Another watch on gas discharge indicators

Over the past couple of months, several designs of watches like NIXIE CLOCK have been presented on the hub A characteristic feature of which is the output of time for gas discharge indicators such as IN12, IN18, IN17 and the like. On the Internet, I have seen many designs of such watches. Something is in them, some kind of soft and warm energy comes from them. I also fired up to do something like that. But not only just a watch, so that they not only show the time, but also delight the eye.

I would like to share my thoughts not only in the circuitry of the watch, but also the ideas that came to mind during the development of the watch design. It seems to me that appearance plays an important role. A thing should delight, create positive emotions, make life a little more colorful.
I offer my design to the court of readers. I accept criticism positively.
Here are the actual watches:

A little about the functionality. They include:
  • date indication (year, month, day);
  • time indication (hours, minutes, seconds);
  • indication of days of the week;
  • alarm clock;
  • correction mode indication;
  • indication "Alarm set."

Only the time and date are set, and an alarm is set. When setting the date, the day of the week is automatically determined. The number of days in months and a leap year are taken into account.

Power is supplied from a switching power supply 12 V. 0.3 A. Small and light. Like this:

The idea to power a device from a 12 V source is caused by two reasons:
  1. Eliminated network bulky transformer
  2. For security.

Not only that, in the circuit there is an anode 180 V (under which, when setting up, I repeatedly fell, it is not enough pleasant). I did not want to delve into the board, where there is also 220 V !!!

In the circuit itself, a DC-DC Step-Down converter was implemented to power the controller, and a Step-Up converter was used to power the anodes. Both converters used MC34063. In my opinion, these are wonderful microcircuits, although they have been manufactured for a very long time.
The circuits of these converters are not original and were taken from the datasheet for these microcircuits.

And here, in fact, is the clock diagram:
image
Assembled like this:


Some of you may reproach me: “Why he did not make a dynamic indication. This would significantly reduce the number of chips. ” And they will probably be right.
The reason is pretty banal. Laziness mother. The fact is that indicators were made much earlier. This is a board with two IN12 and two K155ID1. Under IN12 I did not find the socket, I had to solder it. And it was too lazy to solder. And there was no shortage of ID1 and IR22. And to be honest, in the manufacture of these watches the emphasis was not on circuit design.
To indicate the time, IN12 was used, to indicate the days of the week I used "neonki", which were torn from ancient tube TVs. They stood there in the program selection blocks, if I am not mistaken, they were ANN-1.
In case of power failure, an emergency source is provided in the watch. The indicators go out, but the clock continues to work.

Now about the alarm. I wanted to breathe a little life into the clock.
In old Soviet telephones of the last century, with disk dialers, metal cup-bells were used for a call. So, in some models these cups were made of a special alloy. They are yellow in color, similar to bronze. The sound is clear, transparent, “crystal”. And I decided to use these very bells for the alarm. In my opinion, it turned out pretty well.

The bell-striking device had to be made by itself. For this, I used a coil from the relay. The relay at the right time attracts the tongue (pictured below) and throws the hammer. The sonority of the cups can be adjusted by turning it around its axis (the axis of the bell mount is not in the center).

The case was made of plywood 10 mm thick and covered with mahogany veneer.
I want to share the idea of ​​inscribing metal plates. I think that this method can be useful to anyone who is engaged in the manufacture of various "homemade products", both amateur and professional. And not necessarily electronic devices.
And the method is simple. I applied a film photoresist. The technology is the same as in the manufacture of printed circuit boards. I will not describe it, there is a lot of information on the Internet on the Internet, you can find it without difficulty. I do not pretend to be authorship, I think it was not me alone who thought of it.

Back cover:

Front view:

These are the nameplates: The


heart of the watch is the Atmel ATMega32 microcontroller. It is clocked by 4MHz quartz. To clock the clock logic, I used 32.768 kHz clock quartz.
The program did not cause much difficulty.
First of all, I implemented the logic of the clock and calendar. Everything is simple here - I count second impulses. I counted 60 - increased the minute and so on. The number of days in months is known, except February, it depends on the year. I determine the leap year by the formula . I also consider the day of the week according to the formula . Along the way, I’m checking the alarm, otherwise I have to sound the bells. And at once I deduce everything on indicators.
All these operations take up little CPU time, so I’m polling buttons for the rest of the time. There are four of them: UP, DOWN, MODE / ENTER, ALARM.
Use the UP and DOWN buttons to increase or decrease the parameter to be adjusted in setup mode. In normal mode, any of them switches the display to date display (4 seconds).
MODE / ENTER - enters the clock into the time and date settings mode. All changes are applied by the same button.
ALARM - sets the alarm, or turns it off if the alarm rings or you just want to turn it off in advance.
A little protection from the "fool" - can not be installed manually, for example, April 31, June 31, February 29 in a non-leap year, etc. But then he cheated a little - the year can be set only from 2000 to 2099 (there are two familiarities on the indicators), so, it seemed, should be enough. Although the year is considered completely in the code and, theoretically, the clock can count to 2 ^ 16 years, it is not difficult to change.
Separately realized the ringing of bells. I made a kind of editor, that is, the melody itself is recorded in the form of durations (hit, release) for each cup. What for? I do not know. Anyway, he calls all the “tunes” like “Dean-Don” :).

I wrote everything in Atmel Studio 6 in assembler.
The code is available on github . The project is working, compiled.

A small video demonstration (not a director):


UPD: asked for a good quality circuit diagram. dl.dropbox.com/u/66229373/clock.jpg

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