bell

19 Articles

Breathtaking Alarm Clock Looks Like It Came From A 1960 Fallout Shelter

August 10, 2020 by 24 Comments

All the hardcore geeks have alarm clocks where the bell striker is a hard disk read head… or at least they’ll be building them after seeing this. [Senile Data Systems] created an industrial voltage alarm clock out of decade counters that looks like it was unearthed from a fallout shelter (machine translation).

At first glace you might mistake this for a binary clock since it uses a column of LEDs to indicate each digit of 24-hour time. It’s not, as each row corresponds to a pin on the CD4017 decade counters that make up the timekeeping circuit inside.

Thumbscrew wheel switches at the top of the bulky handheld unit are how the alarm time is set, triggering a bell along the top edge. The clock is driven by the 50 Hz line voltage and [SDS] tried using that AC to drive a solenoid as the striker on the prototype unit but it performed poorly. The use of a hard disk read head turns out to be the perfect striker, as heard in the video after the break. As for triggering from the decade counters, here’s what [SDS] told us about the design:

The switches’ outputs gets ANDed with a 10 Hz signal (on a 60 Hz grid it will become 12 Hz). This drives a slightly beefy transistor which in turn drives an electromagnet to hammer a bell which broke off my bicycle. Yes. This is a digital analog alarm clock. The clock portion is digital but the bell is analog and sounds like Grampa’s old wind up alarm clock.

The build came about when a cache of over 600 industrial LEDs (24 V – 48 V) fell into his lap. This makes the insides of the clock something to behold as point-to-point soldering connects the panel mount lights and all nine logic chips. Add in that transformer for getting the line voltage and we imagine this thing has quite a bit of heft to it.

If you’ve ever had an alarm with a wind-up bell you know there’s no better way to jolt yourself out of a peaceful slumber and into the chaos of the real world. If the gentle tinkle of the hard drive head isn’t enough for you, this fire bell alarm clock will certainly do the trick.

 

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Retrotechtacular: Mobile Phones 1940s Style

March 13, 2020 by 24 Comments

We think of the mobile phone — well, what we would call a cell phone — as something fairly modern. Many of us can still remember when using a ham radio phone patch from your parked car would have people staring and murmuring. But it turns out in the late 1940s, Bell Telephone offered Mobile Telephone Service (MTS). It was expensive and didn’t work as well as what we have now, but it did let you make or receive calls from your automobile. After the break, you can see a promotional film about MTS.

The service rolled out in St. Louis in the middle of 1946. The 80-pound radios went in the trunk with a remote handset wired to the dashboard. At first, there were only 3 channels but later Bell added 29 more to keep up with demand. An operator connected incoming and outbound calls and if three other people were using their mobile phones, you were out of luck.

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The Modular Connector And How It Got That Way

October 2, 2018 by 70 Comments

They adorn the ends of Cat5 network patch cables and the flat satin cables that come with all-in-one printers that we generally either toss in the scrap bin or throw away altogether. The blocky rectangular plugs, molded of clear plastic and holding gold-plated contacts, are known broadly as modular connectors. They and their socket counterparts have become ubiquitous components of the connected world over the last half-century or so, and unsurprisingly they had their start where so many other innovations began: from the need to manage the growth of the telephone network and reduce costs. Here’s how the modular connector got that way.

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This Boxing Bell Is A Trip

February 17, 2018 by 8 Comments

[MeasuredWorkshop] wanted to know how a boxing bell mechanism worked. The best way to learn is by doing, so he jumped right in and built one! Boxing bells are a rare surviving example of the trip bell mechanism. Trip bells were used in schools and public buildings as fire alarms. They’ve since been replaced by modern electric systems.

The mechanical linkage behind the trip bell is a one-way lever. This is the arm you pull on. It has a hinged section which stays rigid when the arm is pulled down, but rotates away when the arm is released. [Measured Workshop] built the mechanics of his bell using rather basic tools. The brunt of the work was handled by an angle grinder and a drill press.

The sounder for this boxing bell came from an old school bell. The industrial grey paint was chemically stripped, and the metal cleaned up for a nice brushed finish. The metal stands out nicely against the wood board [Measured Workshop] used as a base.

The finished product looks and sounds the part – now he just has to find a boxing gym in need of a bell!

We’re really becoming fond of the “wordless workshop” style videos that have been popping up on YouTube. [Jimmy DiResta] has been doing it for years, and relative newcomers [HandToolRescue] and [Measured Workshop] are both producing some great content!

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Flexiphone Rises From The Ashes Of Broken Instruments

February 2, 2018 by 7 Comments

The mechanics of an old Rhodes Piano, and a set of chromatic saucer bells rescued from a reed organ. What do these two things have to do with each other? If you’re [Measured Workshop], they are the makings of a new instrument. The Flexiphone is a transposable instrument with a piano keyboard and interchangeable sound source.

The Rhodes is a great stage instrument. Unlike a piano with strings, it uses tines mounted above the key mechanism. It is also relatively compact for an analog instrument. This made it perfect as a donor for the Flexiphone’s keyboard. [Measured Workshop] cut they mechanism down to 30 keys, just under 2 octaves. The key mechanism was also cleaned up and restored with new felt.

The sounding portion of the Flexiphone is a set of chromatic saucer bells. The bells are mounted on a felt covered threaded rod, which itself sits in a wood frame. The bell frame sits on top of the base in one of three slots. Each slot is a halftone transposed from the last. Simply moving the bells allows the player to transpose the entire instrument. The bells and their rod frame can also be completely removed and replaced with any other sound source.

The Flexiphone sounds great — sometimes. As [Measured Workshop] says, bells contain many harmonics. playing single or double notes sounds rather sweet, but chords can sometimes become a shrill assault on the ears. Still, it’s an awesome hack with plenty of potential for future mods.

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Quasimotor? A Robot Bell Ringer

December 2, 2016 by 11 Comments

In large churches that still use real bells in their bell towers, a large number of them ring bells using a method called full circle ringing. In order to get the bells to sound at exactly the right time, the bells are rung by swinging the entire bell in an almost complete 360-degree arc. This helps to mitigate the fact that often times, the bells weigh more than the person ringing the bells. However, if you don’t have access to a belfry, you can practice ringing bells using this method with your own full circle bell simulator.

The frame for the bell was built from some leftover aluminum extrusion and allows the bell to easily swing on some old skateboard bearings. The mechanism is electrically controlled, too, using a hall effect sensor and a USB adapter so that it can be interfaced with a computer running a virtual bell ringing suite. Once some timing issues are worked out, the bell is all set up and ready to practice ringing changes.

If you’re as fascinated as we are to find that there are entire software suites available to simulate bell ringing, and an entire culture built around something that most of us, perhaps, wouldn’t have given a second thought to outside of walking past a church on a Sunday, there have been a surprising number of other bell-related projects over the years. Bells have been given MIDI interfaces and robotified, and other church instruments like a pipe organ have been created almost from scratch.

Internet Doorbell Gone Full-Hipster

October 24, 2016 by 9 Comments

There are things and there are Things. Hooking up an Internet-connected doorbell that “rings” a piezo buzzer or sends a text message is OK, but it’s not classy. In all of the Internet-of-Things hubbub, too much attention is paid to the “Internet”, which is actually the easy part, and too little attention is paid to the “Things”.

[Moris Metz] is a hacker in Berlin who has a bi-weekly national radio spot. (Only in Germany!) This week, he connected the ubiquitous ESP8266 to a nice old (physical) bell for his broadcast over the weekend. (i”Translated” here.) Check out the video teaser embedded below.

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