I'm at the station, waiting for a train,
and here comes some train,
but it's not my train,
because I don't have a train.
I know that this is not the train I've been waiting for.
It's enough to check what time is on the clock and what time is on the timetable to see that it's not the one.
And that's why the clock on the station is so important.
Thanks to it, I know if my train has already departed or not yet.
Because it's known that trains always arrive and depart according to the time indicated on the timetable.
Or at least that's how it should be in some normal world.
I don't understand how it is that in the 21st century we still deal with trains that don't run on time.
It could be so beautiful.
Just imagine...
And here I'm presenting my utopian vision of the world.
Here we have a train station with some rail vehicles.
But they need some power.
And so I connect these cables here,
I connect a power supply,
And now the rails are electrified, need to be careful.
And here I have a train which doesn't care about the timetable at all,
instead when I put it on the rails, it would like to start going immediately,
it doesn't wait at all.
But now I'm connecting a clock here between the tracks and the power supply,
and now the clock decides when the train can go an and when not.
Now I just have to set the right time and then just wait for the departure
knowing that the train will start exactly at the scheduled time.
And that's it!
Such a simple solution, and how effective.
But now we have to return to the real world, where the clock at the station is still relevant after all
because it allows to determine if it's already the time when the train at least should arrive according to plan.
But I thought that when I am at home, I would also like to know what time it is at the station,
to know when to leave my home to catch the train on time.
I have a clock like this,
but it's not the same. I would like to have one that will show me what time it is at the station, and not at home.
I bought a clock and now I have a clock.
And now the challenge number 1: How do I make it work?
There is some mechanism here,
here we have some wires,
I can turn this thing here and the time is changed,
and what now?
Time for a digression:
Have you ever wondered how it is that all the clocks on the station show exactly the same time
and change at exactly the same moment?
This is very important.
If each platform was in a different time zone,
a situation could happen in which on one platform a train is still standing but on the other platform the same train has already left long ago.
That would be total chaos.
It might seem like a lot of work to set all the clocks perfectly in sync,
but actually it's not.
The secret is that there is only one clock at the station,
and what we see are just multiple dials and hands of the same clock.
And when the time comes, an impulse goes to each one, to switch to the next minute,
and that's exactly what I need here.
Here I have these two coils
and if I apply some voltage here, it will create a magnetic field which will rotate this element here forward.
So now I take this power supply,
plug it in,
here,
And this turned indeed.
And now I disconnect this and connect again.
And no change. Almost standing in place, doesn't want to move forward at all.
For the next step, I have to reverse the polarity.
And it works, but it's inconvenient.
Luckily, I can do it without pulling out the cables.
Now I just have to make sure to switch it at the right moment and the clock is ready.
It would be useful to have some device that would keep the time by itself to switch the minutes.
And here I have this one,
but I don't like it at all.
I mean, it works very well and switches the time when needed,
but it doesn't meet the standards I set for myself a moment ago.
Now I will open it to look inside.
And here I can see that someone has put a lot of effort into this.
There are some kind of things inside, some nice lights,
but that's not what I wanted.
I see that all this is controlled by a quartz resonator circuit.
If I keep it like this, I'll have a clock that's almost like a regular quartz clock that you can find everywhere.
But worse.
By the way, it's worth noticing that a quartz clock actually has a very similar mechanism,
but smaller, and it turns every second, and not minute.
because it has to turn this second hand.
I would like my clock to be better than this.
And I want to keep the aspect of remote control.
And I can have a perfect remote time signal in every electrical outlet.
A nice 50Hz signal repeating endlessly.
Just count how many repetitions there are, and I know how much time has passed.
And that's what I want to use in the device I will build.
I reduce the voltage from the outlet with a transformer to a more safe and practical level.
And I use it to power my device.
I convert the signal from the transformer to a 100Hz square wave
by using two diodes, a voltage divider and a 555 chip.
And I put this signal into a divider circuit which can divide the frequency by any value from 1 to 255.
Here I selected 75,
which gives a pulse repeating every 0.75s.
And this signal I put into a next, very similar divider circuit.
But this time we divide by 80.
This way, pulses with 0.75s length appear exactly every minute.
And here I make one additional small change:
I add a button that, when pressed, removes the wait of 1 minute between the pulses,
which allows me to quickly set the time on the clock.
and these pulses then go to a circuit which reverses the polarity every minute
and turns on relays that alternately apply positive and negative voltage to the clock.
And finally, a chip which resets everything after power ON.
And that's it.
The device is ready.
There is really nothing complicated here.
Everything is very simple,
looks very good,
works very well, ...
All that's left to do is to hang it on the wall,
turn it on
and admire it to the end of the world.
Or until the electricity runs out.
THE END
If you want to see a more detailed and serious description of this device, please visit here: http://bicyclesonthemoon.info/someprojects/zegario
BEWARE OF TRAIN