LED GU10 Wattage question
- Thread starter Diyisfun
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SMD means Surface Mount Device - the 48 LEDs are on the surface.
This is nothing to do with wattage.
Ask the supplier?
This is nothing to do with wattage.
Ask the supplier?
Thanks, I was aware of smd meaning, I thought there might be a correlation between wattage/& no. of smd.
I have contacted the seller, I posted whilst waiting for a reply.
When it gets dark I can compare it against a known 4.5w.
Was there a picture of the 5W ones when you ordered; did they have 60?
I'm not sure if all the LEDs have the same consumption.
Rocky333 will know.
I'm not sure if all the LEDs have the same consumption.
Rocky333 will know.
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That's just the picture. Show us the link with the description too…..it looks like 48 devices.
4 x GU10 48 SMD LED Bulbs Day White Light Spotlight 5W 50W Halogen Lamp Bright
( 151578467276 )
Thanks for the confidence, unfortunately not up to speed with Led yet
At a quess i would have thought the amount of leds or the wattage were unimportant,
The lumen outputs what matter, One make to another could vary even with the same wattage and number i would have thought
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I read up on LED's and it would seem there is a major problem with output. Although we have the lumen some measure each LED and multiply by number of LED's others measure as a package. Also some measure straight away others wait an hour before measuring.
As to the built some have simple resistors others have switch mode controllers.
The net result is neither watts or lumen really give us any idea of the output. Even measuring watts does not help with a switched mode controller as volts drop amps increase with simple resistor the reverse happens.
So down to nitty gritty does it matter?
As to the built some have simple resistors others have switch mode controllers.
The net result is neither watts or lumen really give us any idea of the output. Even measuring watts does not help with a switched mode controller as volts drop amps increase with simple resistor the reverse happens.
So down to nitty gritty does it matter?
LED elements can be made to be brighter by pulsing them with high current pulses that average out to be the maximum permitted current.
A LED element normally supplied with a continuous 1 amp current will look brighter if it is supplied with pulses of 2 amps with a time ratio of 1/3 at 2 amps and 2/3 at zero amps. Average current is less but the LED "appears" brighter but has the disadvantage of a strobe effect due to the light being a series of pulses and not continuous.
The ratio of currents (pulse and average) and the ON to OFF ratio have to be carefully designed to avoid shortening the life of the LED element by exceeding the maximum peak current rating of the element.
Some low cost high brightness lamp manufacturers may not do this design with a long life span in mind.
A LED element normally supplied with a continuous 1 amp current will look brighter if it is supplied with pulses of 2 amps with a time ratio of 1/3 at 2 amps and 2/3 at zero amps. Average current is less but the LED "appears" brighter but has the disadvantage of a strobe effect due to the light being a series of pulses and not continuous.
The ratio of currents (pulse and average) and the ON to OFF ratio have to be carefully designed to avoid shortening the life of the LED element by exceeding the maximum peak current rating of the element.
Some low cost high brightness lamp manufacturers may not do this design with a long life span in mind.
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This was an experiment done by my class in University. Most never managed to complete in time so guessed the results. I was one of the few who did complete the experiment.
The actual results were not as expected. Measured with a light meter the output did not increase as to if it appeared brighter to human eye is hard to say. Also found started to damage LED's so returning to rated current the output was lower.
Since switch mode power supplies do as the name suggests they switch on/off with a variable mark/space ratio you will likely detect some high and low output hopefully a capacitor would mean not actually on/off. Without reverse engineering hard to say if pulsing is actually used to increase output or a by produce of using a switch mode regulator. But I suspect the latter.
With 48 LED's at around 3 volt each that's around 150 volt in series so using a simple resistor to limit current is possible without generating too much heat. To use a switched mode regulator chip for each of the 48 LED's would be too expensive so even if using a chip likely it will not control current but instead voltage and then a simple resistor to each LED to control current or even no current control.
With a single LED however it would make sense to use a current limiting switch mode chip to directly control the current used by the LED.
This is to me the big problem with any of the so called energy saving bulbs. Be is a CFL or a LED both have some electronic circuits in the bulb and we as the user have no idea what is in each bulb. All we can do is read watts and lumen marked on the bulbs.
Reading watts and lumen is interesting as there is a huge variation between how many lumen per watt is claimed from bulb to bulb. My folded fluorescent reading lamp being more efficient than some of my LED GU10 bulbs.
I look at my bedroom reading lights with 2W and 3W LED GU10 and am very satisfied with result. Both my son and I have SES LED's in living room again good results. But my sons kitchen with 7W GU10 LED's is a real disappointment no where near enough light.
I look at his 7W and compare to my 2W and I just can't see the 7W is three times brighter. Yes they are brighter but I don't think 3 times brighter.
The actual results were not as expected. Measured with a light meter the output did not increase as to if it appeared brighter to human eye is hard to say. Also found started to damage LED's so returning to rated current the output was lower.
Since switch mode power supplies do as the name suggests they switch on/off with a variable mark/space ratio you will likely detect some high and low output hopefully a capacitor would mean not actually on/off. Without reverse engineering hard to say if pulsing is actually used to increase output or a by produce of using a switch mode regulator. But I suspect the latter.
With 48 LED's at around 3 volt each that's around 150 volt in series so using a simple resistor to limit current is possible without generating too much heat. To use a switched mode regulator chip for each of the 48 LED's would be too expensive so even if using a chip likely it will not control current but instead voltage and then a simple resistor to each LED to control current or even no current control.
With a single LED however it would make sense to use a current limiting switch mode chip to directly control the current used by the LED.
This is to me the big problem with any of the so called energy saving bulbs. Be is a CFL or a LED both have some electronic circuits in the bulb and we as the user have no idea what is in each bulb. All we can do is read watts and lumen marked on the bulbs.
Reading watts and lumen is interesting as there is a huge variation between how many lumen per watt is claimed from bulb to bulb. My folded fluorescent reading lamp being more efficient than some of my LED GU10 bulbs.
I look at my bedroom reading lights with 2W and 3W LED GU10 and am very satisfied with result. Both my son and I have SES LED's in living room again good results. But my sons kitchen with 7W GU10 LED's is a real disappointment no where near enough light.
I look at his 7W and compare to my 2W and I just can't see the 7W is three times brighter. Yes they are brighter but I don't think 3 times brighter.
That doesn't surprise me. Human visual perception is much more complex, and in many senses more sophisticated, than a standard (e.g. 'photographic') light meter. As bernard has implied, in some situations the human eye senses peak, rather than 'average', light intensity when the intensity is pulsatile. If you could find a light meter that could do the same, it would presumably give a high reading for high intensity light pulses (as compared with continuous light of the same average intensity), just as does human perception.
Kind Regards, John
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