Same way an inductor burns power through inductive reactance - to the current flow, ohms are ohms whether its reactance or resistance. Again this is NOT the same thing as power factor, which is entirely the result of the current/voltage phase shift of a reactive load. That phase shift causes additional heating in the transformer supplying the mains.I guess I don't understand how a capacitor is using real power if not storing it and returning it as in apparent?
That's simply not the case. Total heat dissipated by an inductor is (current) x (resistance + reactance).These are reactive loads though, the only thing dissipating heat in the inductor is the winding resistance of the conductor.
and in a capacitor its (current) x (internal resistance + reactance) squaredThat's simply not the case. Total heat dissipated by an inductor is (current) x (resistance + reactance).
You're thinking of the interaction of a capacitor and an inductor in an oscillator circuit - If you measure the AC current between them it will be higher than the input current - because there is a certain amount of current that moves back and forth between them. Again this is different than the current passing through a series filter. Total power across the device is ALWAYS going to be current times TOTAL impedance squared. Total impedance is resistance plus reactance.can you explain further, this is completely counter-intuitive to the notion that reactive components do not dissipate power.
as far as I know reactive power is shuttled back and forth, it does no work, and any losses are from non-ideal components, not in the reactance
Nope. Reactance is most certainly real - it is impedance to AC current just like resistance, and will ALWAYS produce waste heat in the component.you're talking about losses in non-ideal components; Rac and core losses, eddy current and parasitic capacitance, foil and dielectric losses etc, this is not the same as saying that capacitive or inductive reactance dissipate power in the form of heat, because they don't
But it actually IS the same - that's why reactance is measured in ohms. Ask any electronics engineer if he has to account for reactive heat loss when designing AC circuits.Didn't say reactance isn't real, I'm saying that reactance does not dissipate in the form of true power like a resistor or resistive load
when ac voltage is applied to a cap, it stores energy and returns energy, no net loss via heat (with exceptions to considerations mentioned earlier)
same as when you apply a voltage to an inductor, field builds field collapses,
This is not the same as if we applied the same voltage across a resistor, where we would have say 10VAC / 1k ohms = 10mA = 100mW(true power)
same applied to some capacitor
10VAC to a capacitor at a frequency which brings Xc = 1k
the capacitor is not dissipating 100mW of true power
....this is not the same as the tank current in a resonant circuit
AC passes through a cap VIA the charging and discharging of the plates. Just as it passes from primary to secondary via the magnetic field interaction.AC current doesn't actually pass through the dielectric though, electrons leave one plate as they build on another ....
The "reactive heat loss" you're speaking of I believe would relate again to the power triangle, and accounting for I^2*R losses no?
Power is not dissipated in reactive loads.
OK. I will have to stand corrected here. After thinking about it, and referring to my old textbooks (which did not really address this) I did some research and I think you are more correct in saying reactance itself does not dissipate heat, though a device may experience more heating than its internal resistance accounts for, due to the current/voltage phase shift - the "power triangle" you referred to, and that total heat dissipated is not additive (resistance + reactance), but is dependent on the phase vectors of the voltage and current.AC passes through a cap VIA the charging and discharging of the plates. Just as it passes from primary to secondary via the magnetic field interaction.
Reactive power losses are calculated via the power triangle. But that power is most certainly "lost" in the form of heat. How else would it be lost? It cannot just vanish into thin air.
While it is true that a PURE reactance does not dissipate power - for all practical purposes, such a device does not exist. A pure reactance would be a capacitor with infinite resistance or an inductor with no resistance.
They were film, I made an assumption that since the voltage across the cap was only going to see 30v or so, then they could be rated for a low voltage like 120vac but what got me was the power. So, I gave them a whirl six hey were 3$ a piece. I managed to run a crop under them but they eventually leaked dielectric and became an open circuit. Lesson learned to use a parallel bank of caps.If your capacitor was heating up it likely wasn't rated for the use you were putting in under.
Are these film caps or EL caps we're talking?