Detection circuit and detection method

Abstract

The embodiment of the present disclosure relates to the field of elevators, and provides a detection circuit and a detection method, wherein the detection circuit comprises: a power module; a plurality of parallel safety switch groups, the end of each safety switch being connected to ground; the voltage of the power module and the safety switch groups is detected, it is judged whether the safety switch group is normally grounded or abnormally grounded when the end of the safety switch is connected to ground, the power module is restarted when the safety switch group is normally grounded, and the safety switch is disconnected from the ground; the power module is restarted when the safety switch group is abnormally grounded, and the step of restarting the power module comprises: the power module is restarted in a loop, it is judged whether the safety switch group is restored to normal grounding, the power module is disconnected if the safety switch group is not restored to normal grounding, until the safety switch group is restored to normal grounding, and the safety switch is disconnected from the ground after the safety switch group is restored to normal grounding. The safety switch group can be detected, and the safety switch group can be controlled according to the detection result.

Description

Technical Field

[0001] This disclosure relates to the field of elevators, and in particular to a detection circuit and detection method. Background Technology

[0002] An elevator is a permanent transportation device that serves several specific floors within a building, with its car moving on at least two rigid tracks that are perpendicular to the horizontal plane or have an angle of inclination of less than 15° to the vertical.

[0003] Elevator safety switch failure is a common malfunction during elevator operation. Therefore, rapid diagnosis and timely troubleshooting are crucial to ensuring the normal operation of the elevator. Among these malfunctions, the grounding protection of the safety switch is extremely important. A grounding fault in the safety switch can not only lead to equipment damage and short circuits but also pose a threat to personnel safety.

[0004] Therefore, it is necessary to provide a detection circuit that can detect the safety switch and control the safety switch group based on the detection result. Summary of the Invention

[0005] This disclosure provides a detection circuit and detection method that can at least control a group of safety switches based on the detection results while detecting the safety switch.

[0006] According to some embodiments of this disclosure, one aspect of this disclosure provides a detection circuit for use in an elevator, comprising: a power module for providing a power signal; multiple parallel safety switch groups, each safety switch group including at least one safety switch, the safety switch group also being connected in series with the power module to receive the power signal, and the end of each safety switch being grounded; and a control circuit electrically connected to both the power module and the safety switch groups, respectively detecting the voltage of the power module and the safety switch groups, determining whether the safety switch group to which the safety switch belongs is normally grounded or abnormally grounded when the end of the safety switch is grounded, controlling the power module to restart when the safety switch group is normally grounded, and controlling the safety switch to disconnect from the ground terminal, and attempting to control the power module to restart when the safety switch group is abnormally grounded. The steps of attempting to control the power module to restart include: cyclically controlling the power module to restart, determining whether the safety switch group has returned to normal grounding, disconnecting the power module if it has not returned to normal grounding, until the safety switch group returns to normal grounding, and controlling the safety switch to disconnect from the ground terminal after the safety switch group returns to normal grounding.

[0007] In some embodiments, the control loop includes: an AC / DC module electrically connected to the power module, which detects the voltage generation of the power module and outputs a first detection signal, wherein the first detection signal is a high-level signal when the power module has voltage and a low-level signal when the power module has no voltage; a DC / DC module electrically connected to the safety switch group, which detects the voltage generation of the safety switch group and outputs a second detection signal, wherein the second detection signal is a high-level signal when the safety switch group has voltage and a low-level signal when the safety switch group has no voltage; and a processor electrically connected to both the AC / DC module and the DC / DC module, which receives the first detection signal and the second detection signal, and determines that the safety switch group is abnormally grounded when the first detection signal and the second detection signal are at different levels.

[0008] In some embodiments, the system further includes: a sampling resistor connected between the power module and the safety switch group; and a current detection module that detects the current of the sampling resistor and, during an attempt to control the power module to restart, determines that the safety switch group has not returned to normal grounding if the current of the sampling resistor exceeds a preset value, and determines that the safety switch group has returned to normal grounding if the current of the sampling resistor is within the preset value.

[0009] In some embodiments, during an attempt to control the restart of the power module, the voltage value of the power signal provided by the power module is controlled to be less than or equal to 3V.

[0010] In some embodiments, during the attempt to control the power module restart, the interval between two adjacent power module restarts is 70 to 150 ms.

[0011] In some embodiments, the safety switch group includes a plurality of safety switches connected in series, and the detection circuit further includes: a detection unit, which is electrically connected to one of the safety switches connected in series, for detecting all the safety switches belonging to the safety switch group when the safety switch group is abnormally grounded, and determining which safety switch is abnormally grounded.

[0012] In some embodiments, the power module includes: an AC power supply for providing AC power; a rectifier unit electrically connected to the AC power supply, receiving the AC power to generate and output DC power; and a transformer unit electrically connected to the rectifier unit, receiving the DC power to generate and output the required voltage.

[0013] In some embodiments, the transformer unit includes: a MOSFET, the base of which receives a PWM signal and is turned on by the PWM signal, and the emitter is electrically connected to the negative terminal of the rectifier unit; and a transformer, one end of the primary winding of which is electrically connected to the positive terminal of the rectifier unit, and the other end of which is electrically connected to the collector of the MOSFET, and the secondary winding of which outputs the required voltage.

[0014] In some embodiments, the transformer unit further includes: a diode, the anode of which is electrically connected to the anode of the secondary winding of the transformer; a first capacitor, one end of which is electrically connected to the cathode of the diode and the other end of which is electrically connected to the cathode of the secondary winding; an inductor, one end of which is electrically connected to the cathode of the diode and the other end of which is electrically connected to the safety switch group; and a second capacitor, one end of which is electrically connected to the other end of the inductor and the other end of which is electrically connected to the cathode of the secondary winding.

[0015] According to some embodiments of this disclosure, another aspect of this disclosure also provides a detection method, which can be implemented by the above-described detection circuit, including: detecting the voltage of the power module and the safety switch group respectively; when the end of the safety switch is grounded, determining whether the safety switch group to which the safety switch belongs is normally grounded or abnormally grounded; when the safety switch group is normally grounded, controlling the power module to restart and controlling the safety switch to disconnect from the ground terminal; when the safety switch group is abnormally grounded, attempting to control the power module to restart; the step of attempting to control the power module to restart includes: cyclically controlling the power module to restart, determining whether the safety switch group has returned to normal grounding, and if not, disconnecting the power module until the safety switch group returns to normal grounding, and controlling the safety switch to disconnect from the ground terminal after the safety switch group returns to normal grounding.

[0016] The technical solution provided in this disclosure has at least the following advantages: The control loop can promptly detect and take corresponding measures when the safety switch group is grounded, thereby ensuring the safety and reliability of the elevator and improving the safety of elevator operation. Furthermore, when the safety switch group is normally grounded, the control power module is restarted and the grounded safety switch is no longer grounded, allowing the entire elevator to continue operating without manual reset, saving labor costs. When the safety switch group is abnormally grounded, an attempt is made to restart the control power module. This attempt does not run the entire elevator, preventing safety hazards and allowing the system to determine if the abnormality has been resolved. Once the abnormality is resolved, the control power module is restarted and the grounded safety switch is no longer grounded, allowing the entire elevator to continue operating again without manual reset, saving labor costs. Moreover, different control measures are adopted for normal and abnormal grounding situations, balancing safety and ease of use. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A circuit diagram of a detection circuit provided in one embodiment of this disclosure;

[0019] Figure 2 Another circuit diagram of the detection circuit provided in one embodiment of this disclosure;

[0020] Figure 3 A timing diagram of a detection circuit provided in an embodiment of this disclosure;

[0021] Figure 4 This is a flowchart of a detection method provided in one embodiment of the present disclosure. Detailed Implementation

[0022] As can be seen from the background technology, it is currently necessary to monitor the grounding status of safety switches.

[0023] This disclosure provides a detection circuit that can promptly detect and take corresponding measures when the safety switch group is grounded through a control loop, thereby ensuring the safety and reliability of the elevator and improving the safety of elevator operation. Furthermore, when the safety switch group is normally grounded, the power module is restarted and the grounded safety switch is de-grounded, allowing the elevator to continue operating without manual reset, saving labor costs. When the safety switch group is abnormally grounded, the power module is restarted, but this attempt does not run the entire elevator, avoiding safety hazards and allowing the system to determine if the abnormality has been resolved. Once resolved, the power module is restarted and the grounded safety switch is de-grounded, allowing the elevator to continue operating again without manual reset, saving labor costs. Moreover, different control measures are adopted for normal and abnormal grounding situations, balancing safety and ease of use.

[0024] Terms such as "first" or "second" may be used to describe various components, but these components are not limited by the terms described above. The terms described above are used to distinguish one component from another; for example, without departing from the scope of the concept according to this disclosure, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

[0025] Furthermore, "connected / linked" indicates that one component is directly electrically connected to another component or indirectly electrically connected through another component. Unless otherwise explicitly stated in the sentence, the singular form may include the plural form. Additionally, the terms "comprising / including" or "containing / including" as used in this specification indicate the presence or addition of one or more components, steps, operations, and elements. Specific structural or functional descriptions of examples of embodiments of the concepts disclosed in this specification are merely illustrative to describe examples of embodiments of the concepts, and examples of embodiments of the concepts can be implemented in various forms, but these descriptions are not limited to the examples of embodiments described in this specification.

[0026] Based on the concept, various modifications and changes can be applied to examples of embodiments, such that examples of embodiments will be illustrated in the accompanying drawings and described in the specification. However, examples of embodiments based on the concept are not limited to specific embodiments, but include all changes, equivalents, or substitutions included within the spirit and scope of this disclosure.

[0027] It should be understood that when describing an element as "connected" or "linked" to another element, the element may be directly connected or linked to the other element, or it may be connected or linked to the other element via a third element. Conversely, it should be understood that when an element is described as "directly connected to" or "directly linked to" another element, no other element is placed between them. Other expressions describing relationships between components (i.e., "between" and "directly between" or "adjacent to" and "directly adjacent to") need to be interpreted in the same way.

[0028] The terminology used in this specification is for the purpose of describing specific examples of implementations only and is not intended to limit this disclosure. The singular form may include the plural form unless there is an explicit contrary meaning in the context. It should be understood in this specification that the terms "comprising" or "having" indicate the presence of the features, quantities, steps, operations, components, parts, or combinations thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, quantities, steps, operations, components, parts, or combinations thereof.

[0029] Unless otherwise defined, all terms used herein (including technical or scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art. If a term is not clearly defined in a common dictionary in this specification, it shall be interpreted as having the same meaning as in the context of the relevant art, and not as an ideal or overly formal meaning.

[0030] Descriptions of known components and processing techniques may be omitted to avoid unnecessarily obscuring the embodiments of this disclosure.

[0031] Throughout this specification, the same reference numerals refer to the same elements. Therefore, even if a reference numeral is not mentioned or described with reference to one drawing, it may be mentioned or described with reference to another drawing. Furthermore, even if a reference numeral is not shown in one drawing, it may be mentioned or described with reference to another drawing.

[0032] Additionally, the logic level of a signal may be different from or opposite to the logic level described. For example, a signal described as having a logic "high" level may optionally have a logic "low" level, and a signal described as having a logic "low" level may optionally have a logic "high" level.

[0033] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the disclosure. However, the technical solutions claimed in this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0034] refer to Figures 1 to 3 , Figure 1 A circuit diagram of a detection circuit provided in one embodiment of this disclosure; Figure 2 Another circuit diagram of the detection circuit provided in one embodiment of this disclosure. Figure 3 This is a timing diagram of a detection circuit provided in one embodiment of the present disclosure. It should be noted that... Figure 3 The ABCDE in the middle are respectively Figure 2 A voltage diagram of the signals at positions A, B, C, D, and E in the diagram.

[0035] In some embodiments, the detection circuit may include a power supply module 100, which provides a power signal.

[0036] The detection circuit may also include: multiple parallel safety switch groups 101, each safety switch group 101 including at least one safety switch 111, the safety switch group 101 being connected in series with the power module 100 to receive power signals, and the end system of each safety switch 111 being grounded.

[0037] The detection circuit may further include: a control loop 102, which is electrically connected to the power module 100 and the safety switch group 101 respectively. The control loop 102 detects the voltage of the power module 100 and the safety switch group 101 respectively. When the end of the safety switch 111 is grounded, it determines whether the safety switch group 101 to which the safety switch 111 belongs is normally grounded or abnormally grounded. When the safety switch group 101 is normally grounded, it controls the power module 100 to restart and controls the safety switch 111 to disconnect from the ground. When the safety switch group 101 is abnormally grounded, it attempts to control the power module 100 to restart. The steps of attempting to control the power module 100 to restart include: cyclically controlling the power module 100 to restart, determining whether the safety switch group 101 has returned to normal grounding, and if it has not returned to normal grounding, disconnecting the power module 100 until the safety switch group 101 returns to normal grounding. After the safety switch group 101 returns to normal grounding, it controls the safety switch 111 to disconnect from the ground.

[0038] This disclosure provides a detection circuit that, through control loop 102, can promptly detect and take corresponding measures when the safety switch group 101 is grounded, thereby ensuring the safety and reliability of the elevator and improving the safety of elevator operation. Furthermore, when the safety switch group 101 is normally grounded, the control power module 100 is restarted and the grounded safety switch 111 is de-grounded, allowing the entire elevator to continue operating without manual reset, saving labor costs. When the safety switch group 101 is abnormally grounded, an attempt is made to restart the control power module 100. This attempt does not run the entire elevator, preventing safety hazards and allowing the system to determine if the abnormality has been resolved. Once the abnormality is resolved, the control power module 100 is restarted and the grounded safety switch 111 is de-grounded, allowing the entire elevator to continue operating again without manual reset, saving labor costs. Moreover, different control measures are adopted for normal and abnormal grounding situations, balancing safety and ease of use.

[0039] In some embodiments, the power module 100 may include: an AC power supply 110 for providing AC power; a rectifier unit 120 electrically connected to the AC power supply 110, receiving the AC power to generate DC power; and a transformer unit 130 electrically connected to the rectifier unit 120, receiving the DC power to generate and outputting the required voltage. By setting the AC power supply 110, it can directly utilize the power grid, thus facilitating the wiring and operation of the entire detection circuit. While the rectifier unit 120 converts AC power to DC power, the generated voltage may not be the required voltage during the conversion process. Therefore, the transformer unit 130 is also provided to generate the required voltage.

[0040] It should be noted that AC220V in the figure is an example of the voltage that AC power supply 110 can provide, and is not a limitation on AC power supply.

[0041] In some embodiments, a thermistor RTC may also be included, which is connected in series between the AC power supply 110 and the rectifier unit 120. The thermistor RTC can protect the entire detection circuit.

[0042] The rectifier unit 120 can be a half-wave rectifier circuit, a full-wave rectifier circuit, or a bridge rectifier circuit, etc.

[0043] In some embodiments, the transformer unit 130 may include: a MOSFET Q1, the base of which receives a PWM signal and is turned on by the PWM signal, and the emitter of which is electrically connected to the negative terminal of the rectifier unit 120; and a transformer 140, one end of the primary winding of which is electrically connected to the positive terminal of the rectifier unit, and the other end of which is electrically connected to the collector of the MOSFET Q1, and the secondary winding of which outputs the required voltage.

[0044] The voltage value output through the MOSFET Q1 can be controlled by controlling the duty cycle of the PWM signal. Different voltages can be output according to different needs. With the cooperation of the primary and secondary coils of the transformer 140, the required voltage can be output smoothly. Moreover, by receiving the PWM signal through the MOSFET Q1 and cooperating with the transformer 140, the large voltage can be converted into the required small voltage.

[0045] In some embodiments, the transformer unit 130 may further include: a diode D1, the anode of which is electrically connected to the anode of the secondary winding of the transformer 140; a first capacitor C1, one end of which is electrically connected to the cathode of the diode D1, and the other end of which is electrically connected to the cathode of the secondary winding; an inductor L1, one end of which is electrically connected to the cathode of the diode D1, and the other end of which is electrically connected to the safety switch group 101; and a second capacitor C2, one end of which is electrically connected to the other end of the inductor L1, and the other end of which is electrically connected to the cathode of the secondary winding. The unidirectional conductivity of the diode D1 can be used to control the current flow, thereby ensuring the normal operation of the detection circuit. The cooperation of the first capacitor C1, the inductor L1, and the second capacitor C2 can filter the voltage output through the diode D1, thereby improving the reliability of the voltage output by the power module 100, and thus improving the reliability of the detection circuit.

[0046] In some embodiments, the power module 100 may further include a third capacitor C3, which is connected in parallel across the primary winding of the transformer 140. The third capacitor C3 can also filter the voltage transmitted from the rectifier unit 120 to the transformer unit 130, thereby improving the reliability of voltage transmission.

[0047] In some embodiments, the safety switch group 101 includes multiple safety switches 111 connected in series. The detection circuit further includes a detection unit 104, which is electrically connected to a safety switch 111 connected in series. The detection unit 104 is used to detect all safety switches 111 belonging to the safety switch group 101 when the safety switch group 101 is abnormally grounded, and to determine which safety switch 111 is abnormally grounded.

[0048] Understandably, safety switch groups 101 are connected in parallel, so it is easy to determine which safety switch group 101 is experiencing a grounding fault. However, there may be multiple safety switches 111 within a safety switch group 101, making it more difficult to determine which safety switch 111 is experiencing a grounding fault. Therefore, a detection unit 104 is also provided, which is electrically connected to a safety switch 111. When a grounding fault occurs in a safety switch group 101, the detection unit 104 can be used to directly determine which safety switch 111 is experiencing the fault.

[0049] The detection unit 104 can determine whether the safety switch 111 has a grounding abnormality by: outputting a high-level signal when the safety switch 111 is not grounded, outputting a low-level signal when the safety switch 111 is grounded, and determining that the safety switch 111 has a grounding phenomenon when the detection unit 104 outputs a low-level signal.

[0050] It should be noted that only two detection units 104 are shown in the figure. In reality, each safety switch can be configured to have a corresponding detection unit 104 connected to it.

[0051] The safety switch 111 within the safety switch group 101 may include: car top inspection switch, safety gear electrical switch, inspection operation switch, inspection upward switch, inspection downward switch, car door lock switch, etc.; the safety switch 111 may also include: buffer switch, clamping rope electrical switch, speed governor electrical switch, upper limit switch, lower limit switch, landing door lock switch, etc.; the safety switch 111 may also include: pit switch box emergency stop switch, speed governor tension wheel rope breakage switch, pit inspection box switch, etc.

[0052] For control loop 102, in some embodiments, control loop 102 may include: AC / DC module 112, which is electrically connected to power module 100, detects the voltage generation of power module 100 and outputs a first detection signal, the first detection signal being a high-level signal when there is voltage in power module 100 and a low-level signal when there is no voltage in power module 100; DC / DC module 122, which is electrically connected to safety switch group 101, detects the voltage generation of safety switch group 101 and outputs a second detection signal, the second detection signal being a high-level signal when there is voltage in safety switch group 101 and a low-level signal when there is no voltage in safety switch group 101; and processor 132, which is electrically connected to AC / DC module 112 and DC / DC module 122 respectively, receives the first detection signal and the second detection signal, and determines that safety switch group 101 is abnormally grounded when the first detection signal and the second detection signal are different level signals.

[0053] Referring to the table below, the number 1 represents a high-level signal and the number 0 represents a low-level signal. It can be seen that when a low-level signal is detected in the safety switch group 101, the voltage of the power module 100 needs to be detected through the AC / DC module 112. When there is voltage in the power module 100, it indicates that there is an abnormal grounding phenomenon in the safety switch group 101. When there is no voltage in the power module 100, it indicates that the grounding situation is normal and not a fault. It is only necessary to try to restart the power module 100.

[0054]

[0055] Table 1

[0056] It should be noted that when the power module 100 is de-energized, regardless of whether the safety switch group 101 is grounded or not, the detection safety switch group 101 will output a low-level signal, because there is no voltage signal on the entire detection circuit at this time. Moreover, when the power module is de-energized, the safety switch group 101 will not pose a safety hazard, because the entire power supply system will not have power and will not operate.

[0057] In some embodiments, the detection circuit may further include: a sampling resistor R1 connected between the power module 100 and the safety switch group 101; and a current detection module 105 that detects the current of the sampling resistor R1 and, during an attempt to restart the power module 100, determines that the safety switch group 101 has not returned to normal grounding if the current of the sampling resistor R1 exceeds a preset value, and determines that the safety switch group 101 has returned to normal grounding if the current of the sampling resistor R1 is within the preset value.

[0058] The sampling resistor R1 and the current detection module 105 determine whether the safety switch group 101 in the detection circuit has been repaired. When the safety switch group 101 is still in an abnormal grounding state, the current detection module 105 will detect that the current on the sampling resistor R1 is too large. Therefore, the voltage input can be stopped by controlling the power supply module 100 to be disconnected until the safety switch group 101 is repaired.

[0059] It is understandable that, with a fixed sampling resistor R1, by controlling the output voltage of the power supply module 100 to be constant, a expected current value will be obtained. When the current detection module 105 detects that the current on the sampling resistor R1 is too large, it indicates that the safety switch group 101 is still in an abnormal grounding state.

[0060] In some embodiments, during the restart of the power module 100, the voltage value of the power signal provided by the power module 100 is less than or equal to 3V. By providing a voltage less than or equal to 3V, safety hazards can be avoided. On the one hand, it avoids situations where maintenance personnel are still performing maintenance and suddenly a large voltage is applied. On the other hand, it also avoids the possibility of large voltage being supplied to components in the detection circuit under abnormal conditions, thereby improving the reliability of the entire detection circuit.

[0061] In some embodiments, the interval between two consecutive restarts of the power module 100 is controlled to be 70–150 ms, for example, 80 ms, 90 ms, 100 ms, 110 ms, 120 ms, 130 ms, or 140 ms, etc. The shorter the interval between two consecutive restarts of the power module 100, the more timely the recovery of the entire detection module. However, a shorter interval also increases the likelihood of overload in the power module 100. Therefore, by controlling the interval between two consecutive restarts of the power module 100 to be 70–150 ms, both the reliability of the entire detection circuit and the timeliness of its recovery can be considered.

[0062] This disclosure provides a detection circuit that, through control loop 102, can promptly detect and take corresponding measures when the safety switch group 101 is grounded, thereby ensuring the safety and reliability of the elevator and improving the safety of elevator operation. Furthermore, when the safety switch group 101 is normally grounded, the control power module 100 is restarted and the grounded safety switch 111 is de-grounded, allowing the entire elevator to continue operating without manual reset, saving labor costs. When the safety switch group 101 is abnormally grounded, an attempt is made to restart the control power module 100. This attempt does not run the entire elevator, preventing safety hazards and allowing the system to determine if the abnormality has been resolved. Once the abnormality is resolved, the control power module 100 is restarted and the grounded safety switch 111 is de-grounded, allowing the entire elevator to continue operating again without manual reset, saving labor costs. Moreover, different control measures are adopted for normal and abnormal grounding situations, balancing safety and ease of use.

[0063] Another embodiment of this disclosure also provides a detection method, which can be implemented by the detection circuits in some or all of the above embodiments. The detection method provided by another embodiment of this disclosure will be described below with reference to the accompanying drawings. It should be noted that the same or corresponding parts of the foregoing embodiments can be referred to the corresponding descriptions of the foregoing embodiments, and will not be repeated below.

[0064] refer to Figure 4 , Figure 4 This is a flowchart of a detection method provided in one embodiment of the present disclosure.

[0065] In some embodiments, the detection method may include: S10. Detecting the voltage of the power module and the safety switch group respectively, and determining whether the safety switch group to which the safety switch belongs is normally grounded or abnormally grounded when the end of the safety switch is grounded.

[0066] The detection method may include: S11. When the safety switch group is normally grounded, control the power module to restart and control the safety switch to disconnect from the ground. When the safety switch group is abnormally grounded, attempt to control the power module to restart. The steps of attempting to control the power module to restart include: cyclically controlling the power module to restart, determining whether the safety switch group has returned to normal grounding, and if it has not returned to normal grounding, disconnecting the power module until the safety switch group returns to normal grounding, and controlling the safety switch to disconnect from the ground after the safety switch group returns to normal grounding.

[0067] On the one hand, the detection method provided in this embodiment can detect whether the safety switch group is abnormally grounded. On the other hand, the detection method provided in this embodiment can also attempt to automatically restore the operation of the entire detection system when the safety switch group is grounded, thereby improving the timely recovery of the detection circuit.

[0068] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.

Claims

1. A detection circuit for use inside an elevator, characterized in that, include: A power module, wherein the power module is used to provide a power signal; Multiple safety switch groups connected in parallel, each safety switch group including at least one safety switch, the safety switch group also being connected in series with the power module to receive the power signal, and the end system of each safety switch being grounded; A control loop is provided, which is electrically connected to both the power module and the safety switch group. The control loop detects the voltage of both the power module and the safety switch group. When the end of the safety switch is grounded, it determines whether the safety switch group to which the safety switch belongs is normally grounded or abnormally grounded. If the safety switch group is normally grounded, the control loop restarts the power module and disconnects the safety switch from the ground. If the safety switch group is abnormally grounded, the control loop attempts to restart the power module. The steps of attempting to restart the power module include: cyclically controlling the power module to restart, determining whether the safety switch group has returned to normal grounding, disconnecting the power module if it has not, until the safety switch group returns to normal grounding, and disconnecting the safety switch from the ground after the safety switch group returns to normal grounding.

2. The detection circuit according to claim 1, characterized in that, The control loop includes: An AC / DC module, which is electrically connected to the power supply module, detects the voltage of the power supply module, generates and outputs a first detection signal, which is a high-level signal when there is voltage in the power supply module and a low-level signal when there is no voltage in the power supply module. The DC / DC module is electrically connected to the safety switch group, detects the voltage of the safety switch group, generates and outputs a second detection signal. The second detection signal is a high-level signal when there is voltage in the safety switch group and a low-level signal when there is no voltage in the safety switch group. The processor is electrically connected to the AC / DC module and the DC / DC module respectively, receives the first detection signal and the second detection signal, and determines that the safety switch group is abnormally grounded when the first detection signal and the second detection signal are different level signals.

3. The detection circuit according to claim 1, characterized in that, Also includes: A sampling resistor is connected between the power module and the safety switch group; A current detection module detects the current in the sampling resistor, and during an attempt to restart the power module, if the current in the sampling resistor exceeds a preset value, it determines that the safety switch group has not been restored to normal grounding; if the current in the sampling resistor is within the preset value, it determines that the safety switch group has been restored to normal grounding.

4. The detection circuit according to claim 1, characterized in that, The safety switch group includes multiple safety switches connected in series, and the detection circuit further includes: A detection unit, which is electrically connected to one of the safety switches connected in series, is used to detect all the safety switches belonging to the safety switch group when the safety switch group is abnormally grounded, and to determine which safety switch is abnormally grounded.

5. The detection circuit according to any one of claims 1 to 4, characterized in that, During the attempt to control the restart of the power module, the voltage value of the power signal provided by the power module is controlled to be less than or equal to 3V.

6. The detection circuit according to any one of claims 1 to 4, characterized in that, During the attempt to control the restart of the power module, the interval between two consecutive restarts of the power module is 70 to 150 ms.

7. The detection circuit according to claim 1, characterized in that, The power module includes: An AC power source, wherein the AC power source is used to provide AC power; A rectifier unit, electrically connected to the AC power supply, receives the AC power and generates DC power; a transformer unit, electrically connected to the rectifier unit, receives the DC power and generates the required voltage.

8. The detection circuit according to claim 7, characterized in that, The transformer unit includes: The MOSFET receives a PWM signal at its base and is turned on by the PWM signal, while its emitter is electrically connected to the negative terminal of the rectifier unit. The transformer, wherein one end of the primary winding of the transformer is electrically connected to the positive terminal of the rectifier unit, and the other end is connected to the... The collector of the MOSFET is electrically connected, and the secondary coil of the transformer outputs the required voltage.

9. The detection circuit according to claim 8, characterized in that, The transformer unit also includes: A diode, wherein the anode of the diode is electrically connected to the anode of the secondary winding of the transformer; A first capacitor, one end of which is electrically connected to the negative terminal of the diode, and the other end of which is electrically connected to the negative terminal of the secondary coil; An inductor, one end of which is electrically connected to the negative terminal of the diode, and the other end of which is electrically connected to the safety switch group; The second capacitor has one end electrically connected to the other end of the inductor and the other end electrically connected to the negative terminal of the secondary coil.

10. A detection method, characterized in that, Implemented by the detection circuit according to any one of claims 1 to 9, comprising: The voltages of the power module and the safety switch group are detected respectively. When the end of the safety switch is grounded, it is determined whether the safety switch group to which the safety switch belongs is normally grounded or abnormally grounded. When the safety switch group is normally grounded, the power module is controlled to restart, and the safety switch is controlled to disconnect from the ground. When the safety switch group is abnormally grounded, the power module is attempted to restart. The steps of attempting to restart the power module include: cyclically controlling the power module to restart, determining whether the safety switch group has returned to normal grounding, disconnecting the power module if it has not returned to normal grounding, until the safety switch group returns to normal grounding, and disconnecting the safety switch from the ground after the safety switch group returns to normal grounding.

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