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Wobbly clock

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Re: Wobbly clock

#151

Post by lygaret »

lxgr wrote: post #146
caf wrote: post #140

Earlier quoted context omitted.

It'd be a fun project to make a dial wall clock that uses GPS time.

GPS would be tricky to receive in a typical hotel or office lobby (i.e. far away from any windows at the ground floor, possibly in an urban canyon). In Germany (and in neighboring countries), radio-controlled clocks are quite common for this purpose, listening to DCF77 near Frankfurt [1]. Long wave seems to work a bit better than the L-band for indoor propagation, and it probably also helps that the transmit power is…

WWVB is running at 60kHz, and powers at least a few of the small desk clocks in my home :)

https://en.m.wikipedia.org/wiki/WWVB

Re: Wobbly clock

#152

Post by tdeck »

jedberg wrote: post #109
bmitc wrote: post #101

Earlier quoted context omitted.

How did they know when the next hour started without digital communication?

They had digital communication just not cheap ICs. I don't know how it worked but I imagine it was something like a mechanical switch that held the minute hand until it got a signal from the main office to start moving again. The clocks could even be set for Daylight time centrally, so I assume it had a way to send a signal that triggered a motor to move the hour hand faster.

Since it's a school I wonder if they could just hold them back 1 or 11 hours on the weekend for DST changes. This would eliminate the need for an additional signal and circuitry on each follower clock.

Re: Wobbly clock

#153

Post by jonsen »

doublesocket wrote: post #144
noja wrote: post #143

Earlier quoted context omitted.

Why 58.5 seconds?

Because then any slow clocks have 1.5 seconds to receive additional pulses from the master clock to bring them into sync.

There are no additional pulses. Only minute pulses. It's a motor driving the second hand. The motor starts by the minute pulse and stops itself when reaching the top.

Re: Wobbly clock

#154

Post by spyremeown »

agys wrote: post #39

Made me think about the Swiss Railways clock that has the second hand completing the circle in 58.5 seconds; all the clocks on the network then wait for the sync signal from the “master clock". https://en.wikipedia.org/wiki/Swiss_railway_clock

All clocks from Deutsche Bahn stations are also like this. It's always very amusing.

Re: Wobbly clock

#155

Post by ok123456 »

jaywalk wrote: post #133
ok123456 wrote: post #132

Earlier quoted context omitted.

There may be more, but it includes that functionality at the very least. That would be the absolute base line functionality of a watch that has a bit-mapped display.

I'd argue that the success of the Apple Watch proves that you're incorrect.

Success?

I've never seen one worn in real life.

Personally, they're a less cool version of an 80s swatch.

Re: Wobbly clock

#157

Post by ColinWright »

qrohlf wrote: post #145
ColinWright wrote: post #82

Earlier quoted context omitted.

It's me ... hi! You don't have contact details in your profile, but feel free to email me. I travel a lot and can put you in my geographical address book so that if I come within reach we can get a coffee. Cheers!

Off-topic, but what do you use for your "geographical address book"? I would love to have something that showed all my contacts on a map, but haven't run into any software that does this ever.

It will come as a surprise to no one who knows me ... I wrote my own.

More, I created a system wherein people can register, and then whenever someone is travelling they can tell the system and it automatically emails everyone they know who is close to the destination.

I'm the only one who uses it, although there are a few hundred people on it, so I basically just use it as my geographical address book.

I also put landmarks, museums, and other places I might like to visit. When I tell it where I'm going it then sends me email to remind me of them.

Re: Wobbly clock

#158

Post by mahathu »

rpastuszak wrote: post #117

I love it! And I think that the idea of random intervals averaging to correct values mentioned below would make it beautifully irritating. Not a clock, but I was messing with soft body physics and ended up with this thing this weekend: https://mrrr.vercel.app [1] Consider a v2 where the hands are physically simulated al dente spaghetti. [1] (I ended up making a classic frame-by-frame animation though: http://mrr.sonn…

Oh my god!! I forgot I had my laptop still connected to a bluetooth speaker in a different room and totally freaked out when those lips started making faint noises through a door!

Re: Wobbly clock

#160

Post by orlp »

jedberg wrote: post #83

This clock is great for teaching kids how to tell time! When learning to read a "circle clock", they have a heck of a time understanding what it means when the hour hand is almost but not quite pointing at a number. So when it's 3:45 they will say 4:45 because they know the big hand on 9 means "45" but they get confused because the little hand is almost pointing at 4. This clock solves that problem. Anyone know if I…

> This clock solves that problem.

In English! In Dutch this would actually create a problem, as when it is 3:45 we say it is "15 before 4". I noticed that I actually struggled to interpret the wobbly clock when it was close to changing the hour.

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