Universal fire alarm signal system detector

Abstract

The invention discloses a general fire alarm signal system detector, and belongs to the technical field of aircraft detection. Comprising a power supply unit, a control unit, a first relay matrix, a second relay matrix, an action voltage simulation unit, a resistance measurement module and a display unit, the display unit is connected with the tested equipment and the power supply unit; the tested equipment is connected with the power supply unit; the power supply unit is used for performing power supply management on electric equipment and tested equipment; the control unit is used for controlling the first relay matrix and the second relay matrix to switch working modes and detection channels, reading test data and displaying the test data on the display unit; the resistance measuring unit is used for measuring the resistance of the measured equipment; the action voltage simulation unit is used for outputting a target voltage signal; the power supply unit is powered by various power supplies, so that various detected devices can be detected. Normal work can be realized by adopting any power supply; and a plurality of control boxes with the same working principle and matched sensors can be detected.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft detection, in particular to a universal fire alarm signal system detector. Background Art

[0002] The existing aircraft fire alarm control box comprehensive tester can only use 220V power supply in the field, but some places in the field may not have 220V AC power, which is inconvenient to use. It can only detect four models of rocket control boxes, HKH-2, HKH-3, HKH-2A, and HKH-3A, and cannot detect other fire alarm control boxes with the same working principle such as HKH-11, nor can it detect the resistance value of the fire alarm sensor. Batteries are used as the reference voltage source of millivolt signals, which require regular maintenance and replacement. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a universal fire alarm signal system detector.

[0004] The objective of the present invention is achieved through the following technical solutions: a universal fire alarm signal system detector, comprising a power supply unit and a control unit, wherein the input end of the power supply unit is connected to an external power supply, and the output end of the power supply unit is connected to an electrical device; the control unit is connected to a first relay matrix and a second relay matrix; the first relay matrix is ​​connected to an action voltage simulation unit and a device under test; the second relay matrix is ​​connected to the device under test and a resistance measurement module; the action voltage simulation unit and the resistance measurement module are connected to a display unit; the display unit is connected to the device under test and the power supply unit; the device under test is connected to the power supply unit; the power supply unit is used to perform power management on the electrical device and the device under test; the control unit is used to control the first relay matrix and the second relay matrix to switch the working mode and the detection channel, and read the test data and display it on the display unit; the resistance measurement unit is used to measure the resistance of the device under test; the action voltage simulation unit is used to output a target voltage signal; the power supply unit is powered by a variety of power supplies, so that a variety of devices under test can be detected.

[0005] Preferably, the power supply unit includes a first fuse, a second fuse, a main power switch, a power indicator light, a switching power supply, a rectifier bridge, and a power module; the input ends of the first fuse and the second fuse are connected to an external power supply, and the output ends of the first fuse and the second fuse are connected to the main power switch; the main power switch is connected to the switching power supply and the rectifier bridge; the switching power supply and the rectifier bridge are connected to a display unit, a power indicator light, a power module, and a device under test; the rated currents of the first fuse and the second fuse are different; when the external power supply is supplied by the first power supply, the input to the first fuse enters the switching power supply after passing through the main power switch, is converted to a target voltage by the switching power supply and output to the power module, and the power module converts the target voltage into the power required for work; when the external power supply is supplied by the second power supply, the input to the second fuse passes through the main power switch and the rectifier bridge and is connected in parallel with the output end of the switching power supply.

[0006] Preferably, the rated current of the first fuse is 0.5A, and the rated current of the second fuse is 2A; the first power supply is 220VAC, and the second power supply is 27VDC.

[0007] Preferably, the control unit includes a microcontroller, a toggle switch, a band switch, and an optocoupler matrix; the microcontroller collects the working status of the band switch and the toggle switch through the optocoupler matrix, the microcontroller reads the measurement value of the resistance measurement module through the RS485 interface circuit, reads the output data of the action voltage simulation unit through the I2C interface, and displays it on the display module through the RS485 interface circuit.

[0008] Preferably, the optocoupler matrix includes optocouplers and Schmitt triggers, and the switch signal is isolated by the optocouplers, shaped and filtered by the Schmitt trigger, and finally sent to the microcontroller for collection; a total of 8 optocouplers are used to collect the 6 position states of the band switch and the 2 position states of the button switch. Preferably, the first relay matrix includes relays and drive circuits, which are used for switching the resistance measurement channel, the control voltage output channel, and the millivolt voltage output channel; the circuit structure of the first relay matrix is ​​the same as that of the second relay matrix.

[0009] Preferably, the resistance measurement module adopts a four-wire resistance measurement method, and the test cable adopts a shielded cable.

[0010] Preferably, the action voltage simulation unit includes a reference voltage chip, and the reference voltage chip is connected to a potentiometer, an operational amplifier, and an analog-to-digital converter.

[0011] Preferably, the display unit includes a voltmeter, a multifunction meter, and a signal indicator light, the voltmeter is connected to the power supply unit and the device under test, the multifunction meter is connected to the resistance measurement module and the action voltage simulation unit, and the signal indicator light is connected to the device under test; the test data includes output voltage, action voltage, sensor resistance value, and fire alarm signal.

[0012] Preferably, the universal fire alarm signal system detector is installed in a portable case, the panel of the portable case is made of rust-proof aluminum material, the surface of the panel is sprayed with plastic and then silk-screened, and the fonts on the panel are processed by etching and filling with ink.

[0013] The beneficial effects of the present invention are: 1) It can use 27VDC power supply on the aircraft or on the ground for outdoor in-situ detection, and can use 220VAC / 50Hz power supply for indoor off-site detection. The power supply is adaptively designed and can work normally with any power supply; it can detect other control boxes with the same working principle such as HKH-2, HKH-3, HKH-2A, HKH-3A, HKH-11 and other supporting sensors.

[0014] 2) The equipment has a self-check function, which can perform self-checks on the resistance measurement module and signal indicator light to ensure its own quality and not cause damage to the device under test; it adopts a modular design, and the standard Modbus-RTU communication protocol is used between modules, and hardware resources are reserved to facilitate debugging, maintenance and upgrading.

[0015] 3) It has the function of detecting the working performance of the fire alarm signal system; it has the function of detecting the action voltage of the fire alarm signal system executive components; it has the function of detecting the resistance value of the fire alarm signal system sensor; it has the function of detecting the pull-in voltage of the HKH-2, HKH-3, HKH-2A, HKH-3A, and HKH-11 fire alarm control boxes; it has the function of detecting the release voltage of the HKH-2, HKH-3, HKH-2A, HKH-3A, and HKH-11 fire alarm control boxes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the principle block diagram of the universal fire alarm signal system detector; Figure 2 It is the partial circuit schematic diagram of the power supply unit; Figure 3 This is the schematic diagram of the power module circuit; Figure 4 It is the schematic diagram of the local circuit of the optocoupler matrix; Figure 5 It is the partial circuit schematic diagram of the relay matrix; Figure 6 This is the circuit schematic diagram of the action voltage simulation unit; Figure 7This is the panel layout diagram. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0018] The present invention can be powered by 27×(1±10%)VDC on board or on the ground, or by 220×(1±10%)VAC, 50×(1±10%)Hz of mains electricity. The power supply is adaptively designed, and any power supply can work normally, which is convenient for maintenance personnel to complete the in-situ and out-of-situ working performance detection of fire alarm control boxes with the same working principle such as HKH-2, HKH-3, HKH-2A, HKH-3A, HKH-11, etc. in the field or in the field. At the same time, it has a resistance measurement function and can detect the resistance value of the fire alarm sensor. A voltage reference chip is used to generate a 2.5V reference voltage, which is adjusted by a potentiometer and followed by an operational amplifier to output a 0mV to 50mV voltage, without the need for maintenance or replacement.

[0019] See also Figure 1-Figure 7 The present invention provides a technical solution: a universal fire alarm signal system detector, comprising a power supply unit and a control unit, wherein the input end of the power supply unit is connected to an external power supply, and the output end of the power supply unit is connected to an electrical device; the control unit is connected to a first relay matrix and a second relay matrix; the first relay matrix is ​​connected to an action voltage simulation unit and a device under test; the second relay matrix is ​​connected to the device under test and a resistance measurement module; the action voltage simulation unit and the resistance measurement module are connected to a display unit; the display unit is connected to the device under test and the power supply unit; the device under test is connected to the power supply unit; the power supply unit is used to perform power management on the electrical device and the device under test; the control unit is used to control the first relay matrix and the second relay matrix to switch working modes and detection channels, and read test data and display them on the display unit; the resistance measurement unit is used to measure the resistance of the device under test; the action voltage simulation unit is used to output a target voltage signal; the power supply unit is powered by a variety of power supplies, so that a variety of devices under test can be detected.

[0020] In this embodiment, the device under test is a HKH-2 fire alarm control box or a HKH-3 fire alarm control box or a HKH-2A fire alarm control box or a HKH-3A fire alarm control box or a HKH-11 fire alarm control box or a HG-15 thermal sensor or a HG-16 thermal sensor or a HG-17 thermal sensor; the fire alarm signal system tester uses any power supply of 27× (1±10%) VDC or 220× (1±10%) VAC, 50× (1±10%) Hz as the working power supply. When powered by 220×(1±10%)VAC, 50×(1±10%)Hz, the internal switching power supply of the equipment is converted into a 27VDC output; it is converted into the ±5V and +3.3V power supplies required for the equipment to work through the power module; a 2.5V reference voltage is generated through the voltage reference chip, and is adjusted by the potentiometer and followed by the operational amplifier to output a 0mV~50mV voltage; the line resistance value of each group of thermal sensors is measured through the resistance measurement module; the output millivolt voltage and the measured resistance value are displayed through the multi-function meter; the control unit controls the relay matrix to switch the working mode and detection channel; the signal indicator light indicates the fire alarm signal output by the fire alarm control box.

[0021] In some embodiments, the power supply unit includes a first fuse, a second fuse, a main power switch, a power indicator light, a switching power supply, a rectifier bridge, and a power module; the input ends of the first fuse and the second fuse are connected to an external power supply, and the output ends of the first fuse and the second fuse are connected to the main power switch; the main power switch is connected to the switching power supply and the rectifier bridge; the switching power supply and the rectifier bridge are connected to a display unit, a power indicator light, a power module, and a device under test; the rated currents of the first fuse and the second fuse are different; when the external power supply is supplied by the first power supply, the input to the first fuse passes through the main power switch and then enters the switching power supply, and is converted to a target voltage by the switching power supply and output to the power module, and the power module converts the target voltage into the power required for work; when the external power supply is supplied by the second power supply, the input to the second fuse passes through the main power switch and the rectifier bridge and is connected in parallel with the output end of the switching power supply.

[0022] In this embodiment, the power supply unit is composed of a fuse, a main power switch, a power indicator light, a switching power supply, a rectifier bridge, a power module, etc., which mainly realizes the management of the power required by the fire alarm signal system tester and the test object. Considering the use environment, frequency of use and safety factors of the fire alarm signal system tester, combined with the actual situation of the internal and external fields, and focusing on the principle of convenient operation and use, the fire alarm signal system tester can be powered by 27× (1±10%) VDC on the aircraft or on the ground, or by 220× (1±10%) VAC, 50× (1±10%) Hz of the main power supply. The power supply is adaptively designed and very convenient to use. When 220× (1±10%) VAC, 50× (1±10%) Hz is used for power supply, the external power supply enters the switching power supply after passing through the 0.5A fuse and the main power switch, and is converted to 27VDC output by the switching power supply. The 27VDC is then converted into ±5V and +3.3V power required for the operation of the equipment through the power module. When 27×(1±10%) VDC is used for power supply, the external power supply is connected in parallel with the output terminal of the switching power supply after passing through a 2A fuse, a main power switch, and a rectifier bridge.

[0023] Among them, the 0.5A and 2A fuses use the commonly used 5mm×20mm glass tube fuse, which can effectively protect the fire alarm signal system inspection instrument from overcurrent and short circuit faults.

[0024] The main power switch uses a C6053ALNAE double-pole double-throw rocker switch. The rated current of the rocker switch contacts is 16A, which meets the control requirements of AC 0.5A and DC 2A.

[0025] The switching power supply uses LRS-50-24 switching power supply with an input voltage range of 85VAC~264VAC, a frequency range of 45Hz~63Hz, an output voltage adjustment range of 21.6VDC~28.8VDC, a rated output current of 2.2A, and has overload, overvoltage, and over-temperature protection functions. The output voltage can be adjusted to 27VDC by adjusting the potentiometer on the switching power supply, meeting the working requirements of input 220×(1±10%)VAC, 50×(1±10%)Hz, and output (27±3)VDC.

[0026] In order to prevent the risk of damage to the fire alarm system detector due to reverse connection of the positive and negative poles of the 27×(1±10%)VDC power supply by human factors and improve the ease of use, a rectifier bridge is designed at the DC input port so that the fire alarm system detector can still work normally when the positive and negative poles of the external 27VDC are reversed. The rectifier bridge uses KBPC1502, with a rated voltage of 200V and a rated current of 15A. There is a mounting hole in the center of the component for easy installation on the bottom plate.

[0027] In order to indicate the power supply status of the fire alarm signal system inspection instrument and quickly locate the fault point, a power indicator light is designed. The indicator light adopts the red wave LAS2Y-D type green indicator light. The rated working voltage of the indicator light is 27VDC, which meets the indication requirements of the (27±3) VDC power supply status.

[0028] The WRA2405S isolated DCDC power module converts 27VDC into ±5V to power the operational amplifier. The WRB2405S isolated DCDC power module converts 27VDC into +5V to power relays, multi-function meters, resistance measurement modules and other circuits. The AMS1117-3.3 LDO chip converts +5V into +3.3V to power microcontrollers and other circuits, meeting the ±5V and +3.3V power requirements required for the equipment to work.

[0029] In some embodiments, the rated current of the first fuse is 0.5A, and the rated current of the second fuse is 2A; the first power supply is 220VAC, and the second power supply is 27VDC.

[0030] In some embodiments, the control unit includes a microcontroller, a button switch, a band switch, and an optocoupler matrix; the microcontroller collects the working status of the band switch and the button switch through the optocoupler matrix, and the microcontroller reads the measurement value of the resistance measurement module through the RS485 interface circuit, reads the output data of the action voltage simulation unit through the I2C interface, and displays it on the display module through the RS485 interface circuit.

[0031] In this embodiment, the microcontroller collects the working status of the band switch and the button switch through the optical coupler matrix, controls the relay matrix to switch the working mode and detection channel, reads the measured value of the resistance measurement module through the RS485 interface, reads the conversion value of the analog-to-digital converter through the I2C interface, and displays it on the multi-function meter through the RS485 interface. In order to ensure that the fire alarm signal system inspection instrument has stable signal processing capabilities, the microcontroller uses a 32-bit high-performance ARM Cortex-M3 series MCU as the core controller, and its model is HK32F103CBT6. The controller has rich peripheral resources and stable and high-speed signal processing capabilities, which meets the requirements of the fire alarm signal system inspection instrument to achieve high-speed, multi-channel signal acquisition and output. The communication between the control unit and the resistance measurement module and the multi-function meter adopts the RS485 communication interface. The RS485 communication interface chip adopts TDA51S485HC. The maximum communication rate of this chip is 500kbps, allowing up to 256 transceivers to be installed on the bus, and has an isolation circuit.

[0032] In some embodiments, the optocoupler matrix includes optocouplers and Schmitt triggers. The switch signal is isolated by the optocouplers and then shaped and filtered by the Schmitt trigger and finally sent to the microcontroller for collection; a total of 8 optocouplers are used to collect the 6 position states of the band switch and the 2 position states of the button switch.

[0033] In this embodiment, the optocoupler matrix is ​​mainly composed of optocouplers and Schmitt triggers, which are used to collect the working status of the band switch and the toggle switch. The switch signal is isolated by the LTV-244 optocoupler, shaped and filtered by the 74HC14 Schmitt trigger inverter, and finally sent to the microcontroller for collection. A total of 8 optocouplers are designed to meet the collection requirements of the 6 position states of the band switch and the 2 position states of the toggle switch. The schematic diagram of two of them is shown in Figure 4 shown. In some embodiments, the first relay matrix includes relays and drive circuits for switching resistance measurement channels, control voltage output channels, and millivolt voltage output channels; the circuit structure of the first relay matrix is ​​the same as that of the second relay matrix.

[0034] In this embodiment, the relay matrix is ​​mainly composed of relays and drive circuits, which are used for switching resistance measurement channels, control voltage output channels, and millivolt voltage output channels. A total of 26 relays are designed, and the relays use IM03TS signal relays. The relays are double-pole double-throw, the coil operating voltage is 5VDC, and the contact rated current is 2A. Among them, 14 channels are used for switching 7 resistance measurement channels (including 1 resistance measurement module self-test channel), 6 channels are used for switching control voltage output channels, and 6 channels are used for switching millivolt voltage output channels. Four ULN2803 driver chips are used to drive these 26 relays to meet the detection requirements. The schematic diagram of three of them is as follows Figure 5 shown.

[0035] In some embodiments, the resistance measurement module adopts a four-wire resistance measurement method, and the test cable adopts a shielded cable.

[0036] In this embodiment, the resistance measurement module mainly realizes the measurement of the resistance of 6 groups of thermal sensor lines. The TRMD1002 series resistance measurement module is selected. In order to improve the measurement accuracy and eliminate the errors introduced by relays, test cables and connectors, a four-wire resistance measurement method is adopted, and the test cable uses a shielded cable. The relay matrix is ​​used to scan 7 channels, of which 6 channels are used for external measurement and 1 channel is used for internal 2Ω standard resistance measurement. The internal 2Ω standard resistance is used for self-test of the resistance measurement module.

[0037] In some embodiments, the action voltage simulation unit includes a reference voltage chip, and the reference voltage chip is connected to a potentiometer, an operational amplifier, and an analog-to-digital converter.

[0038] In this embodiment, the action voltage simulation unit is composed of a reference voltage chip, a potentiometer, an operational amplifier, an analog-to-digital converter, etc. It mainly realizes the output of a 0mV to 50mV voltage signal. The ADR421BRZ voltage reference chip is used. The input voltage of the voltage reference chip is 4.5V to 18V, the output voltage is 2.5V, the accuracy is ±0.04%, and the temperature stability is ±3ppm / ℃. The potentiometer uses the WXD3-13-2W-100Ω multi-turn precision potentiometer. The potentiometer adjustment range is 0Ω to 100Ω. By connecting a 4.9kΩ fixed resistor in series, the potentiometer adjusts the voltage range to 0mV to 50mV. The operational amplifier uses the INA105KU precision operational amplifier to achieve impedance matching with the fire alarm control box. The analog-to-digital converter uses the ADS1115IDGSR 16-bit ADC, whose power supply voltage is 2V~5.5V. The chip has a built-in programmable gain amplifier (PGA) and is configured to measure a voltage range of ±256mV. The resolution is 512 / 216=7.8125uV. After measurement and calibration, it meets the requirements of an action voltage measurement range of 0mV~50mV and an accuracy of ±2%FS.

[0039] In some embodiments, the display unit includes a voltmeter, a multi-function meter, and a signal indicator light. The voltmeter is connected to a power supply unit and a device under test, the multi-function meter is connected to a resistance measurement module and an action voltage simulation unit, and the signal indicator light is connected to the device under test; the test data includes output voltage, action voltage, sensor resistance value, and fire alarm signal.

[0040] In this embodiment, the voltmeter uses the HB5740Z-V intelligent voltmeter, which is powered by (27±3) VDC, has a measurement range of 0V to 50V, and an accuracy of ±1%FS, meeting the requirements for the output voltage measurement range and accuracy. The multifunctional meter uses the LED-055 RS485 serial port meter, which is powered by 5VDC, has a display digit of 5, uses the RS485 communication interface and Modbus RTU communication protocol, and meets the requirements for the display of the action voltage and sensor resistance value. The signal indicator uses the red-wave LAS2Y-D green indicator, which has a rated working voltage of 27VDC, meeting the indication requirements for the (27±3) VDC fire alarm signal.

[0041] In some embodiments, the universal fire alarm signal system detector is installed in a portable case, the panel of the portable case is made of rust-proof aluminum material, the surface of the panel is sprayed with plastic and then silk-screened, and the fonts on the panel are processed by etching and filling with ink.

[0042] In this embodiment, in order to facilitate the operation, use and maintenance of the equipment in indoor and outdoor fields, the chassis of the fire alarm signal system inspection instrument adopts a portable chassis design. The outer shell color is military green, the outer dimensions are (340±10) mm×(295±10) mm×(152±10) mm, and the total weight is about (4.1±0.5) kg. It is small in size, light in weight and high in strength. The panel of the equipment is made of 5052 rust-proof aluminum material, and the surface of the panel is screen-printed after spraying to avoid the problem of text falling off and becoming unclear after long-term use. The equipment panel is designed by itself and laid out according to ergonomics and functions. The left side of the panel is from top to bottom, with the power socket, fuse holder, power indicator light, and main power switch. The middle is from top to bottom, with the voltmeter, multi-function meter, and voltage adjustment knob. The right side is from top to bottom, with the test socket, signal indicator light, and channel selection switch. The design of the panel is convenient for operation and observation, and is easy to use. The panel layout of the equipment is as follows Figure 7 shown.

[0043] The fire alarm signal system inspection instrument adopts the Pelican safety box design. The panel is designed by itself. The panel uses 5052 rust-proof aluminum material. The panel diffraction is computer gray, the surface is sandblasted, and the font is etched and filled with ink to prevent surface oxidation.

[0044] The fire alarm sensor resistance value is measured using the TRMD1002 series resistance measurement module. In order to improve the measurement accuracy and eliminate the errors introduced by relays, test cables and connectors, the four-wire resistance measurement method is used, and the test cable uses a shielded cable. The relay matrix is ​​used to scan 7 channels, of which 6 channels are used for external measurement and 1 channel is used for internal 2Ω standard resistance measurement. The internal 2Ω standard resistance is used for self-test of the resistance measurement module. The fire alarm control box action voltage is measured by generating a 2.5V reference voltage through the voltage reference chip, which is adjusted by the potentiometer and the operational amplifier follows the impedance matching to output a 0mV~50mV voltage, which is then displayed by the analog-to-digital converter ADC. The voltage reference chip ADR421BRZ has an input voltage of 4.5V~18V, an output voltage of 2.5V, an accuracy of ±0.04%, and a temperature stability of ±3ppm / ℃. The potentiometer uses the WXD3-13-2W-100Ω multi-turn precision potentiometer, and the potentiometer adjustment range is 0Ω~100Ω. By connecting a 4.9kΩ fixed resistor in series, the potentiometer adjustment voltage range is 0mV~50mV. The operational amplifier uses the INA105KU precision operational amplifier to achieve impedance matching with the fire alarm control box. The analog-to-digital converter uses the ADS1115IDGSR 16-bit ADC, whose power supply voltage is 2V~5.5V. The chip has a built-in programmable gain amplifier (PGA) and is configured with a measurement voltage range of ±256mV. The resolution is 512 / 216=7.8125uV. After measurement and calibration, it meets the requirements of the action voltage measurement range of 0mV~50mV and accuracy of ±2%FS.

[0045] It can use 27VDC power supply on the aircraft or on the ground for outdoor in-situ detection, and 220VAC / 50Hz power supply for indoor off-site detection. The power supply is adaptively designed and can work normally with any power supply. It can detect other control boxes and matching sensors with the same working principle such as HKH-2, HKH-3, HKH-2A, HKH-3A, HKH-11, etc.

[0046] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A universal fire alarm signal system detector, characterized in that: It comprises a power supply unit and a control unit, wherein the input end of the power supply unit is connected to an external power supply, and the output end of the power supply unit is connected to an electrical device; the control unit is connected to a first relay matrix and a second relay matrix; the first relay matrix is ​​connected to an action voltage simulation unit and a device under test; the second relay matrix is ​​connected to the device under test and a resistance measurement module; the action voltage simulation unit and the resistance measurement module are connected to a display unit; the display unit is connected to the device under test and the power supply unit; the device under test is connected to the power supply unit; the power supply unit is used to perform power management on the electrical device and the device under test; the control unit is used to control the first relay matrix and the second relay matrix to switch the working mode and the detection channel, and read the test data and display them on the display unit; the resistance measurement unit is used to measure the resistance of the device under test; the action voltage simulation unit is used to output a target voltage signal; The power supply unit is powered by a variety of power supplies, so that a variety of devices under test can be detected.

2. The universal fire alarm signal system detector according to claim 1, characterized in that: The power supply unit includes a first fuse, a second fuse, a main power switch, a power indicator light, a switching power supply, a rectifier bridge, and a power module; the input ends of the first fuse and the second fuse are connected to an external power supply, and the output ends of the first fuse and the second fuse are connected to the main power switch; the main power switch is connected to the switching power supply and the rectifier bridge; the switching power supply and the rectifier bridge are connected to a display unit, a power indicator light, a power module, and a device under test; the rated currents of the first fuse and the second fuse are different; when the external power supply is supplied by the first power supply, the input to the first fuse passes through the main power switch and then enters the switching power supply, and is converted to a target voltage by the switching power supply and output to the power module, and the power module converts the target voltage into the power required for work; when the external power supply is supplied by the second power supply, the input to the second fuse passes through the main power switch and the rectifier bridge and is connected in parallel with the output end of the switching power supply.

3. The universal fire alarm signal system detector according to claim 2, characterized in that: The rated current of the first fuse is 0.5A, and the rated current of the second fuse is 2A; the first power supply is 220VAC, and the second power supply is 27VDC.

4. The universal fire alarm signal system detector according to claim 1, characterized in that: The control unit includes a microcontroller, a button switch, a band switch, and an optocoupler matrix; the microcontroller collects the working states of the band switch and the button switch through the optocoupler matrix, the microcontroller reads the measured value of the resistance measurement module through the RS485 interface circuit, reads the output data of the action voltage simulation unit through the I2C interface, and displays it on the display module through the RS485 interface circuit.

5. The universal fire alarm signal system detector according to claim 4, characterized in that: The optical coupler matrix includes optical couplers and Schmitt triggers. The switch signal is isolated by the optical couplers and then shaped and filtered by the Schmitt trigger and finally sent to the microcontroller for collection. A total of 8 optical couplers are used to collect the 6 position states of the band switch and the 2 position states of the button switch.

6. The universal fire alarm signal system detector according to claim 1, characterized in that: The first relay matrix includes relays and drive circuits, and is used for switching resistance measurement channels, control voltage output channels, and millivolt voltage output channels; the circuit structure of the first relay matrix is ​​the same as that of the second relay matrix.

7. The universal fire alarm signal system detector according to claim 1, characterized in that: The resistance measurement module adopts a four-wire resistance measurement method, and the test cable adopts a shielded cable.

8. The universal fire alarm signal system detector according to claim 1, characterized in that: The action voltage simulation unit includes a reference voltage chip, and the reference voltage chip is connected to a potentiometer, an operational amplifier, and an analog-to-digital converter.

9. The universal fire alarm signal system detector according to claim 1, characterized in that: The display unit includes a voltmeter, a multifunction meter, and a signal indicator light. The voltmeter is connected to a power supply unit and a device under test, the multifunction meter is connected to a resistance measurement module and an action voltage simulation unit, and the signal indicator light is connected to the device under test; the test data includes output voltage, action voltage, sensor resistance value, and fire alarm signal.

10. The universal fire alarm signal system detector according to any one of claims 1 to 9, characterized in that: The universal fire alarm signal system detector is installed in a portable case. The panel of the portable case is made of rust-proof aluminum material. The surface of the panel is sprayed with plastic and then silk-screened. The fonts on the panel are processed by etching and filling with ink.

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