Electronic clock table repair do it yourself

In detail: do-it-yourself electronic desktop clock repair from a real master for the site my.housecope.com.

I ordered in china through ebay. We worked for about two months and the following happened: VIDEO
There is a great desire to return the device to a working state (I'm used to them).

Photo of the board1:

Photo of the board2:

Image - DIY electronic clock desktop repair

Symptoms of malfunction: if they lie without power for a while, then the first few seconds work fine. And then it starts.
From what I checked: PSU is alive (when running on batteries - the same garbage), diodes, resistors and electrolyte - too. There is a suspicion of “deadness” of the Q8 element (SOT-23 marked “S1”). What could it be? Some of the links say that this is a BBY31 varicap (?!), The other is a FET with a P-channel. Whom to believe and how to be sure?

Shl. In the presence of only a simple tester, a soldering iron and straight (sort of) hands.

Description of electronic clock repair Janus, made in the USSR. The basis of these watches is the K145IK1901 microcircuit - a common Soviet controller for building electronic clocks. The time is displayed on the large green display IVL1-7 / 5. Based on the experience and repair of such watches, it can be concluded that most often the quartz resonator fails, the electrolytic capacitors dry out, and the vacuum indicators fade away. Indicators that failed due to a burnout of the filament have not yet come across. Of course, it is best to repair any electronics with a circuit. Here are two similar schemes. If anything, the K145IK1901 and KR145IK1901 microcircuits are interchangeable during repairs.

SB1 - “M” - setting the current time in minutes, in the “T” mode - in seconds;
SB2 - “H” - setting the current time in hours, in the “T” mode - in minutes;
SB3 - "К" - correction of the current time;
SB4 - "C" - stopwatch mode;
SB5 - “О” - stop indication;
SB6 - “T” - timer mode;
SB7 - “B1” - “alarm clock 1” mode, the time is set using the “H” and “M” buttons.
SB8 - “B” - call the indication of the current time, for example, after setting alarms;
SB9 - “B2” - “alarm clock 2” mode.

Video (click to play).

In this case, the watch lay idle for a long time and finally, after 5 years, it was needed. Initially, there was an idea to buy ready-made LEDs - with large numbers, 5-10 centimeters high. But after looking at the price for 1000 rubles, I realized that it was better to revive the old ones.

We disassemble the case and examine the circuit with details - everything is quite complicated, compared to modern ones, on microcontrollers and LCDs. The power supply seems to be simple - transformerless, but then a reduced voltage of 10 V is converted by a very cunning inverter on a multi-winding ring, into 27 volts of power supply for the anode of the IVL-1 indicator.

There are no signs of life, the fuse and diodes are normal, but the power supply to the filter capacitor (1000 microfarads 16 V) is only 4 volts.

We take a laboratory regulated power supply unit and supply the clock with the 10 V voltage set according to the scheme, controlling the current. Everything worked - the indicator lit up and the dot of seconds began to blink. The current was about 80 mA.

Obviously the problem is in the capacitor. And the culprit was not the electrolyte of the filter, as you might immediately think, but the ballast network, which has almost lost its capacity, at 400 V 1 microfarad. In parallel, a second similar one was soldered to it, and when it was connected to the 220 V network, the device worked. The voltage immediately rose to 10.4 V.

On this, the repair can be considered complete, and 1000 rubles already allocated for the purchase - saved. From this we conclude: do not be lazy to repair household appliances and electronics on your own, because in addition to saving money on buying a new one, you will feel joy from a job successfully done and pride in front of your household 🙂

Where to begin. Some notes from Bogdan J.

This is purely the experience of an amateur who has never been a professional watchmaker. Accordingly, all this is suitable for the amateur. A professional is dear to the school. They will teach everything there.

Start with Pinkin. Or from Troyanovsky.In general, there are books on the topic of clock repair. Download and print. Okay, there is no Internet - everyone will do it for you in any Internet cafe. You must have a book. It can get expensive but well worth it. This book is a guide for the layperson who should be able to understand at least something from this book. Almost our case. I have never done anything like that - and here it was.

Let's make some additions with the amendment for today for those who are pinned.

Screwdrivers. Start simple.

Chinese. I use it. I sharpen it. As for Chinese screwdrivers - look where on the streets watch batteries are changed and batteries and watch straps are sold. Or in the most ordinary households. A set of screwdrivers for small jobs.

You take a screwdriver. If it turns out to be too soft and bends when trying to unscrew something, put a candle next to the screwdriver. You heat the blade of a screwdriver and quickly into wax. This is hardening. Then you take a small stone and sharpen it along Pinkin.

More cool - in a machine on a diamond disc. But it will be later. When the tool and machines appear. Stones are well suited for finishing.

Tweezers (for starters - medical eye tweezers will do).

An alternative is to get acquainted with a radio bazaar (if Moscow - it seems Gorbushka - where they sell radio components, radio stations and computer gadgets) - see the boxes where the instrument is sold. You will be greatly surprised by the abundance. Good tools are surprisingly expensive. Tweezers shapes - see Pinkin. I'm not talking about big watch shops. They would rather be beaten than sold at a normal price. They do not want to breed competitors. And if they do, the prices are simply unrealistic. Doesn't fit into any gate.

There is also a radio bazaar - Galosha gasoline. Wash. It is much drier than kerosene and white spirit.

You take sticks (like Chinese) - finger length - to taste. You stick fishing steel 3-4 cm long into the end - it can be thicker and thinner. 0.1 - 0.15 mm. This is for the fishermen. One meter is enough for 10 years of work.

The very tip with one blow of a hammer (through a punch or a hard piece of iron) is splashed on a hard anvil. You get a little spatula. You make 3-4 of these with different blade sizes and different steel diameters. This will replace butter dosing. As anvils, I use either a roller made of a large bearing or carbide plates for a lathe - your way to the flea market or to friends in the workshop.

Read also: DIY video card repair asus

In approximately the same way - they will come in handy for a start - sticks with ordinary sewing needles - while the hands are frightened and there are no good tweezers - to expose the details (gears in stones, screws, etc.) is an auxiliary tool.

Surgical clamps. Different. Very handy as small and strong pliers. They are usually bought on occasion at a flea market.

Dental spatulas. It is convenient to use in all cases as an auxiliary tool.

Enema. Rubber. From the pharmacy. Big. Blow off dust. The tip must be rubber.

Butter. Or in the workshop (if they don't beat you, although they usually look like rams and pretend that they don't understand what you are talking about at all and are trying to get you off as quickly as possible). Or maybe at a radio store - in the same place where solder and acid are sold. Oil MN-30, MN-45 or watch oil. Although it is not aerobatics, it will go for a start.

It is better to keep it in a dark heavy box - and the sun will not burn and there is less chance that it will turn over.

To open the cases - a large, broken medical tweezers. It is clear that this is not kosher - but it is also possible. Likewise - an old caliper. You just need to correct the edges of the jaws - so that they are more rectangular.

Scalpel - opening of enclosures.

Binocular loupe. It is relatively inexpensive, but without it it is better not even to start. Or photographic goods (classic - where telescopes and binoculars are sold) or a radio bazaar. There are different strengths. If you have money, take two.One is 1.5 times, one is the strongest one sold - it seems up to 2.5 times. They can be sold with an elastic band - you will have to redo them to fit a hard bezel. You can go and talk to the optics workshop - glasses. Maybe they will offer something like pince-nez. Regarding ordinary magnifiers - to my taste - I rarely use them. It turned out to be extremely useful for cutting off the baby's nails - they were not visible at all for the first six months, but it was necessary to cut them off.

Binocular - microscope. Yes. Old. Look. The oldest is MBS-1. It is with a straight image - not upside down - which is what we see. It should cost within $ 50. A very useful thing. In every way. Up to the point that you rip the scrap out of your finger. But this is on occasion and over time. MBS-10 or OGMZ is steeper - the distance from the object to the eyepiece is greater, it is clear that it is more expensive. But all the same, an ordinary screwdriver does not fit under the MBS-10 - it must be shortened. Although on the Site of the Lytkarinsky plant - the manufacturer of MBS-10, there is a link that they sell lenses for MBS-10 with a distance to the object - about 19 cm.This can be a good solution if we got MBS-10. Everything between MBS-1 and MBS-9 is the same. Over time, the lens can be altered by yourself. You take what is cheaper. It's closer to the flea market. The only thing is that it is desirable that there is an illuminator (transformer + light bulb).

All that is further from the instrument - only after evisceration for 4-5 hours.

Where to get a watch - make yourself a fashion to be at a flea market - everything floats there. Often they simply sell mechanisms there. For instance:

When you warm up a little - after buying a binocular microscope - there is also a radio bazaar, shops with tools - they usually sell ultrasonic cleaners. But here is also the question - is it necessary. 50 years before that they did not use them - they took a bath and washed the parts with a brush in gasoline. You can do it, but the weight is not bad. Should cost in the range of $ 50-80. Denatured alcohol and Galosha gasoline were poured into an ultrasound of 30 watts. Working. Does not flash. Washes like a beast, but all the same, sometimes you have to rip something off with a toothpick. At the bazaar, they say that 30-watt sinks - indestructible - work without problems and there is no return due to marriage. If the model is the same as in the figure - what should be done after purchase - disassemble completely (there may be moisture inside, one of the indicators is stylish clicks when working against a background of uniform sound), squeeze the metal tank out of the case and put it back on the Auto Sealant (white , ours, not on transparent silicone). Plumbing does not work - it is highly corrosive. One of the indicators of plumbing is a strong vinegar smell.

Yes, I forgot, a flea market - look for Petri dishes - or maybe in a pharmacy or in a laboratory at a hospital. But you are not their client - there is an expensive flea market - this is the very thing. These are flat round glass or plastic low trays - for details. They are cheap. Take 5 pieces for the current dismantling works. I like glass more - they are heavier, fidget less on the table.

Then, for convenience, in the offices that make business cards, you can sometimes roll up and buy boxes for business cards. Wholesale will cost within $ 0.30 pcs. Transparent ones are also a very convenient thing - but this is for longer storage.

Silica gel. Small bags that are put into new fashionable shoes, equipment, computer components. Absorbs water. It must be dried either in the microwave or at a good temperature - in an electric oven. Gas does not pass - when the gas burns, water is released. After drying, the bag is placed in a box in which small tools and spare parts are stored for a long time so that they do not rust.

Radio bazaar. Snap-on pouches - they sell in the hundreds. Size 4 X 6 cm. Place watches and small items. They are usually packed with small pieces that are sold in the bazaar.

To begin with, the wristwatch can be laid down on the grinder mesh during disassembly. Then you yourself will determine what you need and how it is more convenient for you. The stand can be machined out of brass. Should be heavy enough.

Take a coil from any old starter from electricians - try asking for 380 V. If not, by 220 V. You attach the wires - the demagnetizer is ready. Turn on only for a short time - it gets warm.

About a new instrument. It is not always worth the money. Think how to get out with what you have. It is needed if you make a living with this and the customer pays for everything. If this is a hobby, then not first of all. Calculate the costs like this: I quit smoking (and drinking) and all the savings are on the tool. In this case, it is really a hobby and a useful pastime.

Now the steepness has gone. Machine.

Option 2. High-speed car. 10,000 revolutions. We sharpen with a diamond file. It may well be. There are eagles who did something in this way. But as for me - this is not very correct. If sharpen then sharpen.

Considering the above - if you do not sharpen the axes how to fry pies - then for a non-professional watchmaker-turner, it would be more expedient to take a small-sized precision universal machine. I would say that 20% of the work is axle turning (or even less), 80% is the turning of screws and body parts, various secondary milling work.

Examples I would name the following:

Collet chuck, native collets. On top is a milling corner. A part of the caliper is attached to it and we get a "milling cutter".

- new - Proxxon PD-230 / E, including a milling attachment or FF-230 router. Search on There they even have a price list in the power tool section - that is, they really do it.

Regarding the old MD-65. Axes 0.1 sharpens. Doesn't hit. Any additional clarifications are superfluous.

Now for the next topic. Okay. We got a machine. Well kva. We have a type of computer in the form of a processor, monitor and keyboard. But all this locomotive also needs software. Windows-2000 or Windows-XP and for tough peppers Linux will do. So, the fun begins. Software often costs more than hardware. It's the same story with machine tools. We need fixtures and additional tools. I think that an approximate set of additional accessories for the machine will cost no less than the machine costs. We are now talking about turning + milling. I ended up with MD-65 with a milling angle plate - a milling cutter is clamped in the machine chuck, and the support is turned over like a milling table, only a vertical one + milling vise. The arrows on it are milled. Cut the slots in the screws too.

- incisors - at least a hundred. Fits well in old wooden school boxes.

For precise sharpened incisors, old boxes from under grandmother's silver spoons go very well - incisors are more expensive than spoons, they will not break.

- collets and collet chuck. I have 2 sets - one is native to MD-65 (3-13 mm), the second set is Lorsch (hour, 0-6 mm).

This is in the machine, Lorsch in the adapter.

- indicators. 0.01 and 0.001. It is clear that various attachments are needed for them. Often you have to do the fasteners yourself.

- center detectors - 0.01. Without it, there is simply nothing to do on the machine.

- binocular microscope. Without words. We have already talked about this above.

- 4-jaw chuck. With split jaw release.

- sharpener - sharpen the cutters roughly

- diamond wheels - sharpen cutters precisely

- rotary vise (horizontal rotary system) - drill holes in precisely specified places. Screw holes in the rim of the transparent case back. It is hand drilled. It can be seen that the screws are jumping.

- dividing head. Or with discs or vernier. Cutting gears. Or at least make a square.

- I'm not talking about cutters. And end and for gears. The thickness of the disc cutters - from 0.1-0.15 - is the thickness of the "Neva" blade.

- the measuring tool is for rough work

- and for precise ones - only optics

- then you need to look at what is needed already for the work being performed. You will have to do a lot yourself. To invent a lot. Very often, for the manufacture of one part, it takes more time to make a clamp in order to clamp this part into the machine.

Foil trimming - making a "disk" arrow. Materials at hand.

Now the conversation is where and how to organize all this. It should be dry. Dust free. Not on the head of the family - the family should know that it is yours - and no matter what you do there - they have no entrance there. And there is nothing to howl about the noise from the workshop.Their comments are inappropriate (oh, it's dirty, oh, it stinks with gasoline).

One type I saw a German machine - the type of our school. More precisely, only pre-war. He mounted it under the kitchen table. In the center of the table is a shelf with a machine on it. The top board of the table rises - like in old school desks. He lowered the board, put the tablecloth in place and crumble the onion with the sausage. All the same, there will be no big turning works at home - everything is some kind of small piece.

If the conversation is about a large workshop or a more serious occupation in the restoration business for the soul, then in addition to the small machine, you need to look towards the larger machine - a school one (I don’t want to name the type - there are many different ones), a horizontal milling NGF-110 and a muffle furnace - this is for more rough work and the manufacture of devices. It is clear that all this also needs a trailer of devices and tools. Photo of the basement in the country.

If you can order or buy somewhere, look towards the rollers. They can be quite expensive. Sometimes they help out a lot. Especially in the manufacture of new parts, arrows and shims for lathe cutters.

As a conclusion, let's say this - this process is endless. In one sensible book on choosing a watch lathe, there was a good idea, completely applicable in our case - we are all mortal. All these tools are of interest only to us. Personally. There is no need to expect that someone after us will continue with fire in their eyes what we have begun. The whole instrument must be bought on the basis that after us, our grateful descendants die of all this rubbish and faster. They can also be thrown into the trash. They need a place for a geranium! We need to make sure that they can get more for it, slowly and confidently to all these numerous relatives and posterity, it is necessary to explain that all this is expensive and on this in distant times it will be possible to earn something. And accordingly, if you already buy, then buy a liquid instrument, which will have a price even in 50 years. This is on the one hand. On the other hand, we are all working now. We earn something. This is exactly the right time to prepare for yourself a range of activities for a time when our earnings will decrease, that is, retirement. Good luck.

Electronic watches are subdivided into two main designs. The first one is actually a mechanical watch with a spring motor and an electric winding; the second is an electronic clock, the source of energy for which is an electric battery or accumulator.

There is no motor in this watch, and the energy from the power source is used to directly actuate the governor.

Electrically wound watches have been around for decades; purely electronic watches, especially wrist watches, have appeared in recent decades. All of them are more high-precision than mechanical modifications and can operate continuously without changing the power source for a year or more.

Electromagnetic or magnetoelectric clock

According to the principle of operation, electronic clocks can be divided into contact, non-contact (transistor), synchronous, tuning fork, etc.

In a contact watch, the electric power supply circuit of the governor drive is closed by means of a contact. In contactless watches, a miniature transistor is used for the same purpose. The synchronous clock is driven by a synchronous electric motor. A tuning fork watch has a tiny tuning fork as a regulator, the vibrations of which set their mechanism in motion.

Currently, there are several dozen different types of contact clocks and almost the same number of transistor ones. There is no definite systematization of their designs.

Here are some of the more interesting options.

Electro-mechanical contact wrist watch

The principle of operation of this watch is based on the interaction of a permanent magnet and an electric coil. The impulse that drives the travel regulator in this watch is triggered by an electrical contact.

If in a mechanical watch, the movement of the hands is carried out due to the energy supplied from the mainspring through the engine, and the oscillatory system of balance - the spiral also consumes the energy of the spring to maintain the oscillatory process, while performing the functions of only a stroke regulator, then in an electronic-mechanical watch the balance system - spiral - an electromagnet performs two functions simultaneously: a regulator and a motor. Energy from the balance through the wheel system is transferred directly to the arrows. Thus, the kinematic diagram of a contact electronic-mechanical watch differs markedly from the kinematic diagram of a conventional mechanical watch.

The layout of the mechanism of an electronic mechanical watch is also different from the usual one. In most cases, electronic mechanical watches use balances that are much larger in diameter than balances in mechanical watches of the same size. This is because more balance has more momentum. The use of such a balance in electronic-mechanical watches improves the stability of the watch and greatly facilitates its operation.

The watch mechanism is assembled in three levels. At the top level is the balance, in the middle is the magnetic system, wheel gear and battery, and at the bottom is the switch mechanism. The balance axis passes through all three levels, which is specially lengthened. To protect it from possible shock damage, special shock absorbers are used, similar to the shockproof devices in mechanical watches.

The watch has a battery (battery). With one of its poles, the battery touches the current-collecting bus. Through this bus, the current flows into a column isolated from the rest of the watch mechanism, which carries a contact plate. This plate is threaded through a wire loop attached to a second plate, also insulated from the rest of the mechanism.

The other pole of the battery is in contact with the mass of the entire mechanism. In this direction, the current from the battery flows through the spiral to the balance, and from there - to the coil fixed in the slot of the balance rim. The coil is connected at one end to the balance itself. Keep in mind that all the electronic circuitry of a small watch is very small.

The balance has a contact pin to which the other end of the coil is connected. And under the balance is a permanent magnet of high power made of a special platinum-cobalt alloy. The electrical steel magnetic core creates the required concentration of the magnetic field in the path of the coil and reduces the dissipation of the magnetic field.

A roller is installed on the balance axis, in which an ellipse is fixed. As soon as the balance starts to move and begins to oscillate, the ellipse alternately grabs the ratchet teeth and rotates it. When the ratchet disengages from the ellipse, it is held in place by a magnet, also made of a platinum-cobalt alloy. The teeth of the steel ratchet are alternately attracted to the magnet, thus the ratchet is locked.

When the balance moves in the direction of travel, the ellipse grabs the next ratchet tooth and rotates it, as a result of which the next ratchet tooth is in a magnetic field. The magnetically tightened ratchet locks into position.

The ratchet wheel, in turn, meshes with the second center wheel. This wheel, when rotating, is mated with the minute wheel. A minute tribe is installed on the hub of the minute wheel.Through the bill wheel and its tribe, it is connected to the hour wheel.

The kinematics of the watch is as follows: if you put a battery in it and swing the balance, then the contact pin comes into contact with the plate and the electrical circuit is closed. The current flows through the coil, which will create an electromagnetic field around it. The moment the coil is close to the permanent magnet, the contact is triggered.

Under the influence of the spiral, the balance changes its direction of rotation. Because of this, the coil approaches the permanent magnet again. But no contact occurs as the contact pin goes past the end of the plate without touching it.

Some additional devices are required in a wrist electronic watch. The fact is that when you start the watch, you need to give the balance an initial impulse. A device in the form of a special system of levers is intended for this. At the same time, this device is intended to protect the balance from breakage when moving the arrows.