my recent reads..

LEAP#433 0-30V/3A Adjustable Power Supply Kit

The 0-30V/3A Adjustable Power Supply Kit at the heart of this build will no doubt be instantly recognisable to anyone familiar with the usual online electronics market places. It features continuously variable output voltage, and a variable current limit with overcurrent indicator/shutdown.

It appears the curciot design may have originated from SmartKit in Greece, been improved by various people, and at some point the “canonical design” was picked up for mass production (instantly identifiable by the red PCB and tall cap).

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub

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LEAP#430 Driving Scavenged Linear Steppers

CD/DVD drives are a great source of interesting scavenged components - in particular laser units and stepper motors.

I pulled some of the head control stepper motors some time back. They are small 4-wire bipolar stepper motors with a worm drive for linear motion. Datasheets are non-existent(!), so this is a little project to figure out their specs and demonstrate driving the units with an Arduino and bespoke H Bridge control circuit.

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub

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LEAP#429 3x7 Pomodoro Timer

Over the years, I’ve become habituated to working in a Pomodoro style - make the day a series of tasks worked on in short blocks of time, with regular breaks. But I’ve never actually used a timer - just relied on my internal clock to work in roughly 1 hour increments.

As I was building the Boldport 3x7, it started to appeal to me as a very nice display to use for a non-distracting Pomodoro timer.

After breadboarding the idea my first thought was to make a PCB … but as there’s been a bit of Mohit Bhoite fandom in the Boldport Club recently, I was drawn into a another copper-wire sculpture. Not very ruggedized, but it does look interesting!

Now for the true test - is it actually useful? Well, I’ve started using it for real and so far so good.

Note: the two left-most digits are minutes, the last digit is tenths of minutes. This is actually why I built my 3x7 with the yellow digit on the right;-)

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub

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Here’s a demonstration of a 5 minute countdown. Yes, that’s 5 minutes of your life that is non-refundable!


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LEAP#425 Look Inside a 7-segment with the Boldport 3x7

A lovely PCB and classic Boldport instructions(!):

This project is a challenge to construct.

The Boldport 3x7 is essentially a 3-digit common-cathode 7-segment display, rendered with discrete components.

Since it’s a chance to look inside the workings of a 7-segment display unit, I decided to modify my build to flip the lid and expose the internal wiring for inspection. Now it’s built, more projects to follow!

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image


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