clock

592 Articles

Tricking A Vintage Clock Chip Into Working On 50-Hz Power

June 11, 2018 by 32 Comments

Thanks to microcontrollers, RTC modules, and a plethora of cheap and interesting display options, digital clock projects have become pretty easy. Choose to base a clock build around a chip sporting a date code from the late 70s, though, and your build is bound to be more than run-of-the-mill.

This is the boat that [Fran Blanche] finds herself in with one of her ongoing projects. The chip in question is a Mostek MK50250 digital alarm clock chip, and her first hurdle was find a way to run the clock on 50 Hertz with North American 60-Hertz power. The reason for this is a lesson in the compromises engineers sometimes have to make during the design process, and how that sometimes leads to false assumptions. It seems that the Mostek designers assumed that a 24-hour display would only ever be needed in locales where the line frequency is 50 Hz. [Fran], however, wants military time at 60 Hz, so she came up with a circuit to fool the chip. It uses a 4017 decade counter to divide the 60-Hz signal by 10, and uses the 6-Hz output to turn on a transistor that pulls the 60-Hz output low for one pulse. The result is one dropped pulse out of every six, which gives the Mostek the 50-Hz signal it needs. Sure, the pulse chain is asymmetric, but the chip won’t care, and [Fran] gets the clock she wants. Pretty clever.

[Fran] has been teasing this clock build for a while, and we’re keen to see what it looks like. We hope she’ll be using these outsized not-quite-a-light-pipe LED displays or something similar.

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Watch The Honeycomb Clock Gently Track Time

May 26, 2018 by 19 Comments

We love clocks here at Hackaday, and so does [John Whittington]. Last year he created this hexagonal honey clock (or “Honock”) by combining some RGB LEDs with a laser-cut frame to create a smooth time display that uses color and placement to display time with a simple and attractive system.

The outer ring of twelve hexagons is essentially the hour hand, similar to analog clock faces: twelve is up, three is directly to the right, six is straight down, and nine is to the left. The inner ring represents ten minutes per hex. Each time the inner ring fills, the next hex (hour) on the outer ring lights up. The whole display is flooded with a minute-long rainbow at noon and midnight. Watch it in action in the video, embedded below.

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Linear Clock Is A Different Way To Look At Time

May 25, 2018 by 18 Comments

There are usually two broad user interfaces for clocks. On the one hand you’ve got the dial clock, the default display for centuries, with its numbered face and spinning hands. The other mode is some form of digital clock, where the current time is displayed directly as alphanumeric characters. They’re both useful representations of time, but they both have their limits.

Here’s a third model — the linear clock. [Jan Derogee] came up with it thanks to the inspiration of somewhat dubious run-ins with other kinds of clocks; we feel like this introductory video was made with tongue firmly planted in cheek. Whatever the inspiration, we find this idea clever and well executed. The running gear of the clock is just a long piece of M6 threaded rod and a stepper motor. A pointer connected to a nut rides on the rod, moving as the stepper rotates it. There are scales flanking the vertical rod, with the morning hours going up the left side and afternoon hours coming down the right. The threaded rod rotates one way for twelve hours before switching to the other direction; when the rotation changes, the pointer automatically swivels to the right scale. For alarms, [Jan] has brass rods running along each scale that make contact with the pointer; when they encounter a sliding plastic insulator to break the contact, it triggers an alarm. An ESP8266 controls everything and plays the audio files for the alarm.

Unusual clocks seem to be a thing with [Jan]. His other builds include this neat phosphorescent clock and YouTube subs counter, which is sure to turn heads along with this clock.

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Hawkeye, The 3D-Printed Tourbillon Movement

May 15, 2018 by 10 Comments

As if building tiny mechanisms with dozens of moving parts that all need to mesh together perfectly to work weren’t enough, some clock and watchmakers like to put their horology on hard mode with tourbillon movements. Tourbillons add multiple axes to the typical gear trains in an attempt to eliminate errors caused by the influence of gravity — the movement essentially spins on gimbals while tick-tocking away.

It feels like tourbillons are too cool to lock inside timepieces meant for the ultra-rich. [Alduinien] agrees and democratized the mechanism with this 3D-printed tourbillon. Dubbed “Hawkeye,” [Alduinien]’s tourbillon is a masterpiece of 3D printing. Composed of over 70 pieces, the mechanism is mesmerizing to watch, almost like a three-axis mechanical gyroscope.

The tourbillon is designed to be powered either by the 3D-printed click spring or by a small electric motor. Intended mainly as a demonstration piece, [Alduinien]’s Thingiverse page still only has the files for the assembled mechanism, but he promises to get the files for the individual pieces posted soon. Amateur horologists, warm up your 3D-printers.

Tourbillons are no stranger to these pages, of course. We’ve done an in-depth look at tourbillons for watches, and we’ve even featured a 3D-printed tourbillon clock before. What we like about this one is that it encourages exploration of these remarkable instruments, and we’re looking forward to seeing what people do with this design. For those looking for more background on clock escapements in general, [Manuel] wrote a great article on how we turned repetitive motion into timekeeping.

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Simple Home-built Projection Clock Projects Time

May 5, 2018 by 13 Comments

There are plenty of cheap projection clocks available, but as [Thomas Pototschnig] points out in this project, where’s the fun in just buying something? He set out to build a cheap projection clock using a small LCD screen, a cheap LED backlight, and a cheap lens. Cheap is the order of the day here, and [Thomas] succeeded admirably, creating a design that can be made with a couple of cheap PCBs, a 3D printer and the other parts mentioned above. He does a nice job of laying out his thinking in this design, showing how he calculated the projection path and made other decisions. His project has room to grow as well: it runs from an Arduino compatible STM32 that could handle many things other than showing the time if you were inclined to expand the project further.

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GuerillaClock Could Save This City Thousands

April 22, 2018 by 32 Comments

They say necessity is the mother of invention. But if the thing you need has already been invented but is extremely expensive, another mother of invention might be budget overruns. That was the case when [klinstifen]’s local government decided to put in countdown clocks at bus stops, at a whopping $25,000 per clock. Thinking that was a little extreme, he decided to build his own with a much smaller price tag.

The project uses a Raspberry Pi Zero W as its core, and a 16×32 RGB LED matrix for a display. Some of the work is done already, since the bus system has an API that is readily available for use. The Pi receives the information about bus schedules through this API and, based on its location, is able to determine the next bus arrival time and display it on the LED matrix. With the custom 3D printed enclosure and all of the other material, the cost of each clock is only $100, more than two orders of magnitude less expensive.

Hopefully the local government takes a hint from [klinstifen] and decides to use a more sane solution. In the meantime, you might be able to build your own mass transit clock that you can use inside your own house, rather than at the train station, if you’re someone who has a hard time getting to the bus stop on time.

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Marquee Display Uses Six Dozen Surplus VFD Tubes To Great Effect

April 19, 2018 by 6 Comments

The quest to repurpose surplus parts into new and interesting displays never ends, it seems. And the bigger the display, the better, with extra points for using some really obscure part, like these surplus Russian vacuum-fluorescent tubes turned into a marquee display.

As [tonyp7] freely admits, this is a pet project that’s just for the fun of it, made possible by the flood of surplus parts on the market these days. The VFD tubes are IV-25s, Russian tubes that can be had by the fistful for a song from the usual sources. The seven small elements in the tube were intended to make bar graph displays like VU meters, but [tonyp7] ganged up twelve side by side to make 84-pixel displays. The custom driver board for each matrix needs three of the old SN75518 driver chips, in 40-pin DIPs no less. A 3D-printed bracket holds the tubes and the board for each module; it looks like a clock is the goal, with six modules ganged together. But the marquee display shown below is great too, and we look forward to seeing the finished project.

From faux-Nixies made with LEDs to flip-segment displays driven by relay logic to giant seven-segment LEDs that can be 3D-printed, we really like the trend to unique displays. What are you dreaming up?

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