Car Alternators Make Great Electric Motors; Here’s How

January 16, 2020 by Jenny List 198 Comments

The humble automotive alternator hides an interesting secret. Known as the part that converts power from internal combustion into the electricity needed to run everything else, they can also themselves be used as an electric motor.

The schematic of a simple automotive alternator, from US patent 3329841A filed in 1963 for Robert Bosch GmbH . — The schematic of a simple automotive alternator, from US patent 3329841A filed in 1963 for Robert Bosch GmbH.

These devices almost always take the form of a 3-phase alternator with the magnetic component supplied by an electromagnet on the rotor, and come with a rectifier and regulator pack to convert the higher AC voltage to 12V for the car electrical systems. Internally they have three connections to the stator coils which appear to be universally wired in a delta configuration, and a pair of connections to a set of brushes supplying the rotor coils through a set of slip rings. They have a surprisingly high capacity, and estimates put their capabilities as motors in the several horsepower. Best of all they are readily available second-hand and also surprisingly cheap, the Ford Focus unit shown here came from an eBay car breaker and cost only £15 (about $20).

We already hear you shouting “Why?!” at your magical internet device as you read this. Let’s jump into that.

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Tetraethyl Lead: The Solution To One, And Cause Of Many New Problems

January 15, 2020 by Maya Posch 101 Comments

From the 1920s until the 1970s, most gasoline cars in the USA were using fuel that had lead mixed into it. The reason for this was to reduce the engine knocking effect from abnormal combustion in internal combustion engines of the time. While lead — in the form of tetraethyllead — was effective at this, even the 1920s saw both the existence of alternative antiknock agents and an uncomfortable awareness of the health implications of lead exposure.

We’ll look at what drove the adoption of tetraethyllead, and why it was phased out once the environmental and health-related issues came into focus. But what about its antiknock effects? We’ll also be looking at the alternative antiknock agents that took its place and how this engine knocking issue is handled these days.

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A Vintage Phone In 2020

January 14, 2020 by Jenny List 72 Comments

When we make a telephone call in 2020 it is most likely to be made using a smartphone over a cellular or IP-based connection rather than a traditional instrument on a pair of copper wires to an exchange. As we move inexorably towards a wireless world in which the telephone line serves only as a vehicle for broadband Internet, it’s easy to forget the last hundred years or more of telephone technology that led up to the present.

The iconic British telephone of the 1960s and 1970s, the GPO model 746. Mine is from 1971. (That isn’t my phone number)

In a manner of speaking though, your telephone wall socket hasn’t forgotten. If you like old phones, you can still have one, and picture yourself in a 1950s movie as you twirl the handset cord round your finger while you speak. Continue reading “A Vintage Phone In 2020” →

The Way Of The PCB Artist: How To Make Truly Beautiful Circuit Boards

January 13, 2020 by Zoe Skyforest 8 Comments

Getting your own PCBs made is a rite of passage for the hardware hacker. Oftentimes, it’s a proud moment, and many of us choose to immortalise the achievement with a self-aggrandizing credit on the silk screen, or perhaps a joke or personal logo. However, as far as artistically customized PCBs go, the sky really is the limit, and this is the specialty of [TwinkleTwinkie], whose Supercon talk covers some of the pitfalls you can run into when working at the edges of conventional PCB processes.

[TwinkleTwinkie]’s creations are usually badges of one type or other — they’re meant to be worn on a lanyard around your neck, as a pin, or as a decoration added to another badge. The whole point is the aesthetic, and style is just as important as functionality. With diverse inspirations like Futurama, Alice in Wonderland and the shenanigans of the GIF community, his badges blend brightly colored boards with a big helping of LEDs and artistic silkscreening to create electronic works of art.

Keeping PCB Fab Houses from Upsetting the Artwork

These days, PCB fab houses offer more choice than ever, in terms of silkscreens, soldermask colors, and other options. However, fundamentally, their primary concern is to produce reliable, accurate, electronically functional boards — and it’s something that can cause problems for #badgelife hackers designing for more aesthetic reasons.
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Why Do Resistors Have A Color Code?

January 13, 2020 by Al Williams 226 Comments

One of the first things you learn in electronics is how to identify a resistor’s value. Through-hole resistors have color codes, and that’s generally where beginners begin. But why are they marked like this? Like red stop signs and yellow lines down the middle of the road, it just seems like it has always been that way when, in fact, it hasn’t.

Before the 1920s, components were marked any old way the manufacturer felt like marking them. Then in 1924, 50 radio manufacturers in Chicago formed a trade group. The idea was to share patents among the members. Almost immediately the name changed from “Associated Radio Manufacturers” to the “Radio Manufacturer’s Association” or RMA. There would be several more name changes over the years until finally, it became the EIA or the Electronic Industries Alliance. The EIA doesn’t actually exist anymore. It exploded into several specific divisions, but that’s another story.

This is the tale of how color bands made their way onto every through-hole resistor from every manufacturer in the world.

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Hide Silent, Hide Deep: Submarine Tracking Technologies Of The Cold War

January 10, 2020 by Al Williams 48 Comments

All through the cold war, there was a high-stakes game of cat and mouse in play. Nuclear powers like the United States and the Soviet Union would hide submarines armed with nuclear missiles underwater. The other side would try to know where they were so they could be targeted in the event of war. The common wisdom was that the United States had many high tech gadgets to help track enemy submarines, but that the Soviet Union was way behind in this area. This was proven false when a Soviet Victor-class boat followed a US missile submarine for six days. Now, a recently declassified CIA report shows how the Soviets didn’t use sonar at all but developed their own technology.

There is something fascinating about submarines. Like an old sailing ship, submarines are often out of touch with their command bases and the captain is the final authority. Like a space ship, the submarine has to survive in an inimical environment. I guess in all three cases, the crew doesn’t just use technology, they depend on it.

Although the submarine has some non-military uses, there are probably more military subs than any other type. After all, a sub is as close to a cloaking device as any real-life military vehicle has ever had. Before modern technology offered ways to find submarines using sonar or magnetic anomalies, a completely submerged submarine was effectively invisible.

There was a lot of speculation that the Soviet Union lacked sufficient technology to use sonar the way the US did. However, in some cases, they had simply developed different types of detection — many of which the West had discarded as impractical.

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This Week In Security: Camera Feeds, Python 2, FPGAs

January 10, 2020 by Jonathan Bennett 6 Comments

Networked cameras keep making the news, and not in the best of ways. First it was compromised Ring accounts used for creepy pranks, and now it’s Xiaomi’s stale cache sending camera images to strangers! It’s not hard to imagine how such a flaw could happen: Xiaomi does some video feed transcoding in order to integrate with Google’s Hub service. When a transcoding slot is re-purposed from one camera to another, the old data stays in the buffer until it is replaced by the new camera’s feed. The root cause is probably the same as the random images shown when starting some 3D games.

Python is Dead, Long Live Python

Python 2 has finally reached End of Life. While there are many repercussions to this change, the security considerations are important too. The Python 2 environment will no longer receive updates, even if a severe security vulnerability is found. How often is a security vulnerability found in a language? Perhaps not very often, but the impact can be far-reaching. Let’s take, for instance, this 2016 bug in zipimport. It failed to sanitize the header of a ZIP file being processed, causing all the problems one would expect.

It is quite possible that because of the continued popularity and usage of Python2, a third party will step in and take over maintenance of the language, essentially forking Python. Unless such an event happens, it’s definitely time to migrate away from Python2.
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