In the circuit below, V1 is producing a 0v to 5V square wave. R1 represents your solenoid. You can see it produces a brief 5V pulse across R1 in opposite direections for each transition of the input.

 

Here is an analog clock - LED hands, with 100% analog circuitry - ramp and staircase generators, analog comparators, etc.

ak

 

Hello,

How about a analog meter clock:
https://spectrum.ieee.org/geek-life/hands-on/build-a-retro-timekeeper-that-never-was

Bertus

 

I designed what I call a "RGBinary clock".
As its name implies, it is a a binary display, but by employing RGB LEDs, I have 7 additional states (red, blue, green, cyan, magenta, yellow and white) to convey information.
Thus I use a pair of 4 bit columns, the leftmost displays the hour, the rightmost the minutes. After a few seconds I flip the colors and it now displays month and day.
The three LEDs in the middle column are miniature white LEDs and they pulsate once a second. I have a photocell to dim the LEDs, which are extremely bright, and a speaker which every hour sharp plays the Big Ben theme.

The attached photo does not do justice at how the clock looks like. Unfortunately, the display is heavily multiplexed and a video shows randomly blinking LEDs.
Also as the LEDs themselves are very bright and would completely wash out, I had to take the picture against a heavy backlight, and assign the brightness/ focus setting with the background.
The end result is that in the photo one cannot really appreciate the PWB's look as it is both blurry and dark.

Anyways, here is the clock displaying 2:06 PM.

 

Hello,

How about a analog meter clock:
https://spectrum.ieee.org/geek-life/hands-on/build-a-retro-timekeeper-that-never-was

Bertus

I've got three 270 degree meters that someday I may make into a clock.

 

Here's a more detailed proposal:

​

This design measures 300 x 150 mm, which I considered to be acceptable dimensions for viewing from a distance of at least 5 meters, and makes use of exactly 2,000 brass plated pins

I plan to use 25 mm long, 1.4mm dia pins with 2.8 mm dia heads. Said pin is shown at the left of the image, and if I can make it stick out of the board at least half its length then I'm pretty sure I'll get the desired effect.

 

Hello,

An other weird clock is with a magnetic fluid:
https://www.tuvie.com/rhei-liquid-clock-creates-beautiful-illusion-where-time-always-moves/

More here: https://www.tuvie.com/search/digital+clock+designer

Bertus

Okay, that is F-ing awesome. If this is ferrofluid, I have wanted to play with ferro-fluid, but have been afraid of it getting away- it can be dangerous if not kept carefully contained. This *so* totally rocks.

 

What about a goon clock
Its more mechanics than electronics... but what the heck.

 

Nixie tubes are always cool and another clock I liked were the ones that displayed time in binary. A Google of binary clock brings up several ideas and kits. Before Nixie tubes HP made a frequency counter (The Model 524) before the Nixie 5245L. The display was strings of NE2 lamps 0 through 9. That may make for a cool clock display.

Ron

 

I want my 2 minutes and 33 seconds back. It happens to be 8:04 as I type this.

 

Everyone here keeps approaching the problem of displaying the time from inside the box.

 

Here's a more detailed proposal:

View attachment 232820​

This design measures 300 x 150 mm, which I considered to be acceptable dimensions for viewing from a distance of at least 5 meters, and makes use of exactly 2,000 brass plated pins

I plan to use 25 mm long, 1.4mm dia pins with 2.8 mm dia heads. Said pin is shown at the left of the image, and if I can make it stick out of the board at least half its length then I'm pretty sure I'll get the desired effect.

This design is proving to be a real challenge... my plan is to dip and join the pins at their tips, behind the board, into a single block of resin. But these blocks have to be somehow separated by walls when the resin is poured, and there's very little space between the pins to accomplish that comfortably... maybe if I 3D print said walls/containers?

 

If the pins are evenly and repeatably spaced ...

3-D print, CNC machine, or CNC drill a block with pockets for each pin, maybe 1 or 2 pin diameters in depth, and just barely larger in diameter than the pin diameter. Put a small bit of resin or adhesive in the bottom of each pocket, and press the block onto a group of pins. Now you have a free-moving, non adhesive block with the pins attached, and you control the outside dimensions of the block (so adjacent block areas do not rub together) either directly in the 3-D print or as a post-machining process. No mold forms.

ak

 

If the pins are evenly and repeatably spaced ...

3-D print, CNC machine, or CNC drill a block with pockets for each pin, maybe 1 or 2 pin diameters in depth, and just barely larger in diameter than the pin diameter. Put a small bit of resin or adhesive in the bottom of each pocket, and press the block onto a group of pins. Now you have a free-moving, non adhesive block with the pins attached, and you control the outside dimensions of the block (so adjacent block areas do not rub together) either directly in the 3-D print or as a post-machining process. No mold forms.

ak

That, my friend, is an excellent idea... I do own a good and precise CNC mill that could do the trick. In fact, I'm going to have it drill the board's 2,000 holes. So having it drill and cut solid back supports for each segment should be a piece of cake. Making and assembling the rest of the background with the same technique is going to be far more laborious, but it's feasible nevertheless.

I plan to dip the nail's tips in muriatic acid (and then rinse them with isopropyl alcohol) to etch their surfaces a little and that way improve the glue's adhesion. I also plan to use acrylic for machining the back supports. And the drilling operation should leave an inner surface at the holes rough enough for the glue to make a good grasp.

Question, what do you think would be the best glue/adhesive/resin to use for this application? That is, to glue metal (in this case, brass-plated steel) to acrylic? ... I'm thinking it should be low viscosity and slow curing...

 

There is also the plotclock.

 

There is also the plotclock.

That is hilarious - ! Someone with waaaaaaay too much spare time.

ak

 

@cmartinez any progress on this project? I was eager to see what you'd make.

 

A while back a teacher wanted to have a class project with an electronic clock that did not use any IC devices. The challenge was how to divide a high frequency time base without a huge number of FFs. The solution was stairstep dividers. They predate flipflops and can divide by any rational number without decoding. Dividing by ten and six for minutes and seconds, and then by 12 or 24 for the hours wouold be a reasonable way to go.And the display could be neons or LEDs or???

 

@cmartinez any progress on this project? I was eager to see what you'd make.

Sorry, no progress so far. I'm up to my neck with work right now and haven't made the time to follow this project through ... but I will, eventually ... *sigh* , I've been working practically seven days a week these past few months and I'm feeling burned out ... I need a vacation, or something....

But yes, this project is definitely almost at the top of my bucket list. The design that I plan to build is this one. The challenge is maybe going to be making it as silent as possible

 

(red, blue, green, cyan, magenta, yellow and white) to convey information.

That'd be the death of me. Partial color blindness.

Everyone here keeps approaching the problem of displaying the time from inside the box.

Not a job I'd want. But the clock would be more interesting if the person inside is female, wearing a bikini (from a man's perspective). Even though she'd be obscured, there would be a lot of imagination going on.