The saga of LED lamps. Part 2 - about what is not written on the boxes
The last time , we briefly recall the history of artificial lighting, and talked a bit about what the basic parameters have energy saving lamps and LED lamps in general in particular. Today, as promised, we will move on to measurements and comparisons (but so far without unwinding).
First of all, I was worried about the obvious question - nevertheless, are ordinary LED lamps that can be bought in the store so fabulously effective in real conditions? To answer it, I decided to measure the illumination created in my room by different bulbs screwed into the same (my) chandelier. Initially, there were three twenty- watt CFLs in it."Era"; For comparison, I took three Gauss LED lamps of 12 W each (claimed to be an analogue of a 100 W incandescent lamp) and, for the purity of the experiment, three conventional 95 W incandescent lamps. The measurements were carried out in the center of the room, that is, exactly where the brightness of the lighting is most interesting and necessary for me. I will say right away - from the point of view of photometry, this is probably not entirely correct; but from the point of view of ordinary life, such a comparison, it seems to me, is of main interest, since it reflects the behavior of the light bulb not in the integrating sphere, but in the ordinary chandelier itself.
Measurements were taken with a Mastech MS6610 Luxometer. I excluded third-party illumination with blackout curtains (when the lighting was off, the device showed zero lux). Since the luminous flux of fluorescent and LED lamps depends on their temperature, the illumination values were measured twice - immediately after switching on and after a ten-minute warm-up (it was empirically found that after ten minutes of operation, the illumination changes very slightly). Incandescent lamps, of course, do not need to be heated, so they were measured only once, immediately after switching on, so as not to spoil the chandelier, which, if my memory serves me, does not exceed a maximum of 40 watts (for an incandescent lamp) in each horn. The results of this experiment can be observed in the table below.
Well, it is clear that in this test the LED lamps (at least the ones that I had) really surpass everything that can now be screwed into a regular E27 cartridge (with the possible exception of some kind of exotic). With incandescent lamps, everything is clear - I already guessed that the result would not be too impressive. It is more interesting to compare LED lamps and still popular CFLs.
It is immediately evident that in the first ten minutes, CFLs change the brightness by almost five times. In practice, this means that for the everyday scenario “I went into the room (closet) for two minutes to find something” they are the worst suited - by the time they enter the operating mode they will most likely be turned off. This is in addition to the fact that gas-discharge lamps even do not tolerate frequent switching on, although, suppose, in the storage room they may not be so frequent, but, nevertheless, short-lived. LED lamps, on the contrary, slightly reduce brightness as they warm up - a voltage drop, and, consequently, the power (at constant current) on a heated LED is less. Nevertheless, the difference in brightness here is not as stunning as in the case of CFL (which indirectly indicates a fairly good heat sink specifically in these lamps). By the way, it’s clear that even after warming up, the difference is still in favor of the LEDs, although its size is such that the illumination created by both of them can be considered approximately equal. However, we are talking about approximately equal illumination created by a twenty-watt CFL and a twelve-watt LED lamp - saving almost twice as much power. You can’t even talk about incandescent lamps - with many times more power consumption in the created illumination, they lose both CFL and LEDs. In addition, as I mentioned above, ninety-five-watt lamps cannot be screwed into my chandelier at all, so in reality with incandescent lamps I would not even get these hundred lux. Of course, this limitation is associated with heating. However, we are talking about approximately equal illumination created by a twenty-watt CFL and a twelve-watt LED lamp - saving almost twice as much power. You can’t even talk about incandescent lamps - with many times more power consumption in the created illumination, they lose both CFL and LEDs. In addition, as I mentioned above, ninety-five-watt lamps cannot be screwed into my chandelier at all, so in reality with incandescent lamps I would not even get these hundred lux. Of course, this limitation is associated with heating. However, we are talking about approximately equal illumination created by a twenty-watt CFL and a twelve-watt LED lamp - saving almost twice as much power. You can’t even talk about incandescent lamps - with many times more power consumption in the created illumination, they lose both CFL and LEDs. In addition, as I mentioned above, ninety-five-watt lamps cannot be screwed into my chandelier at all, so in reality with incandescent lamps I would not even get these hundred lux. Of course, this limitation is associated with heating. In addition, as I mentioned above, ninety-five-watt lamps cannot be screwed into my chandelier at all, so in reality with incandescent lamps I would not even get these hundred lux. Of course, this limitation is associated with heating. In addition, as I mentioned above, ninety-five-watt lamps cannot be screwed into my chandelier at all, so in reality with incandescent lamps I would not even get these hundred lux. Of course, this limitation is associated with heating.
Incandescent lamps, obviously, have already fallen, so let's compare CFLs and LED heating lamps.
These images were also shot after a ten-minute warm-up. It can be seen that CFL is heated to a hundred degrees or more, while the maximum temperature of an LED lamp is only about sixty. That is, the possibility of getting burned about CFL, in principle, exists (the protein begins to curl up at eighty degrees Celsius), while with an LED lamp this is impossible in principle. A trifle, but nice.
So, we figured out that from the point of view of those characteristics that come to mind first, LEDs are clearly better. Time to talk about more subtle matters, such as power factor and ripple factor. For some reason they rarely recall these hacktails, and, of course, they (so far?) Are never written on the packaging, but in vain.
The ripple factor is a very important indicator. Despite the fact that our brain does not consciously process changes in brightness with a frequency of more than 16 - 20 Hz, the effect of them is quite noticeable. Significant pulsations of general illumination can lead to increased fatigue, migraines, depression and other unpleasant things in terms of the psyche. This indicator is normalized in SNiP 23-05-95. There are a lot of different tables, but, in general, it can be inferred from them that the ripple coefficient of general lighting should not exceed 20%. It is worth mentioning that talking about all this makes sense up to a frequency of about 300 Hz, since then the retina itself does not have time to react to changes in illumination, and therefore in this case an irritating signal does not come to the brain.
The power factor for the end user is, in principle, unimportant. This parameter shows the ratio of the active power consumed by the device to the total power, taking into account the reactive part, not producing useful work, but, in particular, heating the wires. The name "cosine phi" is also common - this is all because the quantity of interest to us can be introduced as the cosine of a certain conditional angle. The maximum, ideal value of the power factor is 1. Household meters only consider active power, it is also written on the packages; for the consumer in this sense there are no problems. However, if we are talking about a global scale (for example, a millionth city, completely illuminated by LED lights), a low power factor can create big problems for power engineers.
I measured the power and power factor with the muRata ACM20-2-AC1-RC head . The ripple coefficient was measured by a Uni-Trend UTD2052CL oscilloscope , to which the following circuit was connected:
Who cares , this is a classic frequency-compensated current-voltage converter on an operational amplifier, supplemented by an artificial midpoint. It is powered, to avoid interference, from the battery. Diode BPW21R- a photometric class device with a characteristic compensated according to the sensitivity of the human eye. The documentation guarantees the linearity of the current depending on the illumination in the photovoltaic mode, so that the circuit produces a voltage directly proportional to the illumination of the photodiode and is quite suitable for measuring the ripple coefficient. By the way, it is defined as the ratio of the range of pulsations to twice the average value. Both the magnitude and the average value are included in the standard automatic measurements of any modern digital oscilloscope, so there is no problem with this - it remains only to double and divide. Comparison of the measurement results of this improvised design with the values provided by the TKA-PULS device(State Register), showed a discrepancy of the measured pulsation coefficient of not more than a percent.
So, the measurement results for the lamps that were at my fingertips:
With the E27 base:
With cap E14:
As we can see, LED lamps here are not so rosy. A very interesting fact is immediately revealed - it seems that the quality of LED lamps cannot be judged only by the manufacturer; the same brands, generally speaking, set both quality records and anti-records. It should be noted that I rendered the general verdict presented in the table, giving greater importance to the ripple factor than the power factor, for the reasons stated above. But even a ripple factor of 1% cannot fully justify a power factor of 0.5 in the case of an industrial product sold in million copies. However, for a house it is better to take such a lamp than a product with a unit power factor and a ripple level of 50%.
Of course, lamps with a ripple coefficient of more than 20% are categorically not suitable for general lighting (this should not be screwed into a chandelier of six pieces). By the way, for the CFA "Era" I mentioned, it is slightly less than 10%, and for the classic incandescent lamp - about 13%.
The last parameters that you can talk about in passing are color temperature and color rendering index. Despite the fact that they are formalized, at the household level it comes down to “like / dislike”. I must say that all the tested lamps in this regard pleased me - none had a clear bias in blue or excessive yellowness, all had a pleasant white tint. But this, of course, is for my taste, and nothing more.
In the following articles, we will finally look at what the lamps have inside and try to figure out what internal reasons make good lamps good and bad lamps bad.
The choice of lamps for tests is determined solely by the “what was” consideration. If (when) other lamps appear - I will measure and lay out.
Is it worth it?
First of all, I was worried about the obvious question - nevertheless, are ordinary LED lamps that can be bought in the store so fabulously effective in real conditions? To answer it, I decided to measure the illumination created in my room by different bulbs screwed into the same (my) chandelier. Initially, there were three twenty- watt CFLs in it."Era"; For comparison, I took three Gauss LED lamps of 12 W each (claimed to be an analogue of a 100 W incandescent lamp) and, for the purity of the experiment, three conventional 95 W incandescent lamps. The measurements were carried out in the center of the room, that is, exactly where the brightness of the lighting is most interesting and necessary for me. I will say right away - from the point of view of photometry, this is probably not entirely correct; but from the point of view of ordinary life, such a comparison, it seems to me, is of main interest, since it reflects the behavior of the light bulb not in the integrating sphere, but in the ordinary chandelier itself.
Measurements were taken with a Mastech MS6610 Luxometer. I excluded third-party illumination with blackout curtains (when the lighting was off, the device showed zero lux). Since the luminous flux of fluorescent and LED lamps depends on their temperature, the illumination values were measured twice - immediately after switching on and after a ten-minute warm-up (it was empirically found that after ten minutes of operation, the illumination changes very slightly). Incandescent lamps, of course, do not need to be heated, so they were measured only once, immediately after switching on, so as not to spoil the chandelier, which, if my memory serves me, does not exceed a maximum of 40 watts (for an incandescent lamp) in each horn. The results of this experiment can be observed in the table below.
| Lamp type | condition | Measured Light, Lux |
| CFL "Era" 20 W 2700 K | cold start | thirty |
| warmed up | 131 | |
| 95 W incandescent lamp | - | 101 |
| Lamp Gauss LED 2700 K 12 W | cold start | 146 |
| warmed up | 137 |
Well, it is clear that in this test the LED lamps (at least the ones that I had) really surpass everything that can now be screwed into a regular E27 cartridge (with the possible exception of some kind of exotic). With incandescent lamps, everything is clear - I already guessed that the result would not be too impressive. It is more interesting to compare LED lamps and still popular CFLs.
It is immediately evident that in the first ten minutes, CFLs change the brightness by almost five times. In practice, this means that for the everyday scenario “I went into the room (closet) for two minutes to find something” they are the worst suited - by the time they enter the operating mode they will most likely be turned off. This is in addition to the fact that gas-discharge lamps even do not tolerate frequent switching on, although, suppose, in the storage room they may not be so frequent, but, nevertheless, short-lived. LED lamps, on the contrary, slightly reduce brightness as they warm up - a voltage drop, and, consequently, the power (at constant current) on a heated LED is less. Nevertheless, the difference in brightness here is not as stunning as in the case of CFL (which indirectly indicates a fairly good heat sink specifically in these lamps). By the way, it’s clear that even after warming up, the difference is still in favor of the LEDs, although its size is such that the illumination created by both of them can be considered approximately equal. However, we are talking about approximately equal illumination created by a twenty-watt CFL and a twelve-watt LED lamp - saving almost twice as much power. You can’t even talk about incandescent lamps - with many times more power consumption in the created illumination, they lose both CFL and LEDs. In addition, as I mentioned above, ninety-five-watt lamps cannot be screwed into my chandelier at all, so in reality with incandescent lamps I would not even get these hundred lux. Of course, this limitation is associated with heating. However, we are talking about approximately equal illumination created by a twenty-watt CFL and a twelve-watt LED lamp - saving almost twice as much power. You can’t even talk about incandescent lamps - with many times more power consumption in the created illumination, they lose both CFL and LEDs. In addition, as I mentioned above, ninety-five-watt lamps cannot be screwed into my chandelier at all, so in reality with incandescent lamps I would not even get these hundred lux. Of course, this limitation is associated with heating. However, we are talking about approximately equal illumination created by a twenty-watt CFL and a twelve-watt LED lamp - saving almost twice as much power. You can’t even talk about incandescent lamps - with many times more power consumption in the created illumination, they lose both CFL and LEDs. In addition, as I mentioned above, ninety-five-watt lamps cannot be screwed into my chandelier at all, so in reality with incandescent lamps I would not even get these hundred lux. Of course, this limitation is associated with heating. In addition, as I mentioned above, ninety-five-watt lamps cannot be screwed into my chandelier at all, so in reality with incandescent lamps I would not even get these hundred lux. Of course, this limitation is associated with heating. In addition, as I mentioned above, ninety-five-watt lamps cannot be screwed into my chandelier at all, so in reality with incandescent lamps I would not even get these hundred lux. Of course, this limitation is associated with heating.
Incandescent lamps, obviously, have already fallen, so let's compare CFLs and LED heating lamps.
These images were also shot after a ten-minute warm-up. It can be seen that CFL is heated to a hundred degrees or more, while the maximum temperature of an LED lamp is only about sixty. That is, the possibility of getting burned about CFL, in principle, exists (the protein begins to curl up at eighty degrees Celsius), while with an LED lamp this is impossible in principle. A trifle, but nice.
More measurements
So, we figured out that from the point of view of those characteristics that come to mind first, LEDs are clearly better. Time to talk about more subtle matters, such as power factor and ripple factor. For some reason they rarely recall these hacktails, and, of course, they (so far?) Are never written on the packaging, but in vain.
The ripple factor is a very important indicator. Despite the fact that our brain does not consciously process changes in brightness with a frequency of more than 16 - 20 Hz, the effect of them is quite noticeable. Significant pulsations of general illumination can lead to increased fatigue, migraines, depression and other unpleasant things in terms of the psyche. This indicator is normalized in SNiP 23-05-95. There are a lot of different tables, but, in general, it can be inferred from them that the ripple coefficient of general lighting should not exceed 20%. It is worth mentioning that talking about all this makes sense up to a frequency of about 300 Hz, since then the retina itself does not have time to react to changes in illumination, and therefore in this case an irritating signal does not come to the brain.
The power factor for the end user is, in principle, unimportant. This parameter shows the ratio of the active power consumed by the device to the total power, taking into account the reactive part, not producing useful work, but, in particular, heating the wires. The name "cosine phi" is also common - this is all because the quantity of interest to us can be introduced as the cosine of a certain conditional angle. The maximum, ideal value of the power factor is 1. Household meters only consider active power, it is also written on the packages; for the consumer in this sense there are no problems. However, if we are talking about a global scale (for example, a millionth city, completely illuminated by LED lights), a low power factor can create big problems for power engineers.
I measured the power and power factor with the muRata ACM20-2-AC1-RC head . The ripple coefficient was measured by a Uni-Trend UTD2052CL oscilloscope , to which the following circuit was connected:
Who cares , this is a classic frequency-compensated current-voltage converter on an operational amplifier, supplemented by an artificial midpoint. It is powered, to avoid interference, from the battery. Diode BPW21R- a photometric class device with a characteristic compensated according to the sensitivity of the human eye. The documentation guarantees the linearity of the current depending on the illumination in the photovoltaic mode, so that the circuit produces a voltage directly proportional to the illumination of the photodiode and is quite suitable for measuring the ripple coefficient. By the way, it is defined as the ratio of the range of pulsations to twice the average value. Both the magnitude and the average value are included in the standard automatic measurements of any modern digital oscilloscope, so there is no problem with this - it remains only to double and divide. Comparison of the measurement results of this improvised design with the values provided by the TKA-PULS device(State Register), showed a discrepancy of the measured pulsation coefficient of not more than a percent.
So, the measurement results for the lamps that were at my fingertips:
With the E27 base:
| Lamp type | Measured power, W (cold start) | cos (φ) | K p | Generally |
| ASD 11W | 9 | 0.82 | 1% | Very well |
| Gauss 12 w | 12 | 0.62 | 1% | Good |
| Gauss 6.5 w | 6 | 0.50 | 1% | Acceptable |
| SUPRA 11 W | 9 | 0.95 | 35% | poorly |
| ASD 7 W | 4 | 0.45 | 100% | Disgusting |
With cap E14:
| Lamp type | Measured power, W (cold start) | cos (φ) | K p | Generally |
| Gauss 3w | 2 | 0.60 | 1% | Good |
| Gauss 6.5w | 6 | 0.95 | 49% | Very bad |
| Wolta 5w | 2.2 | 0.40 | 68% | Disgusting |
You should talk about the Wolta lamp separately
On the packaging we read the proud inscription:
"Optimal frequency of flicker for the eyes." To go nuts! What kind of frequency is there? Maybe they mean that it is far beyond the limits of 300 Hertz regulated by sanitary standards?
On the oscilloscope we see:
100 Hz, ripple factor 68%. SanPiN does not work. What they mean by optimality is a mystery ...
"Optimal frequency of flicker for the eyes." To go nuts! What kind of frequency is there? Maybe they mean that it is far beyond the limits of 300 Hertz regulated by sanitary standards?
On the oscilloscope we see:
100 Hz, ripple factor 68%. SanPiN does not work. What they mean by optimality is a mystery ...
As we can see, LED lamps here are not so rosy. A very interesting fact is immediately revealed - it seems that the quality of LED lamps cannot be judged only by the manufacturer; the same brands, generally speaking, set both quality records and anti-records. It should be noted that I rendered the general verdict presented in the table, giving greater importance to the ripple factor than the power factor, for the reasons stated above. But even a ripple factor of 1% cannot fully justify a power factor of 0.5 in the case of an industrial product sold in million copies. However, for a house it is better to take such a lamp than a product with a unit power factor and a ripple level of 50%.
Of course, lamps with a ripple coefficient of more than 20% are categorically not suitable for general lighting (this should not be screwed into a chandelier of six pieces). By the way, for the CFA "Era" I mentioned, it is slightly less than 10%, and for the classic incandescent lamp - about 13%.
The last parameters that you can talk about in passing are color temperature and color rendering index. Despite the fact that they are formalized, at the household level it comes down to “like / dislike”. I must say that all the tested lamps in this regard pleased me - none had a clear bias in blue or excessive yellowness, all had a pleasant white tint. But this, of course, is for my taste, and nothing more.
In the following articles, we will finally look at what the lamps have inside and try to figure out what internal reasons make good lamps good and bad lamps bad.
Note:
The choice of lamps for tests is determined solely by the “what was” consideration. If (when) other lamps appear - I will measure and lay out.