abhishek7xavier @ instructables.com writes:
Power supply is an utmost essential tool for an electronic lab. It comes in handy for powering up various applications and circuits. However a fixed voltage, fixed current power supply is sufficient for basic needs but a variable one is good to have because different circuits and components operate at different voltages and consumes different current. When it comes to an electronic hobbyist’s lab, a good power supply is must to have. Also if the power supply boosts additional features like on board voltage and current display, it comes in handy as one can know the exact voltage at the output terminals and also the current drawn by the load. But in the electronic market, those power supplies are not economic are meant for industrial purpose . Here in this article I present an economical and cost effective yet efficient variable bench power supply that is capable of providing 1.2 to 25 Volt variable supply up to 5 Ampere through one channel while 5 Volt, 1 Ampere and 12 Volt, 1 Ampere supply through other two channels thus having one variable and two fixed supply channels.
DIY Variable DC Power Supply with Display and PC interface - [Link]
Kerry D. Wong builds a digitally controlled power supply based on ATmega328P mcu:
In my previous post, I showed my design of a dual tracking ±30V linear power supply. My goal was to use the transformer (28V+28V, center tapped) from an old Deltron W127G open-frame power supply and build a lab supply that can be digitally adjusted in both constant voltage and constant current modes. I also wanted each of the channels to be able to deliver up to 10 Amps of current so that I could fully utilize the 540VA transfomer from the W127G.
A Digitally Controlled Dual Tracking Power Supply - [Link]
Jaanus has been working on a buck-boost converter from LT3791-1:
I’m building quite high power (for me) buck-boost converter for a friend. It takes in 12-45 V and has to output regulated 24 V. Total output power has to be more than 300 W. I don’t understand switching regulators well enough to build more than 100 W regulators from 555 timer (that is basically how your computer power supply is built). Just too much phase shifting and output oscillations and whatever else to take into account. You know, the things you learn in electronics classes (which there was none in my school).
Buck-boost converter from LT3791-1 - [Link]
Saelig Company, Inc. (www.saelig.com) has introduced the PSB-2000 Series Flexible Power Supplies – high power density, programmable and multi-range-output DC power supplies offering flexible high voltage-low current/low voltage-high current output characteristics. V/I combinations for a very wide range of applications at up to 800W are covered by six models, including one power booster. The PSB-2000 Series offers an output voltage of 0 to 80V and 0 to 800V, with an output power of 400W or 800W. Series/parallel connections can be applied to PSB-2000 supplies for higher power outputs.
The stylish PSB-2000 Series provides three sets of preset function keys to memorize regularly used settings of voltage, current and power for rapid recall. A serial-controlled Sequence Function, using an RS232C, USB or optional GPIB interface, can produce output power defined by a sequence of set voltage and current steps provided by an attached PC. This capability is valuable for creating standard test procedures for verifying devices under test by quickly changing operating conditions. Read the rest of this entry »
This is a DC-DC step-up converter based on LM2585-ADJ regulator manufactured by Texas Instruments. This IC was choosen for it’s simplicity of use, requiring minimal external components and for it’s ability to control the output voltage by defining the feedback resistors (R1,R2). NPN switching/power transistor is intergrated inside the regulator and is able to withstand 3A maximum current and 65V maximum voltage. Switching frequency is defined by internal oscillator and it’s fixed at 100KHz.
LM2585 12V to 24V @ 1A Step-up switching regulator - [Link]
You meet them every day without knowing that those are Friwo. However world-class producers know why they use them…
Friwo power supplies guarantee top-level specification and reliability, what can help you to gain and keep customers and a good reputation. To have a trust of customers is usually the most important factor influencing whether you will sell your product or not. And trust of customers is usually built on a reliability of a device…
Nowadays, when a device with almost the same functionality can be bought from several producers, the success or fail on the market is in the hands of seeming trifles. Naturally, there´s often a pressure on a very low price, but hand in hand with this requirement, everyone also wants a reliability.
Designers of electronic devices know, that a device with the same functionality can be designed in two basic ways:
1) in a way that it worked on the edge of its possibilities (weakly dimensioned components, slower semiconductors with higher losses, …). Such a device operates at “usual circumstances” properly, only maybe generating a little more heat (lower efficiency). The problem is usually a lower lifetime and a much higher susceptibility to overvoltages in mains line, disturbances, higher or very low temperatures etc.
2) or in a way that it worked with a reserve even in not always ideal conditions (temperature, voltage spikes, ….) even for a price of slightly higher production costs.
It´s obvious, that a device designed by a “pattern no. 2” provides far higher assumption of a reliable operation without claims, service events or a loss of a good reputation. Friwo as the biggest and the only European producer of power supplies in a given range wagered on quality and no wonder, that it´s the first choice of many renowned producers like Bosch, Metabo, Makita, Braun, Siemens medical, Porsche, Geberit, Sagem,…. If you didn´t meet a mark Friwo yet, it may be because Friwo is first of all the OEM producer and almost everyone of us daily uses some product with a Friwo power supply, without knowing it.
On stock we keep a selected range of adapters, but much more important is the fact, that we´re able to provide you any power supply from Friwo and upon order it´s also possible to produce a power supply exactly according to your demands. Friwo disposes with many production capacities, like laser trimming enabling a flexible adjustment of specification. An image about the Friwo power supplies will give you the document Friwo company profile as well as our article „Your devices will fall in love with premium power supplies Friwo”.
In case of interest, please contact us at email@example.com.
Do you divine where everywhere Friwo adapters and power supplies are used? – [Link]
This application note describes how to recycle lithium-ion (Li+) batteries from older devices for use in other electronic devices, such as toys. This can all be done without the need for a microcontroller (or the required software). One challenge is that the battery charger in these older devices cannot usually be reused. The designer needs to create their own charger circuit, which this application note explains how to do in detail.
Lithium-Ion Battery Recycling Made Easy - [Link]
The LTC®3607 is a 15V dual 600mA monolithic synchronous step-down regulator which has only 55μA quiescent current. Intended for a variety of applications, including dual lithium-ion battery products, it operates from a wide 4.5V to 15V input voltage range. It features a constant 2.25MHz switching frequency, enabling the use of tiny, low cost capacitors and inductors 1mm or less in height. Each output voltage is adjustable from 0.6V to VIN. The internal synchronous power switches provide high efficiency without the need for external Schottky diodes.
LTC3607 – Dual 600mA 15V Monolithic Synchronous Step-Down DC/DC Regulator - [Link]
Here is an app note from Maxim describing the various SMPS regulator topologies for battery powered systems:
This tutorial presents an overview of regulator topologies for battery-powered equipment. The discussion covers linear regulators, charge pumps, buck and boost regulators, inverters, and flyback designs. The importance of peak current is explained, and schematics of each topology are shown.
App note: Regulator topologies for battery-powered systems - [Link]
The MAX17515 is a fixed-frequency, step-down power module in a thermally efficient system-in-package (SIP) package that operates from a 2.4V to 5.5V input supply voltage and supports output currents up to 5A. The device includes switch-mode power-supply controller, dual n-channel MOSFET power switches, a fully shielded inductor, as well as compensation components. The device supports 0.75V to 3.6V programmable output voltage. The high level of integration significantly reduces design complexity, manufacturing risks, and offers a true “plug-and-play” power-supply solution, reducing the time to market.
MAX17515 – 5A, 2.4V to 5.5V Input, High-Efficiency Power Module - [Link]