Question: How to connect a 1UF/400V capacitor in a 220V AC circuit?

book1

Question: How to connect a 1UF/400V capacitor in a 220V AC circuit? [Copy link]

I would like to ask: If a 1UF/400V capacitor is connected in parallel to a 220V AC circuit and a 3.6K/15W resistor is connected in parallel to a 220V AC circuit, are their power consumption (watt-hour meter reading) similar? Thank you!

book1

A 1UF/400V capacitor is connected in parallel to a 220V AC circuit. If one LED is connected in series (assuming the LED has been protected against surges), the current is about 60mA. If 50 LEDs are connected in series, the current is about 40mA. However, the difference in total brightness can be imagined: it is very large, but the total power consumption is reduced, which improves the conversion efficiency. But I didn't look at the watt-hour meter, so I would like a theoretical answer... Thank you!!

maychang

"A 1UF/400V capacitor is connected in parallel to a 220V AC circuit"

If the capacitor is connected in parallel with the AC mains, the watt-hour meter will not count.

maychang

"A 3.6K/15W resistor is connected in parallel to a 220V AC circuit"

In this case, the electricity meter will count that one kilowatt-hour of electricity is consumed in 74.38 hours.

maychang

book1 Published on 2021-5-15 08:33 A 1UF/400V capacitor is connected in parallel to a 220V AC circuit. If a light-emitting diode is connected in series (assuming that the light-emitting diode has been protected against surges), the power...

As mentioned above, if the capacitor is connected in parallel with the AC mains, the meter will not count, that is, no energy is consumed. If the capacitor is connected in series with the LED, the meter will count. The more LEDs are connected in series, the faster the meter will count. The meter counts, indicating that the LED consumes energy. The more LEDs are connected in series, the more energy is consumed.

maychang

book1 Published on 2021-5-15 08:33 A 1UF/400V capacitor is connected in parallel to a 220V AC circuit. If a light-emitting diode is connected in series (assuming that the light-emitting diode has been protected against surges), the power...

"Seeking theoretical answer"

AC power is not the voltage measured by the multimeter multiplied by the current measured by the multimeter. The voltage measured by the multimeter multiplied by the current measured by the multimeter is called apparent power, and the unit is volt-ampere. The power converted into heat or other forms of energy is active power, and the unit is watt. The power that is not converted into other forms of energy is reactive power, and the unit is var, abbreviated as var.

maychang

book1 Published on 2021-5-15 08:33 A 1UF/400V capacitor is connected in parallel to a 220V AC circuit. If a light-emitting diode is connected in series (assuming that the light-emitting diode has been protected against surges), the power...

"If you string one LED in series (assuming the LED has been surge protected), the current is about 60mA. If you string 50, the current is about 40mA. But you can imagine the difference in total brightness: it's huge, but the total power consumption is reduced, which improves the conversion efficiency."

There is no improvement in "conversion efficiency", only the apparent power becomes smaller, but the active power part of the apparent power becomes larger. Of course, the reactive power is smaller at this time.

chunyang

The original poster's question involves active and reactive power. At least the newly installed energy meters are electronic, and many of them support the recording of apparent, active and reactive power. However, traditionally, household energy meters only record active power and charge according to active power. I don't know whether reactive power is involved now, but I guess it should not be the case in most areas.

book1

I would like to thank all the netizens for their wonderful answers, thank you!