The Kynix Blog

As we can know, a new technique that can change plastic's molecular structure to help it cast off heat is a promising step in that direction. Advanced plastics could usher in lighter, cheaper, more energy-efficient product components, including those used in vehicles, LEDs and computers -- if only they were better at dissipating heat. Developed by a team of University of Michigan researchers in materials science and mechanical engineering and detailed in a new study published in Sciene Advances, the process is inexpensive and scalable. The concept can likely be adapted to a variety of other plastics. In preliminary tests, it made a polymer about as thermally conductive as glass -- still far less so than metals or ceramics, but six times better at dissipating heat than the same polymer without the treatment."Plastics are replacing metals and ceramics in many places, but they're such poor heat conductors that nobody even considers them for applications that require heat to be dissipated efficiently," said Jinsang Kim, U-M materials science and engineering professor. "We're working to change that by applying thermal engineering to plastics in a way that hasn't been done before." The process is a major departure from previous approaches, which have focused on adding metallic or ceramic fillers to plastics. This has met with limited success; a large amount of fillers must be added, which is expensive and can change the properties of the plastic in undesirable ways. Instead, the new technique uses a process that engineers the structure of the material itself. Plastics are made of long chains of molecules that are tightly coiled and tangled like a bowl of spaghetti. As heat travels through the material, it must travel along and between these chains -- an arduous, roundabout journey that impedes its progress. The team -- which also includes U-M associate professor of mechanical engineering Kevin Pipe, mechanical engineering graduate researcher Chen Li and materials science and engineering graduate student Apoorv Shanker -- used a chemical process to expand and straighten the molecule chains. This gave heat energy a more direct route through the material. To accomplish this, they started with a typical polymer, or plastic. They first dissolved the polymer in water, then added electrolytes to the solution to raise its pH, making it alkaline. The individual links in the polymer chain -- called monomers -- take on a negative charge, which causes them to repel each other. As they spread apart, they unfurl the chain's tight coils. Finally, the water and polymer solution is sprayed onto plates using a common industrial process called spin casting, which reconstitutes it into a solid plastic film. The uncoiled molecule chains within the plastic make it easier for heat to travel through it. The team also found that the process has a secondary benefit -- it stiffens the polymer chains and helps them pack together more tightly, making them even more thermally conductive. "Polymer molecules conduct heat by vibrating, and a stiffer molecule chain can vibrate more easily," Shanker said. "Think of a tightly stretched guitar string compared to a loosely coiled piece of twine. The guitar string will vibrate when plucked, the twine won't. Polymer molecule chains behave in a similar way." Pipe says that the work can have important consequences because of the large number of polymer applications in which temperature is important. "Researchers have long studied ways to modify the molecular structure of polymers to engineer their mechanical, optical or electronic properties, but very few studies have examined molecular design approaches to engineer their thermal properties," Pipe said. "While heat flow in materials is often a complex process, even small improvements in the thermal conductivities of polymers can have a large technological impact." The team is now looking at making composites that combine the new technique with several other heat dissipating strategies to further increase thermal conductivity. They're also working to apply the concept to other types of polymers beyond those used in this research. A commercial product is likely several years away. "We're looking at using organic solvents to apply this technique to non- water soluble polymers," Li said. "But we believe that the concept of using electrolytes to thermally engineer polymers is a versatile idea that will apply across many other materials." Ref.KY59-GW5BTF50K00KY59-LMR040-0700-40F8-20100EW

Overview: The article discusses the vital role of feedback amplifiers in electronic circuits and examines their types. It also highlights the desirable effects of negative feedback on signal amplification, enhancing overall performance. To improve the reliability and performance of amplification circuits, feedback amplifiers play an essential role in electronics. A feedback loop allows these amplifiers to fine-tune and enhance their output, leading to more accurate and dependable operation. What is feedback?The term "feedback" describes the process of redirecting a portion of an amplifier's output signal into an input signal. Here, the input to the circuit is a portion of the output signal that has been added or reduced to the source signal. Consequently, the amount of feedback may rise or fall based on the operation of adding or subtracting the signal from the source signal. What is a feedback amplifier?An important part of the amplifier is the feedback circuit, which works by feeding back some of the signal's output to the input. These amplifiers have several uses since they provide better control over many parameters.Types of FeedbackPositive FeedbackPositive feedback occurs when feedback is used to increase the input signal. Positive feedback adds to the input signal, and the new input to the circuit is greater than the source signal. For this reason, it is also known as regenerative feedback. Positive feedback occurs when the feedback energy (voltage or current) is in phase with the input signal. Fig. 1 shows that both the amplifier and the feedback network create a 180° phase shift. As a result, the sum of the 360° phase shift around the loop occurs, and the feedback voltage (Vf) becomes in phase with the input signal (Vin). Fig. 1 Illustration of the positive feedback amplifier. Source: Rakesh Kumar, Ph.D.The positive feedback increases the amplifier's gain. However, it has the drawbacks of increased distortion and instability. Positive feedback is, therefore, rarely used in amplifiers. Positive feedback is utilized in oscillators, multivibrator circuits, and some active filters. Negative FeedbackNegative feedback is defined as feedback that decreases the input signal. Degenerative feedback, also known as negative feedback, occurs when the signal feedback is out of phase with the input signal by 180°. Negative feedback occurs when the input signal's voltage or current is out of phase with the feedback energy. The feedback network is supposed to introduce no phase shift, or 0° phase shift, however, the amplifier introduces a 180° phase change into the circuit, as seen in Fig. 2. As a result, the input signal (Vin) and the feedback voltage (Vf) are 180° out of phase. Fig. 2 Illustration of the negative feedback amplifier. Source: Rakesh Kumar, Ph.D. Advantages of Negative Feedback AmplifierA negative feedback amplifier provides several benefits, including lower distortion, more stable gain, wider bandwidth, and better input and output impedances. Negative feedback is used in amplifiers and other control circuits to improve stability. Gain StabilityGain is defined as the ability of a circuit to increase the power or amplitude of a signal. Gain is the ratio of output to input signal in an amplifier and can be expressed as A, as shown in the equation. It can be a voltage gain, a current gain, or a power gain. Gain is typically a unitless measurement.A = Vout / Vin Negative voltage feedback improves the stability of amplifier gain by making it independent of transistor characteristics and supply voltage fluctuations. Desensitizing the gain refers to making the overall gain of an amplifier less sensitive to variations in the amplifier's internal components or operating conditions. The gain only depends on the feedback circuit's parameters. Feedback circuits, which are typically resistive networks, are not impacted by temperature, transistor settings, or frequency changes. Consequently, the gain of the amplifier is extremely stable. This is one of the key benefits of using negative feedback in amplifiers. Non-Linear DistortionNegative feedback plays a crucial role in reducing non-linear distortion and makes the gain of the amplifier almost constant. It helps maintain a more proportional relationship between input and output signals, reducing non-linear distortions that occur when the amplifier operates outside its linear region. Improved BandwidthNegative feedback improves the frequency response and extends the bandwidth of the amplifier. This ensures that the amplifier can handle a wider range of frequencies more effectively, maintaining consistent gain across the spectrum. Input and Output ImpedanceNegative feedback in amplifiers significantly influences both input and output impedances, enhancing the overall performance and stability of the amplifier. NoiseDepending on whether a transistor or tube is employed, an amplifier might have a variety of noise sources. Negative feedback helps reduce the noise in the output signal. To conclude, negative feedback lowers the amplifier's gain. At the same time, negative feedback reduces distortion and noise. This trade-off is generally beneficial, as the improved linearity and reduced distortion often outweigh the loss in gain. A feedback amplifier to considerLM6172The LM6172 is a high-speed, low-power, low-distortion, dual-voltage feedback amplifier designed by Texas Instruments. It is particularly noted for its excellent DC and AC performance, making it suitable for a wide range of applications. The LM6172 boasts a very high slew rate of 3000 V/μs, which allows it to handle rapid changes in input signals without significant delay. It has a unity-gain bandwidth of 100 MHz, ensuring stable operation even at high frequencies.The amplifier is designed to operate efficiently, consuming minimal power, which is crucial for battery-operated and portable devices. The LM6172 features low total harmonic distortion and can operate over a wide supply voltage range from ±2.5V to ±18V, providing flexibility for various design requirements. It operates over a broad temperature range from -55°C to 125°C, making it suitable for industrial and military applications. The LM6172 is available in various packages, including 8-DIP and surface-mount options, providing flexibility for different design and manufacturing requirements. Summarizing the Key PointsFeedback amplifiers play a crucial role in enhancing the efficiency and stability of amplification circuits in electronics.Understanding the types of feedback, such as positive and negative, is essential for optimizing signal amplification.Negative feedback offers benefits like reduced distortion, improved stability, wider bandwidth, and enhanced input/output impedances.The LM6172 amplifier by Texas Instruments exemplifies a high-speed, low-power, low-distortion feedback amplifier suitable for various applications. ReferenceAyobamidele, Segun & Oyebola, Blessed. (2018). Feedback Amplifier, Its Operation, Effect Importance and Connecting Types: A Review. 16-32.ALL ABOUT ELECTRONICS, “Introduction to Feedback Amplifier | The concept of Negative Feedback and its advantages,” July 7, 2024, https://www.youtube.com/watch?v=__8f6AXenYo.

Overview: The article discusses the SC robustness, surge energy, and overvoltage robustness of GaN HEMTs. Additionally, the article highlights recent achievements in ultrafast SC protection circuits and alternative circuit approaches. For many applications, including motor drives, automobile powertrains, and electric grids, the ability of power devices to stand up to overvoltage, overcurrent, and surge-energy events is a crucial need for robustness. For Si and SiC power transistors, UIS (avalanche) and SC tests are typically used to measure robustness.  Does gallium nitride possess SC robustness? It is known that GaN HEMTs lack avalanche capabilities and have restricted SC robustness. Furthermore, compared to Si and SiC devices, GaN HEMTs behave considerably differently in terms of stress tolerance and failure under specific out-of-safe-operating area situations.  The SC robustness, surge energy, and overvoltage robustness of GaN HEMTs will be discussed. Fig. 1 shows an illustration of GaN SP-HEMT and GaN HD-GIT.Fig. 1. Illustration of (a) GaN SP-HEMT and (b) GaN HD-GIT. Source: IEEE Transactions on Power Electronics SC Robustness When there is a conduction path with minimum resistance between the power source and the switching transistor, SC fault occurrences take place. SC events typically drive devices into saturation mode, which stresses the device with high voltage and high conduction current. Objectives Standard SC robustness criteria are:10 μs SC withstanding time (tSC) under the bus voltage (VBUS) The driving conditions must be identical to the application-use operation.Note: The U.S. Department of Energy 2025 Vehicle Drive Roadmap states that a 2 μs tSC of the power device along with the ultrafast protection circuit is required if the 10 μs tSC is not achievable. Types of SC Robustness In power electronics systems, there are typically four types of SC situations that can occur: Arm SC, also known as the hard-switching fault (HSF) or SC type ISeries arm SCOutput SCGround SCHSF is typically used in these situations to assess the robustness of the SC power device. The findings of repeated SC tests, failure modes, and single-event tSC for GaN HEMTs are compiled in this section. Reasons for Restricted SC in GaN HEMT A lot of work has been done to figure out what limits the SC capability of GaN HEMTs, especially when the bus voltage is high. Devices fail thermally in long SC duration tests with low bus voltage. At high bus voltages, several reports point to an electrical failure.  It is suggested that the high electric field produced by the hole accumulation beneath the gate—where the holes are produced by impact ionization—may be the reason for the SC failure. The relationship between electric field crowding at the drain-side gate edge and the high carrier density caused by the SC has been reported. A wafer-level transient voltage measurement keeps track of the potential profile in the gate-drain region under SC stress.  It is found that the failure is dependent on the speed at which the electric field propagates; impact ionization causes the failure when a high electric field reaches the drain edge. Results of Repetitive SC stresses on GaN HEMTs It has been documented that GaN HEMTs are not sufficiently robust to repetitive SC stresses within the single-event SC SOA. In SP-HEMTs, the repetitive SC stresses cause a decrease in drain-leakage currents and a rise in on-resistance (RDS,ON) at lower bus voltages. All of these parametric shifts point to the possibility of electron trapping during the repetitive SC operation in the buffer and gate areas. In HD-GIT repetitive SC tests, the progression of developing cracks and aluminum extrusion at this load has been seen.In cascode HEMT, two additional strategies have been identified to constrain the SC robustness The first thing that can happen is that the parasitics of the Si-GaN chip interconnection can cause the self-sustained gate oscillation to excite. This can make the GaN HEMT turn on by accident and fail. Secondly, the cascode HEMT's thermal self-regulation capability on the gate control is lower than that of HD-GITs and SP-HEMTsMethods to Overcome SC Faults Protection circuits must be included for applications where the SC fault may arise due to the short SC withstanding time of contemporary GaN HEMTs. Within 100–200 ns, the protection circuit should identify the issue and clear it. Conventional desaturation circuits have a long response time, which makes it difficult to achieve this. Ultrafast SC protection circuits for GaN HEMTs have recently been achieved by several groups. These circuits typically exhibit fault detection and clearance times of less than 100 ns. Some other good qualities that have been talked about are strong dv/dt noise immunity, use with parallel-connected GaN HEMTs, and monolithic integration with the GaN device. Alternative circuit approaches to improve the SC capability in addition to quick protection are also suggested, such as coupling the GaN HEMT to a Si mosfet.Device-level enhancements have also been reported to enhance the SC withstanding time of GaN devices, in addition to circuit techniques. Removing parts of the 2DEG channel along the width of the GaN HEMT is an easy way to minimize the saturation current. With this method, an SC withstanding time over 3 μs is possible in industrial cascode GaN HEMTs. Surge Energy Power devices would greatly benefit from the ruggedness against surge energy in addition to SC robustness. Si/SiC MOSFETs and IGBTs have relied on their avalanche ability—an impact ionization and multiplication effect—to support high current at high drain-to-source bias. Why is surge energy important for power devices? When devices are exposed to surge energy, drain-to-source bias quickly climbs to and clamps at avalanche breakdown voltage. Avalanching in the device causes the drain current to decrease to zero and the surge energy to be resistively dissipated. The dissipation of energy stops converters from circulating energy further. For this reason, avalanche ruggedness is another name for surge-energy ruggedness. An essential indicator of device robustness is avalanche energy, which is the maximum energy that a power device can dissipate without causing a thermal runway. Surge Energy in GaN HEMTS However, the intrinsic avalanche capacity is absent from GaN HEMTs. The JEDEC JC 70 committee has just identified their surge-energy robustness as a crucial evaluation problem. GaN HEMTs show a quick rise in drain-to-source bias when they are exposed to surge energy. This is because of the resonance between output capacitance and parasitic inductance in the circuit.  This standing process cannot release energy until the resonance voltage drops, which causes the GaN HEMTs to turn on in reverse. The device's overvoltage margin is the principal cause of electrical failure in the withstand process.  The convergence of overvoltage and surge-energy robustness for GaN HEMTs is demonstrated in the discussion above. GaN HEMTs can generally tolerate higher surge energies at the expense of slower switching speed when they are constructed with a larger output capacitance and a higher dynamic breakdown voltage. Any nonavalanche power device can be designed or chosen with this tradeoff in mind for a variety of applications. Summarizing the Key PointsUIS (avalanche) and SC tests are typically used to measure the robustness of Si and SiC power transistors. GaN HEMTs lack avalanche capabilities and have restricted SC robustness compared to Si and SiC devices. Standard SC robustness criteria include 10 μs SC withstanding time under the bus voltage and identical driving conditions to the application-use operation. Recent achievements in ultrafast SC protection circuits for GaN HEMTs and alternative circuit approaches have improved SC capability. And, device-level enhancements have been reported to enhance the SC withstand time of GaN devices.Surge energy, which is the maximum energy that a power device can dissipate without causing a thermal runway, is also important for power devices in addition to SC robustness since it is an essential indicator of device robustness.GaN HEMTs can generally tolerate higher surge energies at the expense of slower switching speed when they are constructed with a larger output capacitance and a higher dynamic breakdown voltage.ReferenceKozak, Joseph Peter, Ruizhe Zhang, Matthew Porter, Qihao Song, Jingcun Liu, Bixuan Wang, Rudy Wang, Wataru Saito, and Yuhao Zhang. “Stability, Reliability, and Robustness of GaN Power Devices: A Review.” IEEE Transactions on Power Electronics 38, no. 7 (July 2023): 8442–71. https://doi.org/10.1109/tpel.2023.3266365.

Overview: This article presents a review of control and modulation methods for DC-DC power converters. The focus is on high-performance power converters, but the methods are applicable to any DC-DC power converter. Pulse-width modulation (PWM) and small-signal-based feedback controls forms the basis of many commercial controller executions for DC-DC converters. Alternatively, many large-signal approaches are available. This article aims to provide a review of control and modulation methods, as well as methods for controller tuning, for DC-DC switching power converters.Do conventional control methods maximize efficiency?New, higher-level controls are inspired by the development of fast wide-bandgap switches in addition to the ongoing progress in digital signal processing and sensors. Fast processors and digital signal processing make new computational techniques for power converter control possible. Traditional methods of control almost never maximize available performance. The focus here is on high-performance converters, a rapidly expanding industry.Role of Converter TopologyThe converter topology serves as a constraint in the control process. In theory, with the right constraints, a single control method can be applied to a wide variety of circuits. Power regulation for digital electronics is very often done by voltage regulation. Using LED lighting encourages the use of current-regulated loads. Most battery chargers have settings for regulating both the voltage and the current. DC sources and loads in microgrids, as well as digital loads, benefit from droop relationships. The methods presented are not limited to these converter types; rather, they can be used with any DC-DC converter. Hard-switched converters, state feedback control, and large-signal tuning are all highlighted.Control Objectives for DC-DC ConvertersTable 1 summarizes the four different types of goals that DC-DC converter controls should meet. Both static and dynamic conditions are part of the operational necessities. Control is not always related to other operational needs, such as electromagnetic interference (EMI), efficiency, and dependability. The need for fault management and protection are typically dealt with independently. Some large-signal controllers can directly manage many requirements in Table 1 that appear to be independent. The entire set of specifications shown in Table 1 is related to converter design.Table 1. Converter Objectives With Control Implications. Source: IEEE Open Journal of Power Electronics Inductor and capacitor selection affect the ripple bands and slew rate limits. Layout and parasitics both have an impact on EMI. However, it is theoretically possible to define a cost function J(x) that is connected to all of the operating variables and converter parameters, as shown in equation (1)  where ai are weights, x are independent variables, and fi(x) are functions of x and other parameters. The root-mean-square (RMS) current and flux (associated with losses), the output voltage error and ripple, the rise time of the load current, the peak voltage stresses of the device, the peak junction temperature, and the switching frequency variation are examples. To take into account various operating points, converter topologies, and component considerations, the multi-objective optimization of power converters is formulated as a geometric program, a type of convex optimization problem. To increase the power density of DC-DC converters, it is also possible to incorporate electromagnetic effects and thermal management into the electrical design. Similar terms could have been used to define a performance index, which is the opposite of a cost function. An optimization problem can be formed from a design or control problem, and the cost function must be minimized.Control Methods to Address Timing ProblemThe timing issue is simple to frame but difficult to solve in practice. With simplified requirements, it is easy to solve for simple converters. However, the difficulty of the issue increases with the inclusion of further specification details and uncertainty. It does inspire particular methods. The goal of trajectory-based controls is to reformulate the timing problem as one with state variables. Alternatively, fast response relied on dedicated circuits like clamps. A converter is even modified with additional switches and devices to achieve faster disturbance rejection.Challenges with Solving the Timing ProblemBecause there is no simple solution to the generic switch timing problem, designers are limited to feasible methods. This typically adds two additional restrictions to those listed in Table 1. There are limitations on the converter's operating regime. Setting a mandatory minimum switching frequency is a typical example. The foundation for control design and operation is a simplified model of the converter. Implementing a small-signal linearization of an averaged model is a classic example. The first restriction reduces the amount of timing flexibility and makes the issue a cycle-by-cycle duty ratio. The second results in model-limited control, which may prevent access to the converter's full dynamic capabilities.Factors Affecting the Control MethodsThe block diagram of a fundamental feedback and feedforward buck converter control system is shown in Fig. 1. To prevent ripple effects, the feedback sensing block is band limited. Additional signal conditioning and analog-to-digital converters (ADCs) are required for digital control. For accurate output regulation or tracking, output feedback is necessary. Control or current-regulated loads can both benefit from inductor current feedback. Either output feedback or state feedback can be used to control a converter. Using input voltage, load current, or other data, feedforward action can improve disturbance rejection, lower audio susceptibility, and lower output impedance. To produce the gate signal for the controllable switch, the controller drives a modulator. A limiter function is necessary for the modulator in a boost converter. Fig. 1. Feedback control of a buck converter. Source: IEEE Open Journal of Power ElectronicsSmall-Signal ControlThere are a wide variety of uses for small-signal controllers. Network analyzers and other testing tools support the useful connection to conventional frequency-domain design procedures. Small-signal controllers have distinct soft start and inrush management, protection management, and strategies to adapt to a broad load range due to the need to design for a specified operating point. Improvements in dynamic performance are the subject of a large body of research. The advantage of connecting to well-established frequency-domain design tools is a benefit of small-signal models and tuning. However, small-signal methods and models do not offer a systematic way to run dynamic response up to slew rate limits and do not take into account nonlinear factors like duty ratio saturation or current limits. Also, small-signal controls require independent blocks for large-signal startup and fault protection.Large-Signal ControlLarge-signal controllers, on the other hand, can facilitate changes between seemingly incompatible operating states. Conversions can make use of the slew rate capabilities of the converter. Both switching boundaries and operating points can be applied to the problem of starting up and handling faults. Large-signal controllers provide useful alternatives for applications requiring fast dynamic response or a broad range of load conditions. Geometric controls can be visualized as involving multi-segment boundaries for functions like startup and fault protection. To conclude, the robustness and sensitivity issues between small-signal and large-signal methods are actually fairly consistent. Knowing the parameters is helpful for both; feedforward is advantageous for both; the model performs best when it is accurate and complete; and adaptation to changing circumstances is helpful for both.Summarizing the Key PointsNew, higher-level controls for power converters are possible due to the development of fast wide bandgap switches, digital signal processing, and sensors. Converter topology serves as a constraint in the control process, but with the right constraints, a single control method can be applied to a wide variety of circuits. Pulse-width modulation and small-signal based feedback controls are commonly used for converters, but large-signal approaches are also available. Geometric controls based on piecewise-linear large-signal analysis can provide the quickest dynamic response for high-performance DC-DC converters. Low-cost digital controls make it possible to sample quickly and switch boundary controls, and high-performance DC-DC converters may benefit from the use of online adaptive geometric controls.ReferenceKapat, Santanu, and Philip T. Krein “A Tutorial and Review Discussion of Modulation, Control, and Tuning of High-Performance DC-DC Converters Based on Small-Signal and Large-Signal Approaches.” IEEE Open Journal of Power Electronics 1 (2020): 339–71. https://doi.org/10.1109/ojpel.2020.3018311.

An ISA100 Wireless-based field wireless vibration sensor from Yokogawa has the ability to quickly update data as well as a long battery life. ISA100 Wireless is a technology that is based on the ISA100.11a standard. It includes ISA100.11a-2011 communications, an application layer with process control industry standard objects, device descriptions and capabilities, a gateway interface, infrared provisioning, and a backbone router.By providing real-time updates on vibration levels in plant facilities, the new sensor helps users quickly detect equipment anomalies and enables predictive maintenance.With a field wireless system, plant field devices and analysers are able to communicate wirelessly with host-level monitoring and control systems.The rising need to improve productivity and enhance safety by collecting more data on plant operations is driving the demand for field wireless devices, which can be installed even in difficult to access locations.Field wireless devices have the added advantage of reducing installation costs.Vibration sensors are useful for the condition monitoring and predictive maintenance of plant machinery such as compressors, pumps, and motors.Conventional methods for monitoring vibration include the use of vibration sensors that rely on wired communications with a host system, and patrols by maintenance staff to collect vibration data.With the widening use of field wireless systems and the need to reduce installation costs, there is an increasing demand for wireless vibration sensors.Since releasing the world’s first ISA100 Wireless-based field wireless devices and wireless systems, Yokogawa has expanded its lineup of field wireless devices that measure temperature, pressure, flow rate, and the like.This new vibration sensor will meet the company’s customers’ needs for a device that can provide the quick updates on vibration levels needed to detect anomalies at an early stage.The principal components of this field wireless vibration sensor are the FN510 field wireless multifunction module, the LN01 piezoelectric type acceleration sensor, and the FN110 field wireless communication module.Via a gateway device, the FN510 uses the ISA100 Wireless communications protocol to exchange data with a host-level system such as a DCS. The data collected with this vibration sensor enables plant operators and maintenance staff to monitor vibration levels in real time. Both explosion-proof and non-explosion-proof types are available.Reference:D7E-1BU-27135-0001005447-1   

How many users get exasperated when their hard drive slows down? We've all found ourselves annoyed and feeling stressed watching that little spinning wheel. Will it ever stop? Usually the problem is with the hard drive. More often than not has been cluttered with all sorts of unnecessary information either malicious or otherwise. At the extreme, the hard drive becomes so corrupted that a data recovery specialist is needed. However if you keep your hard drive healthy, it can serve you well for many years.Delete your temporary files.The first port of call when your hard drive slows is to delete your temporary files. Internet browsers store these temporary files on your hard drive in an effort to speed up performance. Often they are not needed and many users never delete them. Potentially this can mean than hundreds of thousands of unnecessary files are indexed and stored on your hard disk drive. You can also remove files from your recycle bin that you are sure you want to be deleted forever. These simple actions will create a little bit more space in the data areas. Next time you attempt a read or write, there is much less ‘clutter' for the heads to work through. The result – a faster hard drive! You can always setup an automatic delete function through the operating system, weekly or monthly.Partition your hard drive.Partitioning your hard drive can reduce the risk of files being corrupted by viruses. Viruses are responsible for many performance issues and are very difficult to get rid of. Make sure your hard drive is organised by storing frequently used files and programs near each other. This also boosts the speed of your hard drive. It uses short stroking technology to minimize head repositioning delays. Although this greatly increases speed and performance it also decreases the capacity so is not always the best option, especially if you are nearing full capacity already.Install good anti-virus and anti-Trojan software.All of us understand the need for anti-virus software but how many know the difference between viruses and Trojans? Anti-virus software will not detect Trojans and these are primarily responsible for slow hard drives. Routinely run ‘on demand' scans from various different anti-Trojan applications and be sure to keep your anti-virus software upgraded.   Defrag your hard drive.Defragmenting your hard drive increases the efficiency. Ordering all the blocks and rationalising the free space is a little like tidying up your garage. Next time you need to find something, it won't take you nearly as long! You can use specialised software easily found on your machine which looks at the physical location of the files on your hard drive and optimizes those files so the computer doesn't need to search around to find the information it needs. MyDefrag is a free program that once set up will run at least every other week to ensure that your hard drive is kept running effectively.Upgrade!Sometimes it's simply hardware issues which are affecting the speed of your hard drive. This means you need to just upgrade. Do some research into your current hard drive as well as other popular ones. Consider upgrading to a high efficiency hard drive, or consider an solid state drive（SSD）.ReferenceKY259-SFSA128GV1AA4TO-I-NC-216-STDKY259-SFSA128GM1AA4TO-I-NC-616-STDKY259- SFSA128GV1AA4TO-C-NC-216-STD