Fire-fighting signal acquisition circuit

Abstract

The utility model relates to a fire-fighting signal acquisition circuit, which comprises a signal receiving circuit, an optocoupler, a primary operational amplifier circuit, a pulse conversion circuit and a secondary operational amplifier circuit which are connected in sequence, the pulse conversion circuit comprises a first Schottky diode, a first resistor, a first capacitor, a second resistor and a second Schottky diode, the output end of the primary operational amplifier circuit is sequentially connected with the first Schottky diode, the first resistor, the second Schottky diode and the input end of the secondary operational amplifier circuit, and the first capacitor and the second resistor are connected in parallel. One end of the second-stage operational amplifier circuit is connected with the output end of the first resistor, the other end of the second-stage operational amplifier circuit is grounded, the input end of the second-stage operational amplifier circuit is connected with a third resistor, and the other end of the third resistor is connected with the grounding end of the first capacitor. Compared with the prior art, the device has the advantages of simple and accurate signal acquisition, high reliability and the like.

Description

Technical Field

[0001] This utility model relates to the field of signal acquisition circuits, and in particular to a fire signal acquisition circuit. Background Technology

[0002] The fire control panel, also known as the fire alarm controller, is the heart of the automatic fire alarm system. It connects to the fire monitoring center via a network to achieve real-time and effective monitoring and management of the fire protection system. It enables centralized control, supplies power to detectors, and has the following functions: 1) Receiving fire signals and activating fire alarm devices. This device can also indicate the location of the fire and record relevant information. 2) Activating fire alarm signals via fire alarm transmitters or activating automatic fire extinguishing equipment and fire-fighting linkage control equipment via automatic fire extinguishing control devices. 3) Automatically monitoring the correct operation of the system and providing audible and visual alarms for specific faults.

[0003] For example, the utility model with publication number CN212135604U discloses a fire signal acquisition device for migrant workers' dormitories at construction sites, including several fire detectors installed in the migrant workers' dormitories at construction sites, and an acquisition host connected to the fire detectors; the acquisition host includes a chassis, a communication port, an antenna hole and an indicator light set on the chassis, a shock-absorbing mounting base set at the bottom of the chassis for fixed installation, and a DC power supply module and a fire control board set inside the chassis and electrically connected.

[0004] However, the existing fire signal acquisition circuit described above uses an optocoupler structure to convert the AC fire signal into a pulse signal for detection. The output of this acquisition circuit is a pulse signal, which limits the detection range of the microcontroller at the receiving end and results in a high failure rate. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology, such as the cumbersome detection of the pulse signal output by the acquisition circuit and the high failure rate of the microcontroller at the receiving end, and to provide a fire signal acquisition circuit.

[0006] The objective of this utility model can be achieved through the following technical solutions:

[0007] A fire signal acquisition circuit includes a signal receiving circuit, an optocoupler, a first-stage operational amplifier circuit, a pulse conversion circuit, and a second-stage operational amplifier circuit connected in sequence.

[0008] The pulse conversion circuit includes a first Schottky diode, a first resistor, a first capacitor, a second resistor, and a second Schottky diode. The output terminal of the first-stage operational amplifier circuit is sequentially connected to the first Schottky diode, the first resistor, the second Schottky diode, and the input terminal of the second-stage operational amplifier circuit. The first capacitor and the second resistor are connected in parallel, with one end connected to the output terminal of the first resistor and the other end grounded. The input terminal of the second-stage operational amplifier circuit is connected to a third resistor, and the other end of the third resistor is connected to the ground terminal of the first capacitor.

[0009] Preferably, the signal receiving circuit includes resistor R4, resistor R6, and TVS diode. One end of resistor R4 is connected to the fire protection circuit, and the other end is connected to the light emission input terminal of the optocoupler. The light emission output terminal of the optocoupler is connected to the positive terminal of the TVS diode, and the negative terminal of the TVS diode is connected to the fire protection circuit. One end of resistor R6 is connected to the light emission input terminal of the optocoupler, and the other end is connected to the light emission output terminal of the optocoupler.

[0010] Preferably, the signal receiving circuit further includes a diode D1, the input terminal of which is connected to the light-emitting output terminal of the optocoupler, and the output terminal of which is connected to the light-emitting input terminal of the optocoupler.

[0011] Preferably, the first-stage operational amplifier circuit includes a first-stage comparator and a first-stage voltage regulator circuit, the emitter of the optocoupler is connected to the inverting input of the first-stage comparator, and the output of the first-stage voltage regulator circuit is connected to the non-inverting input of the first-stage comparator.

[0012] Preferably, the first-stage voltage regulator circuit includes a resistor R3 and a Zener diode ZD2. The non-inverting input of the first-stage comparator is connected to one end of the resistor R3 and the output of the Zener diode ZD2, respectively. The input of the Zener diode ZD2 is grounded, and the other end of the resistor R3 is connected to a DC power supply.

[0013] Preferably, the inverting input of the first-stage comparator is connected to a capacitor C1, and the other end of the capacitor C1 is grounded.

[0014] Preferably, the two-stage operational amplifier circuit includes a two-stage comparator and a two-stage voltage regulator circuit, the output terminal of the pulse conversion circuit is connected to the non-inverting input of the two-stage comparator, and the output terminal of the two-stage voltage regulator circuit is connected to the inverting input of the two-stage comparator.

[0015] Preferably, the secondary voltage regulator circuit includes a resistor R1 and a Zener diode ZD1. The inverting terminal of the secondary comparator is connected to one end of the resistor R1 and the output terminal of the Zener diode ZD1, respectively. The input terminal of the Zener diode ZD1 is grounded, and the other end of the resistor R1 is connected to a DC power supply.

[0016] Preferably, the output terminal of the secondary comparator is connected to a capacitor C3, and the other end of the capacitor C3 is grounded.

[0017] Preferably, the output terminal of the secondary comparator is connected to a resistor R9.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] (1) In this scheme, the optocoupler converts the received electrical signal from the signal receiving circuit into a low-level pulse. The low-level pulse is then converted into a high-level pulse by a first-stage operational amplifier circuit for output. During the high-level phase of the high-level pulse, the first capacitor is rapidly charged through the first Schottky diode and the first resistor. During the low-level phase of the high-level pulse, the first capacitor is slowly discharged through the second resistor, the second Schottky diode, and the third resistor. The pulse conversion circuit ensures that the second-stage operational amplifier circuit outputs a continuous high level, which is used for sampling by the microcontroller. When there is no signal, the second-stage operational amplifier circuit outputs a continuous low level.

[0020] By constructing an optocoupler isolation and pulse conversion circuit, and utilizing the charging and discharging characteristics of capacitors and resistors, a specific pulse wave is converted into a continuous high or low level. When an input signal is present, only a high level is output, and when no signal is present, only a low level is output. This allows the microcontroller to sample using a single level, which is simpler and more accurate than pulse signal sampling. The microcontroller also has a lower failure rate and a longer service life.

[0021] (2) In this scheme, based on the pulse conversion circuit, when the fire circuit generates a signal, the output terminal of the acquisition circuit only outputs a high-level signal. Compared with the existing acquisition circuit outputting pulse signals, the high-level signal is more easily recognized by the microcontroller, and has higher accuracy and stronger reliability. Attached Figure Description

[0022] Figure 1 A schematic diagram of the acquisition circuit provided by this utility model. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0028] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] Example 1

[0030] like Figure 1 As shown, this embodiment provides a fire signal acquisition circuit, including a signal receiving circuit, an optocoupler, a first-stage operational amplifier circuit, a pulse conversion circuit, and a second-stage operational amplifier circuit connected in sequence.

[0031] The pulse conversion circuit includes a first Schottky diode SBD1, a first resistor R5, a first capacitor C2, a second resistor R8, and a second Schottky diode SBD2. The output of the first-stage operational amplifier circuit is connected in sequence to the first Schottky diode SBD1, the first resistor R5, the second Schottky diode SBD2, and the input of the second-stage operational amplifier circuit. The first capacitor C2 and the second resistor R8 are connected in parallel, with one end connected to the output of the first resistor and the other end grounded. The input of the second-stage operational amplifier circuit is connected to a third resistor R7, and the other end of the third resistor R7 is connected to the ground of the first capacitor C2.

[0032] Working principle: The optocoupler converts the received electrical signal into a low-level pulse. This low-level pulse is then converted into a high-level pulse by an operational amplifier circuit for output. During the high-level pulse's high-level phase, the first capacitor C2 is rapidly charged through the first Schottky diode SBD1 and the first resistor R5. During the low-level pulse's low-level phase, the first capacitor C2 is discharged through the second resistor R8, the second Schottky diode SBD2, and the third resistor R7. The pulse conversion circuit ensures that the second-level operational amplifier circuit outputs a continuous high level, which is used for sampling by the microcontroller. When there is no signal, the second-level operational amplifier circuit outputs a continuous low level.

[0033] By constructing an optocoupler isolation and pulse conversion circuit, and utilizing the charging and discharging characteristics of capacitors and resistors, a specific pulse wave is converted into a continuous high or low level. When an input signal is present, only a high level is output, and when no signal is present, only a low level is output. This allows the microcontroller to sample using a single level, which is simpler and more accurate than pulse signal sampling. The microcontroller also has a lower failure rate and a longer service life.

[0034] Specifically, the signal receiving circuit includes resistors R4 and R6 and a TVS diode. One end of resistor R4 is connected to the fire protection circuit, and the other end is connected to the light-emitting input terminal of the optocoupler. The light-emitting output terminal of the optocoupler is connected to the positive terminal of the TVS diode, and the negative terminal of the TVS diode is connected to the fire protection circuit. One end of resistor R6 is connected to the light-emitting input terminal of the optocoupler, and the other end is connected to the light-emitting output terminal of the optocoupler.

[0035] The signal receiving circuit also includes diode D1. The input terminal of diode D1 is connected to the output terminal of the optocoupler's light-emitting diode, and the output terminal of diode D1 is connected to the input terminal of the optocoupler's light-emitting diode. By placing diode D1 across the two ends of the optocoupler's light-emitting diode, the light-emitting diode can be short-circuited when a reverse voltage is received, thus protecting the optocoupler's light-emitting diode.

[0036] Specifically, the first-stage operational amplifier circuit includes a first-stage comparator and a first-stage voltage regulator circuit. The emitter of the optocoupler is connected to the inverting input of the first-stage comparator, and the output of the first-stage voltage regulator circuit is connected to the non-inverting input of the first-stage comparator.

[0037] The first-stage voltage regulator circuit includes a resistor R3 and a Zener diode ZD2. The non-inverting input of the first-stage comparator is connected to one end of resistor R3 and the output of Zener diode ZD2, respectively. The input of Zener diode ZD2 is grounded, and the other end of resistor R3 is connected to a DC power supply. The inverting input of the first-stage comparator is connected to a capacitor C1, and the other end of capacitor C1 is grounded.

[0038] Specifically, the two-stage operational amplifier circuit includes a two-stage comparator and a two-stage voltage regulator circuit. The output of the pulse conversion circuit is connected to the non-inverting input of the two-stage comparator, and the output of the two-stage voltage regulator circuit is connected to the inverting input of the two-stage comparator.

[0039] The secondary voltage regulator circuit includes a resistor R1 and a Zener diode ZD1. The inverting terminal of the secondary comparator is connected to one end of the resistor R1 and the output terminal of the Zener diode ZD1, respectively. The input terminal of the Zener diode ZD1 is grounded, and the other end of the resistor R1 is connected to a DC power supply.

[0040] Furthermore, a capacitor C3 is connected to the output of the second-stage comparator, with the other end of capacitor C3 grounded. A resistor R9 is also connected to the output of the second-stage comparator. The signal generated by the second-stage operational amplifier circuit is filtered through resistor R9 and capacitor C3, improving the accuracy of the signal acquired by the microcontroller.

[0041] Specifically, such as Figure 1 As shown, on the light-emitting side of optocoupler OC1, the AC220V voltage between L and N in the fire protection circuit forms a circuit through resistor R4, optocoupler OC1, and TVS diode TVS1 when it is positive, thus turning on optocoupler OC1; when it is negative, it forms a circuit through TVS diode TVS1, resistor R6, diode D1, and resistor R4, at which time optocoupler OC1 is not turned on. D1 is used to protect the internal light-emitting diode of the optocoupler. This generates a low-level pulse VPULSE+.

[0042] The VPULSE+ low-level pulse is input to the inverting input of op-amp U1A. Resistor R3 and Zener diode ZD2 form a voltage regulator circuit to obtain the reference voltage VREF1, which is input to the non-inverting input of U1A for comparison and converted into a VPLUSE- high-level pulse for output.

[0043] During the high-level pulse phase of VPLUSE-, capacitor C2 is rapidly charged through Schottky diode SBD1 and resistor R5. During the low-level pulse phase of VPLUSE-, capacitor C2 is discharged through resistor R8, Schottky diode SBD2, and resistor R7, maintaining the non-inverting input of op-amp U1B at a high level relative to the inverting input VREF2. VREF2 is obtained by a voltage regulation circuit composed of resistor R1 and Zener diode ZD1, thus outputting a continuous high level at the output of U1B. After filtering by resistor R9 and capacitor C3, the signal is sampled at the I / O port of the MCU.

[0044] When there is no signal input, the non-inverting input of operational amplifier U1B is grounded through resistor R7, resulting in a continuous low-level output at the U1B output. This process converts the AC220V fire alarm signal into a high / low level signal. The microcontroller-based detection is simple, accurate, and highly reliable.

[0045] The preferred embodiments of this utility model have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of this utility model without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of this utility model through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A fire signal acquisition circuit, characterized by, The signal receiving circuit, the optical coupler, the first operational amplifier circuit, the pulse conversion circuit and the second operational amplifier circuit are sequentially connected. The pulse conversion circuit comprises a first Schottky diode, a first resistor, a first capacitor, a second resistor and a second Schottky diode, the output end of the first operational amplifier circuit is sequentially connected with the first Schottky diode, the first resistor, the second Schottky diode and the input end of the second operational amplifier circuit, the first capacitor and the second resistor are connected in parallel, one end of which is connected with the output end of the first resistor, and the other end is grounded, the input end of the second operational amplifier circuit is connected with a third resistor, and the other end of the third resistor is connected with the ground end of the first capacitor.

2. The fire signal acquisition circuit according to claim 1, wherein, The signal receiving circuit comprises a resistor R4, a resistor R6 and a TVS diode, one end of the resistor R4 is connected with the fire-fighting circuit, the other end is connected with the light-emitting measurement input end of the optical coupler, the light-emitting measurement output end of the optical coupler is connected with the positive electrode of the TVS diode, the negative electrode of the TVS diode is connected with the fire-fighting circuit, one end of the resistor R6 is connected with the light-emitting measurement input end of the optical coupler, and the other end is connected with the light-emitting measurement output end of the optical coupler.

3. A fire signal acquisition circuit according to claim 2, wherein, The signal receiving circuit further comprises a diode D1, the input end of the diode D1 is connected with the light-emitting measurement output end of the optical coupler, and the output end of the diode D1 is connected with the light-emitting measurement input end of the optical coupler.

4. The fire signal acquisition circuit of claim 1, wherein, The first operational amplifier circuit comprises a first comparator and a first voltage stabilizing circuit, the emitter of the optical coupler is connected with the inverting end of the first comparator, and the output end of the first voltage stabilizing circuit is connected with the non-inverting end of the first comparator.

5. A fire signal acquisition circuit according to claim 4, wherein, The first voltage stabilizing circuit comprises a resistor R3 and a voltage stabilizing diode ZD2, the non-inverting end of the first comparator is connected with one end of the resistor R3 and the output end of the voltage stabilizing diode ZD2 respectively, the input end of the voltage stabilizing diode ZD2 is grounded, and the other end of the resistor R3 is connected with a direct current power supply.

6. A fire signal acquisition circuit according to claim 4, wherein The inverting end of the first comparator is connected with a capacitor C1, and the other end of the capacitor C1 is grounded.

7. The fire signal acquisition circuit according to claim 1, wherein, The second operational amplifier circuit comprises a second comparator and a second voltage stabilizing circuit, the output end of the pulse conversion circuit is connected with the non-inverting end of the second comparator, and the output end of the second voltage stabilizing circuit is connected with the inverting end of the second comparator.

8. A fire signal acquisition circuit according to claim 7, wherein, The second voltage stabilizing circuit comprises a resistor R1 and a voltage stabilizing diode ZD1, the inverting end of the second comparator is connected with one end of the resistor R1 and the output end of the voltage stabilizing diode ZD1 respectively, the input end of the voltage stabilizing diode ZD1 is grounded, and the other end of the resistor R1 is connected with a direct current power supply.

9. The fire signal acquisition circuit of claim 7, wherein, The output end of the second comparator is connected with a capacitor C3, and the other end of the capacitor C3 is grounded.

10. The fire signal acquisition circuit of claim 7, wherein, The output end of the second comparator is connected with a resistor R9.

Images