Safety protection circuit of servo driver

Abstract

The utility model discloses a safety protection circuit of a servo driver, which relates to the technical field of servo drivers and comprises a power supply module used for supplying power; the electric energy control module is used for controlling an electric energy transmission state and supplying power to the servo driving module; the servo driving module is used for inverting work and providing three-phase electric energy for a servo motor connected with the servo motor module; and the driving state detection module is used for detecting the driving state of the servo driving module, controlling the discharging work of the discharging module when the driving is stopped, and controlling the power-off work of the electric energy control module and the standby power supply module to provide standby electric energy for the servo driving module in a time delay manner through the time delay control module. When the safety protection circuit of the servo driver stops driving the servo motor module, discharge protection and power supply switching are carried out, so that the servo driving module is prevented from being influenced by regenerative electric energy, the servo driving module is prevented from being restarted, and the safety of the circuit is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of servo drivers, in particular to a safety protection circuit of a servo driver. Background Art

[0002] A servo drive is a controller used to control a servo motor. When the servo motor is braked, the power is consumed and discharged through a discharge circuit composed of resistors and power tubes. At the same time, in order to avoid the influence of the regenerative power generated by the servo motor on the power supply end of the servo drive, the power supply of the servo drive will be disconnected during the discharge work, which makes it impossible to maintain the working state of the servo drive normally. After the servo drive stops working, it needs to be restarted to re-control the work of the servo motor. The control method is relatively cumbersome and needs to be improved. Utility Model Content

[0003] The embodiment of the utility model provides a safety protection circuit of a servo drive to solve the problems raised in the above background technology.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A safety protection circuit for a servo drive comprises: a power supply module, an electric energy control module, a servo drive module, a servo motor module, a drive state detection module, a delay control module, a backup power supply module and a discharge module;

[0006] The power module is used to receive AC power and rectify and filter the AC power to output DC power;

[0007] The power control module is connected to the power module, the servo drive module and the delay control module, and is used to transmit the DC power to the servo drive module, and stop the transmission of the DC power when receiving the delay control signal output by the delay control module;

[0008] A servo drive module is connected to the power module and the backup power module, and is used to receive the power output by the power control module or the backup power provided by the backup power module, and when outputting a drive signal, inverts the DC power and outputs three-phase power;

[0009] A servo motor module, connected to the servo drive module, for receiving three-phase power and supplying power to the connected servo motor;

[0010] A driving state detection module, connected to the servo driving module, configured to perform rectification and filtering processing on the driving signal and output a first detection signal, and output a first control signal when the first detection signal is received but the driving signal is not received;

[0011] A delay control module, connected to the driving state detection module, configured to receive a first control signal and output a delay control signal with a delay;

[0012] a backup power supply module, connected to the backup power supply module, for providing backup power and transmitting the backup power to the servo drive module upon receiving a delay control signal;

[0013] The discharge module is connected to the servo drive module and the drive state detection module, and is used to receive the first control signal and discharge the regenerative electric energy generated by the servo motor module transmitted by the servo drive module.

[0014] As a further solution of the utility model: the power supply module includes a power supply access port, a first rectifier and a first capacitor; the servo drive module includes a servo drive device and a first inverter; the servo motor module includes a servo motor interface;

[0015] Preferably, the first end and the second end of the power access port are respectively connected to the first end and the second end of the first rectifier, the third end of the first rectifier is connected to one end of the first capacitor and the first input end of the first inverter, the fourth end of the first rectifier is connected to the other end of the first capacitor and the second input end of the first inverter, the first output end, the second output end and the third output end of the first inverter are respectively connected to the first end, the second end and the third end of the servo motor, and the first control end, the second control end, the third control end, the fourth control end, the fifth control end and the sixth control end of the first inverter are respectively connected to the first output end, the second output end, the third output end, the fourth output end, the fifth output end and the sixth output end of the servo drive device.

[0016] As a further solution of the utility model: the driving state detection module includes a seventh diode, an eighth diode, a ninth diode, a fourth diode, a fifth diode, a sixth diode, a second capacitor, a third diode, a first power supply, a fourth resistor, a second diode, a first logic chip and a second logic chip;

[0017] Preferably, the anode of the seventh diode, the anode of the eighth diode, the anode of the ninth diode, the anode of the fourth diode, the anode of the fifth diode and the anode of the sixth diode are respectively connected to the first output end, the second output end, the third output end, the fourth output end, the fifth output end and the sixth output end of the servo drive device, the cathode of the seventh diode is connected to the cathode of the eighth diode, the cathode of the ninth diode, the cathode of the fourth diode, the cathode of the fifth diode, the cathode of the sixth diode, the B end of the first logic chip and the anode of the third diode and are grounded through the second capacitor, the cathode of the third diode is connected to the cathode of the second diode and the A end of the second logic chip, the B end of the second logic chip is connected to the first power supply through the fourth resistor, the F end of the second logic chip is connected to the anode of the second diode and the A end of the first logic chip, and the F end of the first logic chip is connected to the delay control module and the discharge module.

[0018] As a further solution of the utility model: the discharge module includes a first resistor and a first power tube;

[0019] Preferably, the drain of the first power tube is connected to the first input terminal of the first inverter through the first resistor, the source of the first power tube is connected to the second input terminal of the first inverter, and the gate of the first power tube is connected to the F terminal of the first logic chip.

[0020] As a further solution of the utility model: the power control module includes a second power tube, a second resistor, a first switch tube, a third resistor and a first diode;

[0021] Preferably, the drain of the second power tube is connected to the third end of the first rectifier and is connected to the gate of the second power tube and the collector of the first switching tube through the second resistor, the emitter of the first switching tube is connected to the fourth end of the first rectifier, the source of the second power tube is connected to the anode of the first diode, the cathode of the first diode is connected to the power supply end of the servo drive device, the base of the first switching tube is connected to the first end of the third resistor, and the second end of the third resistor is connected to the delay control module.

[0022] As a further solution of the utility model: the backup power supply module includes a third power tube and a backup power supply;

[0023] Preferably, the source of the third power tube is connected to the power supply end of the servo drive device, the drain of the third power tube is connected to one end of the backup power supply, the other end of the backup power supply is connected to the fourth end of the first rectifier, and the gate of the third power tube is connected to the second end of the third resistor and the delay control module.

[0024] As a further solution of the utility model: the delay control module includes a second power supply, a fifth resistor, a second switch tube, a third capacitor, a third switch tube and a sixth resistor;

[0025] Preferably, the second power supply is connected to the collector of the second switching tube and the collector of the third switching tube, the emitter of the second switching tube is connected to one end of the third capacitor and is connected to the base of the third switching tube through a fifth resistor, the emitter of the third switching tube is connected to the second end of the third resistor and the gate of the third power tube and is connected to the other end of the third capacitor and the ground through a sixth resistor, and the base of the second switching tube is connected to the F end of the first logic chip.

[0026] Compared with the prior art, the beneficial effects of the utility model are as follows: the safety protection circuit of the servo driver of the utility model inverts the electric energy output by the power supply module by the servo drive module so as to drive the servo motor connected to the servo motor module, and detects the driving state of the servo drive module by the drive state detection module, and controls the discharge work of the discharge module when the driving work is stopped, so that the delay control module delays the control of the backup power supply module to supply power to the servo drive module, thereby ensuring the driving work of the servo drive module, avoiding the servo drive module from being affected by the regenerated electric energy, avoiding the restart of the servo drive module, and improving the safety of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 The present invention provides a schematic block diagram of a safety protection circuit for a servo drive.

[0029] Figure 2 A circuit diagram of a safety protection circuit of a servo drive provided in an example of the utility model.

[0030] Figure 3 This is a connection circuit diagram of the delay control module provided for an example of the utility model. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] In one embodiment, see Figure 1, a safety protection circuit of a servo drive, comprising: a power supply module 1, a power control module 2, a servo drive module 3, a servo motor module 4, a drive state detection module 5, a delay control module 6, a backup power supply module 7 and a discharge module 8;

[0033] Specifically, the power module 1 is used to receive AC power and perform rectification and filtering on the AC power to output DC power;

[0034] The power control module 2 is connected to the power module 1, the servo drive module 3 and the delay control module 6, and is used to transmit the DC power to the servo drive module 3, and stop the transmission of the DC power when receiving the delay control signal output by the delay control module 6;

[0035] The servo drive module 3 is connected to the power module 1 and the backup power module 7, and is used to receive the power output by the power control module 2 or the backup power provided by the backup power module 7, and when outputting the drive signal, inverts the DC power and outputs three-phase power;

[0036] A servo motor module 4, connected to the servo drive module 3, for receiving three-phase power and supplying power to the connected servo motor;

[0037] A driving state detection module 5, connected to the servo driving module 3, for rectifying and filtering the driving signal and outputting a first detection signal, and outputting a first control signal when the first detection signal is received but the driving signal is not received;

[0038] A delay control module 6, connected to the driving state detection module 5, for receiving a first control signal and delaying output of a delay control signal;

[0039] A backup power supply module 7, connected to the backup power supply module 7, for providing backup power and transmitting the backup power to the servo drive module 3 when receiving a delay control signal;

[0040] The discharge module 8 is connected to the servo drive module 3 and the drive state detection module 5 , and is used to receive the first control signal and discharge the regenerative electric energy generated by the servo motor module 4 transmitted by the servo drive module 3 .

[0041] In a specific embodiment, the power supply module 1 can adopt a power supply circuit composed of a power access port, a rectifier and a capacitor, can access AC power and perform rectification and filtering on the AC power; the power control module 2 can adopt a power control circuit composed of a power tube, a resistor, a triode, etc., to control the transmission state of the power and supply power to the servo drive module 3; the servo drive module 3 can adopt a servo drive circuit composed of a servo drive device and an inverter to invert the input power; the servo motor module 4 can adopt a servo motor circuit composed of a servo motor interface, which is connected to the power supply end of the servo motor and drives the servo motor to work; the above drive state The state detection module 5 can adopt a driving state detection circuit composed of diodes, resistors, logic chips, etc., and can determine whether to stop driving after the servo drive module 3 starts driving; the above-mentioned delay control module 6 can adopt a delay control circuit composed of transistors, capacitors, resistors, etc., which is triggered by the signal output by the driving state detection module 5, and delays the control of the operation of the backup power supply module 7 and the power control module 2; the above-mentioned backup power supply module 7 can adopt a backup power supply circuit composed of a backup power supply and a power tube to provide backup power for the servo drive module 3; the above-mentioned discharge module 8 can adopt a discharge circuit composed of a resistor and a power tube to discharge the generated regenerative electric energy.

[0042] In another embodiment, see Figure 1 , Figure 2 and Figure 3 The power supply module 1 includes a power supply access port, a first rectifier T1 and a first capacitor C1; the servo drive module 3 includes a servo drive device and a first inverter T2; the servo motor module 4 includes a servo motor interface;

[0043] Specifically, the first end and the second end of the power access port are respectively connected to the first end and the second end of the first rectifier T1, the third end of the first rectifier T1 is connected to one end of the first capacitor C1 and the first input end of the first inverter T2, the fourth end of the first rectifier T1 is connected to the other end of the first capacitor C1 and the second input end of the first inverter T2, the first output end, the second output end and the third output end of the first inverter T2 are respectively connected to the first end, the second end and the third end of the servo motor, and the first control end, the second control end, the third control end, the fourth control end, the fifth control end and the sixth control end of the first inverter T2 are respectively connected to the first output end, the second output end, the third output end, the fourth output end, the fifth output end and the sixth output end of the servo drive device.

[0044] In a specific embodiment, the above-mentioned servo drive device can be composed of a drive circuit composed of a single-chip microcomputer and an IR2103 chip, the single-chip microcomputer provides a drive signal, and the drive circuit improves the driving ability of the drive signal; the above-mentioned first inverter T2 can adopt a three-phase inverter composed of six groups of IGBTs to output three-phase electrical energy.

[0045] Further, the driving state detection module 5 includes a seventh diode D7, an eighth diode D8, a ninth diode D9, a fourth diode D4, a fifth diode D5, a sixth diode D6, a second capacitor C2, a third diode D3, a first power supply VCC1, a fourth resistor R4, a second diode D2, a first logic chip J1 and a second logic chip J2;

[0046] Specifically, the anode of the seventh diode D7, the anode of the eighth diode D8, the anode of the ninth diode D9, the anode of the fourth diode D4, the anode of the fifth diode D5 and the anode of the sixth diode D6 are respectively connected to the first output end, the second output end, the third output end, the fourth output end, the fifth output end and the sixth output end of the servo drive device, the cathode of the seventh diode D7 is connected to the cathode of the eighth diode D8, the cathode of the ninth diode D9, the cathode of the fourth diode D4, the cathode of the fifth diode D5, the cathode of the sixth diode D6, the B end of the first logic chip J1 and the anode of the third diode D3 and are grounded through the second capacitor C2, the cathode of the third diode D3 is connected to the cathode of the second diode D2 and the A end of the second logic chip J2, the B end of the second logic chip J2 is connected to the first power supply VCC1 through the fourth resistor R4, the F end of the second logic chip J2 is connected to the anode of the second diode D2 and the A end of the first logic chip J1, and the F end of the first logic chip J1 is connected to the delay control module 6 and the discharge module 8.

[0047] In a specific embodiment, the fourth diode D4, the fifth diode D5, the sixth diode D6, the seventh diode D7, the eighth diode D8, the ninth diode D9 and the second capacitor C2 perform rectification and filtering processing on the signals output from the first output terminal, the second output terminal, the third output terminal, the fourth output terminal, the fifth output terminal and the sixth output terminal of the servo drive device; the second logic chip J2 can be selected as an AND gate chip, which can cooperate with the third diode D3, the second diode D2, the fourth resistor R4 and the first power supply VCC1 to self-lock and output a high-level signal when the servo drive device outputs a driving signal, so as to determine that the servo drive device starts driving work; the second logic chip J2 can be selected as an XOR gate chip.

[0048] Furthermore, the discharge module 8 includes a first resistor R1 and a first power tube Q1;

[0049] Specifically, the drain of the first power tube Q1 is connected to the first input terminal of the first inverter T2 through the first resistor R1, the source of the first power tube Q1 is connected to the second input terminal of the first inverter T2, and the gate of the first power tube Q1 is connected to the F terminal of the first logic chip J1.

[0050] In a specific embodiment, the first power tube Q1 can be an N-channel field effect tube.

[0051] Furthermore, the power control module 2 includes a second power tube Q2, a second resistor R2, a first switch tube V1, a third resistor R3 and a first diode D1;

[0052] Specifically, the drain of the second power tube Q2 is connected to the third end of the first rectifier T1 and is connected to the gate of the second power tube Q2 and the collector of the first switch tube V1 through the second resistor R2, the emitter of the first switch tube V1 is connected to the fourth end of the first rectifier T1, the source of the second power tube Q2 is connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to the power supply end of the servo drive device, the base of the first switch tube V1 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is connected to the delay control module 6.

[0053] In a specific embodiment, the first switch tube V1 may be an NPN transistor to control the cutoff of the second power tube Q2; the second power tube Q2 may be an N-channel field effect tube.

[0054] Further, the backup power supply module 7 includes a third power tube Q3 and a backup power supply;

[0055] Specifically, the source of the third power tube Q3 is connected to the power supply end of the servo drive device, the drain of the third power tube Q3 is connected to one end of the backup power supply, the other end of the backup power supply is connected to the fourth end of the first rectifier T1, and the gate of the third power tube Q3 is connected to the second end of the third resistor R3 and the delay control module 6.

[0056] In a specific embodiment, the third power tube Q3 may be an N-channel field effect tube; the backup power source may be a battery pack.

[0057] Further, the delay control module 6 includes a second power supply VCC2, a fifth resistor R5, a second switch tube V2, a third capacitor C3, a third switch tube V3 and a sixth resistor R6;

[0058] Specifically, the second power supply VCC2 is connected to the collector of the second switch tube V2 and the collector of the third switch tube V3, the emitter of the second switch tube V2 is connected to one end of the third capacitor C3 and is connected to the base of the third switch tube V3 through the fifth resistor R5, the emitter of the third switch tube V3 is connected to the second end of the third resistor R3 and the gate of the third power tube Q3 and is connected to the other end of the third capacitor C3 and the ground through the sixth resistor R6, and the base of the second switch tube V2 is connected to the F end of the first logic chip J1.

[0059] In a specific embodiment, both the second switch tube V2 and the third switch tube V3 can be NPN transistors; the third capacitor C3 stores energy to delay the conduction of the third switch tube V3.

[0060] In a safety protection circuit of a servo driver in the present embodiment, AC power is connected to a power access port, the first rectifier T1 and the first capacitor C1 perform rectification and filtering on the AC power, the second resistor R2 triggers the second power tube Q2 to turn on, and then supplies power to the servo drive device, so that the first output end, the second output end, the third output end, the fourth output end, the fifth output end and the sixth output end of the servo drive device control the first inverter T2 to perform three-phase inversion and output three-phase power to drive the servo motor connected to the servo motor interface. At the same time, the A end of the second logic chip J2 becomes a high level, and cooperates with the third diode D3, the second diode D2, the fourth resistor R4 and the first power supply VCC1 to perform self-locking, and the F end of the second logic chip J2 outputs a high level. If the servo drive device When the driving operation stops, the B terminal of the first logic chip J1 will become a low level. At this time, the F terminal of the first logic chip J1 outputs a high level signal, triggering the first power tube Q1 to turn on and cooperate with the first resistor R1 to discharge the regenerated electric energy generated by the servo motor. At the same time, the F terminal of the first logic chip J1 triggers the second switch tube V2 to turn on, and then triggers the third switch tube V3 to turn on, so that the first switch tube V1 and the third power tube Q3 are turned on, and the backup power supply supplies power to the servo drive device. When the servo drive device resumes driving work, since the third capacitor C3 stores a certain amount of electric energy, the third switch tube V3 will be delayed to turn on, and the backup power supply delays to supply power to the servo drive device until the electric energy stored in the third capacitor C3 can no longer trigger the third switch tube V3 to turn on, and the servo drive device will be powered by the power module 1 again.

[0061] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0062] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A safety protection circuit for a servo drive, characterized in that: The safety protection circuit of the servo drive includes: a power supply module, an electric energy control module, a servo drive module, a servo motor module, a drive state detection module, a delay control module, a backup power supply module and a discharge module; The power module is used to receive AC power and perform rectification and filtering on the AC power to output DC power; The power control module is connected to the power module, the servo drive module and the delay control module, and is used to transmit DC power to the servo drive module, and stop the transmission of DC power when receiving the delay control signal output by the delay control module; The servo drive module is connected to the power module and the backup power module, and is used to receive the power output by the power control module or the backup power provided by the backup power module, and when outputting the drive signal, inverts the DC power and outputs three-phase power; The servo motor module is connected to the servo drive module and is used to receive three-phase power and supply power to the connected servo motor; The driving state detection module is connected to the servo driving module, and is used to perform rectification and filtering processing on the driving signal and output a first detection signal, and output a first control signal when the first detection signal is received but the driving signal is not received; The delay control module is connected to the driving state detection module and is used to receive the first control signal and delay output of the delay control signal; The backup power supply module is connected to the backup power supply module and is used to provide backup power and transmit the backup power to the servo drive module when receiving the delay control signal; The discharge module is connected to the servo drive module and the drive state detection module, and is used to receive the first control signal and discharge the regenerative electric energy generated by the servo motor module transmitted by the servo drive module.

2. A safety protection circuit for a servo drive according to claim 1, characterized in that: The power supply module includes a power access port, a first rectifier and a first capacitor; the servo drive module includes a servo drive device and a first inverter; the servo motor module includes a servo motor interface; The first end and the second end of the power access port are respectively connected to the first end and the second end of the first rectifier, the third end of the first rectifier is connected to one end of the first capacitor and the first input end of the first inverter, the fourth end of the first rectifier is connected to the other end of the first capacitor and the second input end of the first inverter, the first output end, the second output end and the third output end of the first inverter are respectively connected to the first end, the second end and the third end of the servo motor, and the first control end, the second control end, the third control end, the fourth control end, the fifth control end and the sixth control end of the first inverter are respectively connected to the first output end, the second output end, the third output end, the fourth output end, the fifth output end and the sixth output end of the servo drive device.

3. A safety protection circuit for a servo drive according to claim 2, characterized in that: The driving state detection module includes a seventh diode, an eighth diode, a ninth diode, a fourth diode, a fifth diode, a sixth diode, a second capacitor, a third diode, a first power supply, a fourth resistor, a second diode, a first logic chip and a second logic chip; The anode of the seventh diode, the anode of the eighth diode, the anode of the ninth diode, the anode of the fourth diode, the anode of the fifth diode and the anode of the sixth diode are respectively connected to the first output end, the second output end, the third output end, the fourth output end, the fifth output end and the sixth output end of the servo drive device, the cathode of the seventh diode is connected to the cathode of the eighth diode, the cathode of the ninth diode, the cathode of the fourth diode, the cathode of the fifth diode, the cathode of the sixth diode, the B end of the first logic chip and the anode of the third diode and are grounded through the second capacitor, the cathode of the third diode is connected to the cathode of the second diode and the A end of the second logic chip, the B end of the second logic chip is connected to the first power supply through the fourth resistor, the F end of the second logic chip is connected to the anode of the second diode and the A end of the first logic chip, and the F end of the first logic chip is connected to the delay control module and the discharge module.

4. A safety protection circuit for a servo drive according to claim 3, characterized in that: The discharge module includes a first resistor and a first power tube; The drain of the first power tube is connected to the first input terminal of the first inverter through the first resistor, the source of the first power tube is connected to the second input terminal of the first inverter, and the gate of the first power tube is connected to the F terminal of the first logic chip.

5. The safety protection circuit of a servo drive according to claim 3, characterized in that: The power control module includes a second power tube, a second resistor, a first switch tube, a third resistor and a first diode; The drain of the second power tube is connected to the third end of the first rectifier and is connected to the gate of the second power tube and the collector of the first switch tube through the second resistor, the emitter of the first switch tube is connected to the fourth end of the first rectifier, the source of the second power tube is connected to the anode of the first diode, the cathode of the first diode is connected to the power supply end of the servo drive device, the base of the first switch tube is connected to the first end of the third resistor, and the second end of the third resistor is connected to the delay control module.

6. A safety protection circuit for a servo drive according to claim 5, characterized in that: The backup power supply module includes a third power tube and a backup power supply; The source of the third power tube is connected to the power supply end of the servo drive device, the drain of the third power tube is connected to one end of the backup power supply, the other end of the backup power supply is connected to the fourth end of the first rectifier, and the gate of the third power tube is connected to the second end of the third resistor and the delay control module.

7. A safety protection circuit for a servo drive according to claim 6, characterized in that: The delay control module includes a second power supply, a fifth resistor, a second switch tube, a third capacitor, a third switch tube and a sixth resistor; The second power supply is connected to the collector of the second switching tube and the collector of the third switching tube, the emitter of the second switching tube is connected to one end of the third capacitor and is connected to the base of the third switching tube through the fifth resistor, the emitter of the third switching tube is connected to the second end of the third resistor and the gate of the third power tube and is connected to the other end of the third capacitor and the ground through the sixth resistor, and the base of the second switching tube is connected to the F end of the first logic chip.

Images