Multi-Function Bench Power Supply

power supply

Concerned with your project's power consumption but don’t want to constantly leave an ammeter wired in series with your power supply? [Rajendra] feels your pain and has recently documented his solution to the problem: a variable-output bench top power supply that clearly displays load current consumption among other things! Everything is wired up in a nice roomy enclosure that has front-panel … [Read more...]

Cellphone charger has a USB port forced upon it

Nokia-Charger-to-iPod-charger

We still can't figure out why a standard charging scheme hasn't been developed for handheld devices (other than greed). Certainly we understand that many devices have different electrical needs as far as voltage and current are concerned, but we still long for the ability to use one charger for many different doodads. [Rupin] is trying to narrow down the number of dedicated chargers he uses by … [Read more...]

Adjustable breadboard power supply

psboard

This looks like a great addition to your breadboard. [Nerdz] wanted a power supply that was easily portable and adjustable. He built a custom board that plugs directly into the breadboard's power rails. It has a pot attached to the ground of a 7805 voltage regulator so the output can be adjusted from 5V to just under the supply voltage. Anything that makes a breadboard less of a rats nest is … [Read more...]

Parts: LM317 adjustable voltage regulator

lm317

Every project needs a power supply. As 3.3volt logic replaces 5volt systems, we're reaching for the LM317 adjustable voltage regulator, rather than the classic 7805. We've found four different hobbyist-friendly packages for different situations. A simple voltage divider (R1,R2) sets the LM317 output between 1.25volts and 37volts; use this handy LM317 calculator to find resistor values. The … [Read more...]