[Prev][Next][Index][Thread]
RE: 50%
Fred, all,
I think there might be some possible confusion between
conservation of charge and conservation of energy in your reply.....
> >In theory, We should never be more than 50% efficient in energy transfer
> >from one capacitor to another! i.e. the Cprimary to the Csecondary
> >Usually the resonator load capacitance plus Ion cloud loading. This
> >assumes 100% coupling and zero other losses! If fact, we are much lower
> >than that with the finest system in operation.
> >
> >50% of the capacitively stored energy always disappears in circuit loses
> >(resistive and magnetic) even with direct wired connections. There is a
> >lot of additional wasteful garbage going on in between the primary and
> >secondary capacitors.
> >
> >Richard Hull, TCBOR
>
> What are you talikng about? Some specific circuit I presume. Your
> post lacks quoted text and the second paragraph is rather general,
> so I take some exception.
>
> For instance,
>
> If I take a 0.1ufd cap charged at 10KV and another identical one
> but uncharged, and I connect them together (as you said, "direct
> wired connections"), even with a small resisitor in series, I will
> get a final voltage of very close to 5kV, will I not? This is
> nearly 50% of the energy in the first capacitor transferred to the
> second with very little losses to the circuit. There are tiny
> losses in the dielectric and the wires. Typical dielectric
> 'efficiencies' exceed 99% and the resistive losses are trivial.
> This is close to 100% transmission of 50% of the charge. The
> remaining charge stayed on the first capacitor. The losses to the
> **circuit** resistive and magnetic are tiny. Most of the energy is
> still stored *in* the two capacitors.
>
> Fred W. Bach , Operations Group | Internet: music-at-triumf.ca
If the circuit settles down to a steady state (no oscillation),
50% of the energy is indeed lost, but charge is indeed conserved.
Elaborating: E=0.5CV^2 You can see that a cap at half its original
voltage has only 1/4 of its original energy. Two identical caps at
half the original voltage of one has still only half the original
energy.
BUT, since Q=CV, you can see that if you double C and halve V,
Q (charge) remains conserved.
Malcolm