How to calculate the ratio of resistive and reactive load if the impedance/resistance is not measurable?
http://www.ibiblio.org/kuphaldt/electricCircuits/AC/AC_11.html#02216.png
As a practical example, I’d like to measure the cos(phi) of an energy saving light bulb which states to consume 8W but measures 230V * 0.057A = 13.1W.
Of course, believing the manufacturer is the easiest, 13.1W – 8W gives a power factor of 0.61 but I'd like to verify.
Out of circuit, the bulb has an infinite resistance probably caused by the internal ignition circuit.
/Hugo
http://www.ibiblio.org/kuphaldt/electricCircuits/AC/AC_11.html#02216.png
As a practical example, I’d like to measure the cos(phi) of an energy saving light bulb which states to consume 8W but measures 230V * 0.057A = 13.1W.
Of course, believing the manufacturer is the easiest, 13.1W – 8W gives a power factor of 0.61 but I'd like to verify.
Out of circuit, the bulb has an infinite resistance probably caused by the internal ignition circuit.
/Hugo
Hi,
Said bulbs have a complex supply / ignition circuit.
You cannot derive the power factor from that simple formula.
Only way I know of is a small additional resistor and an oscilloscope.
🙂/sreten.
Said bulbs have a complex supply / ignition circuit.
You cannot derive the power factor from that simple formula.
Only way I know of is a small additional resistor and an oscilloscope.
🙂/sreten.
Hi,
Yes. With an oscilloscope you can then see the current and
its relationship with input voltage. May not be continuous.
🙂/sreten.
Yes. With an oscilloscope you can then see the current and
its relationship with input voltage. May not be continuous.
🙂/sreten.
Thanks.
Would there be a way to compensate these bulbs for a higher power factor. I calculated a 457µF (!) capacitor would bring the power factor close to 1. Apart from the fact that its rather silly to do, I'm trying to get a grasp of the basic math.
/Hugo
Would there be a way to compensate these bulbs for a higher power factor. I calculated a 457µF (!) capacitor would bring the power factor close to 1. Apart from the fact that its rather silly to do, I'm trying to get a grasp of the basic math.
/Hugo
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