Inside Mechanical Calculators

May 1, 2018 by Dan Maloney 25 Comments

For as busy as things can get at the grocery store on a typical afternoon just before the dinner hour, at least the modern experience has one thing going for it: it’s relatively quiet. Aside from the mumbled greetings and “Paper or plastic?” questions from the cashier, and the occasional screaming baby in the next aisle, the only sound you tend to hear is the beeping of the barcode scanner as your purchase is tallied up.

Jump back just 40 years and the same scene was raucous, with cashiers reading price tags and pounding numbers into behemoth electromechanical cash registers. Back then, if you wanted help with any arithmetic with more than just a few operations, some kind of mechanical calculator was your only choice. From simple “one-banger” adding machines to complex analog computers, mechanical devices were surprisingly capable data processing tools. Here’s a brief look at how some of the simpler ones worked.

Continue reading “Inside Mechanical Calculators” →

Milspec Teardown: AH-64A Apache Data Entry Panel

April 30, 2018 by Tom Nardi 93 Comments

It’s time once again to see how those tax dollars are spent, this time in the form of a “Data Entry Keyboard” manufactured by Hughes Helicopters. This device was built circa 1986 or so, and was used in the AH-64A Apache. Specifically, this panel would have been located by the gunner’s left knee, and served as a general purpose input device for the Apache’s Fire Control System. Eventually the Apache was upgraded with a so-called “glass cockpit”; consolidating various vehicle functions into a handful of multi-purpose digital displays. As such, this particular device became obsolete and was pulled from the active Apache fleet.

The military vehicle aficionados out there may know that while the Apache is currently a product of Boeing, it was originally designed by Hughes Helicopter. In 1984, McDonnell Douglas purchased Hughes Helicopter and took over production of the Apache, and then McDonnell Douglas themselves were merged with Boeing in 1997.

So it’s somewhat interesting that this device bears the name of Hughes Helicopter, as of the time it was manufactured, they would have been known as McDonnell Douglas Helicopter Systems. Presumably they had to work through existing stock of components that already had Hughes branding on them, leaving some transitional examples such as this one.

But you didn’t come here for a history lesson on the American military-industrial complex, you want to know about the hardware itself. So let’s crack it open to see what we can learn about this piece of aviation history.

Continue reading “Milspec Teardown: AH-64A Apache Data Entry Panel” →

Hackaday Belgrade Schedule Announced

April 29, 2018 by Mike Szczys No comments

Hackaday Belgrade preparations have now passed the flash point and the hacker village that is set to descend on Serbia in a few weeks grows larger and more awesome by the day. Prepare for a massive data dump on what is in store. But before you go any further, make sure you have a ticket.

Continue reading “Hackaday Belgrade Schedule Announced” →

Hackaday Links: April 29, 2018

April 29, 2018 by Brian Benchoff 12 Comments

Amazon has released the Echo Dot Kids Edition, an always-on, Internet-connected microphone. According to Amazon’s Children’s Privacy Disclosure, the Amazon Echo Dot Kids Edition collects data such as, ‘name, birthdate, contact information (including phone numbers and email addresses), voice, photos, videos, location, and certain activity and device information. The Amazon Echo Dot Kids Edition is able to read audiobooks for bedtime reading and teaches your children to live in a dystopian panopticon of Orwellian proportions. It comes in green, red, and blue.

Kim Possible! The biggest news headline this week is the coming end of the Korean War. The peninsula has been in a state of war since 1950, but leaders from both countries have agreed to negotiate a treaty to replace the 60-year-old truce. There is also an agreement between the two countries for complete denuclearization. This is great news for Hackaday. Every day, we’re eyeing our North Korean readership. Some days we get a view, some days we don’t, but year over year we’re always getting more views. Will this treaty result in even more Hackaday readers in North Korea? Only time will tell. Here’s some music. It wasn’t a chicken.

The East Coast RepRap Festival is on. Inspired by the Midwest RepRap Festival, the ERRF is happening north of Baltimore on June 23rd and 24th. What’s it going to be like? Nobody knows! This is the first time ERRF is happening, but judging by MRRF standards, it should be awesome. Also, crab season.

One of the most interesting hacks of this year is [Steve Markgraf]’s tool to allow transmit-only SDR through cheap USB 3.0 to VGA adapters. The hack relies on the Fresco Logic FL2000 chip and gives you the ability to transmit FM, TVB-T, and create your own GSM cell site. You can also spoof GPS to get something besides a rattata in Pokemon Go or hack your ankle bracelet to keep your parole officer off your back. The open question, though, is which USB to VGA adapter has the FL2000 chipset. I can confirm this one on Amazon has the relevant chipset. It’s a bit expensive at $15 (the same chipset is available from the usual eBay and AliExpress suppliers for $6), but if you’re looking for something that is available with Prime, there you go. Now we’re looking for shared OSH Park projects with a VGA input on one end and some antennas on the other. Make it happen, people.

Supercapacitors are awesome, but is it possible to fly a drone with a bank of them? Sure, for about 10 seconds. [dronelab] built a 7-cell, 200F supercap and managed to fly a little racing quad for about ten seconds. Not terribly great, but this is going to be awesome when we get multi-thousand Farad superultramegacaps.

Like Open Hardware? The Open Source Hardware Association is opening up the Ada Lovelace Fellowship for women, LGTBA+ and other minorities to attend the Open Hardware Summit. The deadline is tomorrow, so do it soon.

M3D has announced a new 3D printer that can print with four filaments. The Crane Quad is your basic i3 ripoff with an interesting extruder. It looks like it uses four tiny motors to feed filament into the main extruder motor. This isn’t really anything new; the Prusa i3 multimaterial upgrade does the same thing. However, M3D claims they have mastered color mixing. The Prusa upgrade doesn’t do mixing, and this is most likely the reason it works so well. Can M3D pull it off? This is a very, very, very hard problem.

A Blockchain, Robotics And AI Event In Vietnam

April 27, 2018 by Sean Boyce 7 Comments

Blockchain Education Network Vietnam recently held an event titled “Building a Robotics & Artificial Intelligence Ecosystem with Blockchain”. The title alone has three of my favorite things in it, so when a client of mine asked me if I could put together a little hardware demonstration for the event, I jumped at the opportunity.

I also thought I’d take a moment to write about it, because I haven’t seen much coverage of emerging technology events in the developing world, and the fact is that there’s a consistently high level of interest. I’ve yet to go to an event that wasn’t filled to capacity, and I hope to share some of that enthusiasm with you.

Continue reading “A Blockchain, Robotics And AI Event In Vietnam” →

Circuit VR: Oscillating Bridges

April 27, 2018 by Al Williams 21 Comments

Circuit VR is where we talk about a circuit and examine how it works in simulation with LT Spice. This time we are looking at a common low-frequency oscillator known as the Wien bridge oscillator.

What makes an oscillator oscillate? A circuit with amplification that gets the same amount of the output signal fed back into its input, in phase, will oscillate. This is the Barkhausen criterion. Here, we’re going to look into what makes an oscillator work in simulation, and gain some insight into what happens when there’s too much feedback and too little.

In particular, we’ll look at the Wien bridge oscillator, a very simple design that originated as a way to measure impedance back in 1891. Modern versions add some additional features, but let’s start with the most simple implementation and work our way up.

Continue reading “Circuit VR: Oscillating Bridges” →

Retrotechtacular: Synchros Go To War (and Peace)

April 25, 2018 by Al Williams 41 Comments

Rotation. Motors rotate. Potentiometers and variable capacitors often rotate. It is a common task to have to rotate something remotely or measure the rotation of something. If I asked you today to rotate a volume control remotely, for example, you might offer up an open loop stepper motor or an RC-style servo. If you wanted to measure a rotation, you’d likely use some sort of optical or mechanical encoder. However, there’s a much older way to do those same tasks and one that still sees use in some equipment: a synchro.

The synchro dates back to the early 1900s when the Panama Canal used them to read and control valves and gates. These devices were very common in World War II equipment, too. In particular, they were often part of the mechanisms that set and read gun azimuth and elevation or — like the picture to the left — a position indication of a radar antenna. Even movie cameras used these devices for many years. Today, with more options, you don’t see them as much except in applications where their simplicity and ruggedness is necessary.