An alternating current input detection circuit, control system and elevator

Abstract

The application discloses an alternating current input detection circuit, a control system and an elevator, which are used for being connected with an external power supply, wherein the alternating current input detection circuit comprises an optical coupling isolation unit, a hysteresis comparison unit and a voltage stabilizing output unit; the optical coupling isolation unit is connected with the external power supply; and the optical coupling isolation unit and the voltage stabilizing output unit are connected with the hysteresis comparison unit. The application can be widely applied in the technical field of electronic circuits.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to an AC input detection circuit, a control system, and an elevator. Background Technology

[0002] Traditional hysteresis comparators achieve voltage division through an input resistor connected in series between the signal and the non-inverting input of the comparator, and a feedback resistor between the non-inverting input and the output. In practical applications, the hysteresis range can be changed by adjusting the comparator's reference voltage and the ratio of the input resistor to the feedback resistor to meet the needs of different circuits. However, traditional hysteresis comparator circuits are more suitable for processing relatively low DC signals such as 5V and 12V. When processing AC signals with higher voltages, they may exceed the device derating standards, and external signal interference can lead to a decrease in stability. Therefore, there are still technical problems that need to be solved in this field. Utility Model Content

[0003] The purpose of this application is to at least partially solve one of the technical problems existing in the prior art.

[0004] Therefore, one objective of this application is to provide an AC input detection circuit, a control system, and an elevator, which can improve the practicality of the circuit.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted in this application includes: an AC input detection circuit for connecting to an external power supply and, based on a designed threshold voltage, feeding back the external power supply signal as a voltage signal that meets the requirements of the back-end control system. The circuit includes: The system comprises an optocoupler isolation unit, a hysteresis comparator unit, and a regulated output unit. The optocoupler isolation unit is connected to an external power supply. The hysteresis comparator unit includes a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourth capacitor, and a first comparator. One end of the ninth resistor, one end of the fourth capacitor, and one end of the tenth resistor are connected to the first power supply. The other end of the ninth resistor and one end of the twelfth resistor are connected to the optocoupler isolation unit. The other end of the twelfth resistor and one end of the thirteenth resistor are connected to the non-inverting input of the first comparator. The other end of the tenth resistor and one end of the eleventh resistor are connected to the inverting input of the first comparator. The other end of the thirteenth resistor and the output of the first comparator are connected to the regulated output unit. The other end of the eleventh resistor and the other end of the fourth capacitor are grounded.

[0006] In addition, the AC input detection circuit according to the above embodiments of this utility model may also have the following additional technical features: Furthermore, in this embodiment of the application, the optocoupler isolation unit includes a first optocoupler; the first pin of the first optocoupler is connected to the positive terminal of the external power supply; the second pin of the first optocoupler is connected to the negative terminal of the external power supply; the fourth pin of the first optocoupler is connected to the other end of the ninth resistor; and the third pin of the first optocoupler is grounded.

[0007] Further, in this embodiment, the voltage-regulated output unit includes a first transistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, and a seventeenth resistor; one end of the fourteenth resistor and one end of the seventeenth resistor are connected to the output terminal of the first comparator; the other end of the seventeenth resistor is connected to the base of the first transistor; the other end of the fourteenth resistor and the emitter of the first transistor are connected to the first power supply; one end of the fifteenth resistor is connected to the collector of the first transistor; the other end of the fifteenth resistor is connected to one end of the sixteenth resistor; the other end of the sixteenth resistor is grounded; and one end of the sixteenth resistor serves as the output terminal of the voltage-regulated output unit.

[0008] Furthermore, in this embodiment of the application, the external power supply includes a rectifier bridge and a current limiting unit; the current limiting unit and the AC input power supply are connected to the rectifier bridge.

[0009] Further, in this embodiment, the current limiting unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first capacitor, a second capacitor, and a third capacitor; one end of the first resistor is connected to one end of the rectifier bridge; one end of the second resistor is connected to the other end of the rectifier bridge; the other end of the first resistor is connected to one end of the third resistor; the other end of the second resistor is connected to one end of the fourth resistor; one end of the fifth resistor, one end of the first capacitor, one end of the second capacitor, and one end of the sixth resistor are connected to the other end of the third resistor; the other end of the fifth resistor, the other end of the first capacitor, the other end of the second capacitor, and one end of the seventh resistor are connected to the other end of the fourth resistor; one end of the third capacitor and one end of the eighth resistor are connected to the other end of the sixth resistor; the other end of the third capacitor and the other end of the eighth resistor are connected to the other end of the seventh resistor; one end of the eighth resistor is connected to one end of the optocoupler isolation unit; the other end of the eighth resistor is connected to the other end of the optocoupler isolation unit.

[0010] Furthermore, in this embodiment, the first transistor is a PNP transistor.

[0011] Furthermore, in this embodiment of the application, the effective value of the AC input power supply is 110V. Furthermore, in this embodiment of the application, the voltage of the first power supply is 24V.

[0012] On the other hand, embodiments of this application also provide a control system including the AC input detection circuit described in any of the preceding claims.

[0013] On the other hand, embodiments of this application also provide an elevator, including the control system described above.

[0014] The advantages and beneficial effects of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application: This application achieves electrical isolation between high voltage and hysteresis comparator by setting an optocoupler isolation unit between the external power supply and the hysteresis comparator unit, thereby improving the overall stability of the circuit and enabling the hysteresis comparator unit to be used in circuit topologies with high-voltage AC signal input, thus improving the practicality of the circuit. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the AC input detection circuit in a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the AC input detection circuit in another specific embodiment of the present invention; Figure 3 This is the output characteristic curve of the hysteresis comparator in a specific embodiment of this utility model. Detailed Implementation

[0016] The following detailed description, in conjunction with the accompanying drawings, illustrates the principles and processes of the AC input detection circuit, control system, and elevator in the embodiments of this utility model.

[0017] Reference Figure 1 This application provides an AC input detection circuit. The AC input detection circuit may include at least an optocoupler isolation unit, a hysteresis comparison unit, and a regulated output unit; the optocoupler isolation unit can be connected to an external power supply; wherein, referring to… Figure 1The hysteresis comparator unit may include a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourth capacitor C4, and a first comparator U2A. One end of the ninth resistor R9, one end of the fourth capacitor C4, and one end of the tenth resistor R10 can be connected to the first power supply. The other end of the ninth resistor R9 and one end of the twelfth resistor R12 can be connected to the optocoupler isolation unit. The other end of the twelfth resistor R12 and one end of the thirteenth resistor R13 can be connected to the non-inverting input of the first comparator U2A. The other end of the tenth resistor R10 and one end of the eleventh resistor R11 can be connected to the inverting input of the first comparator U2A. The other end of the thirteenth resistor R13 and the output of the first comparator U2A can be connected to the regulated output unit. The other end of the eleventh resistor R11 and the other end of the fourth capacitor C4 can be grounded.

[0018] Furthermore, in the embodiments of this application, reference is made to Figure 1 The optocoupler isolation unit may include a first optocoupler U1; the first pin of the first optocoupler U1 may be connected to the positive terminal of an external power supply; the second pin of the first optocoupler U1 may be connected to the negative terminal of an external power supply; the fourth pin of the first optocoupler U1 may be connected to the other end of the ninth resistor R9; and the third pin of the first optocoupler U1 may be grounded.

[0019] Furthermore, in the embodiments of this application, reference is made to Figure 1 The voltage regulator output unit may include a first transistor Q1, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, and a seventeenth resistor R17; one end of the fourteenth resistor R14 and one end of the seventeenth resistor R17 may be connected to the output terminal of the first comparator U2A; the other end of the seventeenth resistor R17 may be connected to the base of the first transistor Q1; the other end of the fourteenth resistor R14 and the emitter of the first transistor Q1 may be connected to the first power supply; one end of the fifteenth resistor R15 may be connected to the collector of the first transistor Q1; the other end of the fifteenth resistor R15 may be connected to one end of the sixteenth resistor R16; the other end of the sixteenth resistor R16 is grounded; one end of the sixteenth resistor R16 serves as the output terminal of the voltage regulator output unit.

[0020] Furthermore, in the embodiments of this application, reference is made to Figure 1 The external power supply can include a rectifier bridge and a current limiting unit; the current limiting unit and the AC input power supply can be connected to the rectifier bridge. The main function of the current limiting unit is to step down and limit the current of the power supply, as well as to filter it.

[0021] Furthermore, in the embodiments of this application, reference is made to Figure 1The current limiting unit may include a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first capacitor C1, a second capacitor C2, and a third capacitor C3; one end of the first resistor R1 can be connected to one end of the rectifier bridge; one end of the second resistor R2 can be connected to the other end of the rectifier bridge; the other end of the first resistor R1 can be connected to one end of the third resistor R3; the other end of the second resistor R2 can be connected to one end of the fourth resistor R4; one end of the fifth resistor R5, one end of the first capacitor C1, and one end of the second capacitor C2... One end of the sixth resistor R6 can be connected to the other end of the third resistor R3; the other end of the fifth resistor R5, the other end of the first capacitor C1, the other end of the second capacitor C2, and one end of the seventh resistor R7 can be connected to the other end of the fourth resistor R4; one end of the third capacitor C3 and one end of the eighth resistor R8 can be connected to the other end of the sixth resistor R6; the other end of the third capacitor C3 and the other end of the eighth resistor R8 can be connected to the other end of the seventh resistor R7; one end of the eighth resistor R8 can be connected to one end of the optocoupler isolation unit; the other end of the eighth resistor R8 can be connected to the other end of the optocoupler isolation unit.

[0022] Furthermore, in this embodiment, the first transistor Q1 is a PNP transistor.

[0023] Furthermore, in this embodiment of the application, the effective value of the AC input power supply is 110V.

[0024] Furthermore, in this embodiment of the application, the voltage of the first power supply is 24V.

[0025] The specific application principle of this application will be explained below with reference to the accompanying drawings: Reference Figure 2 and Figure 3 First, when a high AC signal is input, the rectifier bridge converts the AC power into unidirectional DC power. To make the current more stable and allow it to enter subsequent circuits in a more stable state, the DC power after the rectifier bridge continues to pass through a capacitor. Utilizing the capacitor's charge storage characteristic, the signal becomes smoother. Simultaneously, the signal passes through resistors for current limiting and voltage division, reducing the signal voltage to the safe input range of the optocoupler.

[0026] The voltage-divided signal drives the optocoupler, whose internal LED converts the electrical signal into an optical signal. The secondary transistor then converts the optical signal back into a low-voltage DC signal. This conversion process achieves signal isolation between AC and low-voltage DC, completely blocking common-mode noise and ground loop interference.

[0027] The signal, after optocoupler isolation, enters the hysteresis comparator. This hysteresis comparator uses a positive feedback network to adjust the upper and lower threshold values ​​of the voltage to be compared, as shown in the following formulas: Upper limit threshold:

[0028] Lower threshold:

[0029] like The hysteresis width is:

[0030] in, The reference voltage applied to the inverting terminal of the comparator, as well as These are the low-level voltage and high-level voltage at the comparator output, respectively.

[0031] Finally, the comparator output voltage enters the base terminal of the transistor, controlling the transistor to enter either the cutoff or saturation state. Simultaneously, an open-collector output is used, ensuring that when the transistor is cut off, the collector outputs a low level; and when the transistor is cut off, the collector outputs a high level. Furthermore, these high and low levels can be adjusted to the desired voltage using the collector resistor. Ultimately, this achieves a high AC input, followed by hysteresis comparison, and finally selects a low DC output.

[0032] In this section, the externally input AC signal is converted into a DC signal by a rectifier bridge. Then, it passes through appropriate resistors and capacitors to transform the signal into a smoother electrical signal within the safe input range of the optocoupler. Finally, it enters the optocoupler, where its photoelectric characteristics are used to achieve electrical isolation between the input signal and the control signal.

[0033] This section employs a traditional hysteresis comparator circuit. It uses a positive feedback resistor network (R1 and R2) to divide the voltage and, combined with a reference voltage (Vref), generates upper and lower threshold voltages (V+ and V-). This changes the hysteresis range and enables the input signal to switch between high and low threshold levels. Finally, the comparator's output signal flows into the base of the transistor, and a resistor divides the voltage at the collector, allowing for the selection of an appropriate output level as needed.

[0034] Furthermore, an embodiment of this application also provides a control system. This control system may include one or more AC input detection circuits as described in any of the preceding embodiments.

[0035] It should be noted that the contents of the above AC input detection circuit embodiments are all applicable to this semiconductor device embodiment. The specific functions implemented by this semiconductor device embodiment are the same as those of the above AC input detection circuit embodiments, and the beneficial effects achieved are also the same as those achieved by the above AC input detection circuit embodiments.

[0036] Furthermore, an elevator is also provided in the embodiments of this application, which may include one or more control systems described in the above embodiments.

[0037] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the term "switching" should be interpreted broadly, for example, it can mean transformation or conversion; for those skilled in the art, the specific meaning of the above term in this utility model can be understood according to the specific circumstances.

[0038] In this specification, the description of referenced terms refers to a specific structure or feature described in connection with an embodiment or example that is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

[0040] The above is a detailed description of the preferred embodiments of this application, but this application is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. An AC input detection circuit, characterized in that, For connection to an external power supply, the circuit includes: The system comprises an optocoupler isolation unit, a hysteresis comparator unit, and a regulated output unit. The optocoupler isolation unit is connected to an external power supply. The hysteresis comparator unit includes a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourth capacitor, and a first comparator. One end of the ninth resistor, one end of the fourth capacitor, and one end of the tenth resistor are connected to the first power supply. The other end of the ninth resistor and one end of the twelfth resistor are connected to the optocoupler isolation unit. The other end of the twelfth resistor and one end of the thirteenth resistor are connected to the non-inverting input of the first comparator. The other end of the tenth resistor and one end of the eleventh resistor are connected to the inverting input of the first comparator. The other end of the thirteenth resistor and the output of the first comparator are connected to the regulated output unit. The other end of the eleventh resistor and the other end of the fourth capacitor are grounded.

2. The AC input detection circuit according to claim 1, characterized in that, The optocoupler isolation unit includes a first optocoupler; the first pin of the first optocoupler is connected to the positive terminal of the external power supply; the second pin of the first optocoupler is connected to the negative terminal of the external power supply; the fourth pin of the first optocoupler is connected to the other end of the ninth resistor; and the third pin of the first optocoupler is grounded.

3. The AC input detection circuit according to claim 1, characterized in that, The voltage regulator output unit includes a first transistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, and a seventeenth resistor; one end of the fourteenth resistor and one end of the seventeenth resistor are connected to the output terminal of the first comparator; the other end of the seventeenth resistor is connected to the base of the first transistor; the other end of the fourteenth resistor and the emitter of the first transistor are connected to the first power supply; one end of the fifteenth resistor is connected to the collector of the first transistor; the other end of the fifteenth resistor is connected to one end of the sixteenth resistor; the other end of the sixteenth resistor is grounded; and one end of the sixteenth resistor serves as the output terminal of the voltage regulator output unit.

4. The AC input detection circuit according to claim 1, characterized in that, The external power supply includes a rectifier bridge and a current limiting unit; the current limiting unit and the AC input power supply are connected to the rectifier bridge.

5. The AC input detection circuit according to claim 4, characterized in that, The current limiting unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first capacitor, a second capacitor, and a third capacitor; one end of the first resistor is connected to one end of the rectifier bridge; one end of the second resistor is connected to the other end of the rectifier bridge; the other end of the first resistor is connected to one end of the third resistor; the other end of the second resistor is connected to one end of the fourth resistor; one end of the fifth resistor, one end of the first capacitor, one end of the second capacitor, and one end of the sixth resistor are connected to the other end of the third resistor; the other end of the fifth resistor, the other end of the first capacitor, the other end of the second capacitor, and one end of the seventh resistor are connected to the other end of the fourth resistor; one end of the third capacitor and one end of the eighth resistor are connected to the other end of the sixth resistor; the other end of the third capacitor and the other end of the eighth resistor are connected to the other end of the seventh resistor; one end of the eighth resistor is connected to one end of the optocoupler isolation unit; the other end of the eighth resistor is connected to the other end of the optocoupler isolation unit.

6. The AC input detection circuit according to claim 3, characterized in that, The first transistor is a PNP type transistor.

7. The AC input detection circuit according to claim 4, characterized in that, The effective value of the AC input power supply is 110V.

8. The AC input detection circuit according to claim 1, characterized in that, The voltage of the first power supply is 24V.

9. A control system, characterized in that, Includes the AC input detection circuit as described in any one of claims 1-8.

10. An elevator, characterized in that, Includes the control system as described in claim 9.

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