller DC current for the DC output circuit 22. If the power supply 200 works normally, the circuit breaker detection circuit does not detect that the power supply 200 is powered off, and the switch circuit 24 is not turned on. When the power supply 200 is powered off, the circuit breaker detection circuit detects that the power supply 200 is powered off, then the switch circuit 24 is turned on, and the electrolytic capacitor 121 is discharged through the switch circuit 24.

[0040] See also Figure 4 As one embodiment, the DC output circuit 22 includes a first capacitor C1, a first resistor R1, a second resistor R2 and a third resistor R3; one end of the first capacitor C1, one end of the first resistor R1 and one end of the second resistor R2 are all connected to the output end of the light-load rectifier circuit 21, the other end of the second resistor R2 is respectively connected to one end of the third resistor R3 and the power-off detection circuit 23, and the other end of the first capacitor C1, the other end of the first resistor R1 and the other end of the third resistor R3 are all grounded.

[0041] The DC output circuit 22 includes a first capacitor C1, a first resistor R1, a second resistor R2, and a third resistor R3. The first capacitor C1 is connected to the output end of the light-load rectifier circuit 21 to provide a stable DC voltage to prevent false power-off detection due to voltage instability. One end of the first resistor R1 and one end of the second resistor R2 are both connected to the first capacitor C1, and the other end of the second resistor R2 is respectively connected to the third resistor R3 and the power-off detection circuit 23 to provide a suitable conduction current for the power-off detection circuit 23. The resistance values ​​of the first resistor R1, the second resistor R2, and the third resistor R3 can be adjusted to adapt to different types of power-off detection circuits 23.

[0042] As one embodiment, the power-off detection circuit 23 includes a photocoupler OP1, the optical input end of the photocoupler OP1 is connected to the output end of the DC output circuit 22, and the optical output end of the photocoupler OP1 is respectively connected to the power conversion module 300 and the switch circuit 24.

[0043] Among them, Figure 4 As shown, the power-off detection circuit 23 may include a photocoupler OP1, the optical input end of the photocoupler OP1 is connected to the output end of the DC output circuit 22, and is powered by the DC output circuit 22, and the optical output end of the photocoupler OP1 is respectively connected to the power conversion module 300 and the switch circuit 24. Specifically, one pin of the optical output end of the photocoupler OP1 is connected to the first output end VREF of the controller U1 of the power conversion module 300, and the other pin thereof is connected to the switch circuit 24.

[0044] During use, if the power supply 200 is not powered off, the photocoupler OP1 is normally turned on, and the VREF power supply voltage at the first output terminal of the controller U1 controls the switch circuit 24 to be non-conductive through the photocoupler OP1. If the power supply 200 is powered off, the photocoupler OP1 is normally non-conductive, the switch circuit 24 is turned on, and the energy of the electrolytic capacitor 121 can be discharged through the switch circuit 24.

[0045] See also Figure 4As one embodiment, the switch circuit 24 includes a first switch tube Q1, a second switch tube Q2, a second relay, a first diode D1 and a fourth resistor R4; the first electrode of the first switch tube Q1 is used to connect to the first output end of the power conversion module 300, the second electrode of the first switch tube Q1 is connected to one end of the coil of the second relay, the controlled electrode of the first switch tube Q1 is connected to the negative electrode of the first diode D1, the positive electrode of the first diode D1 is connected to the first electrode of the second switch tube Q2, the first electrode of the second switch tube Q2 is also connected to the second output end of the power conversion module 300, the second electrode of the second switch tube Q2 is grounded, and the controlled electrode of the second switch tube Q2 is connected to the optical output end of the photoelectric coupler OP1; the other end of the coil of the second relay is grounded, and the normally open end of the second relay is connected to the electrolytic capacitor 121; one end of the fourth resistor R4 is connected to the optical output end of the photoelectric coupler OP1, and the other end of the fourth resistor R4 is grounded.

[0046] The switch circuit 24 may include a first switch tube Q1, a second switch tube Q2, a second relay, a first diode D1, and a fourth resistor R4, wherein the controlled electrode of the second switch tube Q2 and one end of the fourth resistor R4 are both connected to the photoelectric coupler OP1. At the same time, the first electrode of the first switch tube Q1 is connected to the first output terminal VREF of the controller U1 of the power conversion module 300, the controlled electrode of the first switch tube Q1 is connected to the negative electrode of the first diode D1, the positive electrode of the first diode D1 is connected to the second output terminal COMP of the controller U1 of the power conversion module 300, the second electrode of the first switch tube Q1 is connected to the coil of the second relay, and the normally open end of the second relay is connected in parallel with the electrolytic capacitor 121. Preferably, the first switch tube Q1 and the second switch tube Q2 can both be triodes, and the first diode D1 can be a Zener diode, then the base of the first switch tube Q1 is connected to the power conversion module 300, the emitter of the first switch tube Q1 is connected to the first output terminal VREF of the controller U1 of the power conversion module 300, the collector of the first switch tube Q1 is connected to the first relay K1, the base of the second switch tube Q2 is connected to the photocoupler OP1, the emitter of the second switch tube Q2 is connected to the second output terminal COMP of the controller U1 of the power conversion module 300, and the collector of the second switch tube Q2 is grounded.

[0047] When the power supply 200 is normal, the photocoupler OP1 is turned on. At this time, the VREF power supply voltage at the first output terminal of the controller U1 passes through the photocoupler OP1 and generates a DC voltage higher than the COMP pin on the fourth resistor R4. The second switch tube Q2 is not turned on, and the voltage at the second output terminal COMP of the controller U1 remains normal, and the controller U1 works normally. When the power supply 200 is powered off, the photocoupler OP1 is disconnected, the second switch tube Q2 is turned on, the second output terminal COMP of the controller U1 is pulled down to ground, and the controller U1 cannot output the system power supply voltage. At the same time, the VREF power supply voltage at the first output terminal of the controller U1 passes through the first switch tube Q1, the first diode D1 and the second switch tube Q2, the second relay is triggered, and the electrolytic capacitor 121 is short-circuited, so that the electrolytic capacitor 121 can be quickly discharged.

[0048] See also Figure 4 As one embodiment, the light load rectifier circuit 21 includes a phase load M2 and a second rectifier bridge M3; the input end of the phase load M2 is used to connect to the power supply 200, the output end of the phase load M2 is connected to the input end of the second rectifier bridge M3, and the output end of the second rectifier bridge M3 is connected to the DC output circuit 22.

[0049] The light load rectifier circuit 21 may include a phase load M2 and a second rectifier bridge M3, wherein the input end of the phase load M2 is connected to the power supply 200, the output end of the phase load M2 is connected to the second rectifier bridge M3, and the second rectifier bridge M3 is connected to the DC output circuit 22. The phase load M2 is connected to the power supply 200 to reduce the current output by the power supply 200, and the second rectifier bridge M3 is connected to the phase load M2 to rectify the AC current output by the phase load M2 to provide a DC current for the DC output circuit 22.

[0050] The present invention further provides a servo driver, which includes the fast power-off and restart circuit 100 described in any one of the above embodiments.

[0051] The fast power-off and restart circuit and servo driver disclosed in the present invention can, when powered on, quickly charge the electrolytic capacitor through the first rectifier bridge, thereby improving the power-on speed. At the same time, the discharge module is connected to the electrolytic capacitor. When the power supply is cut off, the energy of the electrolytic capacitor is quickly discharged through the discharge module, which not only shortens the charging time, but also shortens the discharge time, thereby shortening the entire power-off and restart time of the servo driver.

[0052] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A fast power-off restart circuit, characterized in that: The fast power-off restart circuit comprises: A rectifier and filter module, wherein the input end of the rectifier and filter module is connected to the power supply, and the output end of the rectifier and filter module is connected to the power conversion module, and the rectifier and filter module comprises a first rectifier bridge and a start-up circuit, and the start-up circuit comprises an electrolytic capacitor, and the electrolytic capacitor is respectively connected to the first rectifier bridge and the power conversion module; A discharge module, one end of which is connected to the power supply, the other end of which is connected to the power conversion module, and the discharge module is also connected to the electrolytic capacitor; When the servo driver is started, the power supply charges the electrolytic capacitor through the first rectifier circuit, and when the power supply is powered off, the discharge module discharges the energy stored in the electrolytic capacitor.

2. The fast power-off restart circuit according to claim 1, characterized in that: The startup circuit also includes a current limiting circuit; One end of the current limiting circuit is connected to the electrolytic capacitor, and the other end of the current limiting circuit is connected to the power conversion module.

3. The fast power-off restart circuit according to claim 2, characterized in that: The current limiting circuit includes a current limiting resistor and a first relay; One end of the current limiting resistor and the normally open end of the first relay are both connected to the electrolytic capacitor, the other end of the current limiting resistor is grounded, and one end of the coil of the first relay is connected to the first output end of the power conversion module, and the other end of the coil of the first relay is grounded.

4. The fast power-off restart circuit according to claim 1, characterized in that: The discharge module includes a light load rectification circuit, a DC output circuit, a power failure detection circuit and a switch circuit; The input end of the light-load rectifier circuit is connected to the power supply, the output end of the light-load rectifier circuit is connected to the input end of the DC output circuit, the output end of the DC output circuit is connected to the power-off detection circuit, the power-off detection circuit is respectively connected to the power conversion module and the switching circuit, and the switching circuit is also connected to the electrolytic capacitor.

5. The fast power-off restart circuit according to claim 4, characterized in that: The DC output circuit includes a first capacitor, a first resistor, a second resistor and a third resistor; One end of the first capacitor, one end of the first resistor and one end of the second resistor are all connected to the output end of the light-load rectifier circuit, the other end of the second resistor is respectively connected to one end of the third resistor and the power-off detection circuit, and the other end of the first capacitor, the other end of the first resistor and the other end of the third resistor are all grounded.

6. The fast power-off restart circuit according to claim 4, characterized in that: The power-off detection circuit comprises a photoelectric coupler, the optical input end of the photoelectric coupler is connected to the output end of the DC output circuit, and the optical output end of the photoelectric coupler is respectively connected to the power conversion module and the switch circuit.

7. The fast power-off restart circuit according to claim 6, characterized in that: The switch circuit includes a first switch tube, a second switch tube and a second relay; The first electrode of the first switch tube is used to be connected to the first output end of the power conversion module, the second electrode of the first switch tube is connected to one end of the coil of the second relay, and the controlled electrode of the first switch tube is connected to the first electrode of the second switch tube; The first electrode of the second switch tube is also connected to the second output end of the power conversion module, the second electrode of the second switch tube is grounded, and the controlled electrode of the second switch tube is connected to the optical output end connected to the photoelectric coupler; The other end of the coil of the second relay is grounded, and the normally open end of the second relay is connected to the starting circuit.

8. The fast power-off restart circuit according to claim 7, characterized in that: The switch circuit also includes a first diode and a fifth resistor; The cathode of the first diode is connected to the controlled electrode of the first switch tube, and the anode of the first diode is connected to the first electrode of the second switch tube; One end of the fifth resistor is connected to the light output end of the photoelectric coupler, and the other end of the fifth resistor is grounded.

9. The fast power-off circuit according to claim 4, characterized in that: The light load rectifier circuit includes a phase load and a second rectifier bridge; The input end of the phase load is used to be connected to the power supply, the output end of the phase load is connected to the input end of the second rectifier bridge, and the output end of the second rectifier bridge is connected to the DC output circuit.

10. A servo driver, characterized in that: It comprises the fast power-off restart circuit as described in any one of claims 1 to 9.

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