The lamp constantly burns in the same lamp. What is the matter and how to be?

About cases when the lamp constantly burns in the same lamp. On high starting currents in incandescent lamps, on transients and briefly on how to solve the problem.

The flip of a switch: a light flashes in the toilet, momentarily illuminating the modest interior of the restroom, and that’s all. The light was bright, but not for long. Having figured out in the twilight with your natural needs, drag the stool, unscrew the affected lamp. She, of course, can no longer help.

We screw in a new lamp, throw the incident out of our head. And the next day everything suddenly repeats: a click, a flash, and the sudden death of a lamp. What a disaster! Maybe the lamps are unsuccessful, defective? No way - in the corridor it burns exactly the same and without any excesses.

Remembering in vain both Ilyich and Edison, we stock up on light bulbs and reluctantly we exhaust our entire supply to a single lamp - all in the same toilet. And the lamps all burn out and burn out. And it is at the time of inclusion, that is, switching. Well, why, in the end?

In fact, when switching, any electrical equipment suffers, and not just light bulbs. Just the last luck less. The electrical resistance of their filament is very dependent on temperature, and during operation they warm up to more than two thousand degrees Celsius. At the same time, the nominal mode of operation of the lamp corresponds to a heated thread, which has a large resistance. When you turn on the cold spiral, the electric current can be ten times higher than the rated current due to reduced resistance. Figuratively speaking, after turning on the lamp receives a real electric shock of increased power.

Such strokes themselves are unpleasant and do not contribute to the long service life of the lamp and its filament. But the situation can be aggravated by another factor, due to which it turns out that it is in a particular lamp that lamps burn out with enviable constancy. This factor is transients during switching.

After all, the current through the bulb begins to flow immediately after applying voltage. And if the lamp, for example, has a power of 60 watts, then, considering the load is purely active, we conclude that the electric current should be approximately 0.27 amperes. It is in nominal mode. When you turn on the cold thread, all 2.7 amperes are already obtained. But how does the current change from zero to 2.7 amperes? Jumping, immediately after turning on the switch, or smoothly, after a while?

So, according to the theory of transients, the transition from a complete lack of current to 2.7 amperes can not be instantaneous. This, perhaps, is not surprising - after all, there are practically no instant processes in life, there are only processes that occupy very short periods of time from our human point of view. So the process of changing the electric current in the lavatory bulb takes thousandths, maybe hundredths of a second.

Here already, of course, our reasonings give a little philosophy, but the electric current also takes some time in order to accelerate to the speed of light. This is the first. And secondly, the presence / absence of reactive load affects the duration of transients in any circuit. So according to one of the laws of switching, inductor current physically cannot change instantly. The field created by the inductance will prevent the current from changing. And the greater the inductance, the slower the current will reach its steady-state, final value.

According to the second law of switching, the voltage on the capacitive element, that is, the capacitor, cannot sharply drop or increase.A capacitor needs time to give up or accumulate its charge. And the more its electric capacity, the more time will be required for changes.

These laws apply to both alternating and direct current circuits. But someone will say: “What other inductors and capacitors? It was about an ordinary light bulb - what did it have to do with it? ” Indeed, one could agree: after all, the reactance of an incandescent filament of a lamp is only a fraction of a percent of its active resistance. That is why the reactance of an incandescent lamp is neglected in the calculations.

But being neglected does not mean that it is absent. And in addition, the parameters of the entire chain, that is, the entire home network, cannot be thoroughly known to us. Only one thing can be said for sure: the equivalent circuit of an incandescent lamp will contain not only a resistor, but also a reactive element - a capacitor or inductor, and most likely - both at once.

When there are reactive elements in the circuit, the magnitude of the electric current in transients is defined as the sum of the established current and some kind of free component. The free component decreases very quickly after switching, and its maximum value occurs at the first moment after the circuit breaker is turned on.

The magnitude and duration of the action of the free component current, even in DC circuits, is determined by the method of solving complex differential equations that take into account the ratio of all parameters of the equivalent circuit - resistance, inductance and capacitance. In practice, such calculations are very rare - it is so difficult to determine all the parameters with sufficient accuracy.

A light bulb in the toilet is included in the alternating current circuit, for which not only the equivalent circuit parameters play an important role, but also the initial phase of the circuit breaker. If the switch was turned on at a time when the voltage was at zero, the transient may not be noticeable in any way, and the lamp will go into operation under the most favorable conditions.

But if switching occurs when the voltage is at the peak of its value (and for a household network it is approximately 310 volts, by the way), then the bulb may be subjected to a current load that is twice the established value! Of course, given that the inductance and capacitance of the equivalent circuit will be small, the duration of such an overload will be very short. But the lamp is thus subjected to current shock due to the fact that the thread is not warmed up.

So, on the one hand, we have a cold filament, the resistance of which is small, and on the other hand, we have a circuit with unknown substitution parameters. And turn on this circuit is unknown at what point in time in the phase of the current. And if the magnitude of the reactive parameters of the circuit is of any significant importance, and the mains voltage is not lower than the nominal 220 volts, then the bulb will not be greeted.

Trying to find the real reason why lamps in this particular lamp constantly burn out is not a promising thing. After all, we cannot determine all the factors and parameters of the circuit and make the necessary corrections. Therefore, the problem is best solved radically.

The first possible solution is to change the type of lamp, or at least the lamp. For example, the same compact fluorescent lamps, known as energy-saving, are much less prone to the harmful effects of transients. And they have no incandescent filament - neither cold nor hot. The same can be said about LED lamps.

But if incandescent lamps are dear to you, and without their yellow-red light, "the light is not nice," you can do the following:

- install an electronic unit for protecting incandescent lamps. Such a unit not only provides a smooth supply of voltage to the lamp without inrush currents, but also stabilizes the voltage, ensuring optimal operation.

- install a throttle or active resistance in the lamp circuit, thereby lowering the voltage and providing the lamp with a softer mode of operation;

- install in the lamp circuit an ordinary diode corresponding to the rated current. The diode “cuts off” one half of the voltage period, and the lamp will burn twice as weak. For many places, for example, for a closet, or for a larger porch, it happens and is not necessary.

The last two ways to solve the problem are associated not only with a decrease in the brightness of the lamp, but also with the fact that it will work with less efficiency. But since we give preference to incandescent lamps, this fact should not really upset us.

Alexander Molokov

Comments

[#1]

I saw how two incandescent lamps are connected in series. Apparently, for the same reasons ...

[#2]

Pour so much water on an elementary question, no need to recall the laws of switching
they have nothing to do with it - just replace the cartridge.

[#3 Sasha]

eugevict, come on?

The solution, then, of course, is simple. And the bad contact in the cartridge really needed to be mentioned.

But the reasons for the constant burnout of the lamp in one lamp - a lot, including the laws of switching.

[#4]

It is interesting since when in fluorescent lamps, including compact ones, "there is no incandescent filament" ??? 
There are enough available for repeating schemes for smooth inclusion of incandescent lamps in nete, so it is not necessary to use a flickering lamp burning in half-glow.

[#5]

If, when the diode is turned on, the efficiency drops by 2 times, will the capacitor raise it.

[#6]

There was such a defect in the neighbors - I redid the twist in the distribution box and the bulbs stopped blowing out! (There was a very strong oxidation of the wires in a twist after flooding by neighbors from above 4 years ago).

[#7]

But the diode is wise. Just add that you have to look at the 50Hz flashing. I think that you can’t stand it for a long time.

[#8]

Yeah! It was especially interesting to read about the absence of filaments in CFL. Dear author, there are two of them!

[#9 Author]

You guys will eat me now.

1. I am aware of the diode for half voltage and flicker with a frequency of 50 Hertz instead of the usual 100. In some places, I think, you can put up with such a drawback. Not in a hut-reading room, of course, but still. Actually, in the article I do not see statements contradicting this fact.

2. About the efficiency of the capacitor and other pribluda in the lamp circuit, I agree that it is lower than just that of a lamp. Also not a tragedy, in my opinion.

3. Well, for the incandescent threads in CFL, LB, LD, etc. - I sincerely apologize to you. It’s not that I didn’t know about their presence, but simply blurted out without thinking, because their incandescent threads work in completely different, one might say sparing, conditions (with a good ballast).

For sim everything. From now on, I promise to be more careful.

[#10]

Incandescent lamp will not blink at least 20 diodes plug. The laws of physics are such, heating-cooling is very inert.

[#11]

And in what networks is 100 Hertz ????
This is nonsense! The Americans have only 60 Hertz, and we have 50!
And through the diode, the lamp will blink at a frequency of 25 Hertz.
And 50 Hertz the human eye practically does not perceive!

[#12 Author]

Yuri, think carefully. For an incandescent lamp, the direction of the current does not matter. Therefore, although the network frequency is 50 hertz, the frequency of changing the degree of incandescent filament varies with a frequency of 100 hertz. It turns out - for the period twice to the maximum.

[#13]

The speed of the electric current (the speed of the electrons in the conductor) is centimeters per minute. Well, not the speed of light.)))

[#14]

Michael, you confuse the speed of the electrons and the speed of the current. The field arises almost instantly.

[#15]

Author,
Is it really email. Is the current not the movement of electrons?

[#16 Author]

Dmitriy,

Yes, but not really. About the "ordered motion of charged particles" is a slightly inaccurate formulation. After all, there is also an electric field that spreads instantly.

[#17]

five years ago, at the entrance, I installed a 226B diode in the lamp circuit, and the other day I just changed it !!!!

[#18]

This is called a rattling effect. To do this, it is necessary to fix the connecting wires and clean the contacts of the switch and the cartridge with a washing stationery gum.

[#19]

The question is of course interesting ... The simplest TWO options, if it is a living room. Or strip the contacts in the cartridge. Or change it to a brand new one. And if this is the entrance, you can add the THIRD option (diode 226).

[#20]

Article title:
The lamp constantly burns in the same lamp. What is the matter and how to be?

From the text:
Trying to find the real reason why lamps in this particular lamp constantly burn out is a matter of unpromising.

Then why did you pour this "water"?

As the Albanians say, "Aftar, walk escho!"

I uncheck the subscription to your site, this is not the first "masterpiece" in recent times. I signed after reading a series of articles on grounding, but after that cycle nothing useful came up: (((

[#21]

There’s absolutely nothing to do with this article in any article about inductance, capacitance .... the speed of energy propagation along the guide systems .... well, that is, to electrodynamics .... Well and all the more strange the laws of switching mentioned repeatedly look "
What kind of "laws" are these? What section of physics? Who first introduced these "laws" into physics?
In electrical engineering, everything looks much simpler ....:
- an incandescent lamp in a cold state has an resistance an order of magnitude less than in a heated ...
- heating takes place in a split second, but not instantly ...
- the current in the circuit at the time of switching on is maximum and drops rapidly as it warms up
- the more often the lamp is on-off, the more shock loads on it ... that's why the lamps burn out at the moment of switching on ..
- one of the cartridges, wires, contacts ..... and so on in the lamp is weakened ???
This is the reason for the destruction of light bulbs in this link ...
Numerous electric shocks, through rusty contacts (rattling), on a lamp that has not been warmed up to a nominal value, are most likely to destroy it ...
All.
And nothing to do with the capacitance ... inductance ... propagation velocity ... Amplitude values ​​in half-periods ....

[#22 Author]

I found it necessary to turn to ,   and all subsequent angry commentators. Yes, I completely agree with you, the article turned out to be crooked. I became interested in particulars in it, completely losing sight of the important and the whole.

BUT: it is unfortunate that there are no dates for the publication of comments and the article itself. However, according to the total number of comments, one can guess that the article is already over a year old, that only the lazy one has not gone through it, and commenting it in the spirit of "the article is wrong, and the real reasons are in the rattling of contacts, etc." not only gives away by necroposting, but also does not bring absolutely anything new.

I venture to provoke your righteous anger again, but I repeat that the laws of switching (for those who do not know what it is - we look at textbooks on FCE) influence the process. Let their influence is far from paramount, but it is.

[#23 kartallang]

This problem is probably present in every building where there are lighting lamps. Made a simple observation. In the bathroom it’s damp somewhere dry, the temperature is constantly changing ..., the lamp has been working for several years. In the hall there is a 9pcs x 60W chandelier. Steadily burn 1-2 lamps closest to the window. The option with bad lamps and ammunition was dropped when I turned the chandelier 180 degrees. Now other lamps, which are also close to the window, began to burn. The same thing in the nursery and in the kitchen. I tried energy-saving, they burn even faster. The conclusion suggests itself, I have an enemy of light bulbs - air circulation. There is one way out, I think, to make a smooth start.

[#24]

In support of the author.
Transients are obvious in sparks when turning on / off the lamps - sparks are evident. With a purely active load, there would be no sparks.

[#25]

It’s even scary to write what strict niggles there are. Well so, in 90% of cases the cartridge is to blame, you can often hear his “singing”, these are bad contacts. The processes resemble the operation of a classic car ignition system.
There is still an interesting observation. If we take a “deaf” lamp of the NBB type, then with the ceiling version of the installation, the wires connecting the bulb to the base burn out in the bulb, and in the wall version the spiral burns out.

[#26 MaksimovM]

But it still seems to me that incandescent lamps burn out mainly due to factory defects. It happens that there are lamps that last for several years, but there are also those that burn out almost on the first day (or even when you turn it on for the first time). At the same time, the lighting lines are in the same condition and the lamps are used in the same conditions (the number of on / off, the same time).

Oxidized contacts and twists in junction boxes, how can they affect lamp life? The voltage in the lamp holder is either there or not. For example, the twist in the junction box is in unsatisfactory condition, heats up, but at the same time it passes current and there is voltage on the lamp holder.

Sin the same for the duration of the electrical appliance, citing the unsatisfactory condition of the electrical networks as an argument. There are lines on which twists can be found every 20-50 meters. Current leakage, voltage drop on poor-quality contact connections in this case is present, but these circumstances do not affect the operation of electrical appliances included in the network.

[#27]

kartallang,
The article is excellent, but a bit confusing. Described in the majority true. In the comment 26 gives the correct answer to the cause of the failure of the lamps. In the old standard, incandescent lamps had a voltage of 245V, and a euro of 230V, and the Kyrgyz 225v, 245 will burn for years with a normal circuit. 230 from the strength of a year or even earlier, 225 volts only a couple of days and you decide where in the new working lamp that is faulty when the voltage in the network 225-230v.

[#28]

Little is known about electricity, everyone understands it in their own way, so arguing is useless, whoever reveals this secret will be given a noble.

[#29]

“So, according to the theory of transients, the transition from a complete absence of current to 2.7 amperes can never be instantaneous. This, perhaps, is not surprising - after all, there are practically no instantaneous processes in life, there are only processes that take very small periods of time from our human point of view. And here the process of changing the electric current in the light of the restroom takes thousandths, maybe hundredths of a second "-

Well, in this case, you have to explain - how much do you think of an INSTANT? If the speed of electric current is SPEED OF LIGHT. IF AN INSTANT IS IT FASTER THAN ON HOW MUCH?

[#30]

The diode will only reduce the frequency of the appearance of 310 volts to 50 times per second instead of a hundred.

[#31]

Bad twisting, poor soldering - an extra, unstable p-n junction. Not?
I have not yet met articles popular on the effect of an unstable p-n junction on AC 100 - 300 V circuits.
I have stably burned lamps that have incandescent, that energy-saving Ecola, for two wall lights, connected to one switch. But only in the lower cartridges (lamps are directed down).

[#32 Yuri]

Quote: Sasha

But the reasons for the constant burnout of the lamp in one lamp - a lot, including the laws of switching.

The topic of the article is somehow not disclosed.
In the toilet, the lamp burns out, there is no lamp in the corridor ... Commutation laws ...
What switching laws apply only to the toilet light?
Then write that in the toilet it is often switched.
But the thing is different. The topic, I repeat, is not disclosed.
We have a lighting installation (not in the toilet :)) of 5 lamps. All lamps are of the same type, all are installed in the same room on the ceiling, in the same position. In all fixtures, the same type of lamp of the same power. All lamps are switched on in parallel from one switch. But at the same time, one lamp always burns, while the others have been burning for several years.
Do the switching laws in such an installation act selectively?

[#33 Helena]

Alexander, I have exactly the same situation in my kitchen - a wall sconce with a downward direction, when turned on, several energy-saving lamps already exploded. I just stopped screwing them, I can’t find the reason, but I feel sorry for the lamp)) The lamp and the chandelier are almost the same, but in the chandelier the lamps do not burn out ...

[#34 Germann Franz Werker]

Sequential inclusion of two lamps of the same power solves this problem for decades !!! In my house, almost everywhere there are such pairs of 40 watts on each lamp!

[#35 Bady]

The reason is usually the bounce of the switch contacts.

[#36 Viktorb48]

1 When you turn on the light flashed and burned out - this is not uncommon But at the same time the light went out in the apartment - the machine was knocked out.
2 In addition to the transition process, the excess current, I can not explain.
3 But the machine rarely knocks out when the lamp burns, for the first time I
The reason, I think, the percentage change depends on the moment of inclusion
regarding the period of tension - the author spoke about this
4 Combustion due to poor contact (cartridge, off, twisting) -
perhaps . but it’s not very clear to me how this happens — just speculation.