I have measured the power consumption of an LED lamp, but get a varying amperage. I don’t have an analog meter. The base of an LED lamp gets hot, so I suspect a ballast system, which also consumes energy. Is this possible?
Answer
Dear Emeric
Indeed, an LED lamp that is connected to 230VAC always has a ballast system and depending on the quality of the circuit, this system will consume more or less energy. Normally this is little, but the consumption is never 0.
To measure the real consumption you need a good meter, I mean a true rms meter. A simple ammeter assumes that the signal is sinusoidal and will calculate the effective value from this. In most cases the ballast system of the LED lamp will not draw a sinusoidal current and these “simple” meters give an incorrect current value. A true rms meter measures correctly with distorted (non-sinusoidal / clipped) signals.
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Answered by
Ing Bart Smeets
Electronics ICT Electricity
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