Safety interlocking and secondary confirmation loop of isolation door
Through wireless signal transmission and secondary confirmation devices of the transmission module and the receiving module, the problem that the existing electrical interlocking system cannot monitor the isolation door status in real time is solved, and efficient and flexible isolation door status monitoring and safety assurance are achieved.
Patent Information
- Application Number
- CN202422481242.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-14
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-10-14
AI Technical Summary
The existing electrical interlocking system is unable to monitor the specific status of the isolation door in real time, lacks scalability and flexibility, and aging wires lead to unstable signals and pose safety hazards, with high maintenance costs.
The transmission module and receiving module are used for wireless signal transmission, combined with a secondary confirmation device to monitor the isolation door status in real time. The modular design adapts to different needs and prevents the test equipment from starting when the isolation door is not completely closed.
Real-time monitoring of the isolation door status is achieved, which improves the reliability and stability of the system, reduces the maintenance cost caused by aging of wires, and ensures the safety and flexibility of the experiment.
Smart Images
Figure CN223346885U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of electrical equipment, in particular to a safety interlock and secondary confirmation circuit for an isolation door. Background Art
[0002] In the daily operations of electrical equipment laboratories, testing is a crucial step in ensuring product performance, safety, and compliance with national standards. However, these experiments often come with high-risk factors, such as high voltage environments, mechanical impacts, and potential arc flashes, all of which can pose serious threats to laboratory personnel. Therefore, establishing an efficient and reliable safety protection system to ensure the safety of personnel during experiments has become an indispensable part of electrical equipment laboratories.
[0003] To ensure the safety of experimental processes, laboratories typically implement physical isolation measures, namely, installing isolation doors between the experimental site and other areas such as the control room and office area. These isolation doors not only effectively prevent unauthorized personnel from entering the experimental area, but also provide a relatively closed environment during the experiment, reducing external interference and ensuring the accuracy and stability of the experiment. However, relying solely on physical isolation is not enough to completely eliminate safety risks, as potential problems still exist, such as personnel remaining in the experimental site before the experiment begins, isolation doors not being fully closed, or misoperation.
[0004] To address these issues, electrical interlock systems are widely used in existing technologies, integrating the status of isolation doors with the operational control of test equipment. However, the output of existing electrical interlock systems only reflects the overall status of all isolation doors and cannot monitor the specific status of each isolation door in real time. This means that if an isolation door is left ajar due to a fault or its limit switch is damaged, the system cannot accurately identify and locate the problem. In this case, laboratory staff must individually check all isolation doors to determine the fault point, which is undoubtedly a time-consuming and laborious task for large laboratories. Secondly, electrical interlock systems rely on electrical wiring to transmit signals. These wires are prone to aging over time and may even become damaged or exposed. This not only affects signal stability and reliability but also poses electrical safety hazards such as short circuits and leakage. Once a wire is damaged, troubleshooting becomes extremely difficult, requiring a detailed inspection along the complex wiring to identify potential damage points. As laboratory scale expands or experimental requirements change, the number of isolation doors may need to be increased or decreased. However, the hard-wired connection method of existing electrical interlock systems limits their scalability and flexibility, making system adjustments and optimization complex and costly. Because electrical interlock systems involve multiple mechanical and electronic components, routine maintenance and troubleshooting require specialized knowledge and tools. This not only increases laboratory operating costs but can also lead to degraded system performance or increased safety hazards due to untimely maintenance. Utility Model Content
[0005] Addressing the existing problems of electrical interlock systems, which suffer from insufficient monitoring capabilities, system scalability and flexibility, and the tendency of wires to age over long periods of use, the present utility model provides an isolation door safety interlock and secondary confirmation circuit, which improves the monitoring capabilities, system scalability and flexibility of the electrical interlock system. The wireless transmission method avoids the use of large amounts of wires, thereby minimizing the human and material resources required to repair damaged wires.
[0006] In order to achieve the above-mentioned purpose, the present utility model provides the following technical solutions.
[0007] The utility model provides an isolation door safety interlock and secondary confirmation circuit, comprising a transmission module, a receiving module and a secondary confirmation device; the transmission module is used to obtain an isolation door status signal and send the isolation door status signal to the receiving module; the receiving module is used to display the isolation door status according to the isolation door status signal, and adjust the isolation door status to obtain a final isolation door status signal, and send the final isolation door status signal to the secondary confirmation device; the secondary confirmation device is used to start or shut down the test equipment according to the final isolation door status signal and the signal feedback device signal.
[0008] Optionally, the transmission module is connected to a travel switch; the travel switch is set in the closed position of the isolation door, and the transmission module is set in the external area of the isolation door.
[0009] Optionally, the output end of the receiving module is connected to the input end of the secondary confirmation device.
[0010] Optionally, the output end of the receiving module is also connected to a reject button; the output end of the receiving module includes an eleventh output end, a twelfth output end, a twenty-first output end, a twenty-second output end, a thirty-first output end, a thirty-second output end, a forty-first output end and a forty-second output end; the reject buttons include a first reject button, a second reject button, a third reject button and a fourth reject button; the eleventh output end and the twelfth output end are connected to two ends of the first reject button; the twenty-first output end and the twenty-second output end are connected to two ends of the second reject button; the thirty-first output end and the thirty-second output end are connected to two ends of the third reject button; the forty-first output end and the forty-second output end are connected to two ends of the fourth reject button.
[0011] Optionally, one end of the power supply of the receiving module is connected to the eleventh output end; the twelfth output end is connected to the twenty-first output end; the twenty-second output end is connected to the thirty-first output end; the thirty-second output end is connected to the forty-first output end; the forty-second output end is connected to one end of the input end of the secondary confirmation device, and the other end of the input end of the secondary confirmation device is connected to the other end of the power supply of the receiving module.
[0012] Optionally, the receiving module is provided with indicator lights; the number of the indicator lights is equal to the number of the isolation doors.
[0013] Optionally, the output end of the secondary confirmation device is connected to the control relay KA.
[0014] Optionally, the secondary confirmation device is connected to the test equipment via the normally open contact KA1 of the control relay KA.
[0015] Optionally, the secondary confirmation device includes a confirmation device body; and the signal feedback device is installed on the confirmation device body.
[0016] Optionally, there are several signal feedback devices.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] Through the coordinated use of a transmission module and a receiving module, this utility model can accurately acquire and display the isolation door status in real time, thereby enhancing the electrical interlock system's ability to monitor the isolation door status. Real-time monitoring enables timely detection and resolution of abnormal isolation door status, avoiding potential safety hazards. The modular design of the transmission and receiving modules facilitates flexible configuration and expansion according to actual needs. The secondary confirmation device can be customized to suit different test equipment and workflows, improving the system's adaptability and flexibility. Furthermore, the utility model utilizes wireless transmission between the transmission and receiving modules, replacing traditional wired connections. This effectively avoids the problem of wire aging over long-term use. Wireless transmission not only reduces the cost of wire usage and maintenance, but also improves the reliability and stability of the system. By eliminating the need for extensive wiring, the repair effort and cost associated with damaged wires are reduced. The secondary confirmation device determines whether the test equipment is operational based on the final isolation door status signal and the signal feedback device signal. This ensures that the test equipment will not start if the isolation door is not properly closed or locked, or if there is no feedback from the signal feedback device, thereby preventing safety incidents caused by misoperation or equipment failure. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are merely schematic and are used to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention. In the drawings:
[0020] Figure 1 This is an overall schematic diagram of an isolation door safety interlock and secondary confirmation circuit of the utility model;
[0021] Figure 2 This is a schematic diagram of the transmission module of the present utility model;
[0022] Figure 3 This is a schematic diagram of a receiving module of the present invention;
[0023] Figure 4 This is a schematic diagram of the secondary confirmation device of the present utility model.
[0024] In the figure: 101 is the first transmission module; 102 is the second transmission module; 103 is the third transmission module; 104 is the fourth transmission module; 111 is the first travel switch; 112 is the second travel switch; 113 is the third travel switch; 114 is the fourth travel switch; 211 is the eleventh output terminal; 212 is the twelfth output terminal; 213 is the first indicator light; 214 is the first reject button; 221 is the twenty-first output terminal; 222 is the twenty-second output terminal; 223 is the second indicator light; 224 is the second reject button; 231 is the thirty-first output terminal; 232 is the thirty-second output terminal; 233 is the third indicator light; 234 is the third reject button; 241 is the forty-first output terminal; 242 is the forty-second output terminal; 243 is the fourth indicator light; 244 is the fourth reject button; 301 is the secondary confirmation device; 302 is the confirmation device body; 303 is the signal feedback device; 401 is the test equipment. DETAILED DESCRIPTION
[0025] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the following will be combined with the drawings of the embodiments of the present invention to clearly and completely describe the technical solutions of the embodiments of the present invention. Obviously, the embodiments described are only 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 making creative efforts should fall within the scope of protection of the present invention.
[0026] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be an element centered thereon. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an element centered thereon. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.
[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of this invention are for the purpose of describing specific embodiments only and are not intended to limit this invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0028] Glossary:
[0029] Interlocking: The arrangement of operating devices taking into account the following factors: preventing dangerous situations; preventing damage to equipment or materials; preventing specified operations; ensuring correct operation.
[0030] Travel switch: Travel switch, also known as limit switch, is an automatic switch and a type of master electrical appliance. It is usually used to limit the position or stroke of mechanical movement, so that the moving machine can automatically stop, reverse, change speed or automatically move back and forth at a certain position or stroke.
[0031] The utility model discloses a safety interlock and secondary confirmation circuit for an isolation door, comprising a transmission module, a receiving module and a secondary confirmation device.
[0032] like Figure 1 As shown, the transmission module is set on the isolation door, which is used to obtain the isolation door status and transmit the isolation door status signal to the receiving module. The receiving module displays the status of each isolation door according to the isolation door status signal; and transmits the final isolation door status to the secondary confirmation device 301. The secondary confirmation device 301 determines whether the test equipment 401 can be used normally based on the isolation door status signal and the feedback signal of the signal feedback device 303.
[0033] like Figure 2 As shown, the transmission module is arranged at the isolation door, and the power supply of the transmission module is a battery or the like. The limit switch is arranged at the end point of the isolation door closing position. When the isolation door is closed, the limit switch is changed from the normally open state to the closed state, and the signal sent by the transmission module to the receiving module is changed from a low level to a high level.
[0034] The number of transmission modules is adjusted according to the number of isolation doors. When there are four isolation doors, the transmission modules include a first transmission module 101 , a second transmission module 102 , a third transmission module 103 and a fourth transmission module 104 .
[0035] When there are four isolation doors, the travel switches include a first travel switch 111 , a second travel switch 112 , a third travel switch 113 and a fourth travel switch 114 .
[0036] The first transmission module 101 is arranged at the first isolation door, and the first travel switch 111 is arranged at the end of the closing position of the first isolation door. When the first isolation door is closed, the first travel switch 111 is converted from a normally open state to a closed state.
[0037] The second transmission module 102 is arranged at the second isolation door, and the second travel switch 112 is arranged at the end of the closing position of the second isolation door. When the second isolation door is closed, the second travel switch 112 is converted from a normally open state to a closed state.
[0038] The third transmission module 103 is arranged at the third isolation door, and the third travel switch 113 is arranged at the end of the closing position of the third isolation door. When the third isolation door is closed, the third travel switch 113 is converted from a normally open state to a closed state.
[0039] The fourth transmission module 104 is arranged at the fourth isolation door, and the fourth travel switch 114 is arranged at the end of the closing position of the fourth isolation door. When the fourth isolation door is closed, the fourth travel switch 114 is converted from a normally open state to a closed state.
[0040] like Figure 3 As shown, one end of the receiving module power supply is connected to the eleventh output terminal 211 of the receiving module, the twelfth output terminal 212 of the receiving module is connected to the twenty-first output terminal 221 of the receiving module, the twenty-second output terminal 222 of the receiving module is connected to the thirty-first output terminal 231 of the receiving module, the thirty-second output terminal 232 of the receiving module is connected to the forty-first output terminal 241 of the receiving module, the forty-second output terminal 242 of the receiving module is connected to one end of the input terminal of the secondary confirmation device 301, and the other end of the input terminal of the secondary confirmation device 301 is connected to the other end of the receiving module power supply.
[0041] The eleventh output terminal 211 and the twelfth output terminal 212 of the receiving module 1 are connected to both ends of the first reject button 214, the twenty-first output terminal 221 and the twenty-second output terminal 222 of the receiving module 2 are connected to both ends of the second reject button 224, the thirty-first output terminal 231 and the thirty-second output terminal 232 of the receiving module 3 are connected to both ends of the third reject button 234, and the forty-first output terminal 241 and the forty-second output terminal 242 of the receiving module 4 are connected to both ends of the fourth reject button 244;
[0042] The reject button is a self-locking button.
[0043] The receiving module is powered by a battery or the like. When the first isolation door, the second isolation door, the third isolation door and the fourth isolation door are all closed, the first transmission module 101, the second transmission module 102, the third transmission module 103 and the fourth transmission module 104 transmit signals to the receiving module.
[0044] After the receiving module receives high-level signals from the first transmission module 101, the second transmission module 102, the third transmission module 103, and the fourth transmission module 104, the eleventh output terminal 211 and the twelfth output terminal 212 of the receiving module are connected, and the first indicator light 213 is constantly on, thereby indicating the state of the first isolation gate and outputting it; the twenty-first output terminal 221 and the twenty-second output terminal 222 of the receiving module are connected, and the second indicator light 223 is constantly on, thereby indicating the state of the second isolation gate and outputting it; the thirty-first output terminal 231 and the thirty-second output terminal 232 of the receiving module are connected, and the third indicator light 233 is constantly on, thereby indicating the state of the third isolation gate and outputting it; the forty-first output terminal 241 and the forty-second output terminal 242 of the receiving module are connected, and the fourth indicator light 243 is constantly on, thereby indicating the state of the fourth isolation gate and outputting it.
[0045] like Figure 4 As shown, the secondary confirmation device 301 includes a confirmation device body 302 and a signal feedback device 303. The signal feedback device 303 is plugged into the confirmation device body 302. There are multiple signal feedback devices 303.
[0046] The secondary confirmation device 301 has its own power supply connected separately. The output terminal of the secondary confirmation device 301 is connected to the control relay KA, and the normally open contact KA1 of the control relay KA is connected to the test equipment 401 as the output of the interlocking system.
[0047] The secondary confirmation device 301 has a signal intercommunication function, and the secondary confirmation device 301 can perform intercommunication editing.
[0048] When only one secondary confirmation device 301 is used: when all signal feedback devices 303 are in the plugged-in state, the signal feedback device 303 completes signal feedback by default, and when the input end of the secondary confirmation device 301 is at a high level, the output end is also at a high level; when any one of the signal feedback devices 303 is taken out, the secondary confirmation device 301 needs to be at a high level when the input end is high and all signal feedback devices 303 complete signal feedback, and then the output end is at a high level; when the input end of the secondary confirmation device 301 becomes a low level, it needs to repeat the above-mentioned determination procedure.
[0049] When multiple secondary confirmation devices 301 are used to communicate with each other: when the signal feedback devices 303 of all secondary confirmation devices 301 are in the plugged-in state, all secondary confirmation devices 301 are at a high level at the input end, and the output end is at a high level; when any signal feedback device 303 is taken out, all secondary confirmation devices 301 need to have a high level at the input end and all signal feedback devices 303 output a high level at the same time after completing signal feedback. When the input end of any secondary confirmation device 301 becomes a low level, it needs to repeat the above determination procedure.
[0050] The method of using the present invention includes: all personnel entering the experimental site are equipped with a signal feedback device 303, and when the four isolation doors are all closed, the transmission module transmits signals to the receiving device that are all converted from a low level to a high level. At this time, the eleventh output terminal 211 and the twelfth output terminal 212 of the receiving device 1 are connected, the twenty-first output terminal 221 and the twenty-second output terminal 222 of the receiving device 2 are connected, the thirty-first output terminal 231 and the thirty-second output terminal 232 of the receiving device 3 are connected, and the forty-first output terminal 241 and the forty-second output terminal 242 of the receiving device 4 are connected. At the same time, the first indicator light 213, the second indicator light 223, the third indicator light 233, and the fourth indicator light 243 are always on, indicating that the four isolation doors are all in a closed state.
[0051] At this point, the input of the secondary confirmation device 301 is at a high level. After receiving instructions from the experiment leader, the personnel in the experimental site determine their own position. The personnel in the safe area use the signal feedback device 303 to complete signal feedback. When all signal feedback devices 303 complete signal feedback, the output of the secondary confirmation device 301 turns to a high level. The normally open contact KA1 of the control relay KA is energized, and the test equipment 401 can be used normally. When any isolation door is opened, the input of the secondary confirmation device 301 turns to a low level, and the high level of its output disappears. The normally open contact KA1 of the control relay KA is disconnected, and the test equipment 401 cannot be used normally. The power supply to the already applied voltage will be disconnected. At this time, the experimenter needs to judge the status of each isolation door based on the status of the receiving module indicator light. After troubleshooting, the above process can be repeated before the experiment can begin. In addition, the rejection button can remove any one or more isolation doors from the interlocking system according to the actual experimental situation, which is convenient for matching the actual experimental situation.
[0052] This utility model provides an isolation door safety interlock and secondary confirmation circuit. Each isolation door forms a separate circuit consisting of the isolation door, a power supply, a limit switch, and a transmission module. The limit switch collects the status of each isolation door, transmits this status via multiple wireless transmissions, and centrally processes the status of each isolation door via a receiving module. When a single isolation door is closed, the receiving module displays the door's closed state, allowing for timely detection of a door ajar or circuit damage. A rejection mechanism is also provided within the receiving module to facilitate adjustments to the door interlock components under special circumstances. The secondary confirmation circuit includes a secondary confirmation device connected to the output of the receiving module. This device is used to re-confirm the safety of all personnel entering the experimental site after all isolation doors have closed and before the experiment begins, preventing malfunctions of the test equipment in the presence of personnel. The output of the secondary confirmation device is connected to the test equipment control relay. When all isolation doors are closed, the secondary confirmation device input is high. When certain conditions are met, the secondary confirmation device output is high, energizing the control relay and enabling normal operation of the test equipment. If any non-eliminated isolation door is opened, the output of the receiving module is disconnected, the input end of the secondary confirmation device turns to a low level, the output end turns to a low level, the control relay is powered off, and the input side of the test equipment is disconnected. If high voltage is not applied, the test equipment cannot be closed. If high voltage is applied, the high-voltage side of the test equipment is powered off. The experimental process can only be continued after all non-eliminated isolation doors are closed again and the output end of the secondary confirmation device outputs a high level again to ensure the safety of the experimental process.
[0053] In summary, the present invention arranges a separate transmission module on each isolation door and displays the status of each isolation door through a receiving module, so as to facilitate the control of the real-time status of each isolation door and accurately locate any isolation door when it is ajar or damaged, thereby reducing the experimental preparation time and improving the experimental efficiency. Secondly, the present invention avoids the use of a large number of wires through wireless transmission, thereby avoiding the loss of manpower and material resources caused by the repair of damaged wires. At the same time, the present invention adds a safety guarantee before the start of the experiment by setting a secondary confirmation device, thereby avoiding the malfunction of the test equipment caused by the mistaken closure of the isolation door, and ensuring that the experimenters are in a safe position during the experiment, thereby ensuring the standardization and safety of the experimental process. Moreover, the present invention realizes the free combination of the interlocking system by setting a rejection button, thereby meeting the different requirements of interlocking in different experimental situations.
[0054] Upon reading the above description, many embodiments and applications beyond the examples provided will be apparent to those skilled in the art. Therefore, the scope of the present invention should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of completeness, all articles and references, including the disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein from the preceding claims is not a disclaimer of such subject matter, nor should it be interpreted that the applicant did not consider such subject matter to be part of the disclosed subject matter.
[0055] The above content is a further detailed description of the utility model. It cannot be determined that the specific implementation methods of the utility model are limited to this. For ordinary technicians in the technical field to which the utility model belongs, they can make several simple deductions or substitutions without departing from the concept of the utility model, which should be regarded as belonging to the scope of protection of the utility model determined by the submitted claims.
Claims
1. An isolation door safety interlock and secondary confirmation circuit, characterized in that: It includes a transmission module, a receiving module and a secondary confirmation device (301); The transmission module is used to obtain the isolation door status signal and send the isolation door status signal to the receiving module; The receiving module is used to display the isolation door state according to the isolation door state signal, and adjust the isolation door state to obtain a final isolation door state signal, and send the final isolation door state signal to the secondary confirmation device (301); The secondary confirmation device (301) is used to start or shut down the test equipment according to the final isolation door state signal and the signal of the signal feedback device (303).
2. The isolation door safety interlock and secondary confirmation circuit according to claim 1 is characterized in that: The transmission module is connected to the travel switch; The travel switch is arranged at the closed position of the isolation door, and the transmission module is arranged in the outer area of the isolation door.
3. The isolation door safety interlock and secondary confirmation circuit according to claim 1 is characterized in that: The output end of the receiving module is connected to the input end of the secondary confirmation device (301).
4. The isolation door safety interlock and secondary confirmation circuit according to claim 3 is characterized in that: The output end of the receiving module is also connected to a reject button; The output ends of the receiving module include an eleventh output end (211), a twelfth output end (212), a twenty-first output end (221), a twenty-second output end (222), a thirty-first output end (231), a thirty-second output end (232), a forty-first output end (241), and a forty-second output end (242); The reject buttons include a first reject button (214), a second reject button (224), a third reject button (234) and a fourth reject button (244); The eleventh output end (211) and the twelfth output end (212) are connected to two ends of the first rejection button (214); The twenty-first output terminal (221) and the twenty-second output terminal (222) are connected to two ends of the second rejection button (224); The thirty-first output terminal (231) and the thirty-second output terminal (232) are connected to two ends of the third rejection button (234); The forty-first output terminal (241) and the forty-second output terminal (242) are connected to two ends of the fourth rejection button (244).
5. The isolation door safety interlock and secondary confirmation circuit according to claim 4 is characterized in that: One end of the power supply of the receiving module is connected to the eleventh output end (211); The twelfth output terminal (212) is connected to the twenty-first output terminal (221); The twenty-second output terminal (222) is connected to the thirty-first output terminal (231); The thirty-second output terminal (232) is connected to the forty-first output terminal (241); The forty-second output terminal (242) is connected to one end of the input terminal of the secondary confirmation device (301), and the other end of the input terminal of the secondary confirmation device (301) is connected to the other end of the power supply of the receiving module.
6. The isolation door safety interlock and secondary confirmation circuit according to claim 1, characterized in that: The receiving module is provided with an indicator light; The number of the indicator lights is equal to the number of the isolation doors.
7. The isolation door safety interlock and secondary confirmation circuit according to claim 1 is characterized in that: The output end of the secondary confirmation device (301) is connected to the control relay KA.
8. The isolation door safety interlock and secondary confirmation circuit according to claim 7, characterized in that: The secondary confirmation device (301) is connected to the test equipment (401) via the normally open contact KA1 of the control relay KA.
9. The isolation door safety interlock and secondary confirmation circuit according to claim 1, characterized in that: The secondary confirmation device (301) comprises a confirmation device body (302); The signal feedback device (303) is installed on the confirmation device body (302).
10. The isolation door safety interlock and secondary confirmation circuit according to claim 1, characterized in that: The number of the signal feedback devices (303) is several.