Multipath switching value signal acquisition circuit and digital welding power supply
By designing a multi-channel switching signal acquisition circuit, the import conversion module and isolation transmission module are used to convert the multi-channel switching signal into analog signals and perform isolation processing, which solves the high cost of collecting multi-channel switching signals by the existing welding power supply. The complex circuit problem has achieved the effects of resource conservation, circuit simplification and flexible expansion.
Patent Information
- Application Number
- CN202420998687.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-09
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-05-09
AI Technical Summary
When collecting multiple switching signals, the existing welding power supply uses multiple parallel optocouplers to cause high costs, large circuit design area, and difficult to achieve miniaturization. It also occupies a large number of pin resources of welding power supply control modules, resulting in increased costs. and the circuit structure is rigid.
A multi-channel switching signal acquisition circuit is designed, including an import conversion module and an isolation transmission module. The import conversion module converts the multiple switching signal into analog control signals with different amplitudes through the analog conversion unit. The isolation transmission module isolates the linear optocoupler and amplifier, and finally realizes all switching signal through a sampling interface. Status collection.
It effectively reduces the use of limited external interfaces on the welding control module, saves interface resources, simplifies the circuit structure, reduces circuit costs, and reduces the difficulty and cost of switching volume expansion, and improves the flexibility of the circuit.
Smart Images
Figure CN222471044U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of welding, and in particular to a multi-channel switch quantity signal acquisition circuit and a digital welding power supply. Background Art
[0002] Welding power supplies (such as gas shielded welding, argon arc welding, cutting machines, etc.) need to collect multiple switch signals when in use to identify welding start, gas detection, wire feeding and other operating functions. Existing welding power supplies usually use multiple parallel optical couplers to isolate and transmit multiple switch signals when importing switch signals to achieve the import of multiple switch signals. The imported multiple switch signals are then input into the sampling interface of the welding power control module for sampling.
[0003] However, the isolation introduction based on multi-channel parallel optocouplers has resulted in the existing welding power supply switch quantity acquisition circuit being not only costly but also having a large circuit design area and difficult to miniaturize. The direct reading of the multi-channel switch quantity signals after introduction requires the configuration of an equal number of IO ports on the welding power supply control module to read the relevant switch quantities; this acquisition method greatly occupies the pin resources of the welding power supply control module. Under the conditions of tight cost control and tight chip resources, it will lead to a significant increase in the cost of the welding power supply control module, which will bring great difficulties to the design of the welding power supply. In addition, this one-by-one introduction and acquisition method of switch quantity signals also has problems such as rigid circuit structure, difficulty in expanding switch quantity, and high expansion cost. Utility Model Content
[0004] In order to overcome the deficiencies of the prior art, the utility model provides a multi-channel switch quantity signal acquisition circuit and a digital welding power supply.
[0005] In order to achieve the above-mentioned purpose, the utility model provides a multi-channel switch quantity signal acquisition circuit suitable for a digital welding power supply, which includes an import conversion module and an isolation transmission module. The import conversion module includes a switch quantity import interface and an analog quantity conversion unit. The input of the switch quantity import interface is connected to the multi-channel switch quantity control switch of the digital welding power supply, and its output is collected to the trunk of the analog quantity conversion unit; the analog quantity conversion unit includes a voltage divider network, and the multi-channel switch quantity signal is converted into an analog quantity control signal with multiple amplitudes through the voltage divider network, and each switch quantity signal corresponds to an analog quantity control signal amplitude. The isolation transmission module includes a comparator, a linear optocoupler and an amplifier cascaded in sequence. The input end of the comparator is connected to the output of the analog quantity conversion unit to obtain the analog quantity control signal amplitude corresponding to each switch quantity signal and trigger the linear optocoupler to turn on based on the analog quantity control signal amplitude. The linear optocoupler transmits the analog quantity control signal amplitude to the amplifier in a photoelectric isolation manner, and after amplification by the amplifier, it is output to a sampling interface of the digital welding power supply control module in the form of a signal.
[0006] According to one embodiment of the present usage information, the import conversion module includes a wire feeder switch quantity import interface and / or a welding robot switch quantity import interface; the input side of the wire feeder switch quantity import interface is connected to the multi-way switch quantity control switch on the wire feeder, and the input side of the welding robot switch quantity import interface is connected to the multi-way switch quantity control switch on the welding robot; the output ends of the two switch quantity import interfaces are both converged to the main line of the analog quantity conversion unit.
[0007] According to one embodiment of the present usage information, the outer side of the wire feeder switch quantity import interface is respectively connected to the welding switch quantity signal source and the gas detection switch quantity signal source on the wire feeder through two switch quantity control switches to form two parallel switch quantity import paths; at any time, only one switch quantity import path is turned on and forms the corresponding analog quantity control signal amplitude after conversion by the analog quantity conversion unit.
[0008] According to one embodiment of the present usage information, multiple switch quantity control switches of the welding robot are respectively connected to multiple voltage-dividing branches of the analog quantity conversion unit through the switch quantity import interface of the welding robot to form a multi-way parallel switch quantity import path, and each voltage-dividing branch in the analog quantity conversion unit has a unique voltage-dividing value; at any time, only one switch quantity import path is turned on and forms the corresponding analog quantity control signal amplitude after conversion by the analog quantity conversion unit.
[0009] According to an embodiment of the present use information, the analog quantity conversion unit further includes a reverse diode connected in parallel with the main circuit resistor and a conversion filter capacitor connected in series between the main circuit resistor and the ground.
[0010] According to an embodiment of the present usage information, the isolation transmission module also includes a signal follower, which is connected between the analog conversion unit and the comparator, and the signal follower follows the analog control signal corresponding to each switching signal to the positive phase terminal of the comparator.
[0011] According to one embodiment of the present usage information, the linear optocoupler includes a light-emitting diode, an input-side photodiode and an output-side photodiode, the light-emitting diode is connected to the output of the comparator, the input-side photodiode and the output-side photodiode are turned on based on the output of the comparator, the input-side photodiode is connected between the power supply and the reverse end of the comparator, the output-side photodiode is connected between the inverting end and the non-phase end of the amplifier, and an RC network is also connected between the output-side photodiode and the non-phase end of the amplifier.
[0012] According to an embodiment of the present usage information, the multi-channel switch signal acquisition circuit also includes a filtering and regulating module connected to the output end of the isolation transmission module, and the isolated analog control signal is output to a sampling interface of the digital welding power supply control module after filtering and conditioning.
[0013] On the other hand, the utility model also provides a digital welding power supply, which includes the above-mentioned multi-channel switch signal acquisition circuit.
[0014] In summary, in the multi-channel switch quantity signal acquisition circuit provided by the utility model, the analog quantity conversion unit converts the multi-channel switch quantity signals imported by the switch quantity import interface into an analog quantity control signal with different amplitudes, that is, the conversion of the multi-channel switch quantity signals to the single-channel analog quantity signal is realized. The converted single-channel analog quantity control signal with different amplitudes is isolated and processed by the isolation transmission module, and finally the digital welding power supply control module only needs to use the sampling interface of one channel to obtain the status of all switch quantity control signals. This setting effectively reduces the use of the limited external interface on the welding control module and saves interface resources; further, the setting of the analog quantity conversion unit also enables the multi-channel switch quantity signal acquisition circuit provided by the utility model to realize the isolated acquisition of all switch quantity signals by only using one isolation transmission module, which greatly simplifies the circuit structure and reduces the circuit cost; at the same time, this setting also greatly reduces the difficulty and cost of switch quantity expansion, greatly improves the flexibility of the circuit and enables it to match various types of digital welding power supplies.
[0015] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 The figure shows a principle block diagram of a multi-channel switch signal acquisition circuit provided in one embodiment of the utility model.
[0017] Figure 2 Shown Figure 1 The schematic diagram of the imported conversion module connected to the multi-channel switch control switch of the digital welding power supply.
[0018] Figure 3 Shown Figure 1 Schematic diagram of the isolated transmission module.
[0019] Figure 4 Shown is the timing diagram of the multi-channel switch signals imported into the wire feeder.
[0020] Figure 5 Shown is the timing diagram of the multi-channel switch signals imported into the welding robot. DETAILED DESCRIPTION
[0021] like Figures 1 to 3As shown, this embodiment provides a multi-channel switch quantity signal acquisition circuit suitable for a digital welding power supply. The multi-channel switch quantity signal acquisition circuit includes an import conversion module 1 and an isolation transmission module 2. The import conversion module 1 includes a switch quantity import interface and an analog quantity conversion unit 10, the input of the switch quantity import interface is connected to the multi-channel switch quantity control switch of the digital welding power supply, and its output is collected to the trunk 130 of the analog quantity conversion unit. The analog quantity conversion unit 10 includes a voltage divider network, and the multi-channel switch quantity signal is converted into an analog quantity control signal with multiple amplitudes through the voltage divider network, and each switch quantity signal corresponds to an analog quantity control signal amplitude. The isolation transmission module 3 includes a comparator U16A, a linear optocoupler U15 and an amplifier U44A which are cascaded in sequence. The input end of the comparator U16A is connected to the output of the analog conversion unit 2 to obtain the analog control signal amplitude corresponding to each switching signal and trigger the linear optocoupler U15 to turn on based on the analog control signal amplitude. The linear optocoupler U15 transmits the analog control signal amplitude to the amplifier U44A in an optoelectronic isolation manner, and after amplification by the amplifier U44A, it is output to the ADC sampling interface of the digital welding power supply control module 4 in the form of one signal.
[0022] like Figure 1 and Figure 2 As shown, in this embodiment, the import conversion module 1 includes a wire feeder switch quantity import interface MB5 and a welding robot switch quantity import interface MB14. The input side of the wire feeder switch quantity import interface MB5 is connected to the multi-way switch quantity control switches S1 and S2 on the wire feeder. The input side of the welding robot switch quantity import interface MB14 is connected to the multi-way switch quantity control switches S3, S4, S5, S6, and S7 on the welding robot. The output ends of the two switch quantity import interfaces are both collected to the trunk 130 collected to the analog quantity conversion unit 10. The setting of the wire feeder switch quantity import interface MB5 and the welding robot switch quantity import interface MB14 enables the multi-way switch quantity signal acquisition circuit provided by the utility model to collect welding switch quantity signals and gas detection switch quantity signals on ordinary wire feeders, and can also cooperate with the welding robot to collect multi-way switch quantity signals such as the initial detection input instruction switch quantity signal, welding switch quantity signal, gas detection switch quantity signal, wire feeding switch quantity signal, and wire withdrawal switch quantity signal of the welding robot. When the welding robot switch quantity import interface MB14 is used, the wire feeder switch quantity import interface MB5 is in a suspended state; similarly, when the wire feeder switch quantity import interface MB5 is used, the welding robot switch quantity import interface MB14 is also in a suspended state. However, the present invention does not make any limitation to this. In other embodiments, a multi-channel switch quantity signal acquisition circuit may be provided with only the wire feeder switch quantity import interface MB5 or the welding robot switch quantity import interface MB14.
[0023] like Figure 2As shown, the outer side of the wire feeder switch quantity import interface MB5 is connected to the welding switch quantity signal source R1 and the gas detection switch quantity signal source R2 on the wire feeder through two switch quantity control switches S1 and S2 respectively to form two parallel switch quantity import paths. At any time, only one switch quantity import path is turned on and converted by the analog quantity conversion unit 10 to form the corresponding analog quantity control signal amplitude. Specifically, as Figure 4 As shown, when the switch quantity control switches S1 and S2 are both disconnected, the amplitude of the analog quantity control signal output node TP8 is +15VC, which indicates that no switch quantity signal is introduced. When the switch quantity control switch S1 is closed, the switch quantity introduction path where the welding switch quantity signal source R1 is located is turned on, and the welding switch quantity signal source R1 is connected in series to the main circuit resistors R78 and R79 in the analog quantity conversion unit 10; after voltage division, the three form an analog quantity control signal amplitude US1 corresponding to the welding switch quantity signal on the main circuit resistor R78 and output it at the output node TP8. Similarly, when the switch quantity control switch S2 is closed, the switch quantity introduction path where the gas detection switch quantity signal source R2 is located is turned on, and the gas detection switch quantity signal source R2 is connected in series to the main circuit resistors R78 and R79 in the analog quantity conversion unit 10; after voltage division, the three form an analog quantity control signal corresponding to the welding switch quantity signal on the main circuit resistor R78, and its output amplitude is US2.
[0024] As for the welding robot switch quantity import interface MB14, its input side is directly connected to the multiple switch quantity control switches S3, S4, S5, S6, and S7 of the welding robot; its output side is connected to the multiple voltage-dividing branches of the analog quantity conversion unit 10, and each voltage-dividing branch is correspondingly connected to one switch quantity control switch to form a multi-way parallel switch quantity import path, and each voltage-dividing branch in the analog quantity conversion unit 10 has a unique voltage-dividing value; at any time, only one switch quantity import path is turned on and forms the corresponding analog quantity control signal amplitude after conversion by the analog quantity conversion unit 10.
[0025] Specifically, Figure 2 and Figure 5 As shown, when multiple switch quantity control switches S3, S4, S5, S6, and S7 are all disconnected, the amplitude of the output node TP8 is +15VC, indicating that no switch quantity signal is currently being imported. When the switch quantity control switch S3 corresponds to the start-end detection input command switch quantity signal of the welding robot, its voltage-dividing branch is pin 7 on the welding robot switch quantity import interface MB14 → branch resistor R71 → main resistor R79. The power supply +15VC is divided by the main resistors R78, R79, the branch resistor R71, and the grounding resistor R70 to form an analog control signal amplitude US3 corresponding to the start-end detection input command switch quantity signal on the main resistor R78 and output it at the output node TP8. The following will be combined with Figure 5The conversion principle of the analog quantity conversion unit 10 when any of the multi-way switching quantity control switches S3, S4, S5, S6, and S7 is closed will be described in detail.
[0026] Specifically, when the switch control switch S4 corresponding to the welding switch signal is closed, the voltage-dividing branch where it is located is the 4th pin on the welding robot switch import interface MB14 → the main circuit resistor R79, and there is no branch resistor on this voltage-dividing branch; the power supply +15VC is divided by the main circuit resistors R78, R79 and the grounding resistor R70 to form an analog control signal amplitude US4 corresponding to the welding switch signal on the main circuit resistor R78 and output it at the output node TP8.
[0027] When the switch control switch S5 corresponding to the gas detection switch signal is closed, the voltage-dividing branch where it is located is pin 3 on the welding robot switch import interface MB14 → branch resistors R72, R71 → main resistor R79; the power supply +15VC is divided by the main resistors R78, R79, branch resistors R72, R71 and grounding resistor R70 to form an analog control signal amplitude US5 corresponding to the gas detection switch signal on the main resistor R78 and output it at the output node TP8.
[0028] When the switch control switch S6 corresponding to the wire withdrawal switch signal is closed, the voltage-dividing branch where it is located is pin 2 on the welding robot switch import interface MB14 → branch resistors R73, R72, R71 → main resistor R79; the power supply +15VC is divided by the main resistors R78, R79, branch resistors R73, R72, R71 and grounding resistor R70 to form an analog control signal amplitude US6 corresponding to the wire withdrawal switch signal on the main resistor R78 and output it at the output node TP8.
[0029] When the switch control switch S7 corresponding to the wire feeding switch signal is closed, the voltage dividing branch where it is located is pin 1 on the welding robot switch import interface MB14 → branch resistors R74, R73, R72, R71 → main resistor R79; the power supply +15VC is divided by the main resistors R78, R79, branch resistors R74, R73, R72, R71 and grounding resistor R70 to form an analog control signal amplitude US7 corresponding to the wire feeding switch signal on the main resistor R78 and output it at the output node TP8.
[0030] Although the present embodiment is described by taking the five-way switch quantity control switches S3 to S7 as an example. However, the present invention does not impose any limitation on the number of switch quantity control switches connected to the input side of the switch quantity import interface MB14 of the welding robot. The analog quantity conversion unit 10 converts the multi-way switch quantity signals into an analog quantity signal with different amplitudes, and characterizes each switch quantity signal with a different analog quantity amplitude, thereby realizing the collection and import of multi-way switch quantity signals. This import method not only allows the welding control module 4 to use only one interface for sampling, thereby greatly saving the ADC sampling interface; further, the conversion method also allows the multi-way switch quantity signals to be isolated based on an isolation transmission module, greatly reducing the size of the acquisition circuit and reducing the cost, while also greatly facilitating the expansion of the switch quantity, and the structure and cost of the acquisition circuit are minimally affected by the expansion of the switch quantity, thereby greatly facilitating the expansion of the input side switch quantity.
[0031] In this embodiment, if Figure 2 As shown, the analog conversion unit 10 also includes a reverse diode D8 connected in parallel with the main circuit resistor R78 and a conversion filter capacitor C71 connected in series between the main circuit resistor R78 and the ground GNDC. The setting of the reverse diode D8 can effectively prevent damage to various circuit components when the power supply +15VC is reversely connected, and plays a role in preventing reverse connection; and the conversion filter capacitor C71 filters and conditions the analog control signal output by the output node TP8 and outputs it to the isolation transmission module 2.
[0032] In this embodiment, the isolation transmission module 2 further includes a signal follower U16B, which is connected between the analog conversion unit 10 and the comparator U16A, and the signal follower U16B follows the analog control signal corresponding to each switch signal to the positive phase terminal of the comparator U16A. Figure 3 As shown, the analog control signal outputted by the output node TP8 is inputted to the in-phase terminal of the signal follower U16B, and the inverting terminal of the signal follower U16B is connected to its output terminal to realize signal following. The signal after following is filtered and conditioned by the following resistor R210 and the capacitor C72 and then outputted to the in-phase terminal of the comparator U16A. The linear optocoupler U15 includes a light-emitting diode D1, an input-side photodiode D2, and an output-side photodiode D3. The light-emitting diode D1 is connected to the output of the comparator U16A, and the input-side photodiode D2 and the output-side photodiode D3 are turned on based on the output of the comparator U16A. The input-side photodiode D2 is connected between the power supply +15VC and the reverse terminal (pin 2) of the comparator U16A, and the output-side photodiode D3 is connected between the inverting terminal (pin 2) and the non-inverting terminal (pin 3) of the amplifier U44A, and an RC network including a resistor R87 and a capacitor C75 is also connected between the output-side photodiode D3 and the non-inverting terminal of the amplifier U44A.
[0033] Specifically, the analog control signal output by the analog conversion unit 10 completes signal following through the signal follower U16B, realizes voltage division and RC low-pass filtering through resistors R81, R210 and capacitor C72, and then reaches the comparator U16A. When the voltage at the in-phase end (pin 3) of the comparator U16A is higher than the voltage at the inverting end (pin 2), the pin 1 of the comparator U16A outputs a high level, lights up the light-emitting diode D1 through the resistor R82, and touches the input side photodiode D2 connected between the pins 3 and 4 of the linear optocoupler and the output side photodiode D3 connected between the pins 5 and 6 to turn on. When the output side photodiode D3 is turned on, the pin 2 signal of the amplifier U44A starts to charge the capacitor C75 through the resistor R87. At the same time, the conduction of the input side photodiode D2 also causes the power supply +15VC to be directly applied to the inverting terminal (pin 2) of the comparator U16A, causing the voltage of pin 2 of the comparator U16A to be higher than the voltage of pin 3, thereby causing pin 1 of the comparator U16A to output a low level and turning off the input side photodiode D2 and the output side photodiode D3 in the linear optocoupler U15. The capacitor C75 on pin 3 of the linear optocoupler begins to discharge slowly, and pin 2 of the comparator U16A recovers to 0V. The linear optocoupler U15 repeats the above comparison and the on-off process of the two photodiodes at a high speed until pin 1 of the amplifier U44A generates a stable analog control signal, thereby completing the isolated transmission of the analog control signal.
[0034] In this embodiment, the multi-channel switch signal acquisition circuit also includes a filter adjustment module 3 connected to the output end of the isolation transmission module 2, and the isolated analog control signal is output to the sampling interface of the digital welding power control module 4 after filtering and conditioning. Specifically, the filter adjustment module 3 includes a resistor R85 and a capacitor C1, and the output of the filter adjustment module 3 forms a sampling node TP9 to be connected to the sampling interface of the digital welding power supply.
[0035] In this embodiment, the welding power supply control module 4 is a DSP module. However, the present invention does not make any limitation to this. In other embodiments, the welding power supply control module may also be an MCU module.
[0036] Correspondingly, this embodiment also provides a welding power supply including the above-mentioned multi-channel switch signal acquisition circuit, and the digital welding power supply can be any one of a gas shielded welding digital welding power supply, an argon arc welding digital welding power supply or a cutting machine digital welding power supply.
[0037] In summary, in the multi-channel switch quantity signal acquisition circuit provided by the utility model, the analog quantity conversion unit converts the multi-channel switch quantity signals imported by the switch quantity import interface into an analog quantity control signal with different amplitudes, that is, the conversion of the multi-channel switch quantity signals to the single-channel analog quantity signal is realized. The converted single-channel analog quantity control signal with different amplitudes is isolated and processed by the isolation transmission module, and finally the digital welding power supply control module only needs to use the sampling interface of one channel to obtain the status of all switch quantity control signals. This setting effectively reduces the use of the limited external interface on the welding control module and saves interface resources; further, the setting of the analog quantity conversion unit also enables the multi-channel switch quantity signal acquisition circuit provided by the utility model to realize the isolated acquisition of all switch quantity signals by only using one isolation transmission module, which greatly simplifies the circuit structure and reduces the circuit cost; at the same time, this setting also greatly reduces the difficulty and cost of switch quantity expansion, greatly improves the flexibility of the circuit and enables it to match various types of digital welding power supplies.
[0038] Although the present invention has been disclosed as above by the preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make slight changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be based on the scope of protection required by the claims.
Claims
1. A multi-channel switch signal acquisition circuit, characterized in that: Applicable to digital welding power supply, the multi-channel switch signal acquisition circuit includes: The import conversion module includes a switch quantity import interface and an analog quantity conversion unit, wherein the input of the switch quantity import interface is connected to the multi-channel switch quantity control switch of the digital welding power source, and the output thereof is collected to the trunk of the analog quantity conversion unit; the analog quantity conversion unit includes a voltage divider network, and the multi-channel switch quantity signals are converted into an analog quantity control signal with multiple amplitudes through the voltage divider network, and each switch quantity signal corresponds to an analog quantity control signal amplitude; The isolation transmission module includes a comparator, a linear optocoupler and an amplifier cascaded in sequence. The input end of the comparator is connected to the output of the analog conversion unit to obtain the amplitude of the analog control signal corresponding to each switching signal and trigger the linear optocoupler to conduct based on the amplitude of the analog control signal. The linear optocoupler transmits the amplitude of the analog control signal to the amplifier in a photoelectric isolation manner, and after amplification by the amplifier, it is output to a sampling interface of the digital welding power supply control module in the form of one signal.
2. The multi-channel switch signal acquisition circuit according to claim 1, characterized in that: The import conversion module includes a wire feeder switch quantity import interface and / or a welding robot switch quantity import interface; the input side of the wire feeder switch quantity import interface is connected to the multi-way switch quantity control switch on the wire feeder, and the input side of the welding robot switch quantity import interface is connected to the multi-way switch quantity control switch on the welding robot; the output ends of the two switch quantity import interfaces are both connected to the main line of the analog quantity conversion unit.
3. The multi-channel switch signal acquisition circuit according to claim 2, characterized in that: The outer side of the switch quantity introduction interface of the wire feeder is respectively connected to the welding switch quantity signal source and the gas detection switch quantity signal source on the wire feeder through two switch quantity control switches to form two parallel switch quantity introduction paths; At any time, only one switch quantity introduction path is turned on and forms a corresponding analog quantity control signal amplitude after conversion by the analog quantity conversion unit.
4. The multi-channel switch signal acquisition circuit according to claim 2, characterized in that: The multiple switch quantity control switches of the welding robot are respectively connected to the multiple voltage-dividing branches of the analog quantity conversion unit through the switch quantity import interface of the welding robot to form a multi-way parallel switch quantity import path. Each voltage-dividing branch in the analog quantity conversion unit has a unique voltage-dividing value. At any time, only one switch quantity import path is turned on and forms the corresponding analog quantity control signal amplitude after conversion by the analog quantity conversion unit.
5. The multi-channel switch signal acquisition circuit according to claim 1, characterized in that: The analog quantity conversion unit also includes a reverse diode connected in parallel with the main circuit resistor and a conversion filter capacitor connected in series between the main circuit resistor and the ground.
6. The multi-channel switch signal acquisition circuit according to claim 1, characterized in that: The isolation transmission module also includes a signal follower, which is connected between the analog quantity conversion unit and the comparator, and follows the analog quantity control signal corresponding to each switching quantity signal to the non-phase terminal of the comparator.
7. The multi-channel switch signal acquisition circuit according to claim 1, characterized in that: The linear optocoupler includes a light-emitting diode, an input-side photodiode and an output-side photodiode. The light-emitting diode is connected to the output of the comparator. The input-side photodiode and the output-side photodiode are turned on based on the output of the comparator. The input-side photodiode is connected between a power supply and the reverse end of the comparator, the output-side photodiode is connected between the inverting end and the non-phase end of the amplifier, and an RC network is also connected between the output-side photodiode and the non-phase end of the amplifier.
8. The multi-channel switch signal acquisition circuit according to claim 1, characterized in that: The multi-channel switch signal acquisition circuit also includes a filtering and regulating module connected to the output end of the isolation transmission module. The isolated analog control signal is filtered and conditioned and then output to a sampling interface of the digital welding power supply control module.
9. A digital welding power source, characterized in that: It comprises the multi-channel switch signal acquisition circuit as described in any one of claims 1 to 8.