Tool Hacks

2952 Articles

Resistance Is… There’s An Augmented Reality App For That!

September 12, 2015 by 68 Comments

Like many engineers of a certain age I learned the resistor color code using a mnemonic device that is so politically incorrect, only Tosh might venture to utter it in public today. When teaching kids, I have to resort to the old Radio Shack standby: Big Boys Race Our Young Girls But Violet Generally Wins. Doesn’t really roll off the tongue or beg to be remembered. Maybe: Bad Beer Rots Our Young Guts But Vodka Goes Well. But again, when teaching kids that’s probably not ideal either.

Maybe you can forget all those old memory crutches. For one thing, the world’s going surface mount and color coded resistors are becoming a thing of the past. However, if you really need to read the color code, there’s at least three apps on the Google Play Store that try to do the job. The latest one is ScanR, although there is also Resistor Scanner and Resistor Scan. If you use an iPhone, you might try this app, although not being an Apple guy, I can’t give you my feedback on that one.

Continue reading “Resistance Is… There’s An Augmented Reality App For That!” →

Microwaving Things Outside Of The Microwave!

September 11, 2015 by 48 Comments

DISCLAIMER: DO NOT TRY THIS AT HOME!

Ever wonder what would happen if you took a magnetron out of a microwave, strapped it to a stick, and pointed it at random everyday objects? Well, lucky for you a couple young Russians recorded their research before they presumably hurt themselves and were hospitalized, or maybe just became infertile — or caused cataracts — point is don’t do it.

They’ve taken a magnetron out of a microwave, and tied a soup can to the side of it to focus the microwaves. After discovering this, they did the next logical step — point it at various things and see what happens.

In this specific video (they have lots…) you can see them create plasma inside light bulbs, melt light bulbs, light up vacuum tubes, fluorescent bulbs, liquefy metal, and even catch a glimpse of radio waves.

Continue reading “Microwaving Things Outside Of The Microwave!” →

ARM Programming On Mars

September 10, 2015 by 39 Comments

Before you overreact to the title, keep in mind the latest version of Eclipse is code named “Mars.” It is always a bit of a challenge to set up a generic ARM tool chain. If you don’t mind sticking to one vendor, shelling out a lot of money, or using Web-based tools, then you might not have this problem. But getting all the tools together can be annoying, at best.

[Erich Styger] works with students and knows they often stumble on just this step so he’s provided clear documentation for getting Eclipse, the ARM gcc compiler, and a full set of tools installed. He focuses on Windows and the Kinetis platform, but the steps are virtually the same regardless. Just get the right tools for your operating system and skip the Kinetis-specific parts if you don’t need them.

Continue reading “ARM Programming On Mars” →

Phone Scope Build Uses Old Optical Drive

September 10, 2015 by 13 Comments

It is hardly news that you can use your smart phone as a really crummy oscilloscope. You can even use it as an audio frequency signal generator. There are also plenty of projects that allow you to buffer signals going in and out of your phone to make these apps more useful and protect your phone’s circuitry to some degree. What caught our eye with [loboat’s] phone oscilloscope project was its construction.

Continue reading “Phone Scope Build Uses Old Optical Drive” →

Aerogel Insulation For 3D Printers

September 9, 2015 by 8 Comments

A heated bed is nearly essential for printing with ABS. Without it, it is difficult to keep parts from warping as the plastic cools. However, heating up a large print bed is difficult and time consuming. It is true that the printer easily heats the hot end to 200C or higher and the bed’s temperature is only half of that. However, the hot end is a small insulated spot and the bed is a large flat surface. It takes a lot of power and time to heat the bed up and keep the temperature stable.

We’ve used cork and even Reflectix with pretty good results. However, [Bill Gertz] wasn’t getting the performance he wanted from conventional material, so he got a piece of aerogel and used it as insulation. Aerogel material is a gel where a gas replaces the liquid part of the gel. Due to the Knudsen effect, the insulating properties of an aerogel may be greater than the gas it contains.

Continue reading “Aerogel Insulation For 3D Printers” →

Understanding Surface Mount

September 7, 2015 by 30 Comments

Do you know what a MELF is (and, yes, it is safe for work to Google it)? What’s the difference between a QFP, and LCC, and a PLCC package? Do you need a 0603 resistor or a 1206 resistor?

If you are an old hand at surface mount devices (SMDs) you probably know the answers to most of these questions. But if you’ve done most of your work with through hole, it is a confusing mess of acronyms and numbers. Sure, you can Google and find out that at 0603 resistor is .06 inches by .03 inches. [TopLine] has a great booklet that pulls many common definitions in one place available for download that can help you make sense of different SMD nomenclature.

Continue reading “Understanding Surface Mount” →

Using LTSpice To Measure Total Harmonic Distortion

September 7, 2015 by 7 Comments

Audiophiles spend a lot of time and effort worrying about audio specs like Total Harmonic Distortion (THD). Makes sense, because THD affects the quality of audio reproduction. However, THD can also affect interference from radio signals and even losses in power transfer systems. A simplified definition is the THD is the ratio of the sum of the power of all harmonic frequencies to the power of the fundamental frequency.

If a circuit produced a perfect sine wave, there would be no harmonics. There are many ways to measure THD in practice, but [Michael Jackson] has an interesting video showing how he easily visualizes THD using LTSpice. Assuming you already have the system in question in LTSpice (or you could use another simulation tool, if you prefer) it is fairly straightforward.

Continue reading “Using LTSpice To Measure Total Harmonic Distortion” →