Analog timekeeping: a clock built into a voltmeter


#1

Originally published at: http://boingboing.net/2015/11/02/analog-timekeeping-a-clock-bu.html


#2

that is pretty neat. i think i’d still prefer a nixie tube clock, but heck i’d take one of these as well!


#3

I like the version here: 3 meters, with seconds.
http://makezine.com/2008/11/19/analog-amp-meter-clock/


#4

I love that the “twitchy” analog needles that display the time are connected to an Attiny44 CPU.

Why? Am I missing a pun here, or is the Attiny44 a particularly lovable CPU?


#5

It’s the irony that a microcontroller is in no way analog?


#6

I have made things like this with discrete logic chips. Just divide a crystal to seconds, then minutes, then hours - with the latter two counts resetting at appropriate intervals. To drive meters, put the pulses through integrators to get a ramping voltage.


#7

Ah. Don’t you hate when you have to explain a joke?


#8

Yes, but I was going to post about it anyway.


#9

This isn’t a new concept.

The earliest digital displays would have been a string of light bulbs, one for each
bit. Add up the values of those “on” and you get the count.

Later, BCD came along, so the 1-2-4-8 count of every decade count was much
easier to add up.

I have no idea if meters were used in commercial products, but I’ve seen them
in hobby projects from the late sixties and early seventies. I think the 1971 RCA electronic
hobby manual had a couple of projects with meters as displays. It was a time of
cheap small imported meters for tuning meters on receivers, so the cost was minimal.

The counter would feed a set of resistors, a rudimentary D/A converter, and the higher
the count, the higher the meter read. The original scale didn’t matter, you’d add markers
yourself to show each number. You didn’t need a bcd to nixie or 7segment decoder.

It was a brief period, not much longer than digital ICs hit the hobby market, 7 segment
LED readouts became cheap, actually showing directly the number.


#10

I built a similar one called “Chronulator.” Dunno if they’re still in business. The kit included the meters, a PCB, connectors, and a preprogrammed PROM. I added a small solar cell connected to a switch so a string of internal LEDs light up when it’s dark. Fun time designing and building it.


#11

It’s even on Amazon.
I actually think I’d buy this if it were in $50-60 range.


#12

Just don’t try taking it to school.


#13

should be safe - no visible wiring


#14

Has nobody considered replacing the analogue meters with modern digital displays? We’re in the twentieth century y’know. Jeeb.


#15

There is an audiophile version for just $1800.

McIntosh Clock


#16

Is this it?

http://www.sharebrained.com/chronulator/

@Purplecat, @renke : scroll about halfway down on the above link for the “bombulator”. Bonus points for the scary symbols where family-friendly digits should be.


#17

the Cigar Box Chronulator is the scary kind of clock


#18

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