Planet Arduino

Working with electronics requires access to stable power in a variety of voltages. Some components require 3.3V and others require 5V. Still others need 9V or 12V — there are many possibilities. You could keep a variety of wall warts on hand, but a variable benchtop power supply is a more convenient option. Supplino is one choice and this guide from Giovanni Bernardo and Paolo Loberto will walk you through how to build one.

Supplino can accept anything from 4 to 40 volts and can output anything from 1.25 to 36 volts, with a maximum of 5A. An XH-M401 module with an XL4016E1 DC-DC buck converter handles the voltage regulation. Technically, you could use that alone to power your components. But the addition of an Arduino Nano board (or Nano Every) makes the experience far friendlier. It monitors the power supply output and drives a 1.8″ 128×160 TFT LCD screen, which displays the present voltage, amperage, and wattage.

The Arduino receives power from a second 5V buck converter. It uses a relay to control power going to the primary buck converter. A relocated potentiometer controls the voltage. Two banana plug socket make it easy to attach alligator clips or whatever other leads your project requires. You can wrap up all of these components in a tidy and attractive 3D-printed enclosure, which is compact and fits on any desktop. You have many options for the input power, but a laptop power supply is a good choice.

More details on the Supplino can be found in its post here.

The post Supplino is a variable benchtop power supply that you can build yourself appeared first on Arduino Blog.

If you treat your Pi as a wearable or a tablet, you will already have a battery. If you treat your Pi as a desktop you will already have a plug-in power supply, but how about if you live where mains power is unreliable? Like [jwhart1], you may consider building an uninterruptible power supply into a USB cable. UPSs became a staple of office workers when one-too-many IT headaches were traced back to power outages. The idea is that a battery will keep your computer running while the power gets its legs back. In the case of a commercial UPS, most generate an AC waveform which your computer’s power supply converts it back to DC, but if you can create the right DC voltage right to the board, you skip the inverting and converting steps.

Cheap batteries develop a memory if they’re drained often, but if you have enough space consider supercapacitors which can take that abuse. They have a lower energy density rating than lithium batteries, but that should not be an issue for short power losses. According to [jwhart1], this quick-and-dirty approach will power a full-sized Pi, keyboard, and mouse for over a minute. If power is restored, you get to keep on trucking. If your power doesn’t come back, you have time to save your work and shut down. Spending an afternoon on a power cable could save a weekend’s worth of work, not a bad time-gamble.

We see what a supercap UPS looks like, but what about one built into a lightbulb or a feature-rich programmable UPS?

The uninterruptible power supply was once a standard fixture in the small office/home office as a hedge against losing work when the electrons stop flowing from your AC outlet. Somewhat in decline as computing hardware shifts away from dedicated PCs toward tablets, phones and laptops, the UPS still has a lot of SOHO utility, and off-the-shelf AC units are easy to find. But if your needs run more to keeping the electrons flowing in one direction, then you might want to look at [Kedar Nimbalkar]’s programmable DC backup power system.

Built inside a recycled ATX power supply case, [Kedar]’s project is heavy on off-the-shelf components, like a laptop power supply for juice, a buck converter to charge the 12 volt sealed lead acid battery, and a boost converter to raise the output to 19.6 volts. An Arduino and an optoisolator are in charge of controlling the charging cycle and switching the UPS from charging the battery to using it when mains voltage drops.

 If you need a DC UPS but would rather skip the battery, you could try running a Raspberry Pi with electrons stashed in a supercapacitor. Or if you’ve got an aging AC UPS, why not try beefing it up with marine batteries?

[Thanks for the tip, Morris]