The simplest lamp clock. Clock on gas-discharge indicators - etching of circuit boards
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. During installation, we do not push the indicators in completely. 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 circuit. 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. IN 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
This article will focus on making original and unusual watches. Their uniqueness lies in the fact that the time is indicated using digital indicator lamps. A huge number of such lamps were once produced, both here and abroad. They were used in many devices, from watches to measuring equipment. But after the advent of LED indicators, the lamps gradually fell out of use. And so, thanks to the development of microprocessor technology, it became possible to create watches with a relatively simple circuit using digital indicator lamps. I think it would not be amiss to say that mainly two types of lamps were used: fluorescent and gas-discharge. The advantages of luminescent indicators include low operating voltage and the presence of several discharges in one lamp (although such examples are also found among gas-discharge indicators, but they are much more difficult to find). But all the advantages of this type lamps have one huge disadvantage - the presence of a phosphor, which burns out over time, and the glow dims or stops. For this reason, used lamps cannot be used.
Gas discharge indicators are free from this drawback, because a gas discharge glows in them. Essentially, this type of lamp is a neon lamp with multiple cathodes. Thanks to this, the service life of gas-discharge indicators is much longer. In addition, both new and used lamps work equally well (and often used ones work better). However, there are some drawbacks; the operating voltage of gas-discharge indicators is more than 100 V. But solving the problem with voltage is much easier than with a burn-out phosphor. On the Internet, such watches are common under the name NIXIE CLOCK.
The indicators themselves look like this:
So, everything seems clear about the design features, now let’s start designing the circuit of our watch. Let's start by designing a high-voltage voltage source. There are two ways here. The first is to use a transformer with a secondary winding of 110-120 V. But such a transformer will either be too bulky, or you will have to wind it yourself, the prospect is so-so. Yes, and voltage regulation is problematic. The second way is to assemble a step up converter. Well, there will be more advantages here: firstly, it takes up little space, secondly, it has short-circuit protection, and thirdly, you can easily adjust the output voltage. In general, there is everything you need to be happy. I chose the second path, because... I had no desire to look for a transformer and winding wire, and I also wanted something miniature. It was decided to assemble the converter on MC34063, because I had experience working with her. The result is this diagram:
It was first collected at breadboard and showed excellent results. Everything started immediately and no configuration was required. When powered by 12V. the output turned out to be 175V. The assembled power supply of the watch looks like this:
A linear stabilizer LM7805 was immediately installed on the board to power the clock electronics and a transformer.
The next stage of development was the design of the lamp switching circuit. In principle, controlling lamps is no different from controlling seven-segment indicators, with the exception of high voltage. Those. It is enough to apply a positive voltage to the anode and connect the corresponding cathode to the negative supply. At this stage, two tasks need to be solved: matching the levels of the MK (5V) and lamps (170V), and switching the cathodes of the lamps (they are the numbers). After some time of thought and experimentation, the following circuit was created to control the anodes of the lamps:
And controlling the cathodes is very easy; for this they came up with a special K155ID1 microcircuit. True, they have long been discontinued, like lamps, but buying them is not a problem. Those. to control the cathodes, you just need to connect them to the corresponding pins of the microcircuit and submit data in binary format to the input. Yes, I almost forgot, it is powered by 5V, well, a very convenient thing. It was decided to make the display dynamic because otherwise, you would have to install K155ID1 on each lamp, and there will be 6 of them. The general scheme turned out like this:
Under each lamp I installed a bright red LED, it’s more beautiful. When assembled, the board looks like this:
We couldn’t find sockets for the lamps, so we had to improvise. As a result, the old connectors, similar to modern COM, were disassembled, the contacts were removed from them, and after some manipulations with wire cutters and a needle file, they were soldered into the board. I didn’t make panels for the IN-17, I did them only for the IN-8.
The hardest part is over, all that remains is to develop a circuit for the “brain” of the watch. For this I chose the Mega8 microcontroller. Well, then everything is quite easy, we just take it and connect everything to it in the way that is convenient for us. As a result, the clock circuit included 3 buttons for control, a DS1307 real-time clock chip, a DS18B20 digital thermometer, and a pair of transistors for controlling the backlight. For convenience, we connect the anode keys to one port, in this case it is port C. When assembled, it looks like this:
There is a small error on the board, but it has been corrected in the attached board files. The connector for flashing the MK is soldered with wires; after flashing the device, it should be unsoldered.
Well, now it would be nice to draw general scheme, said and done, here it is:
And this is what it all looks like assembled:
Now all that remains is to write the firmware for the microcontroller, which is what was done. The functionality turned out to be as follows:
Display time, date and temperature. When you briefly press the MENU button, the display mode changes.
Mode 1 - time only.
Mode 2 - time 2 min. date 10 sec.
Mode 3 - time 2 min. temperature 10 sec.
Mode 4 - time 2 min. date 10 sec. temperature 10 sec.
When held, the time and date settings are activated, and you can navigate through the settings by pressing the MENU button.
The maximum number of DS18B20 sensors is 2. If the temperature is not needed, you can not set them at all; this will not affect the operation of the watch in any way. The sensor is not hot plugged.
Briefly pressing the UP button turns on the date for 2 seconds. When held, the backlight turns on/off.
By briefly pressing the DOWN button, the temperature is turned on for 2 seconds.
From 00:00 to 7:00 the brightness is reduced.
The whole thing works like this:
Firmware sources are included with the project. The code contains comments so it will not be difficult to change the functionality. The program is written in Eclipse, but the code compiles without any changes in AVR Studio. The MK operates from an internal oscillator at a frequency of 8 MHz. Fuses are set like this:
And in hexadecimal like this: HIGH:D9, LOW: D4
Also included are boards with bugs corrected.
This clock operates for a month. No problems were identified in the work. The LM7805 regulator and converter transistor are barely warm. The transformer heats up to 40 degrees, so if you plan to install the watch in a case without ventilation holes, you will have to use a higher power transformer. In my watch it provides a current of around 200mA. The accuracy of the movement is highly dependent on the quartz used at 32.768 KHz. It is not advisable to install quartz purchased in a store. The best results were shown by quartz from motherboards and mobile phones.
In addition to the lamps used in my circuit, you can install any other gas-discharge indicators. To do this, you will have to change the board layout, and for some lamps the voltage of the boost converter and the resistors on the anodes.
Attention: the device contains a high voltage source!!! The current is small, but quite noticeable!!! Therefore, be careful when working with the device!
One of the options for building this project:
List of radioelements
| Designation | Type | Denomination | Quantity | Note | Shop | My notepad |
|---|---|---|---|---|---|---|
| Gas discharge indicator | IN-8 | 4 | To notepad | |||
| Gas discharge indicator | IN-17 | 2 | To notepad | |||
| CPU | MK AVR 8-bit | ATmega8 | 1 | To notepad | ||
| Real Time Clock (RTC) | DS1307 | 1 | To notepad | |||
| Temperature sensor | DS18B20 | 2 | To notepad | |||
| DD1 | Chip | K155ID1 | 1 | To notepad | ||
| IC1 | DC/DC pulse converter | MC34063A | 1 | To notepad | ||
| VR1 | Linear regulator | LM7805 | 1 | To notepad | ||
| VT1-VT6 | Bipolar transistor | MPSA92 | 6 | To notepad | ||
| VT7-VT12 | Bipolar transistor | MPSA42 | 6 | To notepad | ||
| VT13, VT14 | Bipolar transistor | BC847 | 2 | To notepad | ||
| VT15 | Bipolar transistor | KT3102 | 1 | To notepad | ||
| VT16 | Bipolar transistor | KT3107A | 1 | To notepad | ||
| VT17 | MOSFET transistor | IRF840 | 1 | To notepad | ||
| VDS1 | Diode bridge | 1 | To notepad | |||
| VD1 | Rectifier diode | HER106 | 1 | To notepad | ||
| HL1-HL6 | LED | 6 | To notepad | |||
| C1 | 100 µF | 1 | To notepad | |||
| C2, C3-C5, C7, C9, C11 | Capacitor | 0.1 µF | 7 | To notepad | ||
| C6, C8 | Electrolytic capacitor | 1000 µF | 2 | To notepad | ||
| C10 | Capacitor | 510 pF | 1 | To notepad | ||
| C12 | Electrolytic capacitor | 4.7 µF 400V | 1 | To notepad | ||
| R1-R4, R6-R8 | Resistor | 4.7 kOhm | 7 | To notepad | ||
| R5, R9-R14, R27-R32, R42 | Resistor | 10 kOhm | 14 | To notepad | ||
| R15, R17, R19, R21, R23, R25, R45 | Resistor | 1 MOhm | 7 | To notepad | ||
| R16, R18, R20, R22, R24, R26 | Resistor | 13 kOhm | 6 | To notepad | ||
| R33, R34 | Resistor |
This article will focus on making original and unusual watches. Their uniqueness lies in the fact that the time is indicated using digital indicator lamps. Once upon a time, a huge number of such lamps were produced, both here and abroad. They were used in many devices, from watches to measuring equipment. But after the advent of LED indicators, the lamps gradually fell out of use. And so, thanks to the development of microprocessor technology, it became possible to create watches with a relatively simple circuit using digital indicator lamps.
I think it would not be amiss to say that mainly two types of lamps were used: fluorescent and gas-discharge. The advantages of luminescent indicators include low operating voltage and the presence of several discharges in one lamp (although such examples are also found among gas-discharge indicators, but they are much more difficult to find). But all the advantages of this type of lamp are offset by one huge disadvantage - the presence of a phosphor, which burns out over time, and the glow dims or stops. For this reason, used lamps cannot be used.
Gas discharge indicators are free from this drawback, because a gas discharge glows in them. Essentially, this type of lamp is a neon lamp with multiple cathodes. Thanks to this, the service life of gas-discharge indicators is much longer. In addition, both new and used lamps work equally well (and often used ones work better). However, there are some drawbacks - the operating voltage of gas-discharge indicators is more than 100 V. But solving the problem with voltage is much easier than with a burn-out phosphor. On the Internet, such watches are common under the name NIXIE CLOCK: 
The indicators themselves look like this:
So, everything seems clear about the design features, now let’s start designing the circuit of our watch. Let's start by designing a high-voltage voltage source. There are two ways here. The first is to use a transformer with a secondary winding of 110-120 V. But such a transformer will either be too bulky, or you will have to wind it yourself (the prospect is so-so). Yes, and voltage regulation is problematic. The second way is to assemble a step up converter. Well, there will be more advantages: firstly, it will take up little space, secondly, it has short-circuit protection and, thirdly, you can easily adjust the output voltage. In general, there is everything you need to be happy. I chose the second path, because... I had no desire to look for a transformer and winding wire, and I also wanted something miniature. It was decided to assemble the converter on MC34063, because I had experience working with her. The result is this diagram:
It was first assembled on a breadboard and showed excellent results. Everything started immediately and no configuration was required. When powered by 12V. the output turned out to be 175V. The assembled power supply of the watch looks like this:
A linear stabilizer LM7805 was immediately installed on the board to power the clock electronics and a transformer.
The next stage of development was the design of the lamp switching circuit. In principle, controlling lamps is no different from controlling seven-segment indicators, with the exception of high voltage. Those. It is enough to apply a positive voltage to the anode and connect the corresponding cathode to the negative supply. At this stage, two tasks need to be solved: matching the levels of the MK (5V) and lamps (170V), and switching the cathodes of the lamps (they are the numbers). After some time of thought and experimentation, the following circuit was created to control the anodes of the lamps:
And controlling the cathodes is very easy; for this they came up with a special K155ID1 microcircuit. True, they have long been discontinued, like lamps, but buying them is not a problem. Those. to control the cathodes, you just need to connect them to the corresponding pins of the microcircuit and submit data in binary format to the input. Yes, I almost forgot, it is powered by 5V. (well, a very convenient thing). It was decided to make the display dynamic, because otherwise, you would have to install K155ID1 on each lamp, and there will be 6 of them. The general scheme turned out like this:
Under each lamp I installed a bright red LED (it’s more beautiful this way). When assembled, the board looks like this:
We couldn’t find sockets for the lamps, so we had to improvise. As a result, the old connectors, similar to modern COM, were disassembled, the contacts were removed from them, and after some manipulations with wire cutters and a file, they were soldered into the board. I didn’t make panels for the IN-17, I did them only for the IN-8.
The hardest part is over, all that remains is to develop a circuit for the “brain” of the watch. For this I chose the Mega8 microcontroller. Well, then everything is quite easy, we just take it and connect everything to it in the way that is convenient for us. As a result, the clock circuit included 3 buttons for control, a DS1307 real-time clock chip, a DS18B20 digital thermometer, and a pair of transistors for controlling the backlight. For convenience, we connect the anode keys to one port, in this case it is port C. When assembled, it looks like this:
There is a small error on the board, but it has been corrected in the attached board files. The connector for flashing the MK is soldered with wires; after flashing the device, it should be unsoldered.
Well, now it would be nice to draw a general diagram. No sooner said than done, here it is:
And this is what it all looks like assembled:
Now all that remains is to write the firmware for the microcontroller, which is what was done. The functionality turned out to be as follows:
Display time, date and temperature. When you briefly press the MENU button, the display mode changes.
Mode 1 - time only.
Mode 2 - time 2 min. date 10 sec.
Mode 3 - time 2 min. temperature 10 sec.
Mode 4 - time 2 min. date 10 sec. temperature 10 sec.
When held, the time and date settings are activated, and you can navigate through the settings by pressing the MENU button.
The maximum number of DS18B20 sensors is 2. If the temperature is not needed, you can not install them at all; this will not affect the operation of the watch in any way. There is no provision for hot plugging of sensors.
Briefly pressing the UP button turns on the date for 2 seconds. When held, the backlight turns on/off.
By briefly pressing the DOWN button, the temperature is turned on for 2 seconds.
From 00:00 to 7:00 the brightness is reduced.
The whole thing works like this:
Firmware sources are included with the project. The code contains comments so it will not be difficult to change the functionality. The program is written in Eclipse, but the code compiles without any changes in AVR Studio. The MK operates from an internal oscillator at a frequency of 8 MHz. Fuses are set like this:
And in hexadecimal like this: HIGH:D9, LOW: D4
Also included are boards with bugs corrected:
This clock operates for a month. No problems were identified in the work. The LM7805 regulator and converter transistor are barely warm. The transformer heats up to 40 degrees, so if you plan to install the watch in a case without ventilation holes, you will have to use a higher power transformer. In my watch it provides a current of around 200mA. The accuracy of the movement is highly dependent on the quartz used at 32.768 KHz. It is not advisable to install quartz purchased in a store. The best results were shown by quartz from motherboards and mobile phones.
In addition to the lamps used in my circuit, you can install any other gas-discharge indicators. To do this, you will have to change the board layout, and for some lamps the voltage of the boost converter and the resistors on the anodes.
Attention: the device contains a high voltage source!!! The current is small, but quite noticeable!!! Therefore, you should be careful when working with the device!!!
PS Article one, I might have made a mistake/messed up somewhere - suggestions and suggestions for correction are welcome.
Good day to all dear Muskovites. I want to tell you about an interesting radio design for those who know from which end the soldering iron heats up. 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. Gave a watch to a friend.
But I wanted something else, more interesting and more complicated.
Somehow, while poking around in my father’s garage, I came across the remains of some electronic device 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 found 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 the 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.
Reverse 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 of 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 “brightness”. 
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. Having spent several 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.
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 work you need three components: laser printer, ferric chloride and iron. The method is the simplest and cheapest. It has only one drawback - it is difficult to transfer very thin tracks.
- Photo resist. The following materials are needed for the work: 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. Regular will do food container.
- 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. We 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 making 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
