DIY clock with IN-14 lamps
I have long wanted to post an article on making DIY watches with IN-14 lamps, or as they say, a watch in the steam punk style.
I will try to present only the most important things step by step and focusing on key points. The clock indication is clearly visible both day and night, and they themselves look very nice, especially in a good wooden case. Anyway, let's get started.
Device diagram (to enlarge - like everywhere else - click):
This watch has IN-14 gas-discharge indicators. They can also be replaced with IN-8, naturally taking into account the differences in pinout. The indicator pins are numbered clockwise from the pin side. For IN-14, pin 1 is indicated by an arrow.
Watch characteristics:
| Supply voltage, V | 12 |
| Current consumption, no more, mA | 200 |
| Typical current consumption, mA | 150 |
| Type indicators | IN-14 |
| Time display format | Hours\Minutes\Seconds |
| Date display format | Day month Year |
| Number of control buttons | 2 |
| Alarm clocks | 2 |
| Discreteness of setting the alarm time, min | 5 |
| Software gradations for adjusting the brightness of indicators | 5 |
Atmega8 microcontroller in TQFP package. The clock does not work with a controller in a DIP package. Real time clock DS1307. The sound emitter has a built-in generator and a supply voltage of 5V. All necessary project files - board, controller firmware - download
Fuses:
More photos:
The boost voltage converter is based on the MC34063A chip. (MC33063A). In terms of prevalence and cost, it is somewhat inferior to the 555 timer, on which such a converter can be built, but it is cheaper and more accessible than the MAX1771.
Non-polar capacitors are ceramics, polar capacitors are Low ESR electrolytes. If Low ESR is not available, place ceramics or film parallel to the electrolyte. The choke in the boost converter is 220 µH for a current of 1.2A. The minimum rated inductor value is 180 µH, the minimum rated inductor current is 800 mA.
Two K155ID1 housings operate as decoders. The anode voltage switch uses a TLP627 optocoupler. The values of R23 and R24 must be selected independently, depending on the degree of luminescence. Without them, the currents through the points exceed the permissible level. When installing, we do not push the indicators all the way in. Since the housings of all indicators are individual, they will need to be aligned with respect to the printed circuit board and with each other.
Clock control on IN-14:
The transition from mode to mode occurs along the ring with the button "MODE".
The value is set using the button "SET".
The adjusted value either blinks or is brighter.
Setting the seconds value involves resetting them to zero.
Setting the value of minutes, hours, day, month, year consists of adding 1 to the current value along the ring to the maximum value, after which the value is reset.
The alarm clock minutes are set from zero in increments of 5 minutes (00-05-10-15:55).
If the watch is not in the main mode and you stop pressing the buttons, then after a few minutes the watch returns to the main mode.
Cancel the alarm sound using the button "SET".
In this case, the next time the alarm time is reached, the alarm will be activated. Commas in tens and units of seconds indicate the activity of alarms 1 and 2, respectively. The operating modes of the clock are shown in the table. Red symbolizes brightly lit discharges, orange indicates dimly illuminated discharges, and black indicates extinguished discharges. For time: H - hours, M - minutes, S - seconds. For the date: D - day of the month (day), M - month, G - year. To set an alarm: 1 - alarm 1, 2 - alarm 2, X - no value (switched off).
First switching on, controller programming and setup. First check that the clock circuit is installed correctly. Then check the power circuits for short circuits. If not found, try applying power to the input from a 12V source. If smoke does not come out, check the voltage of the power supply circuit D5V0. Using trimmer resistor RP1, set the output of the boost converter to a voltage of 200V (for the indicated ratings). Wait a few minutes. The circuit elements should not heat up noticeably. This is especially true for the inductor of a high-voltage converter. Its overheating indicates an incorrectly selected rating or a design with too low operating current. This throttle must be replaced with a more suitable one.
From now on, you will need a VT1 battery type CR2032. As a last resort, short-circuit the contacts of the battery socket, but then you will set the time and date every time the power supply is cut off.
Program sequentially Flash And EEPROM microcontroller using the supplied firmware. This operation must be done in the specified sequence. The indicators will show " 21-15-00 ". The seconds will tick by. If you still haven't connected BT1, then instead of the time and date you will see something like " 05-05-05 ".
Set the time, date, and alarms in accordance with the table describing operating modes. When you get to the brightness setting, programmatically turn on the minimum brightness of the indicators. Adjust the boost converter so that each of the indicators glows at minimum brightness, but fully. That is, it should not be the case that part of the indicator number is lit and part is not. Then programmatically set the maximum brightness and check the glow of the indicator numbers.
The indicators should not glow too brightly, and there should be no “volumetric” glow. Brightness correction is again done using RP1. After this, check the glow again at minimum brightness and so on until acceptable results are obtained. If acceptable results are not obtained, try to select the values of the anode resistors and repeat the above steps.
Such watches will compare favorably with ordinary Chinese ones, based on LEDs, which, by the way, cost a lot of money.
Video of work in our VK group
Tube clock in the style of the well-known game "Fallout". Sometimes you wonder what some people are capable of. Fantasy, coupled with straight arms and a clear head, works wonders! Well, it’s time to start talking about a real work of art :)
In his product, the author uses only output components, tracks on a printed circuit board with a width of at least 1 millimeter, which, in turn, is very convenient for beginners and inexperienced radio amateurs. The entire circuit is on a single board, the component values and the components themselves are indicated. Since the author of the product could not decide on the color of the LED backlight of the lamps, it was decided to use the PIC12F765 controller to adjust the RGB LEDs. Incandescent lamps are also used to provide a cozy glow to illuminate the instrument panel and ammeter. Some parts and the case itself were taken from the old (1953 release) Soviet TT-1 multimeter. I would like to use only original parts from this multimeter, so it was decided to keep the ammeter with the instrument panel, and plug gas-discharge indicators into the place under the cover. But the first problem arose - there was too little space under the lid for the indicators, so the lid simply could not close with the indicators inside. But the author found a way out - to slightly recess the panel into the housing and make the ammeter a little smaller in volume.
The hefty ferrite magnet was replaced by two miniature neodymium ones, in general, the author removed all unnecessary parts to make room for the filling, while maintaining the functionality of the TT-1. The ammeter is planned to be connected to the MK leg, which regulates the supply of current to the anode of the sixth lamp, which is responsible for displaying the seconds, so the hand will move in time with the changing seconds on the lamp.
The author used a 0.8A toroidal transformer to convert 220 Volts to 12 Volts. It's a pity that the transformer couldn't be placed outside the case, because it fits the design of Fallout so much.
The board is made according to LUT technology standards. Designed according to the body dimensions.
The author pays special attention to the DS1307 clock chip. In the photo it is in a DIP package, but the wiring for this microcircuit is made like for SMD, so the legs are turned in the other direction, and the microcircuit itself is stuck belly up. Instead of K155ID1, KM155ID1 was used; the author claims that only with the replaced part was it possible to avoid glare. Placement of elements on the board:
The author has assembled a simple LPT programmer for programming K ATMega8 (firmware for ATMega8, all boards, firmware for PIC at the end of the article)
PIC programmer:
IN-14 gas-discharge indicators have long soft leads for soldering, but due to their limited resource, it was decided to make them easily replaceable. Therefore, the author used collets from the DIP chip panel, and shortened the IN-14 legs to the depth of the collets. The holes in the center of the sockets are made specifically for LEDs, which are located under the lamps on a separate board. The LEDs are connected in parallel, one resistor serves to limit the current per color.
This is what gas-discharge indicators look like, mounted in an aluminum corner.
The fastening, which is an aluminum corner, is etched in ferric chloride, because of this it has aged very visually, which gives it more ambience. As it turned out, aluminum reacts very violently with ferric chloride: a very large amount of chlorine and heat are released. Of course, the solution after such tests is no longer suitable for use.
Other parts were made using similar technology (LUT) (the fallout-boy logo, Vault-Tec, as well as the number HB-30YR). The device was intended as a gift to a friend for his 30th birthday. For those who don't understand, the number HB-30YR stands for Happy Birthday - 30 YeaRs :)
The author used a nichrome spiral with F-type antenna connectors at the ends to lay the wiring between the body and the cover. Fortunately, there were 6 holes on the panel in the right place, and they served as connectors for the wire leads.
Hours before full assembly. The wires, of course, are not routed neatly, but this will not affect the functionality in any way.
Power cable. Some old military connectors. The author made the adapter for the plug himself.
Power cable connector, as well as a fuse on the surface of the case at the bottom.
View of the device in a closed state. Indeed, it is not much different from the TT-1.
General view of the device.
Limiter to prevent the lid from tipping back.
The watch looks best in the dark.
I welcome users again and keep my promise!
Today I’m starting to post a detailed photo report on the manufacture of watches using gas discharge indicators (GDI). The IN-14 is taken as the basis.
All manipulations in this and the following posts are accessible to a person without experience, you just need to have a little skill. I will divide the work into several parts, each of which will be described in detail by me and posted online.
Let's proceed to the first stage - etching the boards. After researching the literature, I found several technologies:
- . To operate, you need three components: a laser printer, ferric chloride and an iron. The method is the simplest and cheapest. It has only one drawback - it is difficult to transfer very thin tracks.
- Photo resist. To work, you need the following materials: photo-resist, printer film, soda ash and a UV lamp. The method allows you to etch boards at home. The downside is that it is not cheap.
- Reactive ion etching (RIE). The work requires chemically active plasma, so it cannot be done at home.
Most often, anodic etching is used. The anodic etching process involves the electrolytic dissolution of the metal and the mechanical removal of oxides by the released oxygen.
It is quite understandable that I chose the LUT method for etching the boards. The list of necessary equipment and materials should look something like this:
- Ferric chloride. It is sold in radio products at a price of 100-150 rubles per jar.
- Foil fiberglass. Can be found in radio stores, radio flea markets or factories.
- Capacity. A regular food container will do.
- Iron.
- Glossy paper. Self-adhesive paper or a plain page from a glossy magazine will do.
- Laser printer.
IMPORTANT! The print version must be a mirror image, since when the image is transferred from paper to copper, it will be reflected back.
You need to mark and cut a piece of PCB for the board. This is done with a hacksaw, a breadboard knife or, as in my case, a drill.
After that, I cut out a sketch of the future board from paper and attached the design to the textolite (on the foil side). The paper is taken with a reserve in order to wrap the PCB. We secure the sheet on the reverse side with tape to secure it.
From the side of the drawing, we draw across the future board with an iron several times through sheet A4. It will take at least 2 minutes of intense ironing to transfer the toner to copper.
We place the workpiece under a stream of cold water and easily remove the paper layer (the wet paper should come off freely on its own). If the surface heating was not sufficient, small pieces of toner may come off. We finish them with cheap nail polish. As a result, the blank for the board should look like this:
In a prepared container, prepare a solution of ferric chloride and water. It is better to use hot water for these purposes, this will increase the reaction rate. It is better to avoid boiling water, as high temperatures will deform the board. The finished liquid should have the color of medium-brewed tea. Place the board in the solution and wait for the excess foil to completely dissolve.
If you occasionally stir the solution in the container, the reaction rate will also increase. Ferric chloride is not dangerous for the skin of your hands, but your fingers may become stained.
To make the process more clear, I partially placed the board in the solution. What changes should happen can be seen in the photo:
Excess copper dissolves in the composition after about 40 minutes. After which the etching process can be considered complete. All that remains is to make a few holes. We mark with an awl and drill small holes with a drill. The tool must operate at high speeds so that the drill does not move out. The result should look something like this:
The second stage of manufacturing watches using GRI is soldering the components. I will talk about this in my next post.
Download:
- Program ).
- Post about soldering components - ;
- Post about microcontroller firmware – ;
- Post about making the case - .
Convenient fringe cutter for transformers. Soldering iron heating regulator with power indicator
Good day to all dear Muskovites. I want to tell you about an interesting radio design for those who know which end the soldering iron heats up from. In short: the set brought positive emotions; I recommend it to those interested in this topic.
Details below (caution, lots of photos).
I'll start from afar.
I myself do not consider myself a true radio amateur. But I’m no stranger to a soldering iron and sometimes I want to design/solder something, and I try to carry out minor repairs to the electronics around me first on my own (without causing irreparable harm to the experimental device), and in case of failure I turn to professionals.
One day, under the influence, I bought and assembled the same watch. The design itself is simple and assembly did not pose any difficulties. I put the clock in my son’s room and calmed down for a while.
Then, after reading, I wanted to try to assemble them, at the same time practicing soldering SMD components. In principle, here everything worked right away, only the beeper was silent, I bought it offline, replaced it and that’s it. I gave the watch to a friend.
But I wanted something else, more interesting and more complex.
One day, while poking around in my father’s garage, I came across the remains of some kind of electronic device from the Soviet era. Actually, the remains are a kind of circuit board structure containing 9 IN-14 gas-discharge indicator lamps.
Then the idea came to me - to assemble a watch using these indicators. Moreover, I have been seeing similar clocks, once collected by my father, in my parents’ apartment for 30 years, if not more. I carefully soldered the board and became the owner of 9 lamps manufactured in early 1974. The desire to put these rarities into practice intensified.
Through meticulous questioning from Yandex, I went to the site, which turned out to be simply a storehouse of wisdom on the topic of creating such watches. After looking at several diagrams of such designs, I realized that I wanted a clock controlled by a microcontroller, with a real-time chip (RTC). And if, repeating one of the watch designs, I would be able to program the controller and solder the board, then the question of making the printed circuit board itself puzzled me (I’m not a true radio amateur yet).
In general, it was decided to start by buying a designer of such watches.
this constructor is being discussed, in fact this is the topic of the author (his nickname mss_ja) of this set, where he himself helps with the assembly and launch of his sets. He also has, where there are many photos of finished products. There you can buy not only kits for self-assembly, but also ready-made watches. Look, get inspired.
Some doubts were raised by the issue of delivery, because the respected author lives in Ukraine. But it turned out that the war was just a war, and the post office was working as scheduled. Actually 14 days and I have the parcel.
delivery
Here's a little box.
So what did I buy? And everything is visible in the photo.
The set includes:
printed circuit board (on which the author kindly soldered the controller so that I wouldn’t have to suffer, his legs are too small). The program was already hardcoded into the controller;
Package with design components. Large ones are clearly visible - microcircuits, electrolytic capacitors, tweeters, etc., according to the diagram and description. Under this bag is another one, with small SMD components - resistors, capacitors, transistors. All SMD elements are glued onto paper with denominations written on them, very convenient. The photo was taken during the assembly process.
The blank for the watch case is not included in the set by default, but after contacting the author, I bought it too. This is reinsurance against your possible crookedness, because... I have practically nothing to do with wood and all my experience in processing it comes down to periodically sawing firewood for barbecue at the dacha. But I wanted a classic look - like “glass made of wood,” as they say on the radio cat forum.
So let's get started.
That's all we need to start assembling. And to successfully complete it, we still need a head and hands.
But no, I didn’t show everything. Without this thing, you don't even have to start. These smd elements are so small...
I started the assembly strictly according to the author's recommendation - with power converters. And there are two of them in this design. 12V->3.3V for powering electronics and 12V->180V for operating the indicators themselves. You need to assemble such things very carefully, first making sure that you are soldering exactly what you are soldering, exactly there, and without mixing up the polarity of the components. The printed circuit board itself is of excellent quality, industrial production, soldering is a pleasure.
The power converters were assembled and tested for the appropriate voltages, and then I began installing the remaining components.
When I started the building process, I made a promise to myself to photograph every step of the way. But, carried away by this action, I remembered my desire to write a review only when the board was almost ready. Therefore, the following photo was taken when I started testing the indicators by simply plugging them into the board and applying power. 
Of the nine IN-14 lamps I obtained, one turned out to be completely non-functional, but the rest were in excellent condition, all the numbers and commas glowed perfectly. 6 lamps went to the clock, and two - to the reserve. 
I deliberately did not remove the manufacturing date from the lamps.
back side 
Here you can see a clumsily installed photoresistor; I was looking for its best position.
So, having made sure that the circuit worked and the clock went, I put it aside. And he took up the body. The lower part is made from a piece of fiberglass from which I tore off the foil. And the wooden blank was carefully sanded with fine sandpaper to a state of “pleasant smoothness.” Well, then it was coated with varnish and stain in several layers with intermediate drying and polishing with fine sandpaper. 
It didn't turn out perfect, but in my opinion it turned out good. Especially considering my lack of experience working with wood. 
On the back you can see holes for connecting power and a temperature sensor, which I don’t have yet (yes, it can also show the temperature...). 
Here are some shots of the interior. It’s impossible to take a good photograph; the photos don’t convey all the “blindness”. 
This is a date display. 
Lamp illumination. Well, where would we be without her? It can be turned off; if you don’t like it, don’t turn it on.
Remarkable running accuracy. I've been watching the clock for a week, it's moving second by second. Of course, a week is not a long time, but the trend is obvious.
In conclusion, I will give the characteristics of the watch, which I copied and pasted directly from the website of the author of the project:
Watch features:
Clock, format: 12 / 24
Date, format: HH.MM.YY / HH.MM.D
Alarm clock customizable by day.
Temperature measurement.
Hourly signal (can be switched off).
Automatic brightness adjustment depending on lighting.
High precision (DS3231).
Display effects.
---no effects.
---smooth decay.
---scroll.
---number overlay.
Effects of separation lamps.
---off.
---flashing 1 hertz.
---smooth decay.
---blinking 2 hertz.
---included.
Date display effects.
---no effects.
---Shift.
---Scroll shift.
---Scrolling.
---Replacement of numbers.
Pendulum effect.
---simple.
---difficult.
Backlights
---Blue
---Possibility of illumination of the case. (Optional)
So, let me summarize. I really liked the watch. Assembling a watch from a set is not difficult for a person of average handicap. After spending a few days on a very interesting activity, we get a beautiful and useful device, even with a touch of exclusivity.
Of course, by today's standards the price is not very humane. But firstly, this is a hobby, you don’t mind spending money on it. And secondly, it’s not the author’s fault that the ruble is worth nothing now.
Recently, watches with gas-discharge indicators have become very popular. These clocks give many people the warm light of their lamps, create comfort in the home and an indescribable feeling of breathing the past. Let's figure out in this article what these watches are made of and how they work. I’ll say right away that this is a review article, so many unclear places will be discussed in more detail in the following articles.
The clock can be divided into the following functional blocks:
1)High voltage block
2)Display block
3)Time counter
4)Backlight unit
Let's look at each of them in more detail.
High voltage block
In order for the number inside the lamp to light up, we need to apply voltage to it. The peculiarity of gas-discharge lamps is that the voltage required is quite high, about 200 Volts DC voltage. The current for the lamp, on the contrary, should be very small.
Where can you get this kind of tension? The first thing that comes to mind is a power outlet. Yes, you can use rectified mains voltage. The diagram will look like this:
The disadvantages of this scheme are obvious. This is the absence of galvanic isolation; there is no safety or protection of the circuit at all. Thus, it is better to check the lamps for functionality, while being extremely careful.
In watches, the designers took a different route, increasing the safe voltage to the required level using a DC-DC converter. To put it very briefly, such a converter works on the principle of a swing. We can, by applying a slight hand force to the swing, give it a fairly large acceleration, right? The DC-DC converter is the same: we pump low voltage to high voltage.
I will give one of the most common converter circuits (click to enlarge, the circuit will open in a new window)
A circuit with a so-called semi-driver field-effect transistor. Provides enough power to power six lamps without getting as hot as an iron.
Display block
The next functional block is indication. It consists of lamps in which the cathodes are connected in pairs, and the anodes are connected to optocouplers or transistor switches. Typically, watches use dynamic display in order to save space on the printed circuit board, miniaturize the circuit, and simplify board layout.
Time counter
The next block is a time counter. The easiest way to do this is on a specialized DS1307 chip
It provides excellent time accuracy. Thanks to this chip, the watch maintains the correct time and date, despite a long power outage. The manufacturer promises up to 10 years (!) of battery life from a CR2032 round battery.
Here is a typical connection diagram for the DS1307 chip:
There are also similar microcircuits that are produced by many companies producing radio components. These chips can provide particularly accurate timekeeping, but they will be more expensive. It seems to me that their use in household watches is not advisable.
Backlight block
The backlight unit is the simplest part of the watch. It is installed at will. These are just LEDs under each lamp that provide background lighting. These can be single-color LEDs or RGB LEDs. In the latter case, you can choose any color of the backlight or even make it change smoothly. In the case of RGB, an appropriate controller is required. Most often, this is done by the same microcontroller that counts time, but to simplify programming, you can install an additional one.
Well, now a few photos of a rather complex clock project. It uses two PIC16F628 microcontrollers to control the time and lamps and one PIC12F692 controller to control the RGB backlight.
Turquoise backlight color:
And now green:
Pink color:
All these colors can be adjusted with one button. You can choose any one. RGB diodes are capable of producing any color.
And this is a piece of a high-voltage converter. Below in the photo is a field-effect transistor, an ultra-fast diode and a storage capacitor of a DC-DC converter
The same converter, bottom view. An SMD choke and an SMD version of the MC34063 chip are used. In the photo, the remaining flux has not yet been washed off.
And this is a simplified four-lamp version of the watch. Also with RGB backlighting
Well, this is a classic clock structure based on Sunny Clock gas-discharge lamps, static backlighting and a slightly unusual way of controlling lamps using a pair of K155ID1 decoders
In the next article we will talk in more detail about DC-DC converters and high voltage production. We will also analyze in detail the process of assembling such a converter and run a lamp from it.
Thank you everyone, El Kotto was with you. Join the group in contact