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143 posts

Master Geek
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# 249162 28-Apr-2019 18:59
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I am replacing some lights at home with LED and when reading the specs on the bulb a 10.5 W LED  has a voltage rating of 220 - 240 V at 95 mA that is a lot more than is between 21 and 23 Watts of power draw still a lot less than a 100 Watt roughly equivalent bulb so for those that are totally into power saving this would be slightly less saving than they had planned. Has anyone else noticed this and is this actually false advertising ? 

 

 


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184 posts

Master Geek
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  # 2226945 28-Apr-2019 19:21
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Perhaps the specs are quoting peak current at 95ma ?  If the LED lamps are a reputable brand then I would believe the claimed wattage as being reasonably accurate. 


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  # 2226947 28-Apr-2019 19:24
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Your post would be a lot easier to read, understand, and reply to if you can edit your post to use sentences.


 
 
 
 


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Master Geek
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  # 2226949 28-Apr-2019 19:27
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Peak current is sqrt(2) * Power/Voltage   = SQRT(2) x 10.5/230  = 65mA


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  # 2227045 28-Apr-2019 21:36
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It would be due to power factors.

In AC circuits. You multiply Voltage X Current X power factor to get wattage.

If the load is resistive (filament lamp, heating element etc) then the power factor is 1.

Lots of cheap electronic devices and small electric motors. The power factor is often around 0.6 But it can easily be better or worse.

if we calculate 220V X 0.095A X 0.5PF = 10.45Watts.

So the manufacturer might actually be telling the truth.

But to confirm. You will need to measure the actual power used. And the light output. To make sure that they haven't taken a 5W or 7W fitting and labeled it as a 10.5W fitting.






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  # 2227049 28-Apr-2019 21:51
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The numbers mentioned line up with a Philips LED lamp. Philips quote the nominal PF as 0.5.



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Master Geek
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  # 2227104 29-Apr-2019 09:15
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Thank you for your explanation. I only considered power factor something associated with AC motors and yes they are Philips LED lights.

 

 


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