Electronics-Lab.com Blog

Isolated offline-flyback controller LT3799 enables to create a powerful LED driver with a minimum of external components, which is moreover compatible with common triac dimmers.

At the design of a new LED driver, we usually have to consider more factors like for example an output current stability, shortcut or open LED protection, efficiency, safety (isolated secondary circuit form the primary one), power factor correction, EMI, number of external components and other.

LT3799 meets all these requirements and offers another benefits, like for example a possibility to use a smaller transformer thanks to the use of critical conductivity mode, powerful external MOSFET driver, internal LDO regulator and also a very good output current regulation – typically +-5%, moreover with no opto-isolator. A big bonus is the active power factor correction, thanks to which it reaches typical values of 0,96 (at 230V AC), thus meeting the most stringent requirements in this field, as well as IEC 61000-3-2 class C about harmonic currents emission. When we look closer at the recommended application circuit, we´ll find out that behind a diode bridge we won´t find any (otherwise common) input electrolytic capacitor with value of tens or hundreds of uF. That´s why the input voltage of the controller and a of the power transformer “copies” input sinusoid. Excellent power factor is reached just thanks to it, that LT3799 knows immediate input voltage value and based on this value, it sets the input current limit (in a given cycle of the SMPS), proportionally to the immediate value of the input AC voltage. Further LT3799 gains information about the immediate current from the primary side, that´s why it doesn´t require an opto-coupler. Thanks to this, LT3799 works like a current source in every period of input voltage, that´s why it is even possible to use classic triac regulators, which are often already a part of the buildings installation. In other words – LT3799 doesn´t try to compensate “dropouts” in power supply caused by a phase control of a triac, what causes decreasing of an output LED current and their fluent dimming. Neither this control method doesn´t cause LED blinking, because there is an electrolytic capacitor on the transformer output.

Detailed information you can find in the LT3799 datasheet and in the Design Note 490. For the development support is also available the LT3799 demo board DC1595A.

LT3799 – create a LED driver with an active PFC - [Link]

Company Wago comes with the spring offer, which enables you to buy the whole set of tools and terminals for the convenient price.

Cutting and stripping tools for wires and cables of various diameters – this is naturally the basic equipment for effective electric installation assembly.

Wago Profi set contains all tools necessary for a quality and quick work – wire cutters, stripping tool, stripping tool for round cables with a diameter up to 11 mm and the stripping tool for cables with diameters up to 45 mm. When we add to them 5 types of the most often used push-wire connectors 2273 series (850 pcs in total), we´ll get a set, which will make perhaps every fitter happy. For the price, which is significantly more convenient, than a purchase of single items separately, you have a possibility to gain a complete set. Wago Profi set 1-2012 is available for you directly from our stock.

Assemble professionally – with the Wago profi set! - [Link]

New version of Attend connectors for SIM cards replaces the current one. To make it to you easier, we will keep in stock both types for some time.

It is the six-pin „push-push“ type 115A-ADA0-R02, which will replace the older almost identical type 115A-ADA0-R01. New type differs from the older one only in the width and a position of side mounting lugs, which are soldered on a PCB. Lugs of the new type are somewhat closer to the middle of the connector and they are narrower. The difference is probably best illustrated at the enclosed pictures. Both types also contain a switch for SIM card detection. Detailed information will provide you the 115A-ADA0-R02 and 115A-ADA0-R01 datasheets.

Migrate to a new type of a SIM card connector Attend - [Link]

Panel feed-through terminal blocks Euroclamp MPT series enable to guide the desired signal through a housing panel. From a wide range of sizes, you can easily choose the right type for your application.

MPT series terminal blocks are universally usable, providing a possibility to connect a given device by solid or stranded wires. MPT are suitable for example as input and output terminals and in general everywhere, where it is desired to maintain a maximum connection flexibility of a device.

With a nominal voltage of 450-750V (depending on a type), they suit in all common applications. They also feature a relatively high current rating – already the smallest type MPT 275 has the maximum current up to 24A. Available are types for wires with a 2,5 to 50 mm2 cross section. It is possible to compose terminal blocks of the same size into a row, thus creating a whole array of blocks with a big mechanical robustness and stability. Most of types are available with various rear terminals and also with various methods of mounting to a panel. A reliable mounting of terminal blocks is ensured by a retaining key (sold separately), nut or screws (included). Detailed information will provide you datasheets at given types.

Panel feed-through terminals Euroclamp in sizes from XS to XXL - [Link]

In our portfolio you can also find a DIN rail socket for the ultra slim relay Finder 34 series. It enables to use various relays thus to simply adapt an interface module to a given application.

From nowadays offer of relay interface modules, it is already no problem to choose a type meeting requirements of a given application. But if you need to change a configuration of a device, it is often convenient to change only a relay type. Series 93.01 socket enables this easily, because the protection and indication circuit is designed for a wider range of input voltages. This enables to use a 5V, 12V and 24V Finder relays 34.51 series. A green indication diode indicates presence of a control voltage and the protection circuit protects relay against reverse voltage and suppresses voltage spikes appearing at its switching off. When using 93 series socket, it is even possible to use an AC voltage to supply a DC coil of a relay.

Finder 34 series relays are ultra slim 6A relays with a sensitive DC coil. High 6kV isolation provides a safe disjunction of relay coil from contacts. Finder 34.x can be mounted directly to a PCB, via a PCB socket or to a DIN rail by means of the above mentioned socket. In some applications can also be convenient relatively short switching times – 5/3 ms.

Create a relay interface module according to your needs - [Link]

SolarWorld solar modules excel in efficiency and moreover the producer provides an above-standard guarantee of performance.

Company SolarWorld AG Group is a top German producer of solar (photovoltaic) panels. From the raw silicon, through silicon wafers, to the complete modules, SolarWorld produces all this on its automated production lines with a stringent quality control. Sorting of modules ensures, that only modules meeting a declared performance are dispatched for sale. A big advantage is the 25-year linear power guarantee – SolarWorld guarantees max. 0.7% degradation of the module performance p.a. for over 25 years. It is a considerable difference in comparison to a standard 2-stage guarantee, as you can see in the enclosed picture.

SW80 modules use polycrystaline high efficiency cells. High performance of modules was confirmed also in independent tests, where SolarWorld modules provided 10-12% higher performance. Currently, we offer you SW80 modules for a special price, directly from our stock.

Further information will provide you the SW80 datasheet, user manual and the overview of SolarWorld modules.

Top quality solar panels with a 25-years performance guarantee - [Link]

From a soldering station intended for everyday use, we naturally expect reliability and a robust resistant construction. Soldering station Diametral SBL530.1A is a proven device meeting stringent requirements of a professional production.

Micro soldering station SBL530.1A is equipped with a fluent temperature regulation by a potentiometer. Setting by a potentiometer is very quick and sufficiently accurate, because a a well readable LED display shows a set-up temperature, as well as a real temperature. After turning by a potentiometer or after pressing a button, the display shows a set-up (desired) temperature. The display will switch back to displaying a real temperature after approx. 3 seconds. A soldering tip reaches a set-up temperature in about 30-120 seconds from switch-on of the soldering station, depending on a set-up temperature.

A positive feature of the soldering station is electronic switching of the heating element when intermittent current of a power line is passing zero, what eliminates possible interference or other unwanted influence to a mains power line. You can choose from 9 tips types, from thin ones, suitable for SMT components, up to relatively thick, suitable even for soldering of bigger joints. You will also appreciate thicker soldering tips at soldering of components or leads to bigger pads of multilayer PCBs, which take away the heat from a soldered joint very quickly. Micro soldering station is placed in a rugged metal chassis with a surface treated by a powder enamel – RAL 9005 black colour. SBL530.1a is also equipped with a transformer adequately dimensioned for uninterrupted operation.., cut-out automatics, which switches the soldering station into a stand-by statement after a set-up time of inactivity. That increases safety, decreases power consumption and prolongs soldering tips lifetime.

Soldering station with an outstanding price/performance ratio - [Link]

Gases like hydrogen sulfide and ammonia are dangerous gases, which however can be easily detected.

Hydrogen sulfide and ammonia are relatively common gases arising at an organic material decay, in sewage conduits, poultry farms, and in a technological process of many industrial segments. Despite of the fact, that both gases are irritative and feature a pungent smell, intoxications by these gases aren´t rare. Risk is also increased by a fact, that already after a short exposition to these gases, they subjectively appear to be much less concentrated.

For a production of devices detecting these gases are suitable Figaro sensors TGS8xx series. TGS825 is sensitive to hydrogen sulfide already from 5 ppm concentration. TGS826 is sensitive to ammonia, as well as ethanol, iso-butane and hydrogen. TGS826 is able to detect ammonia already from 30 ppm concentration, that´s why it is suitable for all critical safety-related applications in refrigeration systems and in agriculture. Both sensors use SnO2 based semiconductor sensors featuring high sensitivity and a long lifetime. Sensors are made on a ceramic base resistant to severe environment.

Usage of both sensors is further facilitated by the SR-2 socket. SR-2 is usable for all Figaro sensors TGS8xx series and it enables a troublefree exchange without a necessity of relatively demanding desoldering from a PCB.

Figaro sensors feature a long lifetime, high sensitivity and selectivity to target gases. Despite a long lifetime, in an environment with a high dust nuisance or an aggressive environment, it can be necessary to exchange a sensor after some time. This is also the case of applications where highest reliability and accuracy is required. An easy sensor exchange is also welcome at development or at the change of a sensor type. SR-2 socket, with an over 1000 MOhm insulation resistance and 700V AC insulation strength, is suitable for all applications. Producer also guarantees lifetime of at least 150 insertion cycles (exchanges of a sensor).

Detailed information will provide you the TGS825, TGS826 and SR-2.

Protect health of people by Figaro sensors - [Link]

USB solutions specialist Future Technology Devices International Limited – FTDI, celebrates in these days the 20-th anniversary of its founding.

What can be a better guarantee of competency and quality than many years of experience?
And 20 years is already a decent era, which fully reflects to reliability and quality of USB solutions from FTDI. Those are well known, widely used components, enabling with a minimum effort to add a USB connectivity to a target device. They are available as ready-made modules, cables and chips themselves. For an affordable price they offer ready-to-use solutions with above-standard support, of royalty-free drivers, source codes and application notes.

At the same time, in these days, company FTDI has launched the largest series of products in its history – the X-Chip series. Further information you can find in our article about X-Chip series.

FTDI is on the market already for 20 years! - [Link]

X-chip USB series from FTDI brings even higher functionality on a chip, including battery charging detection. Speeds-up development, saves space and decreases power consumption.

USB solutions specialist Future Technology Devices International Limited – FTDI has supplemented its portfolio of USB to serial interface products with new X-Chip series. X-Chip series consisting of 13 chips (7 types in various package options) complements the existing FT-R and FT-H series. New series supports a broad selection of interface types, such as basic UART, full UART, FIFO and I2C, as well as FTDI’s proprietary FT1248 I/O (including enhanced SPI).

Through X-Chip, engineers are provided with a feature-rich USB 2.0 interface solution with a smaller size and a lower pin count. High level of integration, including integrated crystal and MTP (Multi-time programmable) memory for configuring and storing the device descriptors and an internal clock source, solves major board level concerns, such as better space utilization and reduced power consumption. Devices in the series are capable of data rates of up to 3.4 Mbits/s, while maintaining low power consumption, <8mA (typical) when fully active and <125 μA (typical) while in suspend mode

With recent amendments being made to the USB specification regarding more rapid charging of portable electronics devices, the X-Chip has built-in functionality to detect a charging port (battery charging detection – BCD, dedicated charging port – DCP) and cause a logic to switch from data transfer to charging mode. This feature means that detection does not have to be carried out by the system’s microcontroller, thereby allowing it to focus fully on its core activities. The end result is a simpler detection process and the capability to charge at a higher current level which shortens the time required for battery charging.

The devices in the X-Chip series are offered in compact SSOP, QFN and DFN packages. Each has an operational temperature range of -40 °C to +85 °C. X-chip series has an internal 3.3V converter and supports 1.8 to 3.3V I/O voltages. As all the necessary USB support and bridging intelligence has been integrated into these devices and pre-validated, the expense, time and engineering resource needed to bring Full Speed USB connectivity into system designs is markedly reduced. FTDI provides support and royalty-free downloads for a wide selection of OS: Windows, Android, Mac OS, and Linux.

Overview of all new types will provide you the attached table, X-chip brochure and X-chips overview. Available are 7 basic types – FT200XD, FT201X, FT220X, FT221X, FT230X, FT231X and FT240X. FT200XD is the smallest one, in a tiny 10-pin DFN package. All other types are available in SSOP and QFN packages. Detailed description will provide you FT200XD, FT201X, FT220X, FT221X, FT230X, FT231X and FT240X datasheets. An example of an easy to use I2C/USB slave converter illustrates the picture below. Further details about battery charging you can find in the AN_175 application note.

Together with these chips, FTDI has released a wide-selection of development modules. Also available are so-called breakout modules, providing the simplest method to connect to a USB host. You can choose from 4 types of breakout modules – UMFT200XD, UMFT201XB, UMFT220XB a UMFT230XB. Evaluation modules are larger than breakout modules, but provide access to all pins.

New X-chip series will connect you to USB even easier and faster! - [Link]