Getting Pure Sine Waves from Electronic Inverters

On February 2, 2018, in Other, by Lambert

Digital signal processors (DSPs) are being used in switching power supplies able to synthesize pure sine waves for use in high-reliability (hi-rel) military applications.


Ruggedized digital inverters were installed in the M1068, a Command Communications variant of the U.S. Army’s M113 family of armored personnel carriers. The original M113 Armored Personnel Carrier was first fielded in Vietnam. To date, an estimated 80,000 M113s, including a long list of variants, have been produced and used by over 50 countries worldwide, making it one of the most widely used armored fighting vehicles of all time.


During this time, the M113 has been continuously updated to meet the demands of the modern battlefield. Since then, the M113 family of vehicles are being upgraded, reconfigured and introduced as entirely new systems, including the M1068.


The M1068 variant is used as a tactical operations center capable of long range communications and includes 4.2-kW auxiliary power unit (APU) mounted on the right front of the vehicle to provide 24-V power.


As part of this project, BAE Systems required two hi-rel, ruggedized 2.5-W pure sine wave inverters per vehicle to convert 24 Vdc power generated by the vehicle-mounted APU into usable multi-kilowatt levels of ac for powering communications devices, lighting, computers and other electronic devices.


Although more expensive, pure sine wave inverters provide cleaner utility-grade power than quasi-sine-wave models. Pure sine wave inverters are helpful when operating sensitive electronic devices, including communications equipment, that require high-quality waveform with little harmonic distortion.


In addition, pure sine wave models have a high surge capacity, which means they are able to exceed their rated wattage for a limited time. This lets vehicle motors start easily, though they can draw many times their rated power during start up.


Bob Seidenberg, former Senior Quality Assurance Manager with BAE Systems, explained that the 2.5-kW inverters also had to meet shock and vibration requirements that could only be met by hi-rel inverters.


“The shock requirement for the inverters installed on the M1068 was close to 30 gs, in three directions (vertical, horizontal and transverse) and the vibration spectrum was also demanding,” he said.


The pure sine wave supplies come from Magnetic Design Labs in Santa Ana, Calif. According to Kamran Kazem, MDL VP and chief technology officer, despite the 30-g requirement for the M1068, the military specified that the inverters had to withstand 100 gs. This was well beyond the amount of shock the vehicle would ever realistically experience, based on military tests conducted in the roughest terrain that maxed out at 15 gs.


Kazem added that hi-rel electronic systems and components are no longer the exclusive domain of aerospace and defense. Today, medical, transportation, communications, infrastructure and industrial all have applications where the price of failure is high.


“These power converters might not have to withstand the same extreme conditions as the military, but vibration, shock, humidity and other inherent environmental problems are still factors, so the need for hi-rel and rugged power converters certainly applies to those markets as well.”


DSP is also a key element in a new generation of modular, stackable inverter options designed to provide a range of 1 to 20 kW of dc-ac power through a single, customizable unit. This type of system, available from custom power converter designers like MDL, consists of rack-mounted inverter modules that can stack in a parallel configuration, letting the user add as many inverters as needed to meet the power requirements.


Each unit connects to a communications controller that is responsible for synchronization, load sharing and any external communications. The individual inverters are hot swappable, enabling the addition or replacement of modules on the fly.


“This type of modular design provides project managers with a system that fits their power requirements without having to develop a new unit just for their specific project,” Kazem said. “This eliminates the need for many application-specific designs, and could also enable faster delivery of the power converter at a much more economical cost.”


Article Source: Power Electronic Tips


The Pros and Cons to Different Gear Motors

On January 17, 2018, in Electric Motor, by Lambert

A gearbox is a way to increase or decrease torque, motor speed, and direction. What are the differences between gearbox types? Well, determining which kind of gear motor is most suitable for you will depend on the application you are doing. Every kind of gearbox has its own advantages and disadvantages. For further details, keep reading below for descriptions of the most common gear motors and their pros and cons.


Planetary Gears:


This gear design mimics the planetary rotation, hence the name. Planetary gear motors consist of 1-6 outer spur gears that rotate around a central gear, which is also referred to as the sun gear, and the outer gear, also known as the planet carrier.


This type of gear is compact, highly efficient, emits little noise, and provides excellent torque transmission.



  • Huge Torque Capability
  • Good Load Distribution
  • Handles Extremely Large Reductions
  • Small Size
  • High Efficiency
  • Ease Of Maintenance
  • Generally More Complex
  • High Stress On The Output Shaft Bearings
  • Thermal Limitations On Smaller Sizes



Worm Gears:


Worm gears are used in applications where large gear reductions, torque, and braking are necessary. Some of the more favorable features of worm drives are that they achieve high ratios in a single reduction, ability to handle shock loads and low noise.


One advantage that makes worm drives desirable over other gearboxes is that they have relatively few moving parts in high reduction ratios, simply two shafts – input and output – supported by four bearings.




  • Ease Of Maintenance
  • Low Noise Properties
  • Handles Large Reductions
  • Large Shock Load Capability
  • High Thermal Capacity
  • Moderate Efficiency
  • Large Package In Design
  • Relatively Expensive To Manufacture


Spur Gears:


Spur gears are the most common type of gear. These are used in the simplest of gearbox designs, making them the cheapest and most common to manufacture. Spur gears are straight cut gears that have teeth that is meshed with other spur gears to form the gearbox. This design allows the gears to decrease speed and increase torque.


While spur gears are inexpensive and common, they aren’t always the best solution, especially in cases where high torque or speed is needed. Several spur gears are needed to make large reductions. They can be very loud while in operation, and if too much stress or force is put on the gears they can easily break.




  • Inexpensive To Manufacture
  • Easy To Operate
  • Efficient And Reliable At Low Speeds
  • Require Several Gears For Large Reductions
  • Loud At High Rotational Speeds
  • Not Able To Handle Large Amounts Of Torque


Helical Gears:


Helical gears are similar to spur gears in that they are inexpensive to manufacture but have a few differences that give them an advantage. The teeth in helical gears are cut at a ‘helix’ angle to the leading edge of the gear so the gears to mesh together over the length of the helical cut. This allows for a smoother transfer of torque. Helical gears also make less noise than spur gears do.




  • Inexpensive To Manufacture
  • Easy To Operate
  • Good Torque Capacity
  • Less Noise While Operating
  • Requires Several Gears For Large Reductions
  • Higher Maintenance Costs


If you have any interest in gear motors, I recommend that you can visit the website of Hsiang Neng DC Micro Motor Manufacturing Corp.


The company provides kinds of planetary gear motors, DC gear motors, and much more products. For more details, please visit Hsiang Neng: www.hsiangneng.com



Article Source: http://www.gordonrussell.com/articles-10-the-pros-and-cons-to-different-gear-motors

Wireless mobility typically refers to handheld or belt worn portable printers, scanners or headsets. However, these units can be limited in size, capacity and functionality.


For instance, what if you:


  • Want to print 200+ labels per day?
  • Need both a printer and PC?
  • Need a full computer screen?
  • Need thermal transfer labels?


A PC Workstation or Mobile Powered Cart is designed to hold and power up to pieces of existing hardware for 8 – 12 hours of normal use. This enables “on­ demand” label printing with a high­ volume thermal printer.


The workstation or “Mobile Desk” is always within arm’s length anywhere in a facility and the need for extension cords or data drops from the ceiling are completely eliminated. Mobility enables workers to have real-time access to WMS, ERP and automated data collection capabilities, thereby, improving productivity in a variety of warehouse functions.


Benefits of Upgrading to a Mobile Powered Cart or Workstation:

  • If you integrate mobility into your existing processes, the increased productivity is immediately apparent.
  • You will eliminate the need to walk back and forth to a static desk or printer cart allowing for an expedited work process.
  • Avoid costly interruptions (e.g. chatting with co­workers) since the technology/hardware stays with operator at all times.
  • Eliminate shipping errors within your warehouse.


If you need more information about PC workstation, please visit Modernsolid Industrial Co., Ltd. With the insistence on the ergonomics and high quality, this company has become a recognized specialist in the field of PC workstation. Moreover, successfully certified by ISO 9001, Modernsolid is capable of offering total solutions and doing OEM/ODM projects in accordance with international standards.


More details about professional manufacturer of PC Workstations, you could count on Modernsolid. They will supply you the best products and service.



Article Source: https://www.general-data.com/about/blog/when-you-should-consider-mobile-powered-cart-or-workstation

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What Are LED Bulbs And How Do They Work?


LED stands for light emitting diode. LED lighting products produce light approximately 90% more efficiently than incandescent light bulbs. How do they work? An electrical current passes through a microchip, which illuminates the tiny light sources we call LEDs and the result is visible light. To prevent performance issues, the heat LEDs produce is absorbed into a heat sink.


Lifetime of LED Bulbs


The useful life of LED lighting products is defined differently than that of other light sources, such as incandescent or compact fluorescent lighting (CFL). LEDs typically do not “burn out” or fail. Instead, they experience ‘lumen depreciation’, wherein the brightness of the LED dims slowly over time. Unlike incandescent bulbs, LED “lifetime” is established on a prediction of when the light output decreases by 30 percent.


How is LEDs Used in Lighting?


LEDs are incorporated into bulbs and fixtures for general lighting applications. Small in size, LEDs provide unique design opportunities. Some LED bulb solutions may physically resemble familiar light bulbs and better match the appearance of traditional light bulbs. Some LED light fixtures may have LEDs built in as a permanent light source. There are also hybrid approaches where a non-traditional “bulb” or replaceable light source format is used and specially designed for a unique fixture. LEDs offer a tremendous opportunity for innovation in lighting form factors and fit a wider breadth of applications than traditional lighting technologies.


LEDs and Heat


LEDs use heat sinks to absorb the heat produced by the LED and dissipate it into the surrounding environment. This keeps LEDs from overheating and burning out. Thermal management is generally the single most important factor in the successful performance of an LED over its lifetime. The higher the temperature at which the LEDs are operated, the more quickly the light will degrade, and the shorter the useful life will be.


LED products use a variety of unique heat sink designs and configurations to manage heat. Today, advancements in materials have allowed manufacturers to design LED bulbs that match the shapes and sizes of traditional incandescent bulbs. Regardless of the heat sink design, all LED products that have earned the ENERGY STAR have been tested to ensure that they properly manage the heat so that the light output is properly maintained through the end of its rated life.


How is LED lighting different than other light sources, such as incandescent and Compact Fluorescent (CFL)?


LED lighting differs from incandescent and fluorescent in several ways. When designed well, LED lighting is more efficient, versatile, and lasts longer.


LEDs are “directional” light sources, which mean they emit light in a specific direction, unlike incandescent and CFL, which emit light and heat in all directions. That means LEDs are able to use light and energy more efficiently in a multitude of applications. However, it also means that sophisticated engineering is needed to produce an LED light bulb that shines light in every direction.


Common LED colors include amber, red, green, and blue. To produce white light, different color LEDs are combined or covered with a phosphor material that converts the color of the light to a familiar “white” light used in homes. Phosphor is a yellowish material that covers some LEDs. Colored LEDs are widely used as signal lights and indicator lights, like the power button on a computer.


In a CFL, an electric current flows between electrodes at each end of a tube containing gases. This reaction produces ultraviolet (UV) light and heat. The UV light is transformed into visible light when it strikes a phosphor coating on the inside of the bulb. Learn more about CFLs.


Incandescent bulbs produce light using electricity to heat a metal filament until it becomes “white” hot or is said to incandesce. As a result, incandescent bulbs release 90% of their energy as heat.


If you have any interest in LED lamp manufacturer, try to check out the website of Daina Electronics Co., Ltd... They provide a variety of LED lights like multi-color LED, oval LED, rectangular LED, round LED, SMD LEDs, super bright LED lights, super flux LED, tape LED etc. More details, click here: www.daina-led.com to obtain the information you need.



Article Source: https://www.energystar.gov/products/lighting_fans/light_bulbs/learn_about_led_bulbs

For over a century, biometrics has been used to identify criminals. Today, this technology is quickly becoming a form of identity verification in non-conventional ways. From mobile banking to smartphone security, society is embracing the need to protect important information.


The workplace is no different, with more companies seeking smarter ways to track time and attendance. Recognizing that this area of business operations can impact profits, many are choosing a fingerprinting method.


This allows companies to positively identify each employee. Doing so eliminates wasteful practices. Through the technology of biometric timekeeping systems, companies now have a solution that saves time and money.


Here, we look at seven benefits that using a fingerprint time attendance system provides. Companies that choose to switch from traditional time tracking processes will soon realize it was worth the investment.


  1. Clock-in accuracy is improved.

Fingerprint biometrics is the most reliable personalized way of determining an employee’s identity. No two sets of fingerprints are alike. Employees cannot engage in buddy punching because it is impossible to pretend to be someone else.


This clock in system provides a distinctive, measurable characteristic that makes it is impossible for employees to steal time. Passwords can be easily shared or replicated. However, the biometric clock invalidates punches that do not match stored data.


Unique biometric identifiers guarantee that employees only clock-in for themselves. This gives managers accurate data for attendance reports. Furthermore, this type of system reduces – and possibly eliminates – costly errors.


  1. Internal processes have higher security features.

Businesses that are responsible for securing sensitive data must have solid internal processes. Giving people free access to entering the building is not the best way to ensure data remains safe. Critical information is only as secure as the room in which it is stored.


A time clocking in system that requires fingerprint identification keeps secured information secure. As a convenient security solution, employees are not encumbered with badges or remembering passwords.


The expense of replacing lost badges and ID cards can eat away company profits. Besides, people may forget passwords, making traditional security methods a nuisance to daily operations.


  1. Entry points of a building are secured.

Equally important is making sure all entry points of the building are secure. The added layer of security keeps data and everyone who enters the building safe. This includes visitors who may want to maintain privacy, depending on the type of business.


The fingerprint time system ensures employees check-in for them. It also helps to keep unwanted visitors from entering the building on false pretenses. For example, an employee who works at a bank might lose her ID badge. If someone found it, they could enter a secured area of the bank without having to prove they are the person to whom the badge was issued.


Biometrics keeps the right people in and the wrong people out. Because of the electronic setup, the system can be placed at every entrance.


  1. Fingerprint time clock systems are always available.

Improved synchronization with the Linux operating system makes the latest technology for biometric time clocks consistent. Availability is never in questions because the system uses Dynamic Host Configuration Protocol, or DHCP, for IP addresses.


This delivers remote configuration capabilities so employees can use a web browser to clock in and out. Additionally, time and attendance data is never lost. Stored memory allows employees to enter their arrival and departure during a network outage.


  1. Fingerprint time clocks can integrate with other business systems.

Integration with business systems that are important to daily operations is an added convenience. Onsite installation is possible to ensure an easy centralized network interface exists. Other clocking systems like desktop models or proximity clocks can merge with a biometric system.


HR managers can simplify payroll integration with a faster, more accurate processing system. Biometric time clocks track time and attendance in error-free fashion. Supervisors view and approve electronic timesheets.


The interface with outside payroll providers allows supervisors to export the data at the end of every pay period. Automatic calculations ensure the once time-consuming payroll process is completed quickly with up-to-date work hours.


  1. Companies can easily expand with a scalable system.

Biometric systems are flexible and easily scalable for companies of every size. If expansion is in the future, this investment grows with it. Whether companies add new locations or more employees at one location, investing in a new system is not necessary. Employees connect to a centralized time tracking system in the office, at home or overseas.


  1. An automated workplace functions better with the biometric fingerprint time clock.

Companies are always looking for efficient processes to save on operational and labor costs. Biometric fingerprint time clocks offer these options. Problems with traditional time clock system are eliminated. Employee identification is authenticated at every entry point.


Managers no longer deal with inefficiencies of manual time recording. Instead, companies see real returns with smoother timekeeping processes. Manual processing by payroll clerks and employees over-estimating their time are rife with excessive costs.


The automated platform that comes with fingerprint time clocks help to decrease labor costs. Less time is spent processing payroll. This essential business task becomes easier to complete while eliminating human errors.


Conclusion: Biometric fingerprint time clock and workforce management is the perfect pair.

Companies must consider the benefits of switching from a traditional time tracking method to a fingerprint time clock. Keeping in mind that biometrics has been used effectively in the workplace, it is easy to understand how this technology is beneficial to workforce management.


Misconceptions and confusion persists, despite the reputation of biometric systems. Countering facts with concerns helps to make this an easy choice. Biometrics give employers the ability to capture real-time labor data.


Using a fingerprint time system delivers a secure, safe and accurate way to keep employee attendance records. The broad range of direct and indirect cost benefits allows companies to see a significant reduction in these costs.


Through automated processes and individualized recognition, companies will not lose money or secure data. Employees cannot buddy punch; when they do arrive at work, they can safely enter the building.


If you need an excellent fingerprint time attendance system, try to check out the website of Pongee: www.pongee.com. The company is the professional manufacturer of access controller and time attendance systems. Feel free to contact them.



Article Source: https://advancesystemsinc.com/7-benefits-fingerprint-time-clock-system/

Alternatively known as an AC / DC power adaptor, AC converter or charger, an AC adapter is an external power supply used with devices that run on batteries or have no other power source. AC adapters help reduce the size of a laptop computer by alleviating the need for a standard sized power supply. An AC adapter is made up of a central unit which draws power from an AC outlet. It then converts the power to DC that is used by the computer, and a second cord that plugs into the computer.


Each AC power adaptor has a specific power rating, measured in volts or watts that it can handle and output to an electronic device. Because of the power rating and the type of plug on the end, an AC power adapter is not universal and can only be used with devices with the same requirements and connector.


If necessary, a universal AC power adapter can be used, which is designed to work with many devices, having multiple types and sizes of plugs for connectivity to those devices. A universal AC adapter may also have a voltage or wattage range that it can output, like 100 volts to 240 volts or 70 watts to 125 watts, providing for a greater range of compatible devices.


Founded in 1981, Hon-Kwang Electric Co., Ltd. is a company of power supplies and specializing in the design and manufacture for the domestic and foreign market. Hon-Kwang’s main Power Supply products include Power Transformers, AC/ DC Power Adaptors, Charger, Switching Mode Power Supply, LED Power Supplies and etc. If you need more information about power supply series, try to send inquiries or contact with Hon-Kwang directly!



Article Source: https://www.computerhope.com/jargon/a/acadapte.htm

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The ceramic capacitor is available in many versions including leaded disc ceramic capacitors, surface mount multilayer ceramic capacitors, MLCCs etc.


Ceramic capacitors are one of the most widely used forms of capacitor used in electronics equipment these days.


Ceramic capacitors have also been used for many years, being found in valve or tube circuits dating from the 1930s.


Today ceramic capacitors area available in a variety of formats ranging from leaded components to surface mount technology, SMT varieties. As leaded versions disc ceramic capacitors are widely available, and as SMT devices, multilayer ceramic capacitors or MLCCs are available in all the common formats. As such these ceramic capacitors are used in virtually every type of electronics equipment.


The actual performance of the ceramic capacitors is highly dependent upon the dielectric used. Using modern dielectrics, very high values are available, but it is also necessary to check parameters such as the temperature coefficient and tolerance. Different levels of performance are often governed by the dielectric used, and therefore it is necessary to choose the type of dielectric in the ceramic capacitor.


Ceramic capacitors range in value from figures as low as a few Pico farads to around 0.1 microfarads. In view of the wide range and suitability for RF applications they are used for coupling and decoupling applications in particular. Here they are by far the most commonly used type being cheap and reliable and the loss factor is particularly low although this is dependent on the exact dielectric in use.


Basics of Ceramic Capacitor

Ceramic capacitors are the workhorses of the capacitor world these days. Ceramic capacitors are used in millions as a result of a combination of their cost and performance. There is a wide variety of dielectrics that can be used as described below, but as the name of the ceramic capacitor suggests, they are all ceramic in nature.


In order to ensure that sufficient levels of capacitance can be obtained within a single capacitor package, ceramic capacitors, like types of capacitor have multiple layers. This increases the level of capacitance to enable the required values of capacitance to be achieved.


Ceramic capacitors are available now in three main types although other styles are available:


  • Leaded disc ceramic capacitors for through hole mounting which are resin coated
  • Surface mount multilayer ceramic capacitors
  • Specialist microwave bare leadless disc ceramic capacitors that are designed to sit in a slot in the PCB and are soldered in place


Although it is possible to obtain other types of ceramic capacitor, these are the main types that can be found today. Of these the surface mount variety is used in the greatest quantities by far because of the manufacturing methods used these days for electronic equipment.


Capacitors Supplying Expert

Zonkas Electronic specializes in manufacture of Ceramic Capacitors which are applied to various industries. The ceramic capacitor is a capacitor constructed of alternating layers of metal and ceramic, with the ceramic material acting as the dielectric. The company has well-equipped manufacturing facilities that are operated by a team of experts. The strong team comprises of engineers, technicians, marketing professionals, quality analysts and customer services.


If you want to learn more information about ceramic capacitor manufacturer and capacitors, try to check out Zonkas’s website: www.zonkas-cap.com to obtain the details you need.



Article Source: http://www.radio-electronics.com/info/data/capacitor/ceramic-capacitor.php


Advantages of Using GSM Antennas

On October 24, 2017, in Antenna, by Lambert

“Like any wireless technology, however, GSM communications are dependent on antennas.”


Global System for Mobile (GSM) communication systems are fast becoming the standard in mobile phones everywhere. The GSM system allows users to talk virtually anywhere in the world. It’s essentially a global roaming service that’s based on satellite communications, and it offers extraordinary flexibility and freedom for mobile phone users who have embraced this wireless technology. Like any wireless technology, however, GSM communications are dependent on antennas. That means that GSM services, and later generations of the technology like EDGE, UMTS, and HSDPA, are in constant need of custom antenna designers to help them keep up with customer demand and to introduce new innovations to the marketplace.


There are many advantages to using GSM technology, such as:


  • Global roaming
  • The ability to switch services while keeping the same phone
  • The ability to send text messages
  • A universal emergency number, so emergency services can be called anywhere in the world without knowing the local number


The Leading GSM Antenna, UMTS Antenna Manufacturer

Evercom Communication Technology Co., Ltd. is a leading supplier of mobile antennas company throughout the world. Established in 1993, Evercom specialized in design and manufacture of WIFI, MIMO, GPS, UMTS, DVBT, UHF / VHF, GSM antenna, CB antenna mount, and accessories etc.


Evercom offers innovative design, quality manufacturing and reliable performance. If you need more information about GSM antenna or other antennas, try to visit the website of Evercom: www.evercomtech.com to obtain the details you need.



Article Source: https://www.mobilemark.com/antenna-solutions/gsm-antennas/

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What Is a Solar Charge Controller?

On October 20, 2017, in Solar Equipment, by Lambert

A solar charge controller manages the power going into the battery bank from the solar array.  It ensures that the deep cycle batteries are not overcharged during the day and that the power doesn’t run backwards to the solar panels overnight and drains the batteries. Some charge controllers are available with additional capabilities, like lighting and load control, but managing the power is its primary job.


A solar charge controller is available in two different technologies, PWM and MPPT. How they perform in a system is very different from each other. An MPPT charge controller is more expensive than a PWM charge controller, and it is often worth it to pay the extra money.


PWM Solar Charge Controller

A PWM solar charge controller stands for “Pulse Width Modulation”. These operate by making a connection directly from the solar array to the battery bank. During bulk charging, when there is a continuous connection from the array to the battery bank, the array output voltage is ‘pulled down’ to the battery voltage. As the battery charges, the voltage of the battery rises, so the voltage output of the solar panel rises as well, using more of the solar power as it charges. As a result, you need to make sure you match the nominal voltage of the solar array with the voltage of the battery bank. *Note that when we refer to a 12V solar panel that means a panel that is designed to work with a 12V battery. The actual voltage of a 12V solar panel, when connected to a load, is close to 18 Vmp (Volts at maximum power). This is because a higher voltage source is required to charge a battery. If the battery and solar panel both started at the same voltage, the battery would not charge.


A 12V solar panel can charge a 12V battery. A 24V solar panel or solar array (two 12V panels wired in series) is needed for a 24V battery bank, and 48V array is needed for 48V bank. If you try to charge a 12V battery with a 24V solar panel, you will be throwing over half of the panel’s power away. If you try to charge a 24V battery bank with a 12V solar panel, you will be throwing away 100% of the panel’s potential, and may actually drain the battery as well.


MPPT Solar Charge Controller

An MPPT solar charge controller stands for “Maximum Power Point Tracking”.  It will measure the Vmp voltage of the panel, and down-converts the PV voltage to the battery voltage. Because power into the charge controller equals power out of the charge controller, when the voltage is dropped to match the battery bank, the current is raised, so you are using more of the available power from the panel. You can use a higher voltage solar array than battery, like the 60 cell nominal 20V grid-tie solar panels that are more readily available. With a 20V solar panel, you can charge a 12V battery bank, or two in series can charge up to a 24V battery bank, and three in series can charge up to a 48V battery bank. This opens up a whole wide range of solar panels that now can be used for your off-grid solar system.


The Key Features Of A Solar Charge Controller Are:


  • Multistage Charging Of Battery Bank:

Changes the amount of power set to the batteries based on its charge level, for healthier batteries.

  • Reverse Current Protection:

Stop the solar panels from draining the batteries at night when there is no power coming from the solar panels.

  • Low Voltage Disconnect:

Turn off attached load when battery is low and turns it back on when the battery is charged back up.

  • Lighting Control:

Turn attached light on and off based on dusk and dawn. Many controllers are configurable, allowing settings for a few hours or all night, or somewhere in between.

  • Display:

May show voltage of battery bank, state of charge, amps coming in from solar panel.


If you are looking for high quality solar charge controllers, I recommend that you can visit the website of Power Master Technology Co., Ltd. which is the professional solar panel manufacturer in the industry. You can find numerous solar charge controller related products on their website. Feel free to send inquiries to Power Master to obtain the product you need.



Article Source: https://www.altestore.com/store/info/solar-charge-controller/

The positive temperature coefficient, PTC thermistor has two types: silistor & switching PTC have very different characteristics.


As the name indicates a positive temperature coefficient, PTC thermistor has a response in which the resistance rises with increasing temperature.


There are two types of PTC thermistor which have very different characteristics, one showing a linear increase, whilst the other shows a sudden change in resistance.


PTC thermistor outline


PTC thermistors can be divided into two types according to their structure and the materials used. The two types of PTC thermistor have very different characteristics:


  • Switching PTC thermistor:

This form of PTC thermistor is used in heaters, sensors and specialized versions are also used as resettable fuses. Switching type NTC thermistors have a highly non-linear curve. The resistance at first falls slightly with increasing temperature, and then at a critical temperature the resistance increases dramatically, thereby acting virtually as a switch. This makes it ideal in many protection devices.

  • Silistor:

The silistor PTC thermistor uses a semiconductor as its base material and it is characterized by a linear characteristic and as a result, the silistor is used in temperature sensors. The silistor PTC thermistor is generally manufactured from doped silicon, the level of doping determining the exact characteristics.


Switching PTC thermistor basics


As the switching PTC thermistor is very widely used form, it warrants further explanation as it has an unusual characteristic.


Switching PTC thermistors are typically fabricated from polycrystalline materials including barium carbonate or titanium oxide with added materials including tantalum, silica, or manganese, etc.


The materials are mixed and ground to fine powders and finally compressed into the required shapes before being sintered. Contacts are then added and the thermistor is encapsulated.


The characteristic of the switching PTC thermistor shows that the device has a highly non-linear characteristic. As the temperature increases, the resistance first decreases, then rising slightly before it reaches a critical temperature, TC. At the critical temperature the resistance increases sharply for any increase in temperature, before finally leveling off and falling slightly.


A similar type of device is known as a Polymer PTC. These devices consist of a plastic element into which carbon grains are embedded. When cool, the carbon is able to conduct electricity, but as the temperature increase the carbon grains move further away as a result of expansion and conduction falls rapidly. In this way the device acts like a switch in the same way as the more traditional PTC thermistors.


PTC thermistor operational modes


There are two main ways in which switching PTC thermistors are generally used.


  • Self-heating mode:

When used in the self-heating mode, current is passed through the thermistor, often in series with the item being controlled. As it heats up as a result of the current, it reaches a point where the critical temperature is reached and the resistance increases significantly. In this way it operates in a self-heating mode and can be used as a safety cut-out or regulator.


  • Sensor mode:

In this mode, a minimum amount of current is passed through the device and PTC thermistor senses the surrounding temperature. Keeping the current to a minimum ensures the self-heating effect is negligible and only the surrounding temperature affects the device. As the surroundings heat the device it may reach its critical temperature at which point the resistance will significantly increase.


Switching PTC thermistor applications


Switching thermistors are a very useful form of electronic component. It can perform functions with a single component that would require far more complex circuitry should any other technique be used.


  • In-rush protection:

Some electrical items like motors and transformers have a large surge of current at switch on. This gives rise to very high peaks of current which can cause spikes on the power line, or cause damage in some instances. PTC thermistors can be used to reduce the level of the inrush current and thereby prevent the spikes or damage occurring.


  • Overcurrent protection:

In this application, the PTC thermistor is placed in series with the load and uses the self-heating effect. The current taken under normal conditions should enable the thermistor to operate in its flat resistance curve area. However if an over-current condition arises, then the thermistor will carry more current and the temperature will rise more causing it to rise beyond the critical temperature when the resistance will rise significantly causing the current to drop.


PTC thermistor circuit symbol


It is sometimes necessary to indicate the type of thermistor being used on a circuit diagram. Accordingly the IEC have a special PTC thermistor circuit symbol that can be used.


As seen the circuit symbol utilizes the characters +t° to give an indication of the positive temperature coefficient.


Positive temperature coefficient, PTC thermistors are used in many electronic circuits and for a variety of functions. It is essential to check that the correct type is selected for any given circuit to ensure that its characteristic meets the requirements.


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