Nothing like a bit of clock

[Howardlong]

Not an art lover myself, but this rather caught my eye, I can appreciate this kind of thing whether or not it tells the time...

http://techno-logic-art.com/clock.htm

[BravoV]

Just curious if its possible to hide smd ICs or any other smd/miniaturized complex components behind the 7 segments leds to do the job ?

[T3sl4co1l]

Certainly, but with all those components around, you'd have no need.

Tim

[BravoV]

Certainly, but with all those components around, you'd have no need.

Tim

Then there is possibility that those thru hole components are just dummy which serve only for aesthetic purpose.

[Howardlong]

Certainly, but with all those components around, you'd have no need.

Tim

Then there is possibility that those thru hole components are just dummy which serve only for aesthetic purpose.

Read the FAQ.

[NiHaoMike]

Interesting that he says it's powered by a 12V DC adapter, then goes on to say that it uses the 60Hz to time it.

[Richard Crowley]

Wow, that really is a work of art. Or at least to people who understand electronics.
Especially impressive that it is completely implemented in discrete "RTL" (Resistor-Transistor Logic).
Hope he got a good deal on all those diodes and transistors.
Very clever using reed relays as the adjustment switches.

[Tinkerer]

Wow, now that is impressive. The amount of patience needed to put that together is something.
I do have to wonder how he kept track of what part went where though. Although, it would seem that not many parts are overlapping. So I suppose you could lay that circuit out on computer and print out a large full scale page that would have exactly where everything goes. You then assemble said circuit over top of the page. Heck, I wonder if he even assembled it in layers. I would be willing to bet that the planning took far more time than the actual assembly.

[rob77]

amazing    really a piece of Art !

Hope he got a good deal on all those diodes and transistors.

you can easily source all those parts under 30-40 Euro.

[Yansi]

How's that possible, there is almost equal number of resistors and transistors?   

[SeanB]

Have a look at the other designs where he used LED's instead of regular diodes, so you can see the logic operating.

[T3sl4co1l]

How's that possible, there is almost equal number of resistors and transistors?   

DTL doesn't need very many resistors.  Indeed, it need not be any commercial logic family at all; it can be wired however the hell he wants.

Tim

[Yansi]

Then I have maybe another hell, I have no idea, how his hell works. Because I think DTL logic gate requires for sure more than 1 resistor, maybe at least 3 or 4 per simple gate? 

http://en.wikipedia.org/wiki/Diode–transistor_logic

[SeanB]

DTL requires one resistor per transistor, nothing more, as the collector pull up. the rest is diodes to pull down the base of the next transistor.  You need an extra resistor for an inverter and not much more. That is why the first IC's and digital computers like the LVDC used DTL, as there were fewer components per gate. Slower, has poor noise immunity but still does the job. The extra resistors in the Wiki article are there to speed up the logic and improve the noise immunity so that the devices switch fast and cleanly. If you are running at 120Hz you can tolerate a lot of rise time, provided you do not use any edge triggered logic in the design or latches that are edge triggered. RS and Eccles Jordan bistables work fine, and were common in this family.

[Yansi]

That seems bullshit. How can you pull the base down with an Si diode plus the drop between CE? That's what are the other resistors for. 


Or wait a moment - maybe I got it... It is possible...

[SeanB]

True, but with low gain transistors and leaky diodes it will work at low frequency, as DTL is terrible as to logic levels. Slap a diode or two in series with the base to increase forward voltage drop and it will operate. Not elegant, but there were some old designs that relied on low gain in the transistors, and as they were so expensive the designers used a lot of diodes instead. You might need to tweak resistor values depending on location and transistor gain, but those were done. remember this is slow, very poorly defined logic, more analogue than digital.

[German_EE]

I have been working in electronics since the late 1970's yet once in a while I still come across something that amazes me, this is one of those times.

Thank you.

[TMM]

Interesting that he says it's powered by a 12V DC adapter, then goes on to say that it uses the 60Hz to time it.

Certainly possible with an unregulated DC power adapter.

[fcb]

If he's gone to that much effort, why wouldn't he add a third wire from the PSU with the 60Hz clock on it.

[lapm]

Wish i was rich.. Would buy one. I am too damn lazy to build one myself...

Seriously that's one beautiful piece of digital clock.. 

[rob77]

Wish i was rich.. Would buy one. I am too damn lazy to build one myself...

Seriously that's one beautiful piece of digital clock.. 

probably you could find someone to build it for you for a price you can afford the effort is the biggest contributor - the parts are approx 40Euro + 20-30Euro for the solder and wires and another 30Euro the glass + frame... so let's say 100Euro in material + the effort to build it.

[albert22]

Simpler but hilarious
http://leviuqse.blogspot.com.ar/2008/09/electical-engineers-fantasy-sex.html