Sealing gasket high-temperature performance testing machine

Abstract

The utility model relates to the technical field of sealing gasket testing, in particular to a high-temperature performance testing machine for a sealing gasket. The testing machine comprises a main body frame, a heating control module, a displacement testing module and a safety control module, and the main body frame provides installation sites for the heating control module, the displacement testing module and the safety control module; stand columns are arranged on the two sides of the upper cross beam, the upper cross beam is connected with the floor through the stand columns, the test platform is arranged between the upper cross beam and the bottom plate and connected to the upper surface of the bottom plate through a hydraulic cylinder, and the heating control module is installed on the peripheral edge of the test platform. The current transformer, the signal processing circuit, the comparison and judgment circuit and the control execution circuit in the safety control module work cooperatively, and the safety control module is installed in the test platform and connected with the heating control module, and the displacement test module is fixedly connected with the upper cross beam. And the safety performance is improved while the precision is not influenced.

Description

TECHNICAL FIELD

[0001] The utility model relates to sealing gasket test technical field especially is related to a sealing gasket high temperature performance testing machine. BACKGROUND

[0002] In the energy field, nuclear power plant as important power supply facilities, its safe and stable operation is crucial. Nuclear power plant high temperature waste water pipeline is one of the key components to guarantee the normal operation of nuclear power plant, the pipeline is in the harsh environment of high temperature, high pressure and complex medium for a long time, which puts forward very high requirements for the performance of the sealing gasket of the pipeline connection. Once the sealing gasket has performance problems, it will cause pipeline leakage, which will not only cause energy waste and environmental pollution.

[0003] The traditional sealing gasket performance test equipment has many limitations, which is difficult to meet the strict performance detection requirements of sealing gaskets in nuclear power plant and other fields. The existing test device often has single function, cannot simulate the complex working conditions of high temperature and steam at the same time, so that the performance of sealing gasket in actual use scene is difficult to accurately evaluate. In terms of high temperature test, the sensor precision of traditional test equipment is insufficient, the displacement measurement resolution is low, and it is difficult to accurately obtain the compression rate, rebound rate, permanent deformation amount and other key parameters of the gasket. The leakage detection precision is also difficult to meet the requirements, and the detection ability of small leakage is limited, which cannot accurately evaluate the sealing performance of the sealing gasket, and it is difficult to guarantee the safe operation of nuclear power plant and other key fields. In addition, the traditional test equipment has defects in safety protection, lacks perfect safety protection system, and has insufficient monitoring and response ability for safety hidden troubles such as pressure overload, temperature overload and electric leakage, which cannot effectively guarantee the safety of operators and equipment. When testing various sealing media (such as N2, methane, helium, steam, etc.), the medium input and detection system of traditional equipment is not flexible and accurate enough, which cannot meet the diversified test requirements. At present, a sealing gasket high temperature performance testing machine is needed. UTILITY MODEL CONTENTS

[0004] In order to solve the problems of low accuracy and imperfect safety performance of sealing gasket performance test equipment, the utility model provides a sealing gasket high temperature performance testing machine.

[0005] The utility model provides a sealing gasket high temperature performance testing machine adopts the following technical scheme:

[0006] A sealing gasket high temperature performance testing machine comprises:

[0007] Main body frame, heating control module, displacement test module and safety control module, the main body frame provides the installation site of heating control module, displacement test module and safety control module;

[0008] The main frame comprises an upper beam, a test platform and a bottom plate, both sides of the upper beam are provided with a stand, the upper beam is connected with the floor through the stand, the test platform is arranged between the upper beam and the bottom plate and is connected to the upper surface of the bottom plate through a hydraulic cylinder, the heating control module is installed at the four peripheral edges of the test platform, the safety control module is installed inside the test platform and is connected with the heating control module, and the displacement test module is fixedly connected with the upper beam.

[0009] Further, the heating control module comprises a heating assembly, a temperature sensor and a pressure sensor, the heating assembly is installed around the test platform through a high-temperature resistant support, the temperature sensor is installed on the inner surface of the test platform through a bolt, and the pressure sensor is installed at the steam interface of the test platform through a flange.

[0010] Further, the heating assembly is composed of a plurality of resistance heating wires, and the plurality of resistance heating wires are connected in series.

[0011] Further, the heating control module further comprises an upper heating furnace, a lower heating furnace, a water tank and a steam generator, the upper heating furnace is installed at the bottom of the upper beam through a hanging support, the lower heating furnace is installed below the test platform through a support seat, the water tank is connected with the steam generator, and the steam generator is connected to the steam interface of the test platform through a metal pipeline.

[0012] Further, the frame of the hanging support adopts a symmetrical rectangular structure, and the hanging support is internally provided with a heat insulation layer alternately combined by a plurality of layers of ceramic fiber felt and heat insulation foam.

[0013] Further, the displacement test module comprises a grating ruler and a rigid connecting block, the fixed end of the grating ruler is fixedly connected with the upper beam through a fixed clamp, and the moving end of the grating ruler is connected with the test platform through the rigid connecting block.

[0014] Further, the safety control module comprises a current transformer, a signal processing circuit, a comparison and judgment circuit and a control execution circuit, the output end of the current transformer is connected with the input end of the signal processing circuit through a shielded cable, and the output end of the signal processing circuit is connected with the comparison and judgment circuit and the control execution circuit in sequence.

[0015] Further, the signal processing circuit comprises an amplifier and a filter, the secondary winding output end of the current transformer is connected to the input pin of the amplifier, the output end of the amplifier is connected to the input end of the filter, and the output end of the filter is directly connected to the input pin of the comparison and judgment circuit.

[0016] Further, the comparison judging circuit comprises a comparator and a logic control element, one input pin of the comparator is connected with an output end of a reference voltage source, another input pin of the comparator is connected with an output end of the filter, an output end of the comparator is connected with an input pin of the logic control element, and an output end of the logic control element is connected with an input end of the control executing circuit.

[0017] Further, the control executing circuit comprises a transistor, a relay and a protection diode, a base of the transistor is connected with an output end of the logic control element, an emitter of the transistor is grounded, a collector of the transistor is connected with one end of a coil of the relay, and the coil of the relay is connected with the diode in parallel.

[0018] In summary, the utility model has the beneficial technical effects as follows:

[0019] 1、The displacement test module of the utility model adopts a grating ruler, the fixed end of which is stably connected with the upper cross beam through a fixing clamp, and the moving end is connected with the test platform through a rigid connecting block, so that the grating ruler can accurately follow the displacement change of the test platform, and the displacement data can be accurately measured, thereby providing accurate data support for the deformation amount of the sealing gasket in the test process, and effectively improving the precision of the test result.

[0020] 2、The temperature sensor in the heating control module is bolted to the inner surface of the test platform, so that the temperature of the test platform can be accurately monitored in real time, and the pressure sensor is flange-mounted at the steam interface of the test platform, so that the steam pressure can be accurately measured, which makes the control of the temperature and pressure more accurate during the test, ensures that the sealing gasket is tested under stable and accurate temperature and pressure conditions, avoids test errors caused by temperature and pressure fluctuations, and greatly improves the reliability and accuracy of the test result.

[0021] 3、The current transformer, signal processing circuit, comparison judging circuit and control executing circuit in the safety control module work cooperatively, the current transformer monitors the current of the power supply line in real time, once the leakage is detected, the signal is processed, the comparison judging circuit judges whether to trigger the control executing circuit, and the transistor, relay and protection diode in the control executing circuit cooperate when receiving the trigger signal, the transistor is turned on, the relay is actuated to cut off the power supply, and the protection diode prevents the reverse electromotive force generated when the relay is powered off from damaging the circuit elements, thereby comprehensively ensuring the safety of equipment and personnel and effectively avoiding safety accidents caused by leakage.

[0022] 4、The heating assembly of the heating control module is installed around the test platform by the high-temperature-resistant support, and the upper heating furnace is installed at the bottom of the upper cross beam through the suspension support with a heat insulation layer, and the lower heating furnace is installed below the test platform through the support seat, the multi-layer heat insulation design effectively prevents heat conduction upward from affecting other components, avoids equipment failure or safety problems caused by overheating, and guarantees stable operation and safe use of the equipment in a high-temperature environment.

[0023] 5、The heating assembly is composed of a plurality of series-connected resistance heating wires, can realize uniform heating, and the upper heating furnace and the lower heating furnace are located above and below the test platform respectively, directly heat treat the gasket, guarantee uniform heating of the sealing gasket in the test process, simulate a more real use environment, and improve the effectiveness and reference value of the test result.

[0024] 6、The water tank is connected with the steam generator, the steam generator is connected to the steam interface of the test platform through the metal pipeline, and the pipeline is also provided with flow regulating valves, check valves and other components, so that the steam generation amount and conveying can be accurately controlled, stable steam supply is ensured, and stable and reliable test conditions are provided for performance test of the sealing gasket in a steam environment. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a system principle diagram of the sealing gasket high-temperature performance test machine of the utility model embodiment.

[0026] Figure 2 is a structural schematic view of the sealing gasket high-temperature performance test machine of the utility model embodiment.

[0027] Figure 3 is a control execution circuit schematic view in the sealing gasket high-temperature performance test machine of the utility model embodiment.

[0028] Figure 4 is a signal processing circuit and comparison judgment circuit connection schematic view in the utility model embodiment.

[0029] Figure 5 is a whole circuit connection schematic view of the safety control module in the utility model embodiment.

[0030] 1, medium input channel; 2, test cavity; 3, detection pipeline; 4, safety control module; 5, heating control module; 6, test platform; 7, grating ruler; 8, upper cross beam; 9, test gasket; 10, hydraulic cylinder; 11, bottom plate; 12, loading oil cylinder; 13, lower heating furnace; 14, lower pressing disc; 15, upper heating furnace; 16, high-pressure valve; 17, pressure sensor; 18, high-pressure nitrogen gas inlet; 19, water tank. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below with reference to the accompanying drawings.

[0032] Example 1

[0033] Reference Figure 1 This embodiment of a high-temperature performance testing machine for gaskets includes:

[0034] The system comprises a main frame, a heating control module, a displacement testing module, and a safety control module, wherein the main frame provides mounting points for the heating control module, the displacement testing module, and the safety control module.

[0035] The main frame includes an upper crossbeam, a test platform, and a base plate. Columns are provided on both sides of the upper crossbeam, and the upper crossbeam is connected to the floor through the columns. The test platform is located between the upper crossbeam and the base plate and is connected to the upper surface of the base plate through a hydraulic cylinder. The heating control module is installed at the four edges of the test platform. The safety control module is installed inside the test platform and connected to the heating control module. The displacement testing module is fixedly connected to the upper crossbeam.

[0036] Specifically,

[0037] like Figure 1 , Figure 2 As shown, the main frame serves as the foundational support structure for the entire testing machine, comprising an upper crossbeam 8, a testing platform 6, and a base plate 11. Columns are installed on both sides of the upper crossbeam 8, connecting it to the base plate 11 to form a stable frame structure. The testing platform 6 is positioned between the upper crossbeam 8 and the base plate 11, and is connected to the upper surface of the base plate 11 via a hydraulic cylinder 10. This structure provides mounting points for the heating control module 5, the displacement testing module, and the safety control module 4.

[0038] The heating control module 5 includes a heating element, a temperature sensor, a pressure sensor 17, an upper heating furnace 15, a lower heating furnace 13, a water tank 19, and a steam generator. The heating element consists of multiple resistance heating wires connected in series, which are mounted around the test platform 6 via a high-temperature resistant bracket. The temperature sensor is bolted to the inner surface of the test platform 6, and the pressure sensor 17 is mounted via a flange at the steam interface of the test platform 6. The upper heating furnace 15 is mounted at the bottom of the upper crossbeam 8 via a suspension bracket with multi-layer thermal insulation. The suspension bracket has a symmetrical rectangular structure and an internal insulation layer consisting of alternating layers of ceramic fiber felt and thermal insulation foam material. It is bolted to the upper heating furnace 15 and its height and angle are adjustable. The lower heating furnace 13 is mounted below the test platform 6 via a high-temperature resistant support, which is bolted to the lower heating furnace 13. The water tank 19 is connected to the steam generator via a high-pressure, high-temperature resistant metal pipe, on which a flow regulating valve and a check valve are installed. The steam generated by the steam generator is transported to the steam interface of the test platform 6 through another high-temperature and high-pressure resistant metal pipe. The interface is connected by a sealing flange and a high-temperature resistant sealing gasket is used at the interface.

[0039] During the test, when heating of the sealing gasket is required, current flows through the series-connected resistance heating wire, which heats the space surrounding the test platform 6. Simultaneously, the upper heating furnace 15 and the lower heating furnace 13 heat the gasket directly from above and below, respectively. A temperature sensor monitors the temperature of the test platform 6 in real time and transmits the temperature signal to the control system. The control system, based on a preset temperature value, adjusts the current of the resistance heating wire and the power of the upper and lower heating furnaces 13 to achieve precise control of the test temperature. When a steam environment is required, water from the water tank 19 enters the steam generator under the precise control of the flow regulating valve. The steam generator converts the water into steam, which is then transported through metal pipes to the steam interface of the test platform 6 and enters the test area. A pressure sensor 17 monitors the steam pressure in real time and also transmits the signal to the control system. The control system adjusts the operating status of the steam generator and the valves on the pipeline according to a preset pressure value to ensure that the steam pressure remains stable within the set range.

[0040] The displacement testing module mainly consists of a linear encoder 7 and a rigid connecting block. The fixed end of the linear encoder 7 is securely mounted on the top of the upper crossbeam 8 using a special clamp. The special clamp is made of high-strength alloy material and is tightly fixed to the pre-set mounting holes on the upper crossbeam 8 with bolts. The clamp and the fixed end of the linear encoder 7 are precisely nested together and further precisely positioned using locating pins, and then tightened with bolts. The moving end of the linear encoder 7 is connected to the test platform 6 through the rigid connecting block. The rigid connecting block is made of high-strength, high-rigidity aluminum alloy. One end is connected to the moving end of the linear encoder 7 with bolts, and the connecting surface is machined with high precision. The other end is connected to the connecting seat of the test platform 6 with bolts. The connecting seat and the test platform 6 are integrally formed or welded together.

[0041] During the test, when the test platform 6 is displaced due to the action of the hydraulic cylinder 10 or other test operations, the moving end of the grating ruler 7 connected to the test platform 6 will move synchronously with the test platform 6. The fixed end of the grating ruler 7 is fixed on the upper crossbeam 8 and remains stationary. According to the working principle of the grating ruler 7, the relative displacement between its moving end and fixed end will generate corresponding electrical signal changes. After these signals are processed, the displacement data of the test platform 6 can be accurately measured, thereby obtaining the deformation of the sealing gasket during the test.

[0042] like Figure 3 , Figure 4 , Figure 5 As shown, the safety control module 4 includes a current transformer, a signal processing circuit, a comparison and judgment circuit, and a control execution circuit. The output of the current transformer is connected to the input of the signal processing circuit via a shielded cable. The signal processing circuit includes an amplifier and a filter. The output of the secondary winding of the current transformer is connected to the input pin of the amplifier, the output of the amplifier is connected to the input of the filter, and the output of the filter is directly connected to the input pin of the comparison and judgment circuit. The comparison and judgment circuit includes a comparator and a logic control element. One input pin of the comparator is connected to the output of the reference voltage source, and the other input pin is connected to the output of the filter. The output of the comparator is connected to the input pin of the logic control element, and the output of the logic control element is connected to the input of the control execution circuit. The control execution circuit includes a transistor, a relay, and a protection diode. The base of the transistor is connected to the output of the logic control element, the emitter of the transistor is grounded, and the collector of the transistor is connected to one end of the relay coil. The relay coil is connected in parallel with the diode. The safety control module 4 is installed inside the test platform 6 and connected to the heating control module 5.

[0043] The current transformer monitors the current in the power supply line of the testing machine in real time. Under normal circumstances, the current in the phase line and the neutral line are equal in magnitude and opposite in direction. The induced current output by the current transformer is zero or within a very small error range. When leakage occurs, some current flows into the ground through the leakage path, causing the current in the phase line and the neutral line to become unbalanced. The current transformer will detect the corresponding leakage current signal. This signal is transmitted to the signal processing circuit through a shielded cable. First, the weak leakage current signal is amplified by an amplifier. Then, the interference signal mixed in the signal is filtered out by a filter to obtain a pure leakage current signal. The comparator in the comparison and judgment circuit compares this signal with a preset leakage action threshold provided by a reference voltage source. If the detected leakage current signal exceeds the set threshold, the comparator outputs a trigger signal to the logic control element. After the logic control element performs logic processing on the signal, it outputs a signal to the control execution circuit. The transistor in the control execution circuit conducts after receiving the signal, energizing the relay coil. The relay then cuts off the power supply to the testing machine, thereby preventing accidents such as electric shock and equipment damage. When the relay is de-energized, the protection diode provides a release path for the reverse electromotive force generated by the coil, preventing it from damaging other components in the circuit.

[0044] High-pressure hydrogen gas is supplied to the equipment from an external storage tank via a high-pressure stainless steel pipeline. The pipeline is welded to the high-pressure valve 16, which is connected to the downstream pipeline via a threaded or flanged connection. A pressure sensor 17 is installed on the pipeline downstream of the high-pressure valve 16, directly screwed into the pre-set installation interface of the pipeline. The signal output line of the pressure sensor 17 is connected to the control system via a shielded cable. Additionally, multiple independent media input channels 1 are set up inside the test platform 6, each equipped with a high-precision flow regulating valve and a pressure sensor 17. One end of each channel connects to an external media storage tank, and the other end connects to the test chamber 2 of the pressure-resistant and heat-insulated system via a pipeline. During testing of different sealing media, the operator adjusts the flow regulating valve of each channel according to the test requirements via the PLC controller to precisely control the flow rate of the medium entering the test chamber 2. The pressure sensor 17 monitors the pressure of the medium in the pipeline in real time and feeds the signal back to the PLC controller. Based on the preset pressure value, the flow regulating valve is fine-tuned to ensure that the pressure of the medium entering the test chamber 2 remains stable within the set range. For example, during high-pressure nitrogen testing, high-pressure nitrogen enters from the storage tank through the high-pressure nitrogen inlet 18. Under the coordinated control of the flow regulating valve and the pressure sensor 17, it enters the test chamber 2 with accurate flow and pressure, creating conditions for the performance testing of the test gasket 9 in a nitrogen environment. During the test, if there is a media leak while the test gasket (sealing gasket) is in the test state, the leaked media will enter the detection pipeline 3 through the leak detection interface on the test platform 6, and then reach the corresponding detection equipment. For example, when the test medium is nitrogen, the nitrogen flow sensor will detect the change in the flow rate of the leaking nitrogen; if it is a methane leak, the methane sensor will quickly capture the methane gas and transmit the signal to the control system. A helium mass spectrometer can be used to detect extremely small gas leaks, determining whether there is a leak and the extent of the leak by detecting the mass spectrometric characteristics of the leaking gas. The control system judges the leakage status of the sealing gasket based on the signal fed back from the detection equipment, thereby evaluating its sealing performance.

[0045] When high-pressure hydrogen environment testing of the sealing gasket is required, high-pressure hydrogen flows into the equipment from an external storage tank through a high-pressure stainless steel pipeline. High-pressure valve 16 controls the flow rate and pressure of the hydrogen entering the test system. Operators can control the flow rate and pressure by adjusting the opening of high-pressure valve 16. Pressure sensor 17 monitors the hydrogen pressure in the pipeline in real time and transmits the pressure signal to the control system via a shielded cable. The control system adjusts the opening of high-pressure valve 16 according to a preset pressure range to ensure that the pressure in the test system is within a controllable range, meeting the performance testing requirements of the sealing gasket under different pressure conditions.

[0046] The loading cylinder 12 is located at the bottom of the equipment, and its body is fixed to the foundation frame at the bottom of the equipment with anchor bolts. The piston rod is connected to the lower pressure plate 14 via a ball joint or universal joint. The upper pressure plate is connected to the upper crossbeam 8 via a guide post. One end of the guide post is fixed to the upper crossbeam 8, and the other end passes through the guide hole of the upper pressure plate. A linear bearing or sliding bearing is installed between the guide post and the upper pressure plate. A gasket is placed between the upper pressure plate and the lower pressure plate 14.

[0047] During the loading test of the sealing gasket, the loading cylinder 12 starts working, and the piston rod pushes the lower pressure plate 14 upward. Since the piston rod and the lower pressure plate 14 are connected by a ball joint or universal joint, this connection method can compensate for the angular deviation between the piston rod and the lower pressure plate 14 during the movement, ensuring that the thrust of the piston rod can be evenly transmitted to the lower pressure plate 14. The upper pressure plate is connected to the upper crossbeam 8 through a guide post. The linear bearing between the guide post and the upper pressure plate reduces the frictional force when the upper pressure plate moves, ensuring the smoothness of the upper pressure plate's movement. As the lower pressure plate 14 moves upward, the upper pressure plate moves downward under the restriction of the guide post, thereby applying pressure to the sealing gasket placed between the two, realizing the loading test of the sealing gasket to test its sealing performance under different pressures.

[0048] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A high-temperature performance testing machine for sealing gaskets, characterized in that, include: The system comprises a main frame, a heating control module, a displacement testing module, and a safety control module, wherein the main frame provides mounting points for the heating control module, the displacement testing module, and the safety control module. The main frame includes an upper crossbeam, a test platform, and a base plate. Columns are provided on both sides of the upper crossbeam, and the upper crossbeam is connected to the floor through the columns. The test platform is located between the upper crossbeam and the base plate and is connected to the upper surface of the base plate through a hydraulic cylinder. The heating control module is installed at the four edges of the test platform. The safety control module is installed inside the test platform and connected to the heating control module. The displacement testing module is fixedly connected to the upper crossbeam.

2. The high-temperature performance testing machine for sealing gaskets according to claim 1, characterized in that, The heating control module includes a heating component, a temperature sensor, and a pressure sensor. The heating component is mounted around the test platform via a high-temperature resistant bracket. The temperature sensor is bolted to the inner surface of the test platform, and the pressure sensor is mounted to the steam interface of the test platform via a flange.

3. The high-temperature performance testing machine for sealing gaskets according to claim 2, characterized in that, The heating assembly consists of multiple resistance heating wires connected in series.

4. The high-temperature performance testing machine for sealing gaskets according to claim 1, characterized in that, The heating control module also includes an upper heating furnace, a lower heating furnace, a water tank, and a steam generator. The upper heating furnace is installed at the bottom of the upper crossbeam via a suspension bracket, and the lower heating furnace is installed below the test platform via a support base. The water tank is connected to the steam generator, and the steam generator is connected to the steam interface of the test platform via a metal pipe.

5. The high-temperature performance testing machine for sealing gaskets according to claim 4, characterized in that, The frame of the suspension bracket adopts a symmetrical rectangular structure, and the interior of the suspension bracket is provided with a heat insulation layer composed of alternating layers of ceramic fiber felt and heat insulation foam material.

6. The high-temperature performance testing machine for sealing gaskets according to claim 1, characterized in that, The displacement testing module includes a grating ruler and a rigid connecting block. The fixed end of the grating ruler is fixedly connected to the upper crossbeam through a fixing clamp, and the moving end of the grating ruler is connected to the test platform through the rigid connecting block.

7. The high-temperature performance testing machine for sealing gaskets according to claim 1, characterized in that, The safety control module includes a current transformer, a signal processing circuit, a comparison and judgment circuit, and a control execution circuit. The output terminal of the current transformer is connected to the input terminal of the signal processing circuit through a shielded cable. The output terminal of the signal processing circuit is connected to the comparison and judgment circuit and the control execution circuit in sequence.

8. A high-temperature performance testing machine for sealing gaskets according to claim 7, characterized in that, The signal processing circuit includes an amplifier and a filter. The output terminal of the secondary winding of the current transformer is connected to the input pin of the amplifier, the output terminal of the amplifier is connected to the input terminal of the filter, and the output terminal of the filter is directly connected to the input pin of the comparison and judgment circuit.

9. A high-temperature performance testing machine for sealing gaskets according to claim 8, characterized in that, The comparison and judgment circuit includes a comparator and a logic control element. One input pin of the comparator is connected to the output of a reference voltage source, and the other input pin of the comparator is connected to the output of a filter. The output of the comparator is connected to the input pin of the logic control element, and the output of the logic control element is connected to the input of a control execution circuit.

10. A high-temperature performance testing machine for sealing gaskets according to claim 9, characterized in that, The control execution circuit includes a transistor, a relay, and a protection diode. The base of the transistor is connected to the output terminal of the logic control element, the emitter of the transistor is grounded, the collector of the transistor is connected to one end of the relay coil, and the relay coil is connected in parallel with the diode.

Images