Status Display Lets Them Know You Can’t Play

All this ongoing forced togetherness is great, but sometimes you just need to be able to pretend you’re alone so you can get some work done. So, how do you keep family members out of your home office? Our own [Bob Baddeley]’s free/busy indicator is about as simple as it …read more

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Check Your Pockets for Components

The ideal component tester is like a tricorder for electronics — it can measure whatever it is that you need it to, all the time. Maybe you have a few devices like an ohmmeter and maybe a transistor socket on our multimeter. But what do you do when you need …read more

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Otis Boykin’s Precision Passives Propelled the Pacemaker

The simplest ideas can be the ones that change the world. For Otis Boykin, it was a new way to make wirewound precision resistors. Just like that, he altered the course of electronics with his ideas about what a resistor could be. Now his inventions are in everything from household …read more

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Hacking A ThinkPad USB-C Adapter

USB-C has brought the world much more powerful charging options in a slimline connector. With laptop chargers and portable battery packs using the standard, many with older hardware are converting their devices over to work with USB-C. [victorc] was trying to do just that, purchasing an adapter cable to charge …read more

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Matrix of Resistors Forms the Hot Hands Behind This Thermochromic Analog Clock

If you’re going to ditch work, you might as well go big. A 1,024-pixel thermochromic analog clock is probably on the high side of what most people would try, but apparently [Daniel Valuch] really didn’t want to go to work that day.

The idea here is simple: heat up a …read more

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The $50 Ham: Dummy Loads, Part 2

In the last installment of “The $50 Ham” I built a common tool used by amateur radio operators who are doing any kind of tuning or testing of transmitters: a dummy load. That build resulted in “L’il Dummy”, a small dummy load intended for testing typical VHF-UHF handy talkie (HT) …read more

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Wire Wound Resistors On Your Own

In all kinds of engineering, we build on abstractions in a kind of inverted pyramid. Lots of people can, for example, design a system using ready-made building blocks on printed circuit boards. Fewer people can do the same design using ICs. Fewer still can design with components. But who designs the components? Even fewer people. Then there are the people designing the constituent elements of those components. [Learnelectronics] wanted to break one of those abstraction layers so he shows how to make your own wire-wound resistors.

Wire-wound resistors are often used when you need resistance with a higher power dissipation …read more

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3D Printed Tool Tips to Straighten DIP Chips and Unstraighten Resistors

Watching someone assemble a kit is a great way to see some tools you may have not encountered before and maybe learn some new tricks. During [Marco Reps’] recent build of a GPS synchronized Nixie clock kit we spied a couple of handy tools that you can 3D print for your own bench.

Fresh from the factory Dual Inline Package (DIP) chips come with their legs splayed every so slightly apart — enough to not fit into the carefully designed footprints on a circuit board. You may be used to imprecisely bending them by hand on the surface of the …read more

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Why Won’t This Darn Thing Charge?

What is more fun than plugging in your phone and coming back to find your battery on empty? Stepping on a LEGO block with bare feet or arriving hungry at a restaurant after closing probably qualify. [Alex Sidorenko] won’t clean your floors or order you a pizza, but he can help you understand why cheap chargers won’t always power expensive devices. He also shows how to build an adapter to make them work despite themselves.

The cheapest smart device chargers take electricity from your home or car and convert it to five volts of direct current. That voltage sits on …read more

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