Escalator safety circuit ground short circuit detection circuit

Abstract

The utility model discloses an escalator safety circuit ground short circuit detection circuit, and relates to the technical field of escalators, and the escalator safety circuit ground short circuit detection circuit comprises an input circuit which is used for inputting an electric signal of an escalator safety circuit into a photoelectric coupler; the input end of the photoelectric coupler is connected with the input circuit, and the photoelectric coupler is used for carrying out signal conversion processing on the electric signals and transmitting the electric signals to a main control circuit; the main control circuit is connected with the output end of the photoelectric coupler, and the main control circuit is used for controlling the running state of the escalator. According to the method, the accuracy of judging the grounding of the safety circuit of the escalator is improved, and the safety of the escalator is improved.

Description

Technical Field

[0001] This utility model relates to the field of escalator technology, and more specifically to an escalator safety circuit short-circuit detection circuit to ground. Background Technology

[0002] In the field of escalator technology, the safety circuit protection grounding of escalators and moving walkways mostly utilizes residual current devices (RCDs) to detect the leakage current of the safety circuit to the ground wire, thereby determining whether a grounding fault has occurred. When a grounding fault occurs in the safety circuit, the RCD will automatically trip, de-energizing the downstream circuits of the safety circuit, thus providing ground protection for the safety circuit and ensuring safer operation of escalators and moving walkways.

[0003] However, using a residual current device (RCD) to detect whether the safety circuit is grounded is affected by the impedance of the safety circuit and the impedance to ground, which may result in the grounding protection failing to detect the grounding, causing danger. Therefore, there is an urgent need for an escalator safety circuit grounding short circuit detection circuit that can overcome the above problems. Utility Model Content

[0004] The purpose of this invention is to provide a short-circuit detection circuit for escalator safety circuits to ground, thereby increasing the accuracy of grounding detection of escalator safety circuits and enhancing escalator safety.

[0005] To achieve the above objectives, this utility model provides an escalator safety circuit ground short-circuit detection circuit, comprising:

[0006] The input circuit is used to input the electrical signal of the escalator safety circuit into the optocoupler;

[0007] An optocoupler is connected to an input circuit. It is used to convert electrical signals and transmit them to the main control circuit.

[0008] The main control circuit is connected to the output of the optocoupler and is used to control the operating status of the escalator.

[0009] In another embodiment, the input circuit includes:

[0010] The optocoupler pre-amplifier step-down input circuit has its input terminal connected to the escalator safety circuit. The optocoupler pre-amplifier step-down input circuit is used to step down the electrical signal of the escalator safety circuit.

[0011] In another embodiment, the input circuit further includes:

[0012] The rectifier and filter circuit has its input terminal connected to the output terminal of the optocoupler pre-stage step-down input circuit. The rectifier and filter circuit is used to rectify and filter electrical signals.

[0013] The output of the rectifier filter circuit is connected to the input of the optocoupler to input electrical signals into the optocoupler.

[0014] In another embodiment, the main control circuit includes:

[0015] The output circuit after optocoupler processing is used to output the electrical signal processed by the optocoupler.

[0016] In another embodiment, the main control circuit further includes:

[0017] The main controller's input is connected to the output of the optocoupler's output circuit. The main controller is used to control the escalator's operating status based on the electrical signal output by the optocoupler's output circuit.

[0018] In another embodiment, the present invention provides an escalator that includes the escalator safety circuit ground short-circuit detection circuit of any of the above embodiments.

[0019] The beneficial effects of this utility model are as follows:

[0020] The escalator safety circuit short-circuit detection circuit of this utility model includes: an input circuit for inputting the electrical signal of the escalator safety circuit into an optocoupler; an optocoupler whose input terminal is connected to the input circuit, used for signal conversion processing of the electrical signal and transmission of the electrical signal to the main control circuit; and a main control circuit connected to the output terminal of the optocoupler, used for controlling the operating state of the escalator. This utility model eliminates the traditional reliance on a leakage current device (RCD) to detect short circuits in the escalator safety circuit. When a short circuit occurs in the escalator safety circuit, the electrical signal can be directly transmitted to the optocoupler, and then the main control circuit controls the operating state of the escalator. This design is not affected by ground impedance, greatly increasing the accuracy of grounding detection of the escalator safety circuit and enhancing the safety of the escalator.

[0021] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of an escalator safety circuit ground short circuit detection circuit according to an embodiment of this application;

[0023] Figure 2 This is a circuit diagram of an escalator safety circuit ground short circuit detection circuit according to an embodiment of this application. Detailed Implementation

[0024] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0025] It should be noted that references to "an embodiment," "embodiment," "example embodiment," etc., in this specification refer to the described embodiment including specific features, structures, or characteristics; however, not every embodiment must include these specific features, structures, or characteristics. Furthermore, such expressions do not refer to the same embodiment. Moreover, when describing specific features, structures, or characteristics in conjunction with embodiments, whether or not explicitly described, it is indicated that incorporating such features, structures, or characteristics into other embodiments is within the knowledge of those skilled in the art.

[0026] Furthermore, certain terms are used in the specification and subsequent claims to refer to specific components or parts. Those skilled in the art will understand that manufacturers may use different names or terms to refer to the same component or part. This specification and subsequent claims do not distinguish components or parts by differences in name, but rather by differences in function. The terms "comprising" and "including" used throughout the specification and subsequent claims are open-ended and should be interpreted as "including but not limited to." Additionally, the term "connection" here includes any direct and indirect electrical connection means. Indirect electrical connection means include connections made through other means.

[0027] Please see Figures 1-2 The escalator safety circuit ground short circuit detection circuit includes: an input circuit, which is used to input the electrical signal of the escalator safety circuit into an optocoupler; an optocoupler, whose input terminal is connected to the input circuit, which is used to perform signal conversion processing on the electrical signal and transmit the electrical signal to the main control circuit; and a main control circuit, which is connected to the output terminal of the optocoupler, which is used to control the operating status of the escalator.

[0028] Optionally, the input circuit includes: an optocoupler pre-stage step-down input circuit, the input terminal of which is connected to the escalator safety circuit, used to step down the voltage of the electrical signal from the escalator safety circuit; a rectifier and filter circuit, the input terminal of which is connected to the output terminal of the optocoupler pre-stage step-down input circuit, used to rectify and filter the electrical signal; and an output terminal of which is connected to the input terminal of the optocoupler, used to input the electrical signal into the optocoupler. The main control circuit includes: an optocoupler post-stage output circuit, used to output the electrical signal processed by the optocoupler; and a main controller, the input terminal of which is connected to the output terminal of the optocoupler post-stage output circuit, used to control the escalator's operating status based on the electrical signal output by the optocoupler post-stage output circuit.

[0029] The optocoupler preamplifier step-down input circuit features protection: the step-down circuit protects the LED portion of the optocoupler from damage caused by excessively high input voltage. Especially for AC input voltage, the step-down circuit provides necessary current limiting to prevent excessive current from damaging the optocoupler. Signal conditioning: In addition to simple voltage reduction, the preamplifier circuit may also need to filter and rectify the signal to ensure that the optocoupler receives a stable and clear signal. Electrical isolation: The step-down and signal conditioning functions of the optocoupler preamplifier circuit ensure electrical isolation between the high-voltage and low-voltage control terminals, thereby improving system safety and stability. The optocoupler preamplifier step-down input circuit consists of resistors R1-R12, capacitor C1, and Zener diode D1.

[0030] A rectifier-filter circuit performs two functions: rectification and filtering. Rectification is the process of converting alternating current (AC) into direct current (DC). Alternating current changes periodically, with its voltage and current directions constantly reversing. Direct current, on the other hand, has a unidirectional current flow. The role of the rectifier circuit is to "cut off" the negative half-cycle of the AC current, ensuring that the current always flows in one direction. Since the rectified output voltage is not a perfectly stable DC voltage but exhibits significant pulsation, typically appearing as periodic fluctuations, this pulsating voltage is undesirable for most electronic circuits, especially for devices with high power supply requirements. Therefore, a filter circuit is needed to smooth out these fluctuations as much as possible. The rectifier-filter circuit consists of input current-limiting resistors R13 and R14, capacitors C2, C3, and C4, and rectifier diodes D2 and D3.

[0031] An optocoupler is an electronic component that uses optical signals for signal transmission. It achieves electrical isolation between the input and output terminals through the photoelectric effect. Its main functions are as follows: 1. Electrical isolation: The most important function of an optocoupler is to provide electrical isolation. It isolates the input and output circuits, thus avoiding direct electrical contact between them. This isolation effectively protects low-voltage circuits from interference from high-voltage or noisy circuits. 2. Signal transmission: Optocouplers transmit signals through built-in LEDs and photosensitive elements (such as phototransistors and photodiodes). The electrical signal at the input terminal drives the LED to emit light, and the light signal emitted by the LED is received by the photosensitive element at the output terminal and converted into an electrical signal. Because optocouplers use light as the signal transmission medium, there is no direct electrical connection between different circuits, thus avoiding common-ground interference. 3. Strong anti-interference capability: The electrical isolation provided by optocouplers also enhances the system's immunity to electromagnetic interference (EMI) and common-mode noise suppression. In high-frequency, high-noise environments, optocouplers can effectively prevent electromagnetic interference from power supplies, switching components, or other electrical equipment from affecting the system. 4. Protecting low-voltage circuits: Optocouplers can effectively protect low-voltage circuits from excessive voltage or current. For example, many industrial automation devices use optocouplers to isolate the signal input from the high-voltage side of the control system from the low-voltage circuit, preventing damage to the control system caused by high voltage. 5. Enabling signal transmission between different voltage systems: In multi-voltage systems, optocouplers can enable signal transmission between different voltage levels. For example, in some complex power supply systems, high-voltage AC signals can be transmitted to low-voltage control circuits through optocouplers without direct connection, thus avoiding the safety risks caused by voltage mismatch. 6. Enabling unidirectional or bidirectional communication: While optocouplers are commonly configured for unidirectional signal transmission, bidirectional optocouplers are also available, enabling bidirectional data communication between the two ends. This is very useful for applications requiring bidirectional signal transmission (such as certain serial communication protocols).

[0032] The function of the output circuit after optocoupler stage is to receive the signal from the optocoupler and convert it into an electrical signal or action suitable for controlling the target load. Optocouplers typically output a relatively weak signal (such as current or voltage signals passing through a phototransistor), which usually requires further processing to drive the load. The output circuit amplifies or converts the signal output by the optocoupler into an electrical signal suitable for driving the target load. The output circuit after optocoupler stage consists of resistors R15 and R16, and capacitors C5 and C6.

[0033] The main controller can control the operating status of the escalator.

[0034] Specifically, when a short circuit occurs between the safety circuit input power supply 24V+, 24V- and ground PE, the electrical signal generated by the safety circuit is transmitted to the optocoupler pre-stage step-down input circuit. The optocoupler pre-stage step-down input circuit reduces the voltage of the electrical signal to a voltage range acceptable to the optocoupler, typically a few volts of DC voltage, and inputs it to the rectifier and filter circuit. The true transformer filter circuit converts AC power into a stable DC power supply. Through rectification, the waveform of the AC signal is converted into a unidirectional pulsating DC signal, while filtering reduces these pulsations, making the output voltage more stable. This signal is then input to the optocoupler, which performs photoelectric conversion on the electrical signal and inputs it to the optocoupler post-stage output circuit. The optocoupler post-stage output circuit amplifies the electrical signal and transmits it to the main control circuit, which then controls the escalator to stop running.

[0035] In the above embodiment, the escalator safety circuit short-circuit detection circuit includes: an input circuit for inputting the electrical signal of the escalator safety circuit into an optocoupler; an optocoupler whose input terminal is connected to the input circuit, used for signal conversion processing of the electrical signal and transmission of the electrical signal to the main control circuit; and a main control circuit connected to the output terminal of the optocoupler, used for controlling the escalator's operating state. This invention eliminates the traditional reliance on a leakage current device (RCD) to detect short circuits in the escalator safety circuit. When a short circuit occurs in the escalator safety circuit, the electrical signal can be directly transmitted to the optocoupler, and then the main control circuit can control the escalator's operating state. This design is not affected by ground impedance, greatly increasing the accuracy of the escalator safety circuit grounding detection and enhancing escalator safety.

[0036] In another embodiment, an escalator is also provided, which includes the escalator safety circuit ground short-circuit detection circuit described in the above embodiments.

[0037] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0038] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A short-circuit detection circuit for escalator safety circuit to ground, characterized in that, The escalator safety circuit ground short-circuit detection circuit includes: An input circuit, wherein the input circuit is used to input the electrical signal of the escalator safety circuit into the optocoupler; An optocoupler, wherein the input terminal of the optocoupler is connected to the input circuit, and the optocoupler is used to perform signal conversion processing on the electrical signal and transmit the electrical signal to the main control circuit; The main control circuit is connected to the output terminal of the optocoupler and is used to control the operating status of the escalator.

2. The escalator safety circuit ground short-circuit detection circuit as described in claim 1, characterized in that, The input circuit includes: An optocoupler pre-stage step-down input circuit is provided, the input terminal of which is connected to the escalator safety circuit. The optocoupler pre-stage step-down input circuit is used to step down the electrical signal of the escalator safety circuit.

3. The escalator safety circuit ground short-circuit detection circuit as described in claim 2, characterized in that, The input circuit also includes: A rectifier and filter circuit, wherein the input terminal of the rectifier and filter circuit is connected to the output terminal of the optocoupler pre-stage step-down input circuit, and the rectifier and filter circuit is used to rectify and filter electrical signals; The output terminal of the rectifier filter circuit is connected to the input terminal of the optocoupler, and is used to input electrical signals into the optocoupler.

4. The escalator safety circuit ground short-circuit detection circuit as described in claim 3, characterized in that, The main control circuit includes: The optocoupler output circuit is used to output the electrical signal processed by the optocoupler.

5. The escalator safety circuit ground short-circuit detection circuit as described in claim 4, characterized in that, The main control circuit also includes: The main controller has its input terminal connected to the output terminal of the optocoupler output circuit. The main controller is used to control the operating status of the escalator according to the electrical signal output by the optocoupler output circuit.

6. An escalator, characterized in that, The escalator includes the escalator safety circuit ground short circuit detection circuit as described in any one of claims 1-5.

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