Make a clock using fluorescent lamps with your own hands. Scheme of the simplest electronic clock Clock on willow 8

There was an idea to create a clock using IV lamps; in the bins there were five new IV-11 lamps and the same number of IV-6 lamps, all that remained was to use them.
What should the watch contain?
1. Current time;
2. Alarm clock;
3. Built-in calendar (we take into account the number of days in February, including in a leap year) + calculation of the day of the week;
4. Automatic adjustment of indicator brightness;
5. Sound signal every hour.
Here are the main components of any watch. Adjusting the brightness is necessary because IV lamps shine normally during the day, but at night they are very bright and blind, especially at night when you are sleeping.
Clock diagram

There is nothing new or supernatural in the circuit: a DS1307 real-time clock, dynamic display, several control buttons, all controlled by ATmega8.
To measure the illumination in the room, a photodiode FD-263-01 was used, as the most sensitive one available. True, it has a small problem with spectral sensitivity - the peak of sensitivity is in the infrared range and, as a result, it senses the light of the sun/incandescent lamps very well, and fluorescent lamps/LED lighting - a C grade.
Anode/grid transistors - BC856, PNP with a maximum operating voltage of 80V.
To indicate seconds, the IV-6 is smaller in size, since it has a lower filament voltage - a 5-10 Ohm quenching resistor helps it.
For the alarm signal there is a piezo emitter with a built-in 5V generator.
From the power supply, the entire circuit consumes +9V up to 50mA along the line, the heat is 1.5V 450mA, the heat relative to the ground is at a potential of -40V, consumption is up to 50mA. Total total maximum 3W.
The accuracy of the DS1307 quartz oscillator leaves much to be desired - after washing the board and selecting quartz piping containers, we managed to achieve something like +/-2 seconds per day. More precisely, the frequency fluctuates depending on temperature, humidity and the position of the planets - not at all what we wanted. After thinking a little about the problem, I decided to order a DS32KHZ microcircuit - a fairly popular temperature-compensated quartz oscillator.
It’s not for nothing that the generator is so expensive - according to the reference book, the manufacturer promises to increase the accuracy of the clock to +/- 0.28 seconds per day. In reality, under acceptable power conditions and temperature ranges, I was not able to see a change in frequency due to external factors.
After assembling the case and “combing” the firmware, the watch has 3 buttons left: let’s call them “A” “B” “C”.
In the normal state, the "C" button is responsible for switching the mode from displaying the time "hours - minutes" to the date "day - month", the second indicator displays the day of the week, then by year, then to the "minutes - seconds" mode, in the fourth pressing - to the original state. Button "A" quickly switches to the time display.
From the “hours - minutes” mode, button “A” switches in a circle to the “alarm clock setting” / “time and date setting” / “indicator brightness setting” mode. In this case, the “B” button switches between digits, and the “C” button actually changes the selected digit.
“Alarm setting” mode, the letter A (Alarm) on the middle indicator means that the alarm is on.
Mode “setting time, date” - when the “seconds” digit is selected, the “C” button rounds them (from 00 to 29 resets them to 00, from 30 to 59 resets them to 00 and adds +1 to the minute).
In the “time and date setting” mode, at the SQW output of m/s DS1307 there is a meander of 32.768 kHz - necessary when selecting quartz/capacitors for the generator; in other modes it is 1Hz.
Before turning on the clock, you need to select the current flowing through the filaments, it is adjusted visually so that the filaments on all lamps in the dark are slightly red, so they will live longer

Mode "adjusting the brightness of the indicator": "AU" - automatic, shows the measured illumination in units. ;) "US" - manual setting in the same units.

DS1307 and DS32KHZ are powered by a CR2032 battery and when the power is lost, the time does not stop, but continues to run, only the Mega8 and all its hardware with indicators are turned off, and the stabilized quartz and real-time clock continue to work, they consume extremely little and the batteries should last for a very long time for a long time.

The brightness can be adjusted either manually or automatically, since a simple photodiode did not suit me in terms of its parameters, I had to sculpt a photo relay according to the diagram below:

any photodiode, I used FD-K-155, a tuning resistor is needed to determine the brightness of the response, instead of a relay you need to install a low-voltage reed relay, from its common terminals we connect to the common wire of the clock, and the other two through variable resistors 10-500 kOhm instead of a photodiode to the port PC0 of the controller, so the resistor will replace the photodiode and with a certain value of the resistor you can adjust the brightness you need, which will be day and night when the photo relay operates.

ATmega8 fuses for internal 8 MHz oscillator:

Here's what actually happened in the hardware:

lower part of the case with hidden buttons and a hole for the speaker

separate photo relay board

Scheme: yes (ATmega8)

Pay: There is( Sprint- Layout 6)

Firmware: There is

Source: there is

Description: there is

Features: temperature sensor, alarm clock, miniature indicator, separator effects, number changing effects, light sensor, there are boards for several indicators.

Scheme:

Preface

The impetus for the creation of the watch described below was the purchase on the radio market at a ridiculous price of one of the smallest domestic multi-digit vacuum luminescent indicators (VLI) - the IV-21 indicator, which has 8 digital and one service digit in a bulb only 70 mm long and 15 mm in diameter.

Generally speaking, I don’t really like VLIs compared to gas-discharge indicators (GRI, or the foreign NIXIE), however, I couldn’t pass up this indicator - it looked too beautiful. See for yourself: almost the entire flask is occupied by a pink ceramic substrate, on which seven-segment discharges are applied with a phosphor, and these segments have an unusual shape, as, for example, in LED indicators. On top of the segments are honeycomb meshes that look golden when viewed from certain angles (unfortunately, the photo below doesn't do it justice).

However, the miniature size of the indicator entails many problems. The purpose of creating watches on VLI and GRI is not just to make a device for displaying time. For this, you can also use conventional LED indicators, which are better in many respects and do not require, for example, high voltages and complex control circuits. Aesthetics and the appearance of the finished structure are important here. In this case, a huge amount of time is usually spent on the watch case, often even more than on the manufacture of electronics.

If you place an indicator such as the IV-21 in a huge case, there can be no question of any aesthetics. In addition, the indicator should be visible, and not behind green glass, like in a calculator - what is the point of all this then? Behind the glass, both VLI and LED indicators look almost the same. You should also not forget about reliable fastening - you cannot just take and solder the lamps by the terminals on one side without securing the other side in any way. Therefore, the case must have some kind of stands on both sides that secure the indicator. This immediately makes the case very bulky.

Finally, a compromise solution was found: to make a watch without a case in the usual sense of the word. It was decided to place two horizontal printed circuit boards at the base of the clock, on which to place the main part of the clock circuit, and secure the indicator using two vertical boards connected to the upper horizontal one with pin connectors.

So, we have decided on the appearance of the watch. Now let's move on to the diagram.

Let's start from the beginning, that is, with nutrition.

The power source is required to generate 3 voltages: +5V to power the logical part of the clock, -22V for the cathode IV-21 and ~2.4V to power the incandescent lamp (heater). Everything is clear with the first and third voltages. I’ll explain why you need a negative voltage for the cathode. There are two options for controlling VLI, in which the voltage on the anode segments and grids relative to the cathode exceeds the supply voltage of the logical part - the so-called circuits with “lower” and “upper” power supply of the logical part.

Below is a little theory, where would we be without it!

"Lower" power supply implies that the common wire of the logical part has the same potential as the cathode of the indicator. In this case, a high (relative to the logic supply voltage) voltage of the order of +(20-30)V should be supplied to the anodes. This requires level converters for each anode and each indicator grid, which convert +5V from the output of the logical part to +(20-30)V on the anodes and grids. There are three options for the circuit of such converters. The first - the simplest - is to use a specialized microcircuit to control the VLI. However, such chips are usually expensive and difficult to obtain. The second is to connect all anodes and grids to + (20-30) V through resistors with a nominal value of 10-30 kOhm and, using transistor switches on one NPN transistor, each connect these anodes and grids to a common wire. This option is bad because the entire anode voltage drops across the resistor of the inactive anode or grid, which causes it (the resistor) to heat up and puts an extra load on the anode voltage source. Finally, the third option is to use two-transistor switches on a pair of NPN+PNP transistors. There is nothing wrong with this option, except that each switch requires 2 transistors and at least 3 resistors. The IV-21 needs 17 such keys, 8 for segments and 9 for grids. All this will take up a lot of space on the printed circuit board, which is no good if you need to make the clock as small as possible (the indicator is small!).

Diagram of the variant with “bottom” power supply (simplified, much is not shown):

"Top" called the power supply option when +5V of the logical part supply is the anode voltage, i.e. There is a voltage of +5V on the active anode (grid) (relative to the common wire of the logical part). To ignite the indicator, a voltage of about 20-30V is required at the anodes relative to the cathode, and for this a negative potential must be applied to the cathode. Now, to control the anodes and grids, just a cascade with an OE on a PNP transistor is enough.

Diagram of the version with “top” power supply (also simplified):

Based on the above, the “top” food was chosen.

The diagram below shows a simplified representation of the unit for obtaining the blocking voltage on inactive anodes and grids:

That's it with the theory. Let's move on to practice.

Saved article archive.

I want to tell you about my experience in creating miniature watches using VLI or, as they are also called, VFD.

The project got me interested in these three images on the forum:

The idea of the hull is good, especially since I myself have an IV-18 for a similar project. The diameter of the rings is 22mm!

Of course, it is difficult to do without a transformer with such miniaturization. In addition to everything, the author used a combination of KF1211EU1 + IRF7303.

KF1211EU1 is difficult to get in our area, which is not encouraging.

The core for the transformer costs mere pennies and, most importantly, it can be bought in stores in Ukraine and Russia :).

It turns out this miniature source (the diameter of the core ring is 1 cm):

We must try to check the work of this miracle!

The most common ones I have are SVE 9SS03 (installed in a Samsung 250 cash register), SVE 11MS21 (installed in a Datecs cash register) and SVE-10MS14 (from a Samsung 350 cash register). There are 10 of each. The second and third 11 and 10 bits have disappeared, because... circuit for a 9-digit indicator and I didn’t intend to change anything in the firmware (besides numbering), so I assembled the watch usingSVE 9SS03.

The indicator size is 9 cm by 2 cm. The number size is 8 mm.

As a result we should get miniature clock and powered by USB for a personal computer monitor.

I ordered digital transistors especially for this project. DTA114 on Ali,
which made it possible to distribute the board in one layer.

In the circuit, the assignment of the microcircuit pins has been rearranged for the board, and a different source has been used.

The board is single-sided with several jumpers for SMD.
Not complicated.

Assembly begins with the Power Source and subsequent testing of it.
It is advisable not to turn it on without an incandescent load.

The wire for the transformer was taken from burnt housekeepers

Calculation screen in ExcellentIT:

Really:
Primary 2x5 - 0.3
Recycled 2x35 - 0.1
Filament 2x1 - 0.3 + current limiting resistors 7.4 Ohm.

We make a shuttle, wind about 1-1.5 m of wire on it and wind the anode winding turn to turn. It takes me about 15 minutes.

Quite a long time ago, the idea of replacing my old watch was long overdue - it was not distinguished either by its accuracy or its special appearance. The idea is there, but with the incentive - either there is no time, or there is no desire to make the Chinese out of a standard remake... in general, a complete mess. And then, one day, on the way home, going into a store selling illiquid goods, a display case with radio tubes from the times of the USSR caught my eye. Among other things, I was interested in the IV-12 light bulb lying forlornly in the corner. Remembering the seller’s remarks in the past: “everything that is there is on display,” I asked even without enthusiasm. … “Miracle, miracle, a miracle has happened!” - it turned out that they had a whole box of these indicators! Damn, I wish I hadn’t sooner.... in general, I bought it;)

In anticipation, when I returned home, the first thing I did was apply voltage to them - they were working! Here, here is a kick in the shaggy tail, here is an incentive to see this miracle in action - the work is in full swing.

Terms of reference:
1. The actual watch;
2. Alarm clock;
3. Built-in calendar (we take into account the number of days in February, including in a leap year) + calculation of the day of the week;
4. Automatic adjustment of indicator brightness.

It was not possible to get a socket for the indicators - the thing was too scarce even to order; instead I used “bushings” from a pair of broken connectors of the RS-232 modem cable. We cut off the “tail” of them - it turns out more compact than the original panels. (note - drill the seat carefully, the spots are small)

First samples:

The accuracy of the DS1307 quartz oscillator leaves much to be desired - after washing the board and selecting quartz piping containers, we managed to achieve something like +/-2 seconds per day. More precisely, the frequency fluctuates depending on temperature, humidity and the position of the planets - not at all what we wanted. After thinking a little about the problem, I decided to order a DS32KHZ microcircuit - a fairly popular temperature-compensated quartz oscillator.
We solder the quartz and this animal is conveniently placed in the free space on a piece of PCB. Connection - now by wiring to the nearby DS1307.

It’s not for nothing that the generator is so expensive - according to the reference book, the manufacturer promises to increase the accuracy of the clock to +/- 0.28 seconds per day. In reality, under acceptable power conditions and temperature ranges, I was not able to see a change in frequency due to external factors. In test mode, in a room, the clock worked for about a week, 2 days of which it was in a lethargic sleep, powered by a standard battery - after that, the error, if you believe the exact time services, did not exceed... +0.043 seconds per day!!! This is happiness! Unfortunately, it was not possible to measure it more precisely in such a short period of time.

Housing assembly:

After assembling the case and “combing” the firmware, the watch has 3 buttons left: let’s call them “A” “B” “C”.
In the normal state, the "C" button is responsible for switching the mode from displaying the time "hours - minutes" to the date "day - month", the second indicator displays the day of the week, then by year, then to the "minutes - seconds" mode, in the fourth pressing - to the original state. Button "A" quickly switches to the time display.
From the “hours - minutes” mode, button “A” switches in a circle to the “alarm clock setting” / “time and date setting” / “indicator brightness setting” mode. In this case, the “B” button switches between digits, and the “C” button actually changes the selected digit.
“Alarm setting” mode, the letter A (Alarm) on the middle indicator means that the alarm is on.
Mode “setting time, date” - when the “seconds” digit is selected, the “C” button rounds them (from 00 to 29 resets them to 00, from 30 to 59 resets them to 00 and adds +1 to the minute).
In the “time and date setting” mode, at the SQW output of m/s DS1307 there is a meander of 32.768 kHz - necessary when selecting quartz/capacitors for the generator; in other modes it is 1Hz.
Mode "adjusting the brightness of the indicator": "AU" - automatic, shows the measured illumination in units. ;) "US" - manual setting in the same units.
Phew, looks like I haven’t forgotten anything.

Good evening, Habrazhiteliki.
Many people were interested in my idea of a clock using vacuum fluorescent lamps.
Today I will tell you how this watch was created.

Indicators

The main role is played by gas-discharge indicators. I used IV-6. This is a luminescent seven-segment indicator with a green glow (In the photographs you will see a bluish tint of the glow, this color is distorted when photographing due to the presence of ultraviolet rays). The IV-6 indicator is made in a glass flask with flexible leads. Indication is carried out through the side surface of the cylinder. The anodes of the device are made in the form of seven segments and a decimal point.
You can use indicators IV-3A, IV-6, IV-8, IV-11, IV-12 or even IV-17 with minor changes to the circuit.

First of all, I would like to note where you can find lamps that were produced in 1983.
Mitinsky market. Many and different. In boxes and on boards. There is room for choice.
It’s more difficult in other cities, maybe you’ll be lucky and you’ll find it in a local radio store. Such indicators are found in many domestic calculators.
You can order from Ebay, Yes Yes, Russian indicators at auction. On average $12 for 6 pieces.

Control

Everything is controlled by the AtTiny2313 microcontroller and the DS1307 real-time clock.
The clock, in the absence of voltage, switches to power mode from a CR2032 battery (as on a PC motherboard).
According to the manufacturer, in this mode they will work and will not fail for 10 years.
The microcontroller operates from an internal 8 MHz oscillator. Don't forget to set the fuse bit.
Setting the time is done with one button. Long hold, incriminating hours, then incriminating minutes. There are no difficulties with this.

Drivers

I used KID65783AP as keys for the segments. These are the 8 “top” keys. I made a choice towards this microcircuit only because I had it. This microcircuit is very often found in display boards for washing machines. Nothing prevents you from replacing it with an analogue one. Or pull up the segments with 47KOhm resistors to +50V, and press the popular ULN2003 to the ground. Just don't forget to invert the output to the segments in the program.
The display is made dynamic, so a brutal KT315 transistor is added to each digit.

Printed circuit board

The board is made using the LUT method, you can read about this technology from our friend DIHALT. The clock is made on two boards. Why is this justified? I don’t even know, I just wanted it that way.

power unit

Initially the transformer was 50Hz. And contained 4 secondary windings.
1 winding - voltage on the grid. After the rectifier and capacitor 50 volts. The larger it is, the brighter the segments will glow. But no more than 70 volts. Current not less than 20mA
Winding 2 - to shift the grid potential. Approximately 10-15 volts. The smaller it is, the brighter the indicators glow, but the “not turned on” segments begin to glow just as brightly. The current is also 20mA.
Winding 3 - for powering the microcontroller. 7-10 volts. I = 50mA
4 winding - Heat. For four IV-6 lamps, you need to set the current to 200mA, which is approximately 1.2 volts. For other lamps, the filament current is different, so take this point into account.

Subsequently, I replaced the transformer with a pulse one. I recommend using a power supply for halogen lamps at the lowest power as a basis. All that remains is to wind the windings to the required voltages.
It may turn out that for incandescence 1 turn is not enough, but 2 is too much. Then we wind 2 turns and place a current-limiting resistor of 1-5 Ohms in series

Here is an “electronic transformer” with the lid open

I can suggest the option of making a power supply from a faulty energy-saving lamp. I described it, if anyone is interested, take a look.

Firmware

The firmware is written in C language in the CodeVisionAvr environment.
If anyone undertakes to repeat it, write me a personal message and I’ll send you the .hex and source code.

That's all.

P.S. The material may contain spelling, punctuation, grammatical and other types of errors, including semantic ones. The author will be grateful for information about them ©

UPD: Upon request, I'll add a couple more photos.

Clock circuit with fluorescent lamps

Many people want and are interested circuit diagram of a clock using vacuum indicators old Soviet times. Well, of course there is a lot of interesting things in this. Watch in retro style, and at night you can see what time it is. You can also insert diodes under the bottom, and it will be like a hint. And so let’s begin to consider this circuit.

The main role is occupied by gas discharge indicators. I used IV-6. This is a luminescent seven-segment indicator with a green glow (In the photographs you will see a bluish tint of the glow, this color is distorted when photographing due to the presence of ultraviolet rays). The IV-6 indicator is made in a glass flask with flexible leads. Indication is carried out through the side surface of the cylinder. The anodes of the device are made in the form of seven segments and a decimal point.

Can be applied indicators IV-3A, IV-6, IV-8, IV-11, IV-12 or even IV-17 with minor changes to the design.

First of all, I would like to note where you can find lamps that were produced in 1983.

Mitinsky market. Many and different. In boxes and on boards. There is room for choice.

It’s more difficult in other cities, maybe you’ll be lucky and you’ll find it in a local radio store. Such indicators are found in many domestic calculators.

You can order from Ebay, Yes Yes, Russian indicators at auction. On average $12 for 6 pieces.

Control

Everything is controlled by the AtTiny2313 microcontroller and the DS1307 real-time clock.

The clock, in the absence of voltage, switches to power mode from a CR2032 battery (as on a PC motherboard).

According to the manufacturer, in this mode they will work and will not fail for 10 years.

The microcontroller operates from an internal 8 MHz oscillator. Don't forget to set the fuse bit.

Setting the time is done with one button. Long hold, incriminating hours, then incriminating minutes. There are no difficulties with this.

Drivers

I used KID65783AP as keys for the segments. These are the 8 “top” keys. I made a choice towards this microcircuit only because I had it. This microcircuit is very often found in display boards for washing machines. Nothing prevents you from replacing it with an analogue one. Or pull up the segments with 47KOhm resistors to +50V, and press the popular ULN2003 to the ground. Just don’t forget to invert the output to the segments in the program.

The display is made dynamic, so a brutal KT315 transistor is added to each digit.

Printed circuit board

The payment was made using the LUT method. The clock is made on two boards. Why is this justified? I don’t even know, I just wanted it that way.

power unit

Initially the transformer was 50Hz. And contained 4 secondary windings.

1 winding - voltage on the grid. After the rectifier and capacitor 50 volts. The larger it is, the brighter the segments will glow. But no more than 70 volts. Current not less than 20mA

Winding 2 - to shift the grid potential. Approximately 10-15 volts. The smaller it is, the brighter the indicators glow, but the “not turned on” segments begin to glow just as brightly. The current is also 20mA.

Winding 3 - for powering the microcontroller. 7-10 volts. I = 50mA

4 winding - Heat. For four IV-6 lamps, you need to set the current to 200mA, which is approximately 1.2 volts. For other lamps, the filament current is different, so take this point into account.