Alfred10

Members
  • Content count

    27
  • Joined

  • Last visited

Community Reputation

0 Neutral

About Alfred10

  • Rank
    Member
  1. Hello all. Thanks for taking up your time to read my post. I've bought a AC/DC adapter for MAX253CSA which per its specifications should output 5VDC and deliver 3A. I was going to use this adapter to power my BeagleBone Black (BBB) with. However, when I'm measuring the output from the adapter while it's idle (not powering anything) with a good-quality multimeter, it reads 5.24V. The BBB System Reference Manual (Rev. C) states the following: As one can see, my adapter outputs a voltage that's pretty close to the upper limit of 5.25V that the manual says is the maximum supplied voltage for the BBB. Is it still safe to use it to power my BBB with ? Can anyone help me ? I am very puzzled about this question. I do need your help. thanks in advance
  2. I read an electronic magazine in which there is a report on the controlling functions gets important in programmable logic. After reading, I became interested in programmable logic. So I searched some related materials and information about this topic from google. Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: The selection includes the selection of calculation functions, control functions, communication functions, programming functions, diagnostic functions and processing speed. 1, computing functions Simple programmable logic controller computing functions include logic operations, timing and counting functions; general programmable logic controller computing functions include data shift, comparison and other computing functions; more complex functions such as algebraic operations, data transmission; Large programmable logic controllers also have analog PID operations and other advanced computing functions. With the emergence of an open system, there are communication functions in the programmable logic controller, some products have communication with the lower computer, some products with the same position or the host computer communication, and some products also with the factory or business Network for data communication function. Design selection should be based on the actual application requirements, the rational use of the required computing functions. Most applications require logic operations and timing counting functions. Some applications require data transfer and comparison. When used for analog detection and control, algebraic operations, numerical conversions, and PID operations are used. To display data, you need to decode and encode operations. 2, control function Control functions include PID control operation, feedforward compensation control operation, ratio control operation, etc., should be determined according to control requirements. Programmable logic controller is mainly used for sequential logic control, therefore, most occasions often use single-loop or multi-loop controller to solve the analog control, and sometimes also use a dedicated intelligent input and output unit to complete the required control functions, Programming logic controller processing speed and saving memory capacity. For example, the use of PID control unit, high-speed counter, with speed compensation of the analog unit, ASC code conversion unit. 3, communication function Large and medium programmable logic controller systems should support a variety of fieldbus and standard communication protocols (such as TCP / IP), and should be connected to the plant management network (TCP / IP) when needed. The communication protocol shall conform to the ISO / IEEE communication standard and shall be an open communication network. Programmable logic controller system communication interface should include serial and parallel communication interface, RIO communication port, common DCS interface, etc .; large and medium-sized programmable logic controller communication bus (including interface devices and cables) should be 1: 1 redundant configuration , Communication bus should meet international standards, communication distance should meet the actual requirements of the device. Programmable logic controller system communication network, the higher the network communication rate should be greater than 1Mbps, communication load is not greater than 60%. The main form of communication network of programmable logic controller system has the following forms: 1) PC as the main station, more than the same type of programmable logic controller for the slave, composed of simple programmable logic controller network; 2) 1 programmable logic controller as the main station, the other with the same type of programmable logic controller for the slave, constitute the master-slave programmable logic controller network; 3) Programmable logic controller network through a specific network interface to connect to a large DCS as DCS subnet; 4) Dedicated programmable logic controller network (each vendor's dedicated programmable logic controller communication network). To reduce the CPU communication tasks, according to the actual needs of the network composition, should have different communication functions (such as point to point, field bus,) communication processor. 4, programming function Off-line programming mode: Programmable logic controller and programmer Common a CPU, programmer In programming mode, CPU only for the programmer to provide services, not on-site equipment control. After programming, the programmer switches to run mode, and the CPU controls the field device and can not program it. Offline programming can reduce system costs, but the use and debugging is not convenient. Online programming: CPU and programmer have their own CPU, the host CPU is responsible for field control, and in a scan cycle with the programmer for data exchange, the programmer to the online program or data sent to the host, the next scan cycle, The host will run according to the newly received program. This method is costly, but the system debugging and easy operation, often used in large and medium-sized programmable logic controller. Five standard programming languages: sequential function chart (SFC), ladder diagram (LD), function block diagram (FBD) three kinds of graphical language and statement table (IL), structural text (ST) two kinds of text language. The selected programming language should comply with its standard (IEC6113123), and should also support multiple language programming forms, such as C, Basic, etc., to meet the control requirements of special control situations. 5, diagnostic function The diagnostic functions of the programmable logic controller include hardware and software diagnostics. Hardware Diagnostics Determines the hardware's fault location, hardware diagnostics, and diagnostics by hardware logic. Through the software on the PLC internal performance and function diagnosis is the internal diagnosis, through the software on the programmable logic controller CPU and external input and output information exchange function is diagnosed outside the diagnosis. The strength of the diagnostic function of the programmable logic controller directly affects the technical requirements for the operation and maintenance personnel and affects the average maintenance time. 6, processing speed The programmable logic controller operates in a scan mode. From the real-time requirements, the processing speed should be as fast as possible, if the signal duration is less than the scan time, the programmable logic controller will not scan the signal, resulting in signal data loss. Processing speed and the length of the user program, CPU processing speed, software quality and so on. At present, the programmable logic controller contacts fast response, high speed, each binary instruction execution time of about 0.2 ~ 0.4Ls, it can adapt to the control requirements, the corresponding requirements of the fast application. The scan cycle (processor scan cycle) should be satisfied: the scanning time of the small programmable logic controller is not more than 0.5ms / K; the scanning time of the medium and large programmable logic controller is not more than 0.2ms / K. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of programmable logic. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance
  3. I read an electronic magazine in which there is a report on I can simply describe a level shifter. After reading, I became interested in the circuit of level shifter. So I searched some related materials and information about this topic from google, but it is not specific at all. Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: Level shifters are mainly composed of an NMOS and two pull-up resistors. Its level shift is two-way. But it needs to meet a few conditions, otherwise it may appear leakage situation. First analyze its working principle. First analysis from left to right function: When the NMOS S-level (source) input is high level 3.3V, NMOS does not turn on, and because its D-class (drain) is pulled up to 5V, so the diode does not turn on. So its output is 5V level. When the NMOS S-pole input is low 0V, then NMOS conduction, then the D-pole output will be pulled to 0V. This results in a conversion from left to right. Reanalyze from right to left: When the NMOS D-stage input is 5V high, due to its S pole through the 4.7k resistor pulled up to 3.3V. So the NMOS and the inside of the diode are not conductive, so the S-level is 3.3V When the N-stage input of the NMOS is a low level of 0V, the level of the S-pole is 0V because the diode inside is turned on. The above analysis assumes that the power is ok. So in practical application should pay attention to: 1, NMOS D-level high level of the plane than the S pole to be high. Otherwise the high level will be through the two-level pull the io level into other levels. 2, NMOS D-level level than the S-level earlier power, otherwise the S-pole will pass through the diode to the D-class leakage. 3, NMOS G level of the best and S-level the same. 4, G level of the electrical plane is greater than the NMOS threshold voltage There is also a relatively simple (with reverse) level shift: The PQ8 pin1 level is 3.3V, but through this circuit, you can change the output level to + VDC (12V). In fact, this circuit can also look at the level shift function is achieved, but this is one-way, and is reverse. It should be noted that the input level must be greater than Vth (MOS threshold voltage). The level to be converted is basically no need to consider. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of level shifters. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance
  4. I read an electronic magazine in which there is a report on what are the principles for vibration sensors. After reading, I became interested in the principles for vibration sensors. So I searched some related materials and information about this topic from google. Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: The vibration sensor has vibration displacement, vibration speed and vibration acceleration sensor. In short, the vibration displacement sensor (commonly used eddy current sensor) according to the vibration displacement and output voltage changes in the relationship between the vibration velocity sensor according to the relative movement of the magnetic field lines to produce changes in voltage, vibration acceleration sensor according to the relationship between deformation and charge. The speed sensor can be displaced by hardware or software integral, the acceleration sensor can be obtained through a single integral vibration speed, the second integral can be vibration displacement. Because it is necessary to measure the acceleration, it is necessary to have a vibration acceleration sensor. Displacement measurement: If the non-contact measurement gap changes, you must use the vibration displacement sensor (eddy current sensor); If it is contact measurement, you can use the acceleration sensor through 2 times the integral can also be used to complete the speed sensor 1 points, the specific use What kind of way depends on the measurement object. In general, if gears or rolling bearings are included, use the acceleration sensor, otherwise use the speed sensor. Some vibration sensor measurement principle is actually the principle of measuring displacement only with the displacement sensor to measure the vibration, then the sampling frequency of the sensor must be higher than the vibration frequency of the measured object. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of vibration sensors. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance
  5. I read an electronic magazine in which there is a report on what are the characteristics for fiber optic connectors. After reading, I became interested in fiber optic connectors. So I searched some related materials and information about this topic from google. Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: Optical fiber connector, commonly known as the union, commonly known as fiber optic connector, is used to connect two optical fibers or optical cable to form a continuous optical path can be reused passive devices, has been widely used in optical fiber transmission lines, fiber patch panels And fiber test equipment, instrumentation, is currently the largest number of optical passive devices. The main purpose of fiber optic connectors is to achieve fiber connections. Widely used in optical fiber communication system in the optical fiber connector, its many types, different structures. However, the basic structure of various types of fiber optic connectors is consistent, that is, the vast majority of fiber optic connectors generally use high-precision components (by two pins and a coupling tube composed of three parts) Alignment of the fiber. This method is to penetrate and fixed the fiber in the pin, and the pin surface after polishing, in the coupling tube to achieve alignment. The outer part of the pin is made of metal or nonmetal material. The butt end of the pin must be ground and the other end usually uses a bend limiting member to support the fiber or fiber optic cable to release the stress. Coupling pipe is generally made of ceramic, or bronze and other materials made of two semi-synthetic, fastened cylindrical components made of multi-metal or plastic with a flange, in order to facilitate the installation of the connector fixed. In order to precisely align the optical fiber, the pin and the coupling pipe processing accuracy requirements are high. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of fiber optic connectors. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance
  6. I read an electronic magazine in which there is a report on how to connect wires in temperature probe. After reading, I became interested in wiring connection in temperature probe. So I searched some related materials and information about this topic from google. Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: Thermostat (Thermostat), according to the working environment of the temperature changes in the switch within the physical deformation, resulting in some special effects, resulting in conduction or disconnection of a series of automatic control components, also known as temperature control switch, temperature protection Device, temperature controller, referred to as thermostat. Or through the temperature protection device to the temperature through the temperature controller, the temperature controller issued a switch command to control the operation of the equipment to achieve the desired temperature and energy saving effect, its wide range of applications, according to different types of thermostat applications in Home appliances, motors, refrigeration or heating and many other products. Its working principle is through the temperature sensor to automatically check the ambient temperature, real-time monitoring, when the ambient temperature is higher than the control set value when the control circuit starts, you can set the control hysteresis. If the temperature is still rising, when rising to the set limit alarm temperature point, start the alarm function. When the controlled temperature can not be effectively controlled, in order to prevent the destruction of equipment can also be through the trip function to stop the device to continue running. Mainly used in the power sector to use a variety of high and low voltage switchgear, dry-type transformers, box-type substation and other related temperature use. Wiring Method Look at the three feet on the thermostat, they are used in English letters and numbers in two ways to replace, namely: H (6), L (3), C (4). H (6) then brown line, is the power of the line of fire; L (3) connected to the gray line, is the fire line of light; C (4) then the white line is the fire line of the compressor. Control Method The control method is generally divided into two kinds; one is controlled by the temperature change of the object to be cooled, the steam pressure type temperature controller is used, the other is controlled by the temperature difference of the object to be cooled, and the electronic temperature Controller. Its use of fuzzy control techniques such as PID control, P (Proportional) ratio + I (Integral) + D (Differential) differential control. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of temperature probe. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance
  7. I read an electronic magazine in which there is a report on one laser diode constant power drive circuit can be used. After reading, I became interested in laser diodes. So I searched some related materials and information about this topic from google. Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: Picture One The reference voltage of the circuit does not use the common resistor divider circuit, but uses the Vbe of the transistor Tr1 as the reference voltage, Vbe is about 0.7V, ie (Im-Ib) Vr1 = 0.7V, but Ib is small and can be ignored. Vbe has a temperature characteristic of 2 mV / ° C, the reference voltage will vary with temperature, even if the temperature characteristic is much better than the constant current drive. The entire circuit uses only two crystal transistors, Vr1 for the output adjustment and load resistance, is quite simple APC circuit. This is a circuit designed to improve reliability, sharing five crystal transistors. The main features are as follows: ● The semi-variable resistor for adjusting the output is canceled. ● If there is a short circuit between the BEs of Tr5, the current flowing through resistor R2 becomes almost the base current of Tr1 and Tr2, which will increase the output. However, the base current Ib flowing through Tr2 will make 680Ib + Vbe> 2Vbe, the result Tr4 conduction, bypass part of the current to the ground, so that the output power is subject to certain restrictions. ● If any of Tr1 and Tr2 is short-circuited between C and E, there is no overcurrent due to the presence of another transistor. ● In addition to the five transistors, the short circuit of the remaining components will not cause the output to increase. Circuit R1 is the base resistance, doubling as a current sampling resistor; R5 for the load resistance. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of laser diodes. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance
  8. In recent days I am studying to create panel indicators that can display multiple sub-graphs under the Mastercard chart. I know that few people know how to create panel indicators in detail. Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: First of all you have to determine that with a few sub-indicators, with the use of time-sharing significance, and then set the first in the main map. The detailed steps are as follows: 1 point function - custom layout - new blank layout - right click on the plug - set the unit type - time trend charts - ordinary time chart. If you want to add other points in the left or right to insert their own settings, want to add the conditions, and then pull the boundaries of the left and right to divide the space. 2 the following blank right mouse button to set the unit type - point analysis chart - the general analysis of the map - the first sub-map along the line point to pull the main map to the merger did not release the mouse, and then adjust the upper and lower The distance of the figure. If you want to add other points in the left or right to insert their own settings, want to add the conditions, and then pull the boundaries of the left and right to divide the space. 3 out of the design layout. Save a name you want "time to read the disk." 4 in the re-click function - custom layout - time to read the disk - in the following point analysis cycle -1 minute chart. 5 there is a problem to pay attention to the following time a bit asymmetrical, to tune their own it, in fact, very simple. I added a "blank unit" to the left of the time-sharing indicator to solve the problem of time asymmetry. 6 I seriously control the production of such time-sharing on the multi-indicator problem, is not time-sharing and time-sharing indicators are consistent, after analysis to see how much difference, it is a stock of one minute cycle K line graph, Time-sharing diagram is also in minutes to crossed, you can drag the mouse to verify what. Read the picture. All OK if you feel good, give it to encourage Oh Analysis of your historical data to predict the future, because we do stock analysis of the technical method is based on the three theoretical basis: the history will be repeated, the trend will continue, the price inclusive! In other words, if the technical analysis does not form the index of historical data, technical analysis will lose its meaning, Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of panel indicators. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance
  9. I read an electronic magazine in which there is a report on moisture sensors can be used in soils. After reading, I became interested in the uses of moisture sensors in soils. So I searched some related materials and information from google about this topic. Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: Soil water is the main source of water absorption (except for hydroponic plants), the state and change of soil moisture content, which is the main determinant of plant growth status, which affects human food safety and ecological environment. Thus, the soil and water on Earth are the basis of human and even life, through the soil moisture sensor to measure the water content of the soil, the current well-known mainly for the following purposes: To provide decisive support for scientific irrigation At present, agricultural water consumption accounts for 92% of the world's fresh water consumption. In China, the national average utilization rate of agricultural irrigation water is only 45% (see Baidu Encyclopedia "irrigation water use coefficient"), 55% of the water after extensive irrigation, a large number of leakage into the plant roots below the surface runoff loss, water Channel leakage and other ways to be wasted. In 45% of the water is preserved in the soil, and because of blind irrigation, non-on-demand irrigation, water and fertilizer integration is not in place and other reasons, a lot of water can not be effectively used crops. The use of soil moisture sensor can dynamically track the depth of the crop root in the soil in the specific depth of the crop roots of the dynamic absorption of water consumption; the use of soil moisture sensor recorded soil moisture curve, can be intuitive and quantified way to show The water content of different soil layers in soils changed with time, and then the key factors such as irrigation depth, irrigation amount, irrigation start time, irrigation duration, irrigation limit and soil moisture content were obtained. Scientific irrigation decisions make it useful for the crop to live in a soil where the crop is truly comfortable and to increase crop yields. On the other hand, people do not always want to control the survival of crops in a comfortable environment to increase production, people will consider the quality of agricultural products. For example, the appropriate soil moisture will make the grape yield is high, but the grapes will not necessarily sweet. In the late stages of grape growing, the use of soil moisture sensors is to monitor the soil moisture content, so that the soil moisture content to maintain a relatively low state of the state, in the United States, Spain, the United States and other high-quality wine-producing areas. For the government departments to provide data support, policy basis The soil moisture and soil temperature data monitored by the soil moisture sensor are the relevant government activities, such as agriculture, water conservancy, meteorology and land, and formulate and implement relevant policies. It is also one of the basic public services provided by the government for the people. For example, in recent years, the local governments have been actively launched by the government-funded agricultural information service platform for the local people to provide a lot of soil moisture data, spring water harvesting guide, soil moisture sensor is one of the basic sources of these data. In the national drought and flood control system, there are a large number of installed in the country's drought, moisture monitoring stations, hydrological stations, soil moisture sensors are the most important and most basic instruments of these sites. Provide early warning for natural disasters such as landslides In 2013, there were 15403 geological disasters in China, of which 9849 were landslides, resulting in incalculable personal injury and property damage. A large number of landslides are caused by rainfall and other factors to increase the water content of the mountain, hillside weight increases, the slope of gravity than the lower soil see the friction and then landslides. Soil moisture sensor is the most important and basic instrument of mountain landslide monitoring and early warning system. For the soil, plants, the environment and other scientific research data Soil moisture sensors are widely used in soil science, plant growth in water relations research, landfill leaking monitoring, fertilizer utilization optimization, global warming impact research and other fields. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of moisture sensors. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance
  10. I read an electronic magazine in which there is a report on what are the reed relays used. After reading, I became interested in reed relays. So I searched some related materials and information about this topic. Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: The contact form of the reed relay depends on the reed switch used. Reed switch has normally open (H), normally closed (D) and conversion (Z) three forms. The reed reed of the normally open reed is fixed at both ends of the glass tube, and the magnetic properties at one end are opposite to the other end under the action of the coil (magnet), so the two contacts rely on the magnetic "To close the shrapnel elasticity and closed; normally closed reed rod reed is fixed on the same end of the glass tube, under the action of the external magnetic field produced by the same magnetic, so the two contacts rely on" homosexual repulsion " To overcome the elasticity of the reed and broken; in the normally closed reed on the basis of reed with a normally open reed, it constitutes a conversion type of contact. Reusable sensor quality and reliability The most notable application is for automatic test equipment (ATE). In this equipment technology is first-class, reed switch is used for reed relays, it is used in IC, ASIC, silicon test equipment and printing test equipment, as a switch. In these applications, a test system in the reed switch can reach 20,000. The failure rate of a relay is set at 50ppm, so to meet this requirement, the quality of the reed relay is much better than the 50ppm requirement. So far, has not heard of a mechanical and electrical devices have such a level of quality. Similarly, it also applies to some semiconductor devices. Once the quality test of the initial work is done, the reed relay needs to perform well within its lifespan. At this point they have proven to be better than all other switching devices. This is because in many cases, ATE work 24 hours a day, 7 days a week, it is the cost of the most important. So the working life of the reed relay needs millions of times. Another example of a reed relay is that it is used as a balloon sensor in which it passes time tests in harsh security applications. Reed switch is widely used in many demanding automotive safety equipment (such as the height of sensitive brake fluid), in many medical equipment applications, including cautery equipment, pacemakers and other medical electronic equipment. On these devices, the reed relay relieves a small leakage current. Reed relays are electromagnetic interrupters with sealed contacts. Reed relays can reflect the voltage, current, power and current polarity and other signals, in the detection, automatic control, computer control technology and other fields widely used. Reed relays are mainly composed of dry reed and reed coils. Reed relays have: simple structure, small size. Contact life, generally up to 10 of the 7 side or so. Reed relays can also be used to drive permanent magnets, reflecting non-electrical signals, for limit and stroke control and non-power detection. The main components for the reed relay reed water level signal for industrial and civil buildings in the water tank, water towers and pools and other open containers of water level control and water level alarm. Electromagnetic relay is the use of electromagnets to control the working circuit off the switch. (1) Structure: The main components of the electromagnetic relay are electromagnet A, armature B, spring C and movable contact D, static contact E. (as shown) (2) The working circuit can be divided into two parts: low voltage control circuit and high voltage working circuit. The low voltage control circuit includes electromagnetic relay coil (electromagnet A), low voltage power supply E1, switch S; high voltage working circuit includes high voltage power supply E2, motor M, Relay contacts D, E parts. (3) working principle - closed low-voltage control circuit switch S, the current through the solenoid A coil to produce a magnetic field, so that the armature B gravity, the dynamic and static contact D and E contact, the working circuit is closed, the motor work ; When the low-voltage switch S is disconnected, the current in the coil disappears, and the armature B, under the action of the spring C, disengages the movable and static contacts D, E, the working circuit is disconnected and the motor stops working. As long as the coil at both ends with a certain voltage, the coil will flow through a certain current, resulting in electromagnetic effects, the armature will be attracted by the role of electromagnetic force to overcome the return of the spring to pull the iron core, Moves the contact with the static contact (normally open contact). When the coil is powered off, the electromagnetic force will disappear, the armature will return to the original position of the spring, so that the movable contact with the original static contact (normally closed contact) release. So that pull, release, so as to achieve the circuit in the conduction, cut off the purpose. For the relay "normally open, normally closed" contacts, it can be distinguished: relay coil is not in power when the state of the static contact, known as the "normally open contact"; in the state of the static contact As "normally closed contact". Electromagnetic relay is an important part of the bell, telephone and automatic control circuit device. Its essence is the switch controlled by the electromagnet, which plays a similar role in the circuit: (1) control the high voltage with low voltage and weak current, High current; (2) to achieve long-range operation and automatic control. Electromagnetic relays are widely used in automatic control (eg, refrigerators, cars, elevators, machine tools, etc.), which can be used to control high voltage and high current working circuits with low voltage and weak current control circuits, and can realize remote control and production automation In the control circuit) and the field of communication. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of reed relays. I need continual learnings. For more information, please feel free to visit the site at the following link: http://www.kynix.com/Parts/3882497/W117SIP-6.html. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance
  11. I read an electronic magazine in which there is a report on there is a traditional method that can control ICLs. After reading, I became interested in inrush current limiters. So I searched some related materials and information about this topic. Today I come to this forum to turn to you to discuss my ideas are appropriate. Here are my personal understandings: In the AC / DC converter start moment, because the filter capacitor charging will produce a large inrush current, it is more than the system normal current Times to several times. Surge current will seriously pollute the power supply network, affecting the normal operation of other electronic equipment. Sometimes damage the power switch, fuse, EMI filters, rectifier bridge, filter capacitors, and even printed circuit boards and other components. Sometimes, although no visible damage is seen, recessive damage reduces the device The reliability of this is even worse. In order to improve the input characteristics of switching power supply, improve its reliability, reduce the pollution of the power grid, improve the electronic design The use of the environment must be limited to the surge current. The traditional method of limiting the inrush current is that the power consumption is large, the second surge, and the instantaneous power Can not move and other issues. The new inrush current limiting device, the KJH inrush current limiter, fundamentally solves these problems. It is well known that when the AC / DC converter is powered up, the surge current can be reduced by increasing the loop resistance of the charging capacitor C charging circuit. There are two traditional methods: 1. In the circuit in series with a suitable resistor (the resistance into a negative temperature coefficient thermistor is an improvement), both the surge current can be limited to an acceptable range, without affecting the normal work of the converter; 2. In the circuit in series with a pair of contacts in parallel with a combination of contacts, so that the contact at power on, the resistance in series in the loop to limit the role of inrush current, when the power into a certain state Contact connected, the resistance short circuit to reduce power consumption, to ensure the normal operation of the power supply. Inrush current limiter, which is the use of negative temperature coefficient thermistor and half bridge switch to complete the combination of limiting inrush current function. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of inrush current limiters. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance
  12. I am an electronic engineer in the field of shift registers and my work is working on various different projects for electronics. In recent days I am going to make a project for shift registers. Today I come to this forum to turn to you to discuss my understandings are appropriate. The project for shift registers begins now: In a digital circuit, the circuit used to store binary data or code is called a register. The registers are composed of flip-flops with memory functions. A trigger can store a binary code, stored in the N-bit binary code register, need to use n flip-flop to form. According to the function can be divided into: the basic register and shift register. The data in the shift register can be shifted right or left one by one in the direction of the shift pulse. The data can be input in parallel, parallel output, serial input, serial output, serial output, Serial input, parallel output, very flexible, use is also very wide. There are many types of integrated shift registers commonly used, such as 74164, 74165, 74166, 74595 are eight one-way shift register, 74195 for the four one-way shifter, 74194 for the four-way two-way shifter, 74198 for the eight Bit bidirectional register. The shift register not only registers the digital, but also has a shift function. Shift is a very important feature in digital systems and computer technology. If the binary number 0101 is multiplied by 2, it can be done by shifting 0101 to the left by one bit; the divide by 2 operation can be done by shifting one bit to the right. There are many types of shift registers, there are left shift register, right shift register, bidirectional shift register and cyclic shift register. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of shift registers. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance
  13. I am an electronic engineer in the field of digital isolators. In recent days in my spare time, I make a project for new digital isolators on my own and in the process of making, I found one magical case that new digital isolator enhances PLC performance. Today I come to this forum to turn to you to discuss my understandings are appropriate. The project for new digital isolators begins now: Four major technical challenges in industrial automation In order to help the industry to accelerate the implementation of related solutions, this paper in addition to the industrial automation target market for isolation applications, focusing on programmable logic controller (PLC) and factory automation development of detailed market and technical analysis, but also a detailed description of the new Complementary metal-oxide-semiconductor (CMOS) digital isolators compared to traditional optical coupling isolation solutions for industrial automation applications brought significant advantages. Many of the technical challenges involved in the development of industrial automation include: 1st, Equipment security can not compromise The Security features are critical. The The product must be stable under high stress. 2nd, Normal work in high-noise environments The The external electrical / magnetic field of the factory has high anti-interference. The High voltage transient noise has strong anti - interference ability. 3rd, Long product life The The entire temperature range, different VDD voltage, and long-term use, the key parameters must be stable. The Under high stress, the product has a long service life. 4th, High performance The Product performance must be the world's top. The Low latency and low latency bias to ensure high efficiency and throughput. Based on the above technical challenges, high-performance isolation products for industrial automation must also be highly safe, highly resistant to interference and long life. There are many high-voltage equipment in the factory, through the isolation program can not only protect the electronic systems and personnel, but also to suppress noise to ensure the reliability and stability of the equipment. With the industrial automation applications to improve the performance requirements of related equipment, built-in isolation technology has begun to change, the traditional isolation using optical coupling technology, due to inherent characteristics gradually difficult to meet the needs of industrial automation design, including poor reliability, timing characteristics Poor, non-surplus common mode transient noise immunity (CMTI), low energy efficiency, so that the industry began to look to the new CMOS capacitor-coupled digital isolator program. The use of differential capacitive coupling technology CMOS digital isolator is highly efficient CMOS digital isolator using switch key modulation technology CMOS design, and the use of differential capacitive coupling, can achieve high reliability and stability, not with the temperature, operating voltage and product life and change, in addition to excellent timing characteristics, Including low transmission delay, low transmission delay deviation and so on. More importantly, the CMOS digital isolator has a high common mode transient noise immunity (CMTI) and requires less power than the optocoupler, thus reducing overall system power consumption. Figure 1 and Figure 2 for the traditional optocoupler and CMOS digital isolation scheme comparison. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of new digital isolators. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance.
  14. I read an electronic magazine in which there is a report on heat shrink tube. After reading, I became interested in this topic, so I searched some relevant materials and information about it, but found that it is not specific at all. Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: Heat shrinkage tube extrusion production is prone to abnormal phenomena, causes and solutions A, abnormal phenomenon: pipe extrusion surface rough reasons: 1, in the production of smaller specifications of the pipe when the melt fracture 2, mixed uneven 3, the material there is moisture 4, the extrusion temperature is low 5, the masterbatch of its melt strength is poor (such as halogen-free masterbatch) To solve the problem: 1, to increase the length of the straight part of the die, or reduce the screw speed 2, to improve the extrusion pressure, fully mixed or the use of shallow thread screw 3, the use of masterbatch to be fully dry 4, to improve the extrusion temperature 5, adjust the masterbatch, improve the masterbatch extrusion melt strength B, abnormal phenomenon: The vertical wall thickness fluctuations reasons: 1, the extruder is running uneven, uneven material, extruder material uneven 2, the traction device running fluctuations 3, the temperature changes caused by the solution: 1 , Adjust the extruder speed, mixing evenly, the extruder under the mouth to control the barrel temperature, to prevent the phenomenon of melt bonding. Consider the size of the masterbatch particles and, if necessary, reduce the size of the masterbatch particles. 2. Correct the stability of the traction device and the traction roller 3, Adjust the temperature of the material and mold, and adjust the extrusion pressure C, abnormal phenomenon: Extruder die powder material serious reasons: 1, the use of masterbatch in the plastic melt after the poor mobility 2, the mold extrusion temperature is high 3, the extrusion die mandrel And die in the scraper material To solve the method: 1, strict control of the processing properties of masterbatch, including (processing additives use, type) MFR index detection 2, adjust the mold extrusion temperature 3, the use of tools on the mold scraping Wound for polishing Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of heat shrink tubes. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance.
  15. I guess almost everyone sees rectangular connectors, however do you know why rectangular connectors are called so ? I am an electronic engineer in the field of rectangular connectors and my job is making various different electronic projects, such as rectangular connectors. Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: As the structure of the connector is increasingly diversified, new structures and applications continue to emerge, trying to use a fixed pattern to solve the classification and naming problems, has become difficult to adapt. Nonetheless, some basic classifications are still valid. 1. Interconnection level According to the function of internal and external connection of electronic equipment, interconnection can be divided into five levels. ① The internal connection of the chip package ② IC package pin and PCB connection. Typical connector IC socket. ③ printed circuit and wire or printed circuit board connection. Typical connectors are printed circuit connectors. ④ the bottom plate and the floor of the connection. Typical connectors are cabinet connectors. ⑤ connection between equipment and equipment. Typical products are round connectors. The third and fourth levels have some overlap. In the five levels of the connector, the highest market value is the third and fifth level of the product, and the fastest growing is the third level of the product. 2. The level of the connector specification. According to the classification of the International Electrotechnical Commission (IEC), connectors are electromechanical components for electronic equipment, the specification level is: Examples of connectors Sub-family Example: Round connector Type (type) Example: YB type round connector Variety (style) Example: YB3470 Variant 3. In China's industry management, the connector and switch, keyboard, etc. collectively referred to as electrical connector components, and electrical connectors and relays are referred to as electromechanical components. 4. The product category of the connector. Connector product type division Although some confusion, but technically, the connector product category only two basic division: ① by the shape of structure: round and rectangular (cross-section) ② by operating frequency: low frequency and high frequency (to 3MHz bounded) In the above division, the coaxial connectors are round and the printed circuit connectors are rectangular (historically, the printed circuit connectors are indeed separated from the rectangular connector) and are currently popular The rectangular connector has a trapezoidal cross section, approximately rectangular. To 3MHz for the boundaries of low frequency and high frequency and radio frequency division is basically the same. As for the other uses, installation, special structure, special performance, etc. can also be divided into many different types, and often appear in the publications and manufacturers of promotional materials, but generally only to highlight a feature and use, the basic classification is still Did not exceed the above division principle. Taking into account the technical development of the connector and the actual situation, from its versatility and related technical standards, the connector can be divided into the following categories (sub-categories): ① low-frequency circular connector; ② rectangular connector; ③ printed circuit connector; ④ RF connector; ⑤ fiber connector. 5. The model of the connector is named. The model name of the connector is the basis for the customer's production and the manufacturer's production. In the domestic and international connector industry, the product model name has two kinds of ideas: one is to use the letter code plus digital approach, and strive to model the name of the product reflects the main structural features. The benefits of this approach are easy to identify, but the arrangement is too long, too complicated, with the miniaturization of the connector, to print a lot of difficulties. At present, China is still popular in this way, and in some industry standards or even made in the national standard, such as SJ2298-83 (printed circuit connector), SJ2297-83 (rectangular connector), SJ2459-84 (ribbon cable connection Device), GB9538-88 (ribbon cable connector) and so on. Due to the increasing diversity of the connector structure, it is becoming increasingly difficult to cover a certain type of connector with a naming convention in practice. Another idea is to use Arabic numerals. The benefits of this approach are concise, easy to print for computer management and logo for small products. International major connector manufacturers are currently using this approach. It is expected that the naming scheme that reflects the characteristics of the manufacturers will gradually replace the way in which a naming convention is prescribed by the whole industry under the planned economy system. As the structure of the connector is increasingly diversified, new structures and applications continue to emerge, trying to use a fixed pattern to solve the classification and naming problems, has become difficult to adapt. Nonetheless, some basic classifications are still valid. Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of rectangular connectors. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance.